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!Scape2/s/dith
This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.
Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.
| Tape/disk: | Home » Archimedes archive » Archimedes World » AW-1996-06-Disc 1.adf » !AcornAns_AcornAns |
| Filename: | !Scape2/s/dith |
| Read OK: | ✔ |
| File size: | 460E bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
Duplicates
There are 2 duplicate copies of this file in the archive:
- Archimedes archive » Archimedes World » AW-1996-04-Disc2.adf » !AcornAns_AcornAns » !Scape2/s/dith
- Archimedes archive » Archimedes World » AW_Vol15_Issue7 CD ROM Index Disc.adf » coders » vsn2/s/dith
- Archimedes archive » Archimedes World » AW-1996-06-Disc 1.adf » !AcornAns_AcornAns » !Scape2/s/dith
File contents
; g256wnp_internal
; a leaf APCS function
; to dither from source to destination sprite
;
; C prototype
; void g256wnp_internal(int x, int y, char *dp, char *sp, compact_dither_error *de, char *lut, unsigned int *pal256def)
; x is sprite width in pixels, y is height in pixels,
; dp pts to destination sprite image (8bpp),
; sp pts to source image (32bpp),
; de pts to line buffer to hold compact_dither_errors (each of form er,eg,eb,byte-to-pad - all signed chars),
; lut pts to 32768 byte look up table to map 15 bit rbg colour to nearest available colour number in default palette,
; pal256def pts to 256 int list of default palette
;
^ 4, fp
dxp # 4
dyp # 4
ddp # 4
dsp # 4
dde # 4
dlut # 4
dpal256def # 4
gwi_xp RN r0
gwi_yp RN r1 ;nb also is gwi_m4
gwi_m4 RN r1 ;nb also is gwi_yp
gwi_dp RN r2
gwi_sp RN r3
gwi_de RN r4
gwi_lut RN r5
gwi_pal256def RN r6
gwi_r RN r7
gwi_g RN r8
gwi_b RN r9
gwi_i RN r10
gwi_m3 RN r11 ;nb also is fp
gwi_m2 RN r12
gwi_m1 RN r13
gwi_lde RN r14
ASSERT gwi_m1>gwi_m2 :LAND: gwi_m2>gwi_m3 :LAND: gwi_m3>gwi_m4
;Note, scanning of image is done in a serpentine fashion to reduce dither
;pattern effects, & to maintain speed the main processing code is replicated,
MACRO ;more or less, three times: 1st to scan the top row (for which we have no
$label gwi_seg1 ;precalculated errors from a row above), & then twice more, once to scan odd
;rows right to left & once for scanning even rows left to right.
;This macro contains code common to each of the three incidents - it is
;entered with gwi_r, _g & _b containing the desired destination colour
;(including any error terms added in), & it writes to destination image the
;nearest colour available, then calculates the error term for this pixel in
;gwi_lde (last dither error).
$label MOV gwi_m1, gwi_r, ASR #3 ;from here . . .
CMP gwi_r, #255
MOVGT gwi_m1, #31
CMP gwi_r, #0
MOVLT gwi_m1, #0 ;to here, round r component down to 5 bits & clip to 0-31 (into _m1 bits 0-4)
MOV gwi_m2, gwi_g, ASR #3
CMP gwi_g, #255
MOVGT gwi_m2, #31
CMP gwi_g, #0
MOVLT gwi_m2, #0
ADD gwi_m1, gwi_m1, gwi_m2, ASL #5 ;as above, for g component, into _m1 bits 5-9
MOV gwi_m2, gwi_b, ASR #3
CMP gwi_b, #255
MOVGT gwi_m2, #31
CMP gwi_b, #0
MOVLT gwi_m2, #0
ADD gwi_m1, gwi_m1, gwi_m2, ASL #10 ;as above, for b component, into _m1 bits 10-14
;ie _m1 is now the desired 15 bits rgb colour
LDRB gwi_m1, [gwi_lut, gwi_m1] ;set _m1 to number of nearest available colour via a look up table
STRB gwi_m1, [gwi_dp, #0] ;write this to destination image
LDR gwi_m1, [gwi_pal256def, gwi_m1, ASL #2] ;read the 24 bit rgb value of the colour just written
MOV gwi_m2, gwi_m1, LSL #16 ;from here . . .
SUB gwi_m3, gwi_r, gwi_m2, LSR #24
CMP gwi_m3, #127
MOVGT gwi_m3, #127
CMP gwi_m3, #-127
MOVLT gwi_m3, #-127
AND gwi_m3, gwi_m3, #255 ;to here, calc (desired red)-(used red), & clip to a signed 8 bit value
MOV gwi_m2, gwi_m1, LSL #8
SUB gwi_m2, gwi_g, gwi_m2, LSR #24
CMP gwi_m2, #127
MOVGT gwi_m2, #127
CMP gwi_m2, #-127
MOVLT gwi_m2, #-127
AND gwi_m2, gwi_m2, #255
ADD gwi_m3, gwi_m3, gwi_m2, LSL #8 ;as above, for green, inserting the error into correct bits in _m3
SUB gwi_m2, gwi_b, gwi_m1, LSR #24
CMP gwi_m2, #127
MOVGT gwi_m2, #127
CMP gwi_m2, #-127
MOVLT gwi_m2, #-127
AND gwi_m2, gwi_m2, #255
ADD gwi_lde, gwi_m3, gwi_m2, LSL #16 ;as above, for blue - _lde now holds all three signed
;8 bit error terms
MEND
gwi_asl DCD 0 ;storage for sl, fp & sp, during internal calcs
gwi_afp DCD 0
gwi_asp DCD 0
gwi_aj DCD 0 ;current row number
EXPORT g256wnp_internal
gwinsta DCB "g256wnp_internal", 0
ALIGN
gwinend DCD &ff000000 + gwinend - gwinsta
g256wnp_internal
MOV ip, sp
STMFD sp!, {a1-a4} ;stack fn args x,y,dp & sp onto stack below remaining args de,lut & pal256def
STMFD sp!, {r4-r9, fp, ip, lr, pc}
SUB fp, ip, #20 ;leaf fn & little need of stack, so don't bother with stack checking
STR sl, gwi_asl
STR fp, gwi_afp
STR sp, gwi_asp ; strictly, don't need to save this, as restore frame from fp which
; contains old sp, however keep it here in case change code st need
; to make an external APCS call
;set up regs now
LDR gwi_xp, dxp ;note dxp etc are register relative - so this actually does LDR _xp, [fp, #4]
LDR gwi_yp, dyp ;sprite heights in pixels (xp is corresponding widths)
LDR gwi_dp, ddp ;ptr to destination sprite image (ie image data itself & not the spr hdr)
LDR gwi_sp, dsp ;ptr to source sprite image
LDR gwi_de, dde ;ptr to a buffer for error terms (must be xp words long)
LDR gwi_lut, dlut ;ptr to lut to map 15bit rgb colour to nearest available in default 8bpp pal
LDR gwi_pal256def, dpal256def ;ptr to default 8bpp 256 entry palette (used to calc errors)
;code
MOV gwi_i, gwi_xp ;current column number (actually, xp-number)
CMP gwi_i, #0
BLE gwi_xloop1done
gwi_xloop1
LDR gwi_m1, [gwi_sp, #0]
AND gwi_r, gwi_m1, #255 ;from here . . .
MOV gwi_g, gwi_m1, LSR #8
AND gwi_g, gwi_g, #255
MOV gwi_b, gwi_m1, LSR #16
AND gwi_b, gwi_b, #255 ;to here, extract three r,g & b 8 bit components into _r, _g & _b
CMP gwi_i, gwi_xp
BEQ gwi_xl1_b1
;if not on first pixel in row, there is an error term to add in from left:
MOV gwi_m1, gwi_lde, LSL #24 ;extract red error from _lde &
MOV gwi_m1, gwi_m1, ASR #24 ;sign extend it to 32 bits
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3 ;from here . . .
ADDMI gwi_m1, gwi_m1, #15 ; (need to ensure *7/16 will round towards 0, rather than down)
ADD gwi_r, gwi_r, gwi_m1, ASR #4 ;to here, add to _r 7/16 lde red error term
MOV gwi_m1, gwi_lde, LSL #16 ;from here . . .
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4 ;to here, extract green error & add 7/16 of it into _g
MOV gwi_m1, gwi_lde, LSL #8 ;from here . . .
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;to here, extract blue error from lde & add 7/16 into _b
STR gwi_lde, [gwi_de, gwi_i, ASL #2] ;buffer lde for when processing row below
gwi_xl1_b1
gwi_seg1 ;write to destination image & calculate error for this pixel (into lde)
ADD gwi_dp, gwi_dp, #1 ;step through destination image one pixel
ADD gwi_sp, gwi_sp, #4 ;step through source image one pixel
SUBS gwi_i, gwi_i, #1
BGT gwi_xloop1 ;& repeat till all of first row processed
gwi_xloop1done
;now step down to next row (remember, serpentine scanning)
RSB gwi_m2, gwi_xp, #4
AND gwi_m1, gwi_m2, #3 ; . . . to get past righthand wastage of last row, dest image
ADD gwi_m1, gwi_m1, gwi_xp ; . . . to get past end of next row
SUB gwi_m1, gwi_m1, #1 ; . . . to get back to last pixel on that row
ADD gwi_dp, gwi_dp, gwi_m1 ;make the adjustment to _dp
ADD gwi_sp, gwi_sp, gwi_xp, LSL #2 ;from here . . .
SUB gwi_sp, gwi_sp, #4 ;to here, as above for src image (note, it has 4*xp bytes per row)
SUBS gwi_m1, gwi_yp, #2
BMI gwi_yloopdone ;carry on with next row, unless all rows done (note, subtract
STR gwi_m1, gwi_aj ; 2 from yp initially since yp is # rows counting from 1, &
; branch cond is MI, ie loop counts rows including 0)
;note, de buffer holds errors for row above, running from right in low
;memory to left side in high mem. Next row will be scanned right to
gwi_yloop ;left, so need extract errors from buffer in increasing memory order.
STR gwi_lde, [gwi_de, #0] ;buffer error for final pixel from last row
MOV gwi_i, #1
CMP gwi_i, gwi_xp
BGT gwi_xloop2done
;all remaining code is similar to preceeding, except have to add in
gwi_xloop2 ;errors from row above, & scan row in reverse direction
LDR gwi_m1, [gwi_sp, #0]
AND gwi_r, gwi_m1, #255 ;from here . . .
MOV gwi_g, gwi_m1, LSR #8
AND gwi_g, gwi_g, #255
MOV gwi_b, gwi_m1, LSR #16
AND gwi_b, gwi_b, #255 ;to here, extract three r,g & b 8 bit components into _r, _g & _b
SUB gwi_m4, gwi_i, #1 ;from here . . .
LDR gwi_m4, [gwi_de, gwi_m4, ASL #2]
MOV gwi_m1, gwi_m4, LSL #24
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #2
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #16
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #2
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #8
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #2
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;to here, add in 5/16 error for pixel above
CMP gwi_i, #1
BEQ gwi_xl2_b1
SUB gwi_m2, gwi_i, #2 ;similiarly (if not on rightmost column) . . .
LDR gwi_m4, [gwi_de, gwi_m2, ASL #2]
MOV gwi_m1, gwi_m4, LSL #24
MOVS gwi_m1, gwi_m1, ASR #24
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #16
MOVS gwi_m1, gwi_m1, ASR #24
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #8
MOVS gwi_m1, gwi_m1, ASR #24
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;add in 1/16 error for pixel to above right
STR gwi_lde, [gwi_de, gwi_m2, ASL #2] ;can now safely overwrite value in buffer with lde for next row
MOV gwi_m1, gwi_lde, LSL #24
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_lde, LSL #16
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_lde, LSL #8
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;now add in 7/16 error for pixel to right
gwi_xl2_b1
CMP gwi_i, gwi_xp
BEQ gwi_xl2_b2
LDR gwi_m4, [gwi_de, gwi_i, ASL #2] ;if not on far left column . . .
MOV gwi_m1, gwi_m4, LSL #24
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #1
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #16
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #1
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #8
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #1
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;add in 3/16 error for pixel to above left
gwi_xl2_b2
gwi_seg1 ;write destination pixel & calc new error for pixel
SUB gwi_dp, gwi_dp, #1
SUB gwi_sp, gwi_sp, #4
ADD gwi_i, gwi_i, #1
CMP gwi_i, gwi_xp
BLE gwi_xloop2 ;loop back til all of right to left row processed
gwi_xloop2done
RSB gwi_m2, gwi_xp, #4
AND gwi_m1, gwi_m2, #3
ADD gwi_m1, gwi_m1, gwi_xp
ADD gwi_m1, gwi_m1, #1
ADD gwi_dp, gwi_dp, gwi_m1
ADD gwi_sp, gwi_sp, gwi_xp, LSL #2
ADD gwi_sp, gwi_sp, #4 ;step sp, dp to next row (to be scanned left to right)
LDR gwi_m1, gwi_aj
SUBS gwi_m1, gwi_m1, #1
STR gwi_m1, gwi_aj
BMI gwi_yloopdone ;continue with next row, unless all done
SUB gwi_m1, gwi_xp, #1
STR gwi_lde, [gwi_de, gwi_m1, ASL #2] ;buffer error for final pixel on last row
MOV gwi_i, gwi_xp
CMP gwi_i, #0
BLE gwi_xloop3done
gwi_xloop3
LDR gwi_m1, [gwi_sp, #0]
AND gwi_r, gwi_m1, #255 ;from here . . .
MOV gwi_g, gwi_m1, LSR #8
AND gwi_g, gwi_g, #255
MOV gwi_b, gwi_m1, LSR #16
AND gwi_b, gwi_b, #255 ;to here, extract three r,g & b 8 bit components into _r, _g & _b
SUB gwi_m4, gwi_i, #1 ;for pixel above . . .
LDR gwi_m4, [gwi_de, gwi_m4, ASL #2]
MOV gwi_m1, gwi_m4, LSL #24
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #2
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #16
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #2
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #8
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #2
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;add in 5/16 error
CMP gwi_i, gwi_xp
BEQ gwi_xl3_b1
;if not on leftmost column . . .
LDR gwi_m4, [gwi_de, gwi_i, ASL #2]
MOV gwi_m1, gwi_m4, LSL #24
MOVS gwi_m1, gwi_m1, ASR #24
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #16
MOVS gwi_m1, gwi_m1, ASR #24
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #8
MOVS gwi_m1, gwi_m1, ASR #24
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;add in 1/16 error for pixel to above left
STR gwi_lde, [gwi_de, gwi_i, ASL #2] ;buffer last error
MOV gwi_m1, gwi_lde, LSL #24
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_lde, LSL #16
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_lde, LSL #8
MOV gwi_m1, gwi_m1, ASR #24
RSBS gwi_m1, gwi_m1, gwi_m1, ASL #3
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;& add in 7/16 error for pixel to left
gwi_xl3_b1
CMP gwi_i, #1
BEQ gwi_xl3_b2
;if not on far right . . .
SUB gwi_m2, gwi_i, #2
LDR gwi_m4, [gwi_de, gwi_m2, ASL #2]
MOV gwi_m1, gwi_m4, LSL #24
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #1
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_r, gwi_r, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #16
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #1
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_g, gwi_g, gwi_m1, ASR #4
MOV gwi_m1, gwi_m4, LSL #8
MOV gwi_m1, gwi_m1, ASR #24
ADDS gwi_m1, gwi_m1, gwi_m1, ASL #1
ADDMI gwi_m1, gwi_m1, #15
ADD gwi_b, gwi_b, gwi_m1, ASR #4 ;add in 3/16 error for pixel to above right
gwi_xl3_b2
gwi_seg1 ;write destination pixel & calc its error
ADD gwi_dp, gwi_dp, #1
ADD gwi_sp, gwi_sp, #4
SUBS gwi_i, gwi_i, #1
BGT gwi_xloop3 ;continue till all of left to right row processed
gwi_xloop3done
RSB gwi_m2, gwi_xp, #4
AND gwi_m1, gwi_m2, #3
ADD gwi_m1, gwi_m1, gwi_xp
SUB gwi_m1, gwi_m1, #1
ADD gwi_dp, gwi_dp, gwi_m1
ADD gwi_sp, gwi_sp, gwi_xp, LSL #2
SUB gwi_sp, gwi_sp, #4 ;step dp, sp to start of next right-to-left row
LDR gwi_m1, gwi_aj
SUBS gwi_m1, gwi_m1, #1
STR gwi_m1, gwi_aj
BPL gwi_yloop ;& repeat, until all rows done
gwi_yloopdone
;all done
LDR sp, gwi_asp
LDR fp, gwi_afp
LDR sl, gwi_asl
LDMEA fp, {r4-r9, fp, sp, pc}^ ;get out of here!
END
00000000 0a 3b 20 67 32 35 36 77 6e 70 5f 69 6e 74 65 72 |.; g256wnp_inter|
00000010 6e 61 6c 0a 3b 20 61 20 6c 65 61 66 20 41 50 43 |nal.; a leaf APC|
00000020 53 20 66 75 6e 63 74 69 6f 6e 0a 3b 20 74 6f 20 |S function.; to |
00000030 64 69 74 68 65 72 20 66 72 6f 6d 20 73 6f 75 72 |dither from sour|
00000040 63 65 20 74 6f 20 64 65 73 74 69 6e 61 74 69 6f |ce to destinatio|
00000050 6e 20 73 70 72 69 74 65 0a 3b 0a 3b 20 43 20 70 |n sprite.;.; C p|
00000060 72 6f 74 6f 74 79 70 65 0a 3b 20 76 6f 69 64 20 |rototype.; void |
00000070 67 32 35 36 77 6e 70 5f 69 6e 74 65 72 6e 61 6c |g256wnp_internal|
00000080 28 69 6e 74 20 78 2c 20 69 6e 74 20 79 2c 20 63 |(int x, int y, c|
00000090 68 61 72 20 2a 64 70 2c 20 63 68 61 72 20 2a 73 |har *dp, char *s|
000000a0 70 2c 20 63 6f 6d 70 61 63 74 5f 64 69 74 68 65 |p, compact_dithe|
000000b0 72 5f 65 72 72 6f 72 20 2a 64 65 2c 20 63 68 61 |r_error *de, cha|
000000c0 72 20 2a 6c 75 74 2c 20 75 6e 73 69 67 6e 65 64 |r *lut, unsigned|
000000d0 20 69 6e 74 20 2a 70 61 6c 32 35 36 64 65 66 29 | int *pal256def)|
000000e0 0a 3b 20 78 20 69 73 20 73 70 72 69 74 65 20 77 |.; x is sprite w|
000000f0 69 64 74 68 20 69 6e 20 70 69 78 65 6c 73 2c 20 |idth in pixels, |
00000100 79 20 69 73 20 68 65 69 67 68 74 20 69 6e 20 70 |y is height in p|
00000110 69 78 65 6c 73 2c 0a 3b 20 64 70 20 70 74 73 20 |ixels,.; dp pts |
00000120 74 6f 20 64 65 73 74 69 6e 61 74 69 6f 6e 20 73 |to destination s|
00000130 70 72 69 74 65 20 69 6d 61 67 65 20 28 38 62 70 |prite image (8bp|
00000140 70 29 2c 0a 3b 20 73 70 20 70 74 73 20 74 6f 20 |p),.; sp pts to |
00000150 73 6f 75 72 63 65 20 69 6d 61 67 65 20 28 33 32 |source image (32|
00000160 62 70 70 29 2c 0a 3b 20 64 65 20 70 74 73 20 74 |bpp),.; de pts t|
00000170 6f 20 6c 69 6e 65 20 62 75 66 66 65 72 20 74 6f |o line buffer to|
00000180 20 68 6f 6c 64 20 63 6f 6d 70 61 63 74 5f 64 69 | hold compact_di|
00000190 74 68 65 72 5f 65 72 72 6f 72 73 20 28 65 61 63 |ther_errors (eac|
000001a0 68 20 6f 66 20 66 6f 72 6d 20 65 72 2c 65 67 2c |h of form er,eg,|
000001b0 65 62 2c 62 79 74 65 2d 74 6f 2d 70 61 64 20 2d |eb,byte-to-pad -|
000001c0 20 61 6c 6c 20 73 69 67 6e 65 64 20 63 68 61 72 | all signed char|
000001d0 73 29 2c 0a 3b 20 6c 75 74 20 70 74 73 20 74 6f |s),.; lut pts to|
000001e0 20 33 32 37 36 38 20 62 79 74 65 20 6c 6f 6f 6b | 32768 byte look|
000001f0 20 75 70 20 74 61 62 6c 65 20 74 6f 20 6d 61 70 | up table to map|
00000200 20 31 35 20 62 69 74 20 72 62 67 20 63 6f 6c 6f | 15 bit rbg colo|
00000210 75 72 20 74 6f 20 6e 65 61 72 65 73 74 20 61 76 |ur to nearest av|
00000220 61 69 6c 61 62 6c 65 20 63 6f 6c 6f 75 72 20 6e |ailable colour n|
00000230 75 6d 62 65 72 20 69 6e 20 64 65 66 61 75 6c 74 |umber in default|
00000240 20 70 61 6c 65 74 74 65 2c 0a 3b 20 70 61 6c 32 | palette,.; pal2|
00000250 35 36 64 65 66 20 70 74 73 20 74 6f 20 32 35 36 |56def pts to 256|
00000260 20 69 6e 74 20 6c 69 73 74 20 6f 66 20 64 65 66 | int list of def|
00000270 61 75 6c 74 20 70 61 6c 65 74 74 65 0a 3b 0a 0a |ault palette.;..|
00000280 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00000290 5e 20 20 20 20 20 20 20 34 2c 20 66 70 0a 64 78 |^ 4, fp.dx|
000002a0 70 20 20 20 20 20 20 20 20 20 20 20 20 20 23 20 |p # |
000002b0 20 20 20 20 20 20 34 0a 64 79 70 20 20 20 20 20 | 4.dyp |
000002c0 20 20 20 20 20 20 20 20 23 20 20 20 20 20 20 20 | # |
000002d0 34 0a 64 64 70 20 20 20 20 20 20 20 20 20 20 20 |4.ddp |
000002e0 20 20 23 20 20 20 20 20 20 20 34 0a 64 73 70 20 | # 4.dsp |
000002f0 20 20 20 20 20 20 20 20 20 20 20 20 23 20 20 20 | # |
00000300 20 20 20 20 34 0a 64 64 65 20 20 20 20 20 20 20 | 4.dde |
00000310 20 20 20 20 20 20 23 20 20 20 20 20 20 20 34 0a | # 4.|
00000320 64 6c 75 74 20 20 20 20 20 20 20 20 20 20 20 20 |dlut |
00000330 23 20 20 20 20 20 20 20 34 0a 64 70 61 6c 32 35 |# 4.dpal25|
00000340 36 64 65 66 20 20 20 20 20 20 23 20 20 20 20 20 |6def # |
00000350 20 20 34 0a 0a 67 77 69 5f 78 70 20 20 20 20 20 | 4..gwi_xp |
00000360 20 20 20 20 20 52 4e 20 20 20 20 20 20 72 30 0a | RN r0.|
00000370 67 77 69 5f 79 70 20 20 20 20 20 20 20 20 20 20 |gwi_yp |
00000380 52 4e 20 20 20 20 20 20 72 31 20 20 20 20 20 20 |RN r1 |
00000390 3b 6e 62 20 61 6c 73 6f 20 69 73 20 67 77 69 5f |;nb also is gwi_|
000003a0 6d 34 0a 67 77 69 5f 6d 34 20 20 20 20 20 20 20 |m4.gwi_m4 |
000003b0 20 20 20 52 4e 20 20 20 20 20 20 72 31 20 20 20 | RN r1 |
000003c0 20 20 20 3b 6e 62 20 61 6c 73 6f 20 69 73 20 67 | ;nb also is g|
000003d0 77 69 5f 79 70 0a 67 77 69 5f 64 70 20 20 20 20 |wi_yp.gwi_dp |
000003e0 20 20 20 20 20 20 52 4e 20 20 20 20 20 20 72 32 | RN r2|
000003f0 0a 67 77 69 5f 73 70 20 20 20 20 20 20 20 20 20 |.gwi_sp |
00000400 20 52 4e 20 20 20 20 20 20 72 33 0a 67 77 69 5f | RN r3.gwi_|
00000410 64 65 20 20 20 20 20 20 20 20 20 20 52 4e 20 20 |de RN |
00000420 20 20 20 20 72 34 0a 67 77 69 5f 6c 75 74 20 20 | r4.gwi_lut |
00000430 20 20 20 20 20 20 20 52 4e 20 20 20 20 20 20 72 | RN r|
00000440 35 0a 67 77 69 5f 70 61 6c 32 35 36 64 65 66 20 |5.gwi_pal256def |
00000450 20 20 52 4e 20 20 20 20 20 20 72 36 0a 67 77 69 | RN r6.gwi|
00000460 5f 72 20 20 20 20 20 20 20 20 20 20 20 52 4e 20 |_r RN |
00000470 20 20 20 20 20 72 37 0a 67 77 69 5f 67 20 20 20 | r7.gwi_g |
00000480 20 20 20 20 20 20 20 20 52 4e 20 20 20 20 20 20 | RN |
00000490 72 38 0a 67 77 69 5f 62 20 20 20 20 20 20 20 20 |r8.gwi_b |
000004a0 20 20 20 52 4e 20 20 20 20 20 20 72 39 0a 67 77 | RN r9.gw|
000004b0 69 5f 69 20 20 20 20 20 20 20 20 20 20 20 52 4e |i_i RN|
000004c0 20 20 20 20 20 20 72 31 30 0a 67 77 69 5f 6d 33 | r10.gwi_m3|
000004d0 20 20 20 20 20 20 20 20 20 20 52 4e 20 20 20 20 | RN |
000004e0 20 20 72 31 31 20 20 20 20 20 3b 6e 62 20 61 6c | r11 ;nb al|
000004f0 73 6f 20 69 73 20 66 70 0a 67 77 69 5f 6d 32 20 |so is fp.gwi_m2 |
00000500 20 20 20 20 20 20 20 20 20 52 4e 20 20 20 20 20 | RN |
00000510 20 72 31 32 0a 67 77 69 5f 6d 31 20 20 20 20 20 | r12.gwi_m1 |
00000520 20 20 20 20 20 52 4e 20 20 20 20 20 20 72 31 33 | RN r13|
00000530 0a 67 77 69 5f 6c 64 65 20 20 20 20 20 20 20 20 |.gwi_lde |
00000540 20 52 4e 20 20 20 20 20 20 72 31 34 0a 0a 20 20 | RN r14.. |
00000550 20 20 20 20 20 20 41 53 53 45 52 54 20 20 67 77 | ASSERT gw|
00000560 69 5f 6d 31 3e 67 77 69 5f 6d 32 20 3a 4c 41 4e |i_m1>gwi_m2 :LAN|
00000570 44 3a 20 67 77 69 5f 6d 32 3e 67 77 69 5f 6d 33 |D: gwi_m2>gwi_m3|
00000580 20 3a 4c 41 4e 44 3a 20 67 77 69 5f 6d 33 3e 67 | :LAND: gwi_m3>g|
00000590 77 69 5f 6d 34 0a 09 09 09 09 3b 4e 6f 74 65 2c |wi_m4.....;Note,|
000005a0 20 73 63 61 6e 6e 69 6e 67 20 6f 66 20 69 6d 61 | scanning of ima|
000005b0 67 65 20 69 73 20 64 6f 6e 65 20 69 6e 20 61 20 |ge is done in a |
000005c0 73 65 72 70 65 6e 74 69 6e 65 20 66 61 73 68 69 |serpentine fashi|
000005d0 6f 6e 20 74 6f 20 72 65 64 75 63 65 20 64 69 74 |on to reduce dit|
000005e0 68 65 72 0a 09 09 09 09 3b 70 61 74 74 65 72 6e |her.....;pattern|
000005f0 20 65 66 66 65 63 74 73 2c 20 26 20 74 6f 20 6d | effects, & to m|
00000600 61 69 6e 74 61 69 6e 20 73 70 65 65 64 20 74 68 |aintain speed th|
00000610 65 20 6d 61 69 6e 20 70 72 6f 63 65 73 73 69 6e |e main processin|
00000620 67 20 63 6f 64 65 20 69 73 20 72 65 70 6c 69 63 |g code is replic|
00000630 61 74 65 64 2c 0a 20 20 20 20 20 20 20 20 4d 41 |ated,. MA|
00000640 43 52 4f 09 09 09 3b 6d 6f 72 65 20 6f 72 20 6c |CRO...;more or l|
00000650 65 73 73 2c 20 74 68 72 65 65 20 74 69 6d 65 73 |ess, three times|
00000660 3a 20 31 73 74 20 74 6f 20 73 63 61 6e 20 74 68 |: 1st to scan th|
00000670 65 20 74 6f 70 20 72 6f 77 20 28 66 6f 72 20 77 |e top row (for w|
00000680 68 69 63 68 20 77 65 20 68 61 76 65 20 6e 6f 0a |hich we have no.|
00000690 24 6c 61 62 65 6c 20 20 67 77 69 5f 73 65 67 31 |$label gwi_seg1|
000006a0 09 09 3b 70 72 65 63 61 6c 63 75 6c 61 74 65 64 |..;precalculated|
000006b0 20 65 72 72 6f 72 73 20 66 72 6f 6d 20 61 20 72 | errors from a r|
000006c0 6f 77 20 61 62 6f 76 65 29 2c 20 26 20 74 68 65 |ow above), & the|
000006d0 6e 20 74 77 69 63 65 20 6d 6f 72 65 2c 20 6f 6e |n twice more, on|
000006e0 63 65 20 74 6f 20 73 63 61 6e 20 6f 64 64 0a 09 |ce to scan odd..|
000006f0 09 09 09 3b 72 6f 77 73 20 72 69 67 68 74 20 74 |...;rows right t|
00000700 6f 20 6c 65 66 74 20 26 20 6f 6e 63 65 20 66 6f |o left & once fo|
00000710 72 20 73 63 61 6e 6e 69 6e 67 20 65 76 65 6e 20 |r scanning even |
00000720 72 6f 77 73 20 6c 65 66 74 20 74 6f 20 72 69 67 |rows left to rig|
00000730 68 74 2e 0a 09 09 09 09 3b 54 68 69 73 20 6d 61 |ht......;This ma|
00000740 63 72 6f 20 63 6f 6e 74 61 69 6e 73 20 63 6f 64 |cro contains cod|
00000750 65 20 63 6f 6d 6d 6f 6e 20 74 6f 20 65 61 63 68 |e common to each|
00000760 20 6f 66 20 74 68 65 20 74 68 72 65 65 20 69 6e | of the three in|
00000770 63 69 64 65 6e 74 73 20 2d 20 69 74 20 69 73 0a |cidents - it is.|
00000780 09 09 09 09 3b 65 6e 74 65 72 65 64 20 77 69 74 |....;entered wit|
00000790 68 20 67 77 69 5f 72 2c 20 5f 67 20 26 20 5f 62 |h gwi_r, _g & _b|
000007a0 20 63 6f 6e 74 61 69 6e 69 6e 67 20 74 68 65 20 | containing the |
000007b0 64 65 73 69 72 65 64 20 64 65 73 74 69 6e 61 74 |desired destinat|
000007c0 69 6f 6e 20 63 6f 6c 6f 75 72 0a 09 09 09 09 3b |ion colour.....;|
000007d0 28 69 6e 63 6c 75 64 69 6e 67 20 61 6e 79 20 65 |(including any e|
000007e0 72 72 6f 72 20 74 65 72 6d 73 20 61 64 64 65 64 |rror terms added|
000007f0 20 69 6e 29 2c 20 26 20 69 74 20 77 72 69 74 65 | in), & it write|
00000800 73 20 74 6f 20 64 65 73 74 69 6e 61 74 69 6f 6e |s to destination|
00000810 20 69 6d 61 67 65 20 74 68 65 0a 09 09 09 09 3b | image the.....;|
00000820 6e 65 61 72 65 73 74 20 63 6f 6c 6f 75 72 20 61 |nearest colour a|
00000830 76 61 69 6c 61 62 6c 65 2c 20 74 68 65 6e 20 63 |vailable, then c|
00000840 61 6c 63 75 6c 61 74 65 73 20 74 68 65 20 65 72 |alculates the er|
00000850 72 6f 72 20 74 65 72 6d 20 66 6f 72 20 74 68 69 |ror term for thi|
00000860 73 20 70 69 78 65 6c 20 69 6e 0a 09 09 09 09 3b |s pixel in.....;|
00000870 67 77 69 5f 6c 64 65 20 28 6c 61 73 74 20 64 69 |gwi_lde (last di|
00000880 74 68 65 72 20 65 72 72 6f 72 29 2e 0a 24 6c 61 |ther error)..$la|
00000890 62 65 6c 20 20 4d 4f 56 20 20 20 20 20 67 77 69 |bel MOV gwi|
000008a0 5f 6d 31 2c 20 67 77 69 5f 72 2c 20 41 53 52 20 |_m1, gwi_r, ASR |
000008b0 23 33 09 3b 66 72 6f 6d 20 68 65 72 65 20 2e 20 |#3.;from here . |
000008c0 2e 20 2e 0a 20 20 20 20 20 20 20 20 43 4d 50 20 |. .. CMP |
000008d0 20 20 20 20 67 77 69 5f 72 2c 20 23 32 35 35 0a | gwi_r, #255.|
000008e0 20 20 20 20 20 20 20 20 4d 4f 56 47 54 20 20 20 | MOVGT |
000008f0 67 77 69 5f 6d 31 2c 20 23 33 31 0a 20 20 20 20 |gwi_m1, #31. |
00000900 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 5f | CMP gwi_|
00000910 72 2c 20 23 30 0a 20 20 20 20 20 20 20 20 4d 4f |r, #0. MO|
00000920 56 4c 54 20 20 20 67 77 69 5f 6d 31 2c 20 23 30 |VLT gwi_m1, #0|
00000930 09 09 3b 74 6f 20 68 65 72 65 2c 20 72 6f 75 6e |..;to here, roun|
00000940 64 20 72 20 63 6f 6d 70 6f 6e 65 6e 74 20 64 6f |d r component do|
00000950 77 6e 20 74 6f 20 35 20 62 69 74 73 20 26 20 63 |wn to 5 bits & c|
00000960 6c 69 70 20 74 6f 20 30 2d 33 31 20 28 69 6e 74 |lip to 0-31 (int|
00000970 6f 20 5f 6d 31 20 62 69 74 73 20 30 2d 34 29 0a |o _m1 bits 0-4).|
00000980 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 | MOV |
00000990 67 77 69 5f 6d 32 2c 20 67 77 69 5f 67 2c 20 41 |gwi_m2, gwi_g, A|
000009a0 53 52 20 23 33 0a 20 20 20 20 20 20 20 20 43 4d |SR #3. CM|
000009b0 50 20 20 20 20 20 67 77 69 5f 67 2c 20 23 32 35 |P gwi_g, #25|
000009c0 35 0a 20 20 20 20 20 20 20 20 4d 4f 56 47 54 20 |5. MOVGT |
000009d0 20 20 67 77 69 5f 6d 32 2c 20 23 33 31 0a 20 20 | gwi_m2, #31. |
000009e0 20 20 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 | CMP gw|
000009f0 69 5f 67 2c 20 23 30 0a 20 20 20 20 20 20 20 20 |i_g, #0. |
00000a00 4d 4f 56 4c 54 20 20 20 67 77 69 5f 6d 32 2c 20 |MOVLT gwi_m2, |
00000a10 23 30 0a 20 20 20 20 20 20 20 20 41 44 44 20 20 |#0. ADD |
00000a20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
00000a30 31 2c 20 67 77 69 5f 6d 32 2c 20 41 53 4c 20 23 |1, gwi_m2, ASL #|
00000a40 35 09 3b 61 73 20 61 62 6f 76 65 2c 20 66 6f 72 |5.;as above, for|
00000a50 20 67 20 63 6f 6d 70 6f 6e 65 6e 74 2c 20 69 6e | g component, in|
00000a60 74 6f 20 5f 6d 31 20 62 69 74 73 20 35 2d 39 0a |to _m1 bits 5-9.|
00000a70 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 | MOV |
00000a80 67 77 69 5f 6d 32 2c 20 67 77 69 5f 62 2c 20 41 |gwi_m2, gwi_b, A|
00000a90 53 52 20 23 33 0a 20 20 20 20 20 20 20 20 43 4d |SR #3. CM|
00000aa0 50 20 20 20 20 20 67 77 69 5f 62 2c 20 23 32 35 |P gwi_b, #25|
00000ab0 35 0a 20 20 20 20 20 20 20 20 4d 4f 56 47 54 20 |5. MOVGT |
00000ac0 20 20 67 77 69 5f 6d 32 2c 20 23 33 31 0a 20 20 | gwi_m2, #31. |
00000ad0 20 20 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 | CMP gw|
00000ae0 69 5f 62 2c 20 23 30 0a 20 20 20 20 20 20 20 20 |i_b, #0. |
00000af0 4d 4f 56 4c 54 20 20 20 67 77 69 5f 6d 32 2c 20 |MOVLT gwi_m2, |
00000b00 23 30 0a 20 20 20 20 20 20 20 20 41 44 44 20 20 |#0. ADD |
00000b10 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
00000b20 31 2c 20 67 77 69 5f 6d 32 2c 20 41 53 4c 20 23 |1, gwi_m2, ASL #|
00000b30 31 30 09 3b 61 73 20 61 62 6f 76 65 2c 20 66 6f |10.;as above, fo|
00000b40 72 20 62 20 63 6f 6d 70 6f 6e 65 6e 74 2c 20 69 |r b component, i|
00000b50 6e 74 6f 20 5f 6d 31 20 62 69 74 73 20 31 30 2d |nto _m1 bits 10-|
00000b60 31 34 0a 09 09 09 09 09 3b 69 65 20 5f 6d 31 20 |14......;ie _m1 |
00000b70 69 73 20 6e 6f 77 20 74 68 65 20 64 65 73 69 72 |is now the desir|
00000b80 65 64 20 31 35 20 62 69 74 73 20 72 67 62 20 63 |ed 15 bits rgb c|
00000b90 6f 6c 6f 75 72 0a 20 20 20 20 20 20 20 20 4c 44 |olour. LD|
00000ba0 52 42 20 20 20 20 67 77 69 5f 6d 31 2c 20 5b 67 |RB gwi_m1, [g|
00000bb0 77 69 5f 6c 75 74 2c 20 67 77 69 5f 6d 31 5d 09 |wi_lut, gwi_m1].|
00000bc0 3b 73 65 74 20 5f 6d 31 20 74 6f 20 6e 75 6d 62 |;set _m1 to numb|
00000bd0 65 72 20 6f 66 20 6e 65 61 72 65 73 74 20 61 76 |er of nearest av|
00000be0 61 69 6c 61 62 6c 65 20 63 6f 6c 6f 75 72 20 76 |ailable colour v|
00000bf0 69 61 20 61 20 6c 6f 6f 6b 20 75 70 20 74 61 62 |ia a look up tab|
00000c00 6c 65 0a 20 20 20 20 20 20 20 20 53 54 52 42 20 |le. STRB |
00000c10 20 20 20 67 77 69 5f 6d 31 2c 20 5b 67 77 69 5f | gwi_m1, [gwi_|
00000c20 64 70 2c 20 23 30 5d 09 09 3b 77 72 69 74 65 20 |dp, #0]..;write |
00000c30 74 68 69 73 20 74 6f 20 64 65 73 74 69 6e 61 74 |this to destinat|
00000c40 69 6f 6e 20 69 6d 61 67 65 0a 20 20 20 20 20 20 |ion image. |
00000c50 20 20 4c 44 52 20 20 20 20 20 67 77 69 5f 6d 31 | LDR gwi_m1|
00000c60 2c 20 5b 67 77 69 5f 70 61 6c 32 35 36 64 65 66 |, [gwi_pal256def|
00000c70 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c 20 23 32 |, gwi_m1, ASL #2|
00000c80 5d 09 3b 72 65 61 64 20 74 68 65 20 32 34 20 62 |].;read the 24 b|
00000c90 69 74 20 72 67 62 20 76 61 6c 75 65 20 6f 66 20 |it rgb value of |
00000ca0 74 68 65 20 63 6f 6c 6f 75 72 20 6a 75 73 74 20 |the colour just |
00000cb0 77 72 69 74 74 65 6e 0a 20 20 20 20 20 20 20 20 |written. |
00000cc0 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 32 2c 20 |MOV gwi_m2, |
00000cd0 67 77 69 5f 6d 31 2c 20 4c 53 4c 20 23 31 36 09 |gwi_m1, LSL #16.|
00000ce0 09 3b 66 72 6f 6d 20 68 65 72 65 20 2e 20 2e 20 |.;from here . . |
00000cf0 2e 0a 09 53 55 42 09 67 77 69 5f 6d 33 2c 20 67 |...SUB.gwi_m3, g|
00000d00 77 69 5f 72 2c 20 67 77 69 5f 6d 32 2c 20 4c 53 |wi_r, gwi_m2, LS|
00000d10 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 43 4d |R #24. CM|
00000d20 50 20 20 20 20 20 67 77 69 5f 6d 33 2c 20 23 31 |P gwi_m3, #1|
00000d30 32 37 0a 20 20 20 20 20 20 20 20 4d 4f 56 47 54 |27. MOVGT|
00000d40 20 20 20 67 77 69 5f 6d 33 2c 20 23 31 32 37 0a | gwi_m3, #127.|
00000d50 20 20 20 20 20 20 20 20 43 4d 50 20 20 20 20 20 | CMP |
00000d60 67 77 69 5f 6d 33 2c 20 23 2d 31 32 37 0a 20 20 |gwi_m3, #-127. |
00000d70 20 20 20 20 20 20 4d 4f 56 4c 54 20 20 20 67 77 | MOVLT gw|
00000d80 69 5f 6d 33 2c 20 23 2d 31 32 37 0a 20 20 20 20 |i_m3, #-127. |
00000d90 20 20 20 20 41 4e 44 20 20 20 20 20 67 77 69 5f | AND gwi_|
00000da0 6d 33 2c 20 67 77 69 5f 6d 33 2c 20 23 32 35 35 |m3, gwi_m3, #255|
00000db0 09 09 3b 74 6f 20 68 65 72 65 2c 20 63 61 6c 63 |..;to here, calc|
00000dc0 20 28 64 65 73 69 72 65 64 20 72 65 64 29 2d 28 | (desired red)-(|
00000dd0 75 73 65 64 20 72 65 64 29 2c 20 26 20 63 6c 69 |used red), & cli|
00000de0 70 20 74 6f 20 61 20 73 69 67 6e 65 64 20 38 20 |p to a signed 8 |
00000df0 62 69 74 20 76 61 6c 75 65 0a 20 20 20 20 20 20 |bit value. |
00000e00 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 32 | MOV gwi_m2|
00000e10 2c 20 67 77 69 5f 6d 31 2c 20 4c 53 4c 20 23 38 |, gwi_m1, LSL #8|
00000e20 0a 20 20 20 20 20 20 20 20 53 55 42 20 20 20 20 |. SUB |
00000e30 20 67 77 69 5f 6d 32 2c 20 67 77 69 5f 67 2c 20 | gwi_m2, gwi_g, |
00000e40 67 77 69 5f 6d 32 2c 20 4c 53 52 20 23 32 34 0a |gwi_m2, LSR #24.|
00000e50 20 20 20 20 20 20 20 20 43 4d 50 20 20 20 20 20 | CMP |
00000e60 67 77 69 5f 6d 32 2c 20 23 31 32 37 0a 20 20 20 |gwi_m2, #127. |
00000e70 20 20 20 20 20 4d 4f 56 47 54 20 20 20 67 77 69 | MOVGT gwi|
00000e80 5f 6d 32 2c 20 23 31 32 37 0a 20 20 20 20 20 20 |_m2, #127. |
00000e90 20 20 43 4d 50 20 20 20 20 20 67 77 69 5f 6d 32 | CMP gwi_m2|
00000ea0 2c 20 23 2d 31 32 37 0a 20 20 20 20 20 20 20 20 |, #-127. |
00000eb0 4d 4f 56 4c 54 20 20 20 67 77 69 5f 6d 32 2c 20 |MOVLT gwi_m2, |
00000ec0 23 2d 31 32 37 0a 20 20 20 20 20 20 20 20 41 4e |#-127. AN|
00000ed0 44 20 20 20 20 20 67 77 69 5f 6d 32 2c 20 67 77 |D gwi_m2, gw|
00000ee0 69 5f 6d 32 2c 20 23 32 35 35 0a 20 20 20 20 20 |i_m2, #255. |
00000ef0 20 20 20 41 44 44 20 20 20 20 20 67 77 69 5f 6d | ADD gwi_m|
00000f00 33 2c 20 67 77 69 5f 6d 33 2c 20 67 77 69 5f 6d |3, gwi_m3, gwi_m|
00000f10 32 2c 20 4c 53 4c 20 23 38 09 3b 61 73 20 61 62 |2, LSL #8.;as ab|
00000f20 6f 76 65 2c 20 66 6f 72 20 67 72 65 65 6e 2c 20 |ove, for green, |
00000f30 69 6e 73 65 72 74 69 6e 67 20 74 68 65 20 65 72 |inserting the er|
00000f40 72 6f 72 20 69 6e 74 6f 20 63 6f 72 72 65 63 74 |ror into correct|
00000f50 20 62 69 74 73 20 69 6e 20 5f 6d 33 0a 20 20 20 | bits in _m3. |
00000f60 20 20 20 20 20 53 55 42 20 20 20 20 20 67 77 69 | SUB gwi|
00000f70 5f 6d 32 2c 20 67 77 69 5f 62 2c 20 67 77 69 5f |_m2, gwi_b, gwi_|
00000f80 6d 31 2c 20 4c 53 52 20 23 32 34 0a 20 20 20 20 |m1, LSR #24. |
00000f90 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 5f | CMP gwi_|
00000fa0 6d 32 2c 20 23 31 32 37 0a 20 20 20 20 20 20 20 |m2, #127. |
00000fb0 20 4d 4f 56 47 54 20 20 20 67 77 69 5f 6d 32 2c | MOVGT gwi_m2,|
00000fc0 20 23 31 32 37 0a 20 20 20 20 20 20 20 20 43 4d | #127. CM|
00000fd0 50 20 20 20 20 20 67 77 69 5f 6d 32 2c 20 23 2d |P gwi_m2, #-|
00000fe0 31 32 37 0a 20 20 20 20 20 20 20 20 4d 4f 56 4c |127. MOVL|
00000ff0 54 20 20 20 67 77 69 5f 6d 32 2c 20 23 2d 31 32 |T gwi_m2, #-12|
00001000 37 0a 20 20 20 20 20 20 20 20 41 4e 44 20 20 20 |7. AND |
00001010 20 20 67 77 69 5f 6d 32 2c 20 67 77 69 5f 6d 32 | gwi_m2, gwi_m2|
00001020 2c 20 23 32 35 35 0a 20 20 20 20 20 20 20 20 41 |, #255. A|
00001030 44 44 20 20 20 20 20 67 77 69 5f 6c 64 65 2c 20 |DD gwi_lde, |
00001040 67 77 69 5f 6d 33 2c 20 67 77 69 5f 6d 32 2c 20 |gwi_m3, gwi_m2, |
00001050 4c 53 4c 20 23 31 36 09 3b 61 73 20 61 62 6f 76 |LSL #16.;as abov|
00001060 65 2c 20 66 6f 72 20 62 6c 75 65 20 2d 20 5f 6c |e, for blue - _l|
00001070 64 65 20 6e 6f 77 20 68 6f 6c 64 73 20 61 6c 6c |de now holds all|
00001080 20 74 68 72 65 65 20 73 69 67 6e 65 64 0a 09 09 | three signed...|
00001090 09 09 09 09 09 3b 38 20 62 69 74 20 65 72 72 6f |.....;8 bit erro|
000010a0 72 20 74 65 72 6d 73 0a 20 20 20 20 20 20 20 20 |r terms. |
000010b0 4d 45 4e 44 0a 0a 67 77 69 5f 61 73 6c 20 44 43 |MEND..gwi_asl DC|
000010c0 44 20 20 20 20 20 30 09 09 09 09 09 3b 73 74 6f |D 0.....;sto|
000010d0 72 61 67 65 20 66 6f 72 20 73 6c 2c 20 66 70 20 |rage for sl, fp |
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000010f0 65 72 6e 61 6c 20 63 61 6c 63 73 0a 67 77 69 5f |ernal calcs.gwi_|
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00001120 0a 67 77 69 5f 61 6a 20 20 20 20 20 20 20 20 20 |.gwi_aj |
00001130 20 44 43 44 20 20 20 20 20 30 09 09 09 09 3b 63 | DCD 0....;c|
00001140 75 72 72 65 6e 74 20 72 6f 77 20 6e 75 6d 62 65 |urrent row numbe|
00001150 72 0a 0a 20 20 20 20 20 20 20 20 45 58 50 4f 52 |r.. EXPOR|
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00001170 6e 61 6c 0a 0a 67 77 69 6e 73 74 61 20 44 43 42 |nal..gwinsta DCB|
00001180 20 20 20 20 20 22 67 32 35 36 77 6e 70 5f 69 6e | "g256wnp_in|
00001190 74 65 72 6e 61 6c 22 2c 20 30 0a 20 20 20 20 20 |ternal", 0. |
000011a0 20 20 20 41 4c 49 47 4e 0a 67 77 69 6e 65 6e 64 | ALIGN.gwinend|
000011b0 20 44 43 44 20 20 20 20 20 26 66 66 30 30 30 30 | DCD &ff0000|
000011c0 30 30 20 2b 20 67 77 69 6e 65 6e 64 20 2d 20 67 |00 + gwinend - g|
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000011e0 69 6e 74 65 72 6e 61 6c 0a 0a 20 20 20 20 20 20 |internal.. |
000011f0 20 20 4d 4f 56 20 20 20 20 20 69 70 2c 20 73 70 | MOV ip, sp|
00001200 0a 20 20 20 20 20 20 20 20 53 54 4d 46 44 20 20 |. STMFD |
00001210 20 73 70 21 2c 20 7b 61 31 2d 61 34 7d 09 09 3b | sp!, {a1-a4}..;|
00001220 73 74 61 63 6b 20 66 6e 20 61 72 67 73 20 78 2c |stack fn args x,|
00001230 79 2c 64 70 20 26 20 73 70 20 6f 6e 74 6f 20 73 |y,dp & sp onto s|
00001240 74 61 63 6b 20 62 65 6c 6f 77 20 72 65 6d 61 69 |tack below remai|
00001250 6e 69 6e 67 20 61 72 67 73 20 64 65 2c 6c 75 74 |ning args de,lut|
00001260 20 26 20 70 61 6c 32 35 36 64 65 66 0a 20 20 20 | & pal256def. |
00001270 20 20 20 20 20 53 54 4d 46 44 20 20 20 73 70 21 | STMFD sp!|
00001280 2c 20 7b 72 34 2d 72 39 2c 20 66 70 2c 20 69 70 |, {r4-r9, fp, ip|
00001290 2c 20 6c 72 2c 20 70 63 7d 0a 20 20 20 20 20 20 |, lr, pc}. |
000012a0 20 20 53 55 42 20 20 20 20 20 66 70 2c 20 69 70 | SUB fp, ip|
000012b0 2c 20 23 32 30 20 20 20 20 20 20 20 20 20 20 20 |, #20 |
000012c0 20 20 3b 6c 65 61 66 20 66 6e 20 26 20 6c 69 74 | ;leaf fn & lit|
000012d0 74 6c 65 20 6e 65 65 64 20 6f 66 20 73 74 61 63 |tle need of stac|
000012e0 6b 2c 20 73 6f 20 64 6f 6e 27 74 20 62 6f 74 68 |k, so don't both|
000012f0 65 72 20 77 69 74 68 20 73 74 61 63 6b 20 63 68 |er with stack ch|
00001300 65 63 6b 69 6e 67 0a 0a 20 20 20 20 20 20 20 20 |ecking.. |
00001310 53 54 52 20 20 20 20 20 73 6c 2c 20 67 77 69 5f |STR sl, gwi_|
00001320 61 73 6c 0a 20 20 20 20 20 20 20 20 53 54 52 20 |asl. STR |
00001330 20 20 20 20 66 70 2c 20 67 77 69 5f 61 66 70 0a | fp, gwi_afp.|
00001340 20 20 20 20 20 20 20 20 53 54 52 20 20 20 20 20 | STR |
00001350 73 70 2c 20 67 77 69 5f 61 73 70 20 20 20 20 20 |sp, gwi_asp |
00001360 20 20 20 20 20 20 20 20 3b 20 73 74 72 69 63 74 | ; strict|
00001370 6c 79 2c 20 64 6f 6e 27 74 20 6e 65 65 64 20 74 |ly, don't need t|
00001380 6f 20 73 61 76 65 20 74 68 69 73 2c 20 61 73 20 |o save this, as |
00001390 72 65 73 74 6f 72 65 20 66 72 61 6d 65 20 66 72 |restore frame fr|
000013a0 6f 6d 20 66 70 20 77 68 69 63 68 0a 20 20 20 20 |om fp which. |
000013b0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
*
000013d0 20 20 20 20 3b 20 63 6f 6e 74 61 69 6e 73 20 6f | ; contains o|
000013e0 6c 64 20 73 70 2c 20 68 6f 77 65 76 65 72 20 6b |ld sp, however k|
000013f0 65 65 70 20 69 74 20 68 65 72 65 20 69 6e 20 63 |eep it here in c|
00001400 61 73 65 20 63 68 61 6e 67 65 20 63 6f 64 65 20 |ase change code |
00001410 73 74 20 6e 65 65 64 0a 20 20 20 20 20 20 20 20 |st need. |
00001420 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
*
00001440 3b 20 74 6f 20 6d 61 6b 65 20 61 6e 20 65 78 74 |; to make an ext|
00001450 65 72 6e 61 6c 20 41 50 43 53 20 63 61 6c 6c 0a |ernal APCS call.|
00001460 20 20 20 20 20 20 20 20 3b 73 65 74 20 75 70 20 | ;set up |
00001470 72 65 67 73 20 6e 6f 77 0a 20 20 20 20 20 20 20 |regs now. |
00001480 20 4c 44 52 20 20 20 20 20 67 77 69 5f 78 70 2c | LDR gwi_xp,|
00001490 20 64 78 70 09 09 3b 6e 6f 74 65 20 64 78 70 20 | dxp..;note dxp |
000014a0 65 74 63 20 61 72 65 20 72 65 67 69 73 74 65 72 |etc are register|
000014b0 20 72 65 6c 61 74 69 76 65 20 2d 20 73 6f 20 74 | relative - so t|
000014c0 68 69 73 20 61 63 74 75 61 6c 6c 79 20 64 6f 65 |his actually doe|
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000014e0 23 34 5d 0a 20 20 20 20 20 20 20 20 4c 44 52 20 |#4]. LDR |
000014f0 20 20 20 20 67 77 69 5f 79 70 2c 20 64 79 70 09 | gwi_yp, dyp.|
00001500 09 3b 73 70 72 69 74 65 20 68 65 69 67 68 74 73 |.;sprite heights|
00001510 20 69 6e 20 70 69 78 65 6c 73 20 28 78 70 20 69 | in pixels (xp i|
00001520 73 20 63 6f 72 72 65 73 70 6f 6e 64 69 6e 67 20 |s corresponding |
00001530 77 69 64 74 68 73 29 0a 20 20 20 20 20 20 20 20 |widths). |
00001540 4c 44 52 20 20 20 20 20 67 77 69 5f 64 70 2c 20 |LDR gwi_dp, |
00001550 64 64 70 09 09 3b 70 74 72 20 74 6f 20 64 65 73 |ddp..;ptr to des|
00001560 74 69 6e 61 74 69 6f 6e 20 73 70 72 69 74 65 20 |tination sprite |
00001570 69 6d 61 67 65 20 28 69 65 20 69 6d 61 67 65 20 |image (ie image |
00001580 64 61 74 61 20 69 74 73 65 6c 66 20 26 20 6e 6f |data itself & no|
00001590 74 20 74 68 65 20 73 70 72 20 68 64 72 29 0a 20 |t the spr hdr). |
000015a0 20 20 20 20 20 20 20 4c 44 52 20 20 20 20 20 67 | LDR g|
000015b0 77 69 5f 73 70 2c 20 64 73 70 09 09 3b 70 74 72 |wi_sp, dsp..;ptr|
000015c0 20 74 6f 20 73 6f 75 72 63 65 20 73 70 72 69 74 | to source sprit|
000015d0 65 20 69 6d 61 67 65 0a 20 20 20 20 20 20 20 20 |e image. |
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000015f0 64 64 65 09 09 3b 70 74 72 20 74 6f 20 61 20 62 |dde..;ptr to a b|
00001600 75 66 66 65 72 20 66 6f 72 20 65 72 72 6f 72 20 |uffer for error |
00001610 74 65 72 6d 73 20 28 6d 75 73 74 20 62 65 20 78 |terms (must be x|
00001620 70 20 77 6f 72 64 73 20 6c 6f 6e 67 29 0a 20 20 |p words long). |
00001630 20 20 20 20 20 20 4c 44 52 20 20 20 20 20 67 77 | LDR gw|
00001640 69 5f 6c 75 74 2c 20 64 6c 75 74 09 09 3b 70 74 |i_lut, dlut..;pt|
00001650 72 20 74 6f 20 6c 75 74 20 74 6f 20 6d 61 70 20 |r to lut to map |
00001660 31 35 62 69 74 20 72 67 62 20 63 6f 6c 6f 75 72 |15bit rgb colour|
00001670 20 74 6f 20 6e 65 61 72 65 73 74 20 61 76 61 69 | to nearest avai|
00001680 6c 61 62 6c 65 20 69 6e 20 64 65 66 61 75 6c 74 |lable in default|
00001690 20 38 62 70 70 20 70 61 6c 0a 20 20 20 20 20 20 | 8bpp pal. |
000016a0 20 20 4c 44 52 20 20 20 20 20 67 77 69 5f 70 61 | LDR gwi_pa|
000016b0 6c 32 35 36 64 65 66 2c 20 64 70 61 6c 32 35 36 |l256def, dpal256|
000016c0 64 65 66 09 3b 70 74 72 20 74 6f 20 64 65 66 61 |def.;ptr to defa|
000016d0 75 6c 74 20 38 62 70 70 20 32 35 36 20 65 6e 74 |ult 8bpp 256 ent|
000016e0 72 79 20 70 61 6c 65 74 74 65 20 28 75 73 65 64 |ry palette (used|
000016f0 20 74 6f 20 63 61 6c 63 20 65 72 72 6f 72 73 29 | to calc errors)|
00001700 0a 0a 20 20 20 20 20 20 20 20 3b 63 6f 64 65 0a |.. ;code.|
00001710 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 | MOV |
00001720 67 77 69 5f 69 2c 20 67 77 69 5f 78 70 09 09 3b |gwi_i, gwi_xp..;|
00001730 63 75 72 72 65 6e 74 20 63 6f 6c 75 6d 6e 20 6e |current column n|
00001740 75 6d 62 65 72 20 28 61 63 74 75 61 6c 6c 79 2c |umber (actually,|
00001750 20 78 70 2d 6e 75 6d 62 65 72 29 0a 20 20 20 20 | xp-number). |
00001760 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 5f | CMP gwi_|
00001770 69 2c 20 23 30 0a 20 20 20 20 20 20 20 20 42 4c |i, #0. BL|
00001780 45 20 20 20 20 20 67 77 69 5f 78 6c 6f 6f 70 31 |E gwi_xloop1|
00001790 64 6f 6e 65 0a 0a 67 77 69 5f 78 6c 6f 6f 70 31 |done..gwi_xloop1|
000017a0 0a 09 4c 44 52 09 67 77 69 5f 6d 31 2c 20 5b 67 |..LDR.gwi_m1, [g|
000017b0 77 69 5f 73 70 2c 20 23 30 5d 0a 20 20 20 20 20 |wi_sp, #0]. |
000017c0 20 20 20 41 4e 44 20 20 20 20 20 67 77 69 5f 72 | AND gwi_r|
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000017e0 66 72 6f 6d 20 68 65 72 65 20 2e 20 2e 20 2e 0a |from here . . ..|
000017f0 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 | MOV |
00001800 67 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 4c |gwi_g, gwi_m1, L|
00001810 53 52 20 23 38 0a 20 20 20 20 20 20 20 20 41 4e |SR #8. AN|
00001820 44 20 20 20 20 20 67 77 69 5f 67 2c 20 67 77 69 |D gwi_g, gwi|
00001830 5f 67 2c 20 23 32 35 35 0a 20 20 20 20 20 20 20 |_g, #255. |
00001840 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 62 2c 20 | MOV gwi_b, |
00001850 67 77 69 5f 6d 31 2c 20 4c 53 52 20 23 31 36 0a |gwi_m1, LSR #16.|
00001860 20 20 20 20 20 20 20 20 41 4e 44 20 20 20 20 20 | AND |
00001870 67 77 69 5f 62 2c 20 67 77 69 5f 62 2c 20 23 32 |gwi_b, gwi_b, #2|
00001880 35 35 09 3b 74 6f 20 68 65 72 65 2c 20 65 78 74 |55.;to here, ext|
00001890 72 61 63 74 20 74 68 72 65 65 20 72 2c 67 20 26 |ract three r,g &|
000018a0 20 62 20 38 20 62 69 74 20 63 6f 6d 70 6f 6e 65 | b 8 bit compone|
000018b0 6e 74 73 20 69 6e 74 6f 20 5f 72 2c 20 5f 67 20 |nts into _r, _g |
000018c0 26 20 5f 62 0a 20 20 20 20 20 20 20 20 43 4d 50 |& _b. CMP|
000018d0 20 20 20 20 20 67 77 69 5f 69 2c 20 67 77 69 5f | gwi_i, gwi_|
000018e0 78 70 0a 20 20 20 20 20 20 20 20 42 45 51 20 20 |xp. BEQ |
000018f0 20 20 20 67 77 69 5f 78 6c 31 5f 62 31 0a 09 09 | gwi_xl1_b1...|
00001900 09 09 09 3b 69 66 20 6e 6f 74 20 6f 6e 20 66 69 |...;if not on fi|
00001910 72 73 74 20 70 69 78 65 6c 20 69 6e 20 72 6f 77 |rst pixel in row|
00001920 2c 20 74 68 65 72 65 20 69 73 20 61 6e 20 65 72 |, there is an er|
00001930 72 6f 72 20 74 65 72 6d 20 74 6f 20 61 64 64 20 |ror term to add |
00001940 69 6e 20 66 72 6f 6d 20 6c 65 66 74 3a 0a 20 20 |in from left:. |
00001950 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 | MOV gw|
00001960 69 5f 6d 31 2c 20 67 77 69 5f 6c 64 65 2c 20 4c |i_m1, gwi_lde, L|
00001970 53 4c 20 23 32 34 09 3b 65 78 74 72 61 63 74 20 |SL #24.;extract |
00001980 72 65 64 20 65 72 72 6f 72 20 66 72 6f 6d 20 5f |red error from _|
00001990 6c 64 65 20 26 0a 20 20 20 20 20 20 20 20 4d 4f |lde &. MO|
000019a0 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
000019b0 69 5f 6d 31 2c 20 41 53 52 20 23 32 34 09 09 3b |i_m1, ASR #24..;|
000019c0 73 69 67 6e 20 65 78 74 65 6e 64 20 69 74 20 74 |sign extend it t|
000019d0 6f 20 33 32 20 62 69 74 73 0a 20 20 20 20 20 20 |o 32 bits. |
000019e0 20 20 52 53 42 53 20 20 20 20 67 77 69 5f 6d 31 | RSBS gwi_m1|
000019f0 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 |, gwi_m1, gwi_m1|
00001a00 2c 20 41 53 4c 20 23 33 09 3b 66 72 6f 6d 20 68 |, ASL #3.;from h|
00001a10 65 72 65 20 2e 20 2e 20 2e 0a 20 20 20 20 20 20 |ere . . .. |
00001a20 20 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d 31 | ADDMI gwi_m1|
00001a30 2c 20 67 77 69 5f 6d 31 2c 20 23 31 35 09 09 3b |, gwi_m1, #15..;|
00001a40 09 28 6e 65 65 64 20 74 6f 20 65 6e 73 75 72 65 |.(need to ensure|
00001a50 20 2a 37 2f 31 36 20 77 69 6c 6c 20 72 6f 75 6e | *7/16 will roun|
00001a60 64 20 74 6f 77 61 72 64 73 20 30 2c 20 72 61 74 |d towards 0, rat|
00001a70 68 65 72 20 74 68 61 6e 20 64 6f 77 6e 29 0a 20 |her than down). |
00001a80 20 20 20 20 20 20 20 41 44 44 20 20 20 20 20 67 | ADD g|
00001a90 77 69 5f 72 2c 20 67 77 69 5f 72 2c 20 67 77 69 |wi_r, gwi_r, gwi|
00001aa0 5f 6d 31 2c 20 41 53 52 20 23 34 09 3b 74 6f 20 |_m1, ASR #4.;to |
00001ab0 68 65 72 65 2c 20 61 64 64 20 74 6f 20 5f 72 20 |here, add to _r |
00001ac0 37 2f 31 36 20 6c 64 65 20 72 65 64 20 65 72 72 |7/16 lde red err|
00001ad0 6f 72 20 74 65 72 6d 0a 20 20 20 20 20 20 20 20 |or term. |
00001ae0 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 |MOV gwi_m1, |
00001af0 67 77 69 5f 6c 64 65 2c 20 4c 53 4c 20 23 31 36 |gwi_lde, LSL #16|
00001b00 09 3b 66 72 6f 6d 20 68 65 72 65 20 2e 20 2e 20 |.;from here . . |
00001b10 2e 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |.. MOV |
00001b20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00001b30 2c 20 41 53 52 20 23 32 34 0a 20 20 20 20 20 20 |, ASR #24. |
00001b40 20 20 52 53 42 53 20 20 20 20 67 77 69 5f 6d 31 | RSBS gwi_m1|
00001b50 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 |, gwi_m1, gwi_m1|
00001b60 2c 20 41 53 4c 20 23 33 0a 20 20 20 20 20 20 20 |, ASL #3. |
00001b70 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d 31 2c | ADDMI gwi_m1,|
00001b80 20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 20 20 | gwi_m1, #15. |
00001b90 20 20 20 20 20 41 44 44 20 20 20 20 20 67 77 69 | ADD gwi|
00001ba0 5f 67 2c 20 67 77 69 5f 67 2c 20 67 77 69 5f 6d |_g, gwi_g, gwi_m|
00001bb0 31 2c 20 41 53 52 20 23 34 09 3b 74 6f 20 68 65 |1, ASR #4.;to he|
00001bc0 72 65 2c 20 65 78 74 72 61 63 74 20 67 72 65 65 |re, extract gree|
00001bd0 6e 20 65 72 72 6f 72 20 26 20 61 64 64 20 37 2f |n error & add 7/|
00001be0 31 36 20 6f 66 20 69 74 20 69 6e 74 6f 20 5f 67 |16 of it into _g|
00001bf0 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 |. MOV |
00001c00 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6c 64 65 | gwi_m1, gwi_lde|
00001c10 2c 20 4c 53 4c 20 23 38 09 09 3b 66 72 6f 6d 20 |, LSL #8..;from |
00001c20 68 65 72 65 20 2e 20 2e 20 2e 0a 20 20 20 20 20 |here . . .. |
00001c30 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d | MOV gwi_m|
00001c40 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 |1, gwi_m1, ASR #|
00001c50 32 34 0a 20 20 20 20 20 20 20 20 52 53 42 53 20 |24. RSBS |
00001c60 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
00001c70 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c 20 23 |1, gwi_m1, ASL #|
00001c80 33 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 |3. ADDMI |
00001c90 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00001ca0 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 |, #15. AD|
00001cb0 44 20 20 20 20 20 67 77 69 5f 62 2c 20 67 77 69 |D gwi_b, gwi|
00001cc0 5f 62 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 |_b, gwi_m1, ASR |
00001cd0 23 34 09 3b 74 6f 20 68 65 72 65 2c 20 65 78 74 |#4.;to here, ext|
00001ce0 72 61 63 74 20 62 6c 75 65 20 65 72 72 6f 72 20 |ract blue error |
00001cf0 66 72 6f 6d 20 6c 64 65 20 26 20 61 64 64 20 37 |from lde & add 7|
00001d00 2f 31 36 20 69 6e 74 6f 20 5f 62 0a 20 20 20 20 |/16 into _b. |
00001d10 20 20 20 20 53 54 52 20 20 20 20 20 67 77 69 5f | STR gwi_|
00001d20 6c 64 65 2c 20 5b 67 77 69 5f 64 65 2c 20 67 77 |lde, [gwi_de, gw|
00001d30 69 5f 69 2c 20 41 53 4c 20 23 32 5d 09 3b 62 75 |i_i, ASL #2].;bu|
00001d40 66 66 65 72 20 6c 64 65 20 66 6f 72 20 77 68 65 |ffer lde for whe|
00001d50 6e 20 70 72 6f 63 65 73 73 69 6e 67 20 72 6f 77 |n processing row|
00001d60 20 62 65 6c 6f 77 0a 0a 67 77 69 5f 78 6c 31 5f | below..gwi_xl1_|
00001d70 62 31 0a 0a 20 20 20 20 20 20 20 20 67 77 69 5f |b1.. gwi_|
00001d80 73 65 67 31 09 09 09 09 3b 77 72 69 74 65 20 74 |seg1....;write t|
00001d90 6f 20 64 65 73 74 69 6e 61 74 69 6f 6e 20 69 6d |o destination im|
00001da0 61 67 65 20 26 20 63 61 6c 63 75 6c 61 74 65 20 |age & calculate |
00001db0 65 72 72 6f 72 20 66 6f 72 20 74 68 69 73 20 70 |error for this p|
00001dc0 69 78 65 6c 20 28 69 6e 74 6f 20 6c 64 65 29 0a |ixel (into lde).|
00001dd0 0a 20 20 20 20 20 20 20 20 41 44 44 20 20 20 20 |. ADD |
00001de0 20 67 77 69 5f 64 70 2c 20 67 77 69 5f 64 70 2c | gwi_dp, gwi_dp,|
00001df0 20 23 31 09 09 3b 73 74 65 70 20 74 68 72 6f 75 | #1..;step throu|
00001e00 67 68 20 64 65 73 74 69 6e 61 74 69 6f 6e 20 69 |gh destination i|
00001e10 6d 61 67 65 20 6f 6e 65 20 70 69 78 65 6c 0a 20 |mage one pixel. |
00001e20 20 20 20 20 20 20 20 41 44 44 20 20 20 20 20 67 | ADD g|
00001e30 77 69 5f 73 70 2c 20 67 77 69 5f 73 70 2c 20 23 |wi_sp, gwi_sp, #|
00001e40 34 09 09 3b 73 74 65 70 20 74 68 72 6f 75 67 68 |4..;step through|
00001e50 20 73 6f 75 72 63 65 20 69 6d 61 67 65 20 6f 6e | source image on|
00001e60 65 20 70 69 78 65 6c 0a 20 20 20 20 20 20 20 20 |e pixel. |
00001e70 53 55 42 53 20 20 20 20 67 77 69 5f 69 2c 20 67 |SUBS gwi_i, g|
00001e80 77 69 5f 69 2c 20 23 31 0a 20 20 20 20 20 20 20 |wi_i, #1. |
00001e90 20 42 47 54 20 20 20 20 20 67 77 69 5f 78 6c 6f | BGT gwi_xlo|
00001ea0 6f 70 31 09 09 09 3b 26 20 72 65 70 65 61 74 20 |op1...;& repeat |
00001eb0 74 69 6c 6c 20 61 6c 6c 20 6f 66 20 66 69 72 73 |till all of firs|
00001ec0 74 20 72 6f 77 20 70 72 6f 63 65 73 73 65 64 0a |t row processed.|
00001ed0 67 77 69 5f 78 6c 6f 6f 70 31 64 6f 6e 65 0a 09 |gwi_xloop1done..|
00001ee0 09 09 09 09 09 3b 6e 6f 77 20 73 74 65 70 20 64 |.....;now step d|
00001ef0 6f 77 6e 20 74 6f 20 6e 65 78 74 20 72 6f 77 20 |own to next row |
00001f00 28 72 65 6d 65 6d 62 65 72 2c 20 73 65 72 70 65 |(remember, serpe|
00001f10 6e 74 69 6e 65 20 73 63 61 6e 6e 69 6e 67 29 0a |ntine scanning).|
00001f20 20 20 20 20 20 20 20 20 52 53 42 20 20 20 20 20 | RSB |
00001f30 67 77 69 5f 6d 32 2c 20 67 77 69 5f 78 70 2c 20 |gwi_m2, gwi_xp, |
00001f40 23 34 0a 20 20 20 20 20 20 20 20 41 4e 44 20 20 |#4. AND |
00001f50 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
00001f60 32 2c 20 23 33 09 09 3b 20 2e 20 2e 20 2e 20 74 |2, #3..; . . . t|
00001f70 6f 20 67 65 74 20 70 61 73 74 20 72 69 67 68 74 |o get past right|
00001f80 68 61 6e 64 20 77 61 73 74 61 67 65 20 6f 66 20 |hand wastage of |
00001f90 6c 61 73 74 20 72 6f 77 2c 20 64 65 73 74 20 69 |last row, dest i|
00001fa0 6d 61 67 65 0a 20 20 20 20 20 20 20 20 41 44 44 |mage. ADD|
00001fb0 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 | gwi_m1, gwi|
00001fc0 5f 6d 31 2c 20 67 77 69 5f 78 70 09 09 3b 20 2e |_m1, gwi_xp..; .|
00001fd0 20 2e 20 2e 20 74 6f 20 67 65 74 20 70 61 73 74 | . . to get past|
00001fe0 20 65 6e 64 20 6f 66 20 6e 65 78 74 20 72 6f 77 | end of next row|
00001ff0 0a 20 20 20 20 20 20 20 20 53 55 42 20 20 20 20 |. SUB |
00002000 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
00002010 20 23 31 09 09 3b 20 2e 20 2e 20 2e 20 74 6f 20 | #1..; . . . to |
00002020 67 65 74 20 62 61 63 6b 20 74 6f 20 6c 61 73 74 |get back to last|
00002030 20 70 69 78 65 6c 20 6f 6e 20 74 68 61 74 20 72 | pixel on that r|
00002040 6f 77 0a 20 20 20 20 20 20 20 20 41 44 44 20 20 |ow. ADD |
00002050 20 20 20 67 77 69 5f 64 70 2c 20 67 77 69 5f 64 | gwi_dp, gwi_d|
00002060 70 2c 20 67 77 69 5f 6d 31 09 09 3b 6d 61 6b 65 |p, gwi_m1..;make|
00002070 20 74 68 65 20 61 64 6a 75 73 74 6d 65 6e 74 20 | the adjustment |
00002080 74 6f 20 5f 64 70 0a 09 41 44 44 20 20 20 20 20 |to _dp..ADD |
00002090 67 77 69 5f 73 70 2c 20 67 77 69 5f 73 70 2c 20 |gwi_sp, gwi_sp, |
000020a0 67 77 69 5f 78 70 2c 20 4c 53 4c 20 23 32 09 3b |gwi_xp, LSL #2.;|
000020b0 66 72 6f 6d 20 68 65 72 65 20 2e 20 2e 20 2e 0a |from here . . ..|
000020c0 20 20 20 20 20 20 20 20 53 55 42 20 20 20 20 20 | SUB |
000020d0 67 77 69 5f 73 70 2c 20 67 77 69 5f 73 70 2c 20 |gwi_sp, gwi_sp, |
000020e0 23 34 09 09 3b 74 6f 20 68 65 72 65 2c 20 61 73 |#4..;to here, as|
000020f0 20 61 62 6f 76 65 20 66 6f 72 20 73 72 63 20 69 | above for src i|
00002100 6d 61 67 65 20 28 6e 6f 74 65 2c 20 69 74 20 68 |mage (note, it h|
00002110 61 73 20 34 2a 78 70 20 62 79 74 65 73 20 70 65 |as 4*xp bytes pe|
00002120 72 20 72 6f 77 29 0a 0a 20 20 20 20 20 20 20 20 |r row).. |
00002130 53 55 42 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 |SUBS gwi_m1, |
00002140 67 77 69 5f 79 70 2c 20 23 32 0a 20 20 20 20 20 |gwi_yp, #2. |
00002150 20 20 20 42 4d 49 20 20 20 20 20 67 77 69 5f 79 | BMI gwi_y|
00002160 6c 6f 6f 70 64 6f 6e 65 09 09 09 3b 63 61 72 72 |loopdone...;carr|
00002170 79 20 6f 6e 20 77 69 74 68 20 6e 65 78 74 20 72 |y on with next r|
00002180 6f 77 2c 20 75 6e 6c 65 73 73 20 61 6c 6c 20 72 |ow, unless all r|
00002190 6f 77 73 20 64 6f 6e 65 20 28 6e 6f 74 65 2c 20 |ows done (note, |
000021a0 73 75 62 74 72 61 63 74 0a 20 20 20 20 20 20 20 |subtract. |
000021b0 20 53 54 52 20 20 20 20 20 67 77 69 5f 6d 31 2c | STR gwi_m1,|
000021c0 20 67 77 69 5f 61 6a 09 09 09 3b 20 32 20 66 72 | gwi_aj...; 2 fr|
000021d0 6f 6d 20 79 70 20 69 6e 69 74 69 61 6c 6c 79 20 |om yp initially |
000021e0 73 69 6e 63 65 20 79 70 20 69 73 20 23 20 72 6f |since yp is # ro|
000021f0 77 73 20 63 6f 75 6e 74 69 6e 67 20 66 72 6f 6d |ws counting from|
00002200 20 31 2c 20 26 0a 09 09 09 09 09 09 3b 20 62 72 | 1, &.......; br|
00002210 61 6e 63 68 20 63 6f 6e 64 20 69 73 20 4d 49 2c |anch cond is MI,|
00002220 20 69 65 20 6c 6f 6f 70 20 63 6f 75 6e 74 73 20 | ie loop counts |
00002230 72 6f 77 73 20 69 6e 63 6c 75 64 69 6e 67 20 30 |rows including 0|
00002240 29 0a 09 09 09 09 09 3b 6e 6f 74 65 2c 20 64 65 |)......;note, de|
00002250 20 62 75 66 66 65 72 20 68 6f 6c 64 73 20 65 72 | buffer holds er|
00002260 72 6f 72 73 20 66 6f 72 20 72 6f 77 20 61 62 6f |rors for row abo|
00002270 76 65 2c 20 72 75 6e 6e 69 6e 67 20 66 72 6f 6d |ve, running from|
00002280 20 72 69 67 68 74 20 69 6e 20 6c 6f 77 0a 09 09 | right in low...|
00002290 09 09 09 3b 6d 65 6d 6f 72 79 20 74 6f 20 6c 65 |...;memory to le|
000022a0 66 74 20 73 69 64 65 20 69 6e 20 68 69 67 68 20 |ft side in high |
000022b0 6d 65 6d 2e 20 4e 65 78 74 20 72 6f 77 20 77 69 |mem. Next row wi|
000022c0 6c 6c 20 62 65 20 73 63 61 6e 6e 65 64 20 72 69 |ll be scanned ri|
000022d0 67 68 74 20 74 6f 0a 67 77 69 5f 79 6c 6f 6f 70 |ght to.gwi_yloop|
000022e0 09 09 09 09 3b 6c 65 66 74 2c 20 73 6f 20 6e 65 |....;left, so ne|
000022f0 65 64 20 65 78 74 72 61 63 74 20 65 72 72 6f 72 |ed extract error|
00002300 73 20 66 72 6f 6d 20 62 75 66 66 65 72 20 69 6e |s from buffer in|
00002310 20 69 6e 63 72 65 61 73 69 6e 67 20 6d 65 6d 6f | increasing memo|
00002320 72 79 20 6f 72 64 65 72 2e 0a 0a 20 20 20 20 20 |ry order... |
00002330 20 20 20 53 54 52 20 20 20 20 20 67 77 69 5f 6c | STR gwi_l|
00002340 64 65 2c 20 5b 67 77 69 5f 64 65 2c 20 23 30 5d |de, [gwi_de, #0]|
00002350 09 3b 62 75 66 66 65 72 20 65 72 72 6f 72 20 66 |.;buffer error f|
00002360 6f 72 20 66 69 6e 61 6c 20 70 69 78 65 6c 20 66 |or final pixel f|
00002370 72 6f 6d 20 6c 61 73 74 20 72 6f 77 0a 20 20 20 |rom last row. |
00002380 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 | MOV gwi|
00002390 5f 69 2c 20 23 31 0a 20 20 20 20 20 20 20 20 43 |_i, #1. C|
000023a0 4d 50 20 20 20 20 20 67 77 69 5f 69 2c 20 67 77 |MP gwi_i, gw|
000023b0 69 5f 78 70 0a 20 20 20 20 20 20 20 20 42 47 54 |i_xp. BGT|
000023c0 20 20 20 20 20 67 77 69 5f 78 6c 6f 6f 70 32 64 | gwi_xloop2d|
000023d0 6f 6e 65 0a 09 09 09 09 09 3b 61 6c 6c 20 72 65 |one......;all re|
000023e0 6d 61 69 6e 69 6e 67 20 63 6f 64 65 20 69 73 20 |maining code is |
000023f0 73 69 6d 69 6c 61 72 20 74 6f 20 70 72 65 63 65 |similar to prece|
00002400 65 64 69 6e 67 2c 20 65 78 63 65 70 74 20 68 61 |eding, except ha|
00002410 76 65 20 74 6f 20 61 64 64 20 69 6e 0a 67 77 69 |ve to add in.gwi|
00002420 5f 78 6c 6f 6f 70 32 09 09 09 09 3b 65 72 72 6f |_xloop2....;erro|
00002430 72 73 20 66 72 6f 6d 20 72 6f 77 20 61 62 6f 76 |rs from row abov|
00002440 65 2c 20 26 20 73 63 61 6e 20 72 6f 77 20 69 6e |e, & scan row in|
00002450 20 72 65 76 65 72 73 65 20 64 69 72 65 63 74 69 | reverse directi|
00002460 6f 6e 0a 09 4c 44 52 09 67 77 69 5f 6d 31 2c 20 |on..LDR.gwi_m1, |
00002470 5b 67 77 69 5f 73 70 2c 20 23 30 5d 0a 20 20 20 |[gwi_sp, #0]. |
00002480 20 20 20 20 20 41 4e 44 20 20 20 20 20 67 77 69 | AND gwi|
00002490 5f 72 2c 20 67 77 69 5f 6d 31 2c 20 23 32 35 35 |_r, gwi_m1, #255|
000024a0 09 3b 66 72 6f 6d 20 68 65 72 65 20 2e 20 2e 20 |.;from here . . |
000024b0 2e 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |.. MOV |
000024c0 20 20 67 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c | gwi_g, gwi_m1,|
000024d0 20 4c 53 52 20 23 38 0a 20 20 20 20 20 20 20 20 | LSR #8. |
000024e0 41 4e 44 20 20 20 20 20 67 77 69 5f 67 2c 20 67 |AND gwi_g, g|
000024f0 77 69 5f 67 2c 20 23 32 35 35 0a 20 20 20 20 20 |wi_g, #255. |
00002500 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 62 | MOV gwi_b|
00002510 2c 20 67 77 69 5f 6d 31 2c 20 4c 53 52 20 23 31 |, gwi_m1, LSR #1|
00002520 36 0a 20 20 20 20 20 20 20 20 41 4e 44 20 20 20 |6. AND |
00002530 20 20 67 77 69 5f 62 2c 20 67 77 69 5f 62 2c 20 | gwi_b, gwi_b, |
00002540 23 32 35 35 09 3b 74 6f 20 68 65 72 65 2c 20 65 |#255.;to here, e|
00002550 78 74 72 61 63 74 20 74 68 72 65 65 20 72 2c 67 |xtract three r,g|
00002560 20 26 20 62 20 38 20 62 69 74 20 63 6f 6d 70 6f | & b 8 bit compo|
00002570 6e 65 6e 74 73 20 69 6e 74 6f 20 5f 72 2c 20 5f |nents into _r, _|
00002580 67 20 26 20 5f 62 0a 0a 20 20 20 20 20 20 20 20 |g & _b.. |
00002590 53 55 42 20 20 20 20 20 67 77 69 5f 6d 34 2c 20 |SUB gwi_m4, |
000025a0 67 77 69 5f 69 2c 20 23 31 09 3b 66 72 6f 6d 20 |gwi_i, #1.;from |
000025b0 68 65 72 65 20 2e 20 2e 20 2e 0a 20 20 20 20 20 |here . . .. |
000025c0 20 20 20 4c 44 52 20 20 20 20 20 67 77 69 5f 6d | LDR gwi_m|
000025d0 34 2c 20 5b 67 77 69 5f 64 65 2c 20 67 77 69 5f |4, [gwi_de, gwi_|
000025e0 6d 34 2c 20 41 53 4c 20 23 32 5d 0a 20 20 20 20 |m4, ASL #2]. |
000025f0 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f | MOV gwi_|
00002600 6d 31 2c 20 67 77 69 5f 6d 34 2c 20 4c 53 4c 20 |m1, gwi_m4, LSL |
00002610 23 32 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 |#24. MOV |
00002620 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
00002630 6d 31 2c 20 41 53 52 20 23 32 34 0a 20 20 20 20 |m1, ASR #24. |
00002640 20 20 20 20 41 44 44 53 20 20 20 20 67 77 69 5f | ADDS gwi_|
00002650 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f |m1, gwi_m1, gwi_|
00002660 6d 31 2c 20 41 53 4c 20 23 32 0a 20 20 20 20 20 |m1, ASL #2. |
00002670 20 20 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d | ADDMI gwi_m|
00002680 31 2c 20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 |1, gwi_m1, #15. |
00002690 20 20 20 20 20 20 20 41 44 44 20 20 20 20 20 67 | ADD g|
000026a0 77 69 5f 72 2c 20 67 77 69 5f 72 2c 20 67 77 69 |wi_r, gwi_r, gwi|
000026b0 5f 6d 31 2c 20 41 53 52 20 23 34 0a 20 20 20 20 |_m1, ASR #4. |
000026c0 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f | MOV gwi_|
000026d0 6d 31 2c 20 67 77 69 5f 6d 34 2c 20 4c 53 4c 20 |m1, gwi_m4, LSL |
000026e0 23 31 36 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 |#16. MOV |
000026f0 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
00002700 6d 31 2c 20 41 53 52 20 23 32 34 0a 20 20 20 20 |m1, ASR #24. |
00002710 20 20 20 20 41 44 44 53 20 20 20 20 67 77 69 5f | ADDS gwi_|
00002720 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f |m1, gwi_m1, gwi_|
00002730 6d 31 2c 20 41 53 4c 20 23 32 0a 20 20 20 20 20 |m1, ASL #2. |
00002740 20 20 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d | ADDMI gwi_m|
00002750 31 2c 20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 |1, gwi_m1, #15. |
00002760 20 20 20 20 20 20 20 41 44 44 20 20 20 20 20 67 | ADD g|
00002770 77 69 5f 67 2c 20 67 77 69 5f 67 2c 20 67 77 69 |wi_g, gwi_g, gwi|
00002780 5f 6d 31 2c 20 41 53 52 20 23 34 0a 20 20 20 20 |_m1, ASR #4. |
00002790 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f | MOV gwi_|
000027a0 6d 31 2c 20 67 77 69 5f 6d 34 2c 20 4c 53 4c 20 |m1, gwi_m4, LSL |
000027b0 23 38 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 |#8. MOV |
000027c0 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
000027d0 31 2c 20 41 53 52 20 23 32 34 0a 20 20 20 20 20 |1, ASR #24. |
000027e0 20 20 20 41 44 44 53 20 20 20 20 67 77 69 5f 6d | ADDS gwi_m|
000027f0 31 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d |1, gwi_m1, gwi_m|
00002800 31 2c 20 41 53 4c 20 23 32 0a 20 20 20 20 20 20 |1, ASL #2. |
00002810 20 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d 31 | ADDMI gwi_m1|
00002820 2c 20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 20 |, gwi_m1, #15. |
00002830 20 20 20 20 20 20 41 44 44 20 20 20 20 20 67 77 | ADD gw|
00002840 69 5f 62 2c 20 67 77 69 5f 62 2c 20 67 77 69 5f |i_b, gwi_b, gwi_|
00002850 6d 31 2c 20 41 53 52 20 23 34 09 3b 74 6f 20 68 |m1, ASR #4.;to h|
00002860 65 72 65 2c 20 61 64 64 20 69 6e 20 35 2f 31 36 |ere, add in 5/16|
00002870 20 65 72 72 6f 72 20 66 6f 72 20 70 69 78 65 6c | error for pixel|
00002880 20 61 62 6f 76 65 0a 0a 20 20 20 20 20 20 20 20 | above.. |
00002890 43 4d 50 20 20 20 20 20 67 77 69 5f 69 2c 20 23 |CMP gwi_i, #|
000028a0 31 0a 20 20 20 20 20 20 20 20 42 45 51 20 20 20 |1. BEQ |
000028b0 20 20 67 77 69 5f 78 6c 32 5f 62 31 0a 0a 20 20 | gwi_xl2_b1.. |
000028c0 20 20 20 20 20 20 53 55 42 20 20 20 20 20 67 77 | SUB gw|
000028d0 69 5f 6d 32 2c 20 67 77 69 5f 69 2c 20 23 32 09 |i_m2, gwi_i, #2.|
000028e0 09 3b 73 69 6d 69 6c 69 61 72 6c 79 20 28 69 66 |.;similiarly (if|
000028f0 20 6e 6f 74 20 6f 6e 20 72 69 67 68 74 6d 6f 73 | not on rightmos|
00002900 74 20 63 6f 6c 75 6d 6e 29 20 2e 20 2e 20 2e 0a |t column) . . ..|
00002910 20 20 20 20 20 20 20 20 4c 44 52 20 20 20 20 20 | LDR |
00002920 67 77 69 5f 6d 34 2c 20 5b 67 77 69 5f 64 65 2c |gwi_m4, [gwi_de,|
00002930 20 67 77 69 5f 6d 32 2c 20 41 53 4c 20 23 32 5d | gwi_m2, ASL #2]|
00002940 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 |. MOV |
00002950 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 34 2c | gwi_m1, gwi_m4,|
00002960 20 4c 53 4c 20 23 32 34 0a 20 20 20 20 20 20 20 | LSL #24. |
00002970 20 4d 4f 56 53 20 20 20 20 67 77 69 5f 6d 31 2c | MOVS gwi_m1,|
00002980 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 32 34 | gwi_m1, ASR #24|
00002990 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 20 |. ADDMI |
000029a0 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
000029b0 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 44 | #15. ADD|
000029c0 20 20 20 20 20 67 77 69 5f 72 2c 20 67 77 69 5f | gwi_r, gwi_|
000029d0 72 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 |r, gwi_m1, ASR #|
000029e0 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |4. MOV |
000029f0 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 34 | gwi_m1, gwi_m4|
00002a00 2c 20 4c 53 4c 20 23 31 36 0a 20 20 20 20 20 20 |, LSL #16. |
00002a10 20 20 4d 4f 56 53 20 20 20 20 67 77 69 5f 6d 31 | MOVS gwi_m1|
00002a20 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 32 |, gwi_m1, ASR #2|
00002a30 34 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 |4. ADDMI |
00002a40 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00002a50 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 |, #15. AD|
00002a60 44 20 20 20 20 20 67 77 69 5f 67 2c 20 67 77 69 |D gwi_g, gwi|
00002a70 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 |_g, gwi_m1, ASR |
00002a80 23 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 |#4. MOV |
00002a90 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
00002aa0 34 2c 20 4c 53 4c 20 23 38 0a 20 20 20 20 20 20 |4, LSL #8. |
00002ab0 20 20 4d 4f 56 53 20 20 20 20 67 77 69 5f 6d 31 | MOVS gwi_m1|
00002ac0 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 32 |, gwi_m1, ASR #2|
00002ad0 34 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 |4. ADDMI |
00002ae0 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00002af0 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 |, #15. AD|
00002b00 44 20 20 20 20 20 67 77 69 5f 62 2c 20 67 77 69 |D gwi_b, gwi|
00002b10 5f 62 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 |_b, gwi_m1, ASR |
00002b20 23 34 09 3b 61 64 64 20 69 6e 20 31 2f 31 36 20 |#4.;add in 1/16 |
00002b30 65 72 72 6f 72 20 66 6f 72 20 70 69 78 65 6c 20 |error for pixel |
00002b40 74 6f 20 61 62 6f 76 65 20 72 69 67 68 74 0a 0a |to above right..|
00002b50 20 20 20 20 20 20 20 20 53 54 52 20 20 20 20 20 | STR |
00002b60 67 77 69 5f 6c 64 65 2c 20 5b 67 77 69 5f 64 65 |gwi_lde, [gwi_de|
00002b70 2c 20 67 77 69 5f 6d 32 2c 20 41 53 4c 20 23 32 |, gwi_m2, ASL #2|
00002b80 5d 09 3b 63 61 6e 20 6e 6f 77 20 73 61 66 65 6c |].;can now safel|
00002b90 79 20 6f 76 65 72 77 72 69 74 65 20 76 61 6c 75 |y overwrite valu|
00002ba0 65 20 69 6e 20 62 75 66 66 65 72 20 77 69 74 68 |e in buffer with|
00002bb0 20 6c 64 65 20 66 6f 72 20 6e 65 78 74 20 72 6f | lde for next ro|
00002bc0 77 0a 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 |w.. MOV |
00002bd0 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6c | gwi_m1, gwi_l|
00002be0 64 65 2c 20 4c 53 4c 20 23 32 34 0a 20 20 20 20 |de, LSL #24. |
00002bf0 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f | MOV gwi_|
00002c00 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 |m1, gwi_m1, ASR |
00002c10 23 32 34 0a 20 20 20 20 20 20 20 20 52 53 42 53 |#24. RSBS|
00002c20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
00002c30 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c 20 |m1, gwi_m1, ASL |
00002c40 23 33 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 |#3. ADDMI|
00002c50 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
00002c60 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 |1, #15. A|
00002c70 44 44 20 20 20 20 20 67 77 69 5f 72 2c 20 67 77 |DD gwi_r, gw|
00002c80 69 5f 72 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 |i_r, gwi_m1, ASR|
00002c90 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 | #4. MOV |
00002ca0 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
00002cb0 6c 64 65 2c 20 4c 53 4c 20 23 31 36 0a 20 20 20 |lde, LSL #16. |
00002cc0 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 | MOV gwi|
00002cd0 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 |_m1, gwi_m1, ASR|
00002ce0 20 23 32 34 0a 20 20 20 20 20 20 20 20 52 53 42 | #24. RSB|
00002cf0 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |S gwi_m1, gwi|
00002d00 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c |_m1, gwi_m1, ASL|
00002d10 20 23 33 0a 20 20 20 20 20 20 20 20 41 44 44 4d | #3. ADDM|
00002d20 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f |I gwi_m1, gwi_|
00002d30 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 |m1, #15. |
00002d40 41 44 44 20 20 20 20 20 67 77 69 5f 67 2c 20 67 |ADD gwi_g, g|
00002d50 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |wi_g, gwi_m1, AS|
00002d60 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 |R #4. MOV|
00002d70 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 | gwi_m1, gwi|
00002d80 5f 6c 64 65 2c 20 4c 53 4c 20 23 38 0a 20 20 20 |_lde, LSL #8. |
00002d90 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 | MOV gwi|
00002da0 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 |_m1, gwi_m1, ASR|
00002db0 20 23 32 34 0a 20 20 20 20 20 20 20 20 52 53 42 | #24. RSB|
00002dc0 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |S gwi_m1, gwi|
00002dd0 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c |_m1, gwi_m1, ASL|
00002de0 20 23 33 0a 20 20 20 20 20 20 20 20 41 44 44 4d | #3. ADDM|
00002df0 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f |I gwi_m1, gwi_|
00002e00 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 |m1, #15. |
00002e10 41 44 44 20 20 20 20 20 67 77 69 5f 62 2c 20 67 |ADD gwi_b, g|
00002e20 77 69 5f 62 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |wi_b, gwi_m1, AS|
00002e30 52 20 23 34 09 3b 6e 6f 77 20 61 64 64 20 69 6e |R #4.;now add in|
00002e40 20 37 2f 31 36 20 65 72 72 6f 72 20 66 6f 72 20 | 7/16 error for |
00002e50 70 69 78 65 6c 20 74 6f 20 72 69 67 68 74 0a 0a |pixel to right..|
00002e60 67 77 69 5f 78 6c 32 5f 62 31 0a 20 20 20 20 20 |gwi_xl2_b1. |
00002e70 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 5f 69 | CMP gwi_i|
00002e80 2c 20 67 77 69 5f 78 70 0a 20 20 20 20 20 20 20 |, gwi_xp. |
00002e90 20 42 45 51 20 20 20 20 20 67 77 69 5f 78 6c 32 | BEQ gwi_xl2|
00002ea0 5f 62 32 0a 0a 20 20 20 20 20 20 20 20 4c 44 52 |_b2.. LDR|
00002eb0 20 20 20 20 20 67 77 69 5f 6d 34 2c 20 5b 67 77 | gwi_m4, [gw|
00002ec0 69 5f 64 65 2c 20 67 77 69 5f 69 2c 20 41 53 4c |i_de, gwi_i, ASL|
00002ed0 20 23 32 5d 09 3b 69 66 20 6e 6f 74 20 6f 6e 20 | #2].;if not on |
00002ee0 66 61 72 20 6c 65 66 74 20 63 6f 6c 75 6d 6e 20 |far left column |
00002ef0 2e 20 2e 20 2e 0a 20 20 20 20 20 20 20 20 4d 4f |. . .. MO|
00002f00 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
00002f10 69 5f 6d 34 2c 20 4c 53 4c 20 23 32 34 0a 20 20 |i_m4, LSL #24. |
00002f20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 | MOV gw|
00002f30 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00002f40 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 |R #24. AD|
00002f50 44 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |DS gwi_m1, gw|
00002f60 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00002f70 4c 20 23 31 0a 20 20 20 20 20 20 20 20 41 44 44 |L #1. ADD|
00002f80 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |MI gwi_m1, gwi|
00002f90 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 |_m1, #15. |
00002fa0 20 41 44 44 20 20 20 20 20 67 77 69 5f 72 2c 20 | ADD gwi_r, |
00002fb0 67 77 69 5f 72 2c 20 67 77 69 5f 6d 31 2c 20 41 |gwi_r, gwi_m1, A|
00002fc0 53 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f |SR #4. MO|
00002fd0 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
00002fe0 69 5f 6d 34 2c 20 4c 53 4c 20 23 31 36 0a 20 20 |i_m4, LSL #16. |
00002ff0 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 | MOV gw|
00003000 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00003010 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 |R #24. AD|
00003020 44 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |DS gwi_m1, gw|
00003030 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00003040 4c 20 23 31 0a 20 20 20 20 20 20 20 20 41 44 44 |L #1. ADD|
00003050 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |MI gwi_m1, gwi|
00003060 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 |_m1, #15. |
00003070 20 41 44 44 20 20 20 20 20 67 77 69 5f 67 2c 20 | ADD gwi_g, |
00003080 67 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 41 |gwi_g, gwi_m1, A|
00003090 53 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f |SR #4. MO|
000030a0 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
000030b0 69 5f 6d 34 2c 20 4c 53 4c 20 23 38 0a 20 20 20 |i_m4, LSL #8. |
000030c0 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 | MOV gwi|
000030d0 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 |_m1, gwi_m1, ASR|
000030e0 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 44 | #24. ADD|
000030f0 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |S gwi_m1, gwi|
00003100 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c |_m1, gwi_m1, ASL|
00003110 20 23 31 0a 20 20 20 20 20 20 20 20 41 44 44 4d | #1. ADDM|
00003120 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f |I gwi_m1, gwi_|
00003130 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 |m1, #15. |
00003140 41 44 44 20 20 20 20 20 67 77 69 5f 62 2c 20 67 |ADD gwi_b, g|
00003150 77 69 5f 62 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |wi_b, gwi_m1, AS|
00003160 52 20 23 34 09 3b 61 64 64 20 69 6e 20 33 2f 31 |R #4.;add in 3/1|
00003170 36 20 65 72 72 6f 72 20 66 6f 72 20 70 69 78 65 |6 error for pixe|
00003180 6c 20 74 6f 20 61 62 6f 76 65 20 6c 65 66 74 0a |l to above left.|
00003190 0a 67 77 69 5f 78 6c 32 5f 62 32 0a 0a 20 20 20 |.gwi_xl2_b2.. |
000031a0 20 20 20 20 20 67 77 69 5f 73 65 67 31 09 09 09 | gwi_seg1...|
000031b0 09 3b 77 72 69 74 65 20 64 65 73 74 69 6e 61 74 |.;write destinat|
000031c0 69 6f 6e 20 70 69 78 65 6c 20 26 20 63 61 6c 63 |ion pixel & calc|
000031d0 20 6e 65 77 20 65 72 72 6f 72 20 66 6f 72 20 70 | new error for p|
000031e0 69 78 65 6c 0a 0a 20 20 20 20 20 20 20 20 53 55 |ixel.. SU|
000031f0 42 20 20 20 20 20 67 77 69 5f 64 70 2c 20 67 77 |B gwi_dp, gw|
00003200 69 5f 64 70 2c 20 23 31 0a 20 20 20 20 20 20 20 |i_dp, #1. |
00003210 20 53 55 42 20 20 20 20 20 67 77 69 5f 73 70 2c | SUB gwi_sp,|
00003220 20 67 77 69 5f 73 70 2c 20 23 34 0a 20 20 20 20 | gwi_sp, #4. |
00003230 20 20 20 20 41 44 44 20 20 20 20 20 67 77 69 5f | ADD gwi_|
00003240 69 2c 20 67 77 69 5f 69 2c 20 23 31 0a 20 20 20 |i, gwi_i, #1. |
00003250 20 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 | CMP gwi|
00003260 5f 69 2c 20 67 77 69 5f 78 70 0a 20 20 20 20 20 |_i, gwi_xp. |
00003270 20 20 20 42 4c 45 20 20 20 20 20 67 77 69 5f 78 | BLE gwi_x|
00003280 6c 6f 6f 70 32 09 09 09 3b 6c 6f 6f 70 20 62 61 |loop2...;loop ba|
00003290 63 6b 20 74 69 6c 20 61 6c 6c 20 6f 66 20 72 69 |ck til all of ri|
000032a0 67 68 74 20 74 6f 20 6c 65 66 74 20 72 6f 77 20 |ght to left row |
000032b0 70 72 6f 63 65 73 73 65 64 0a 67 77 69 5f 78 6c |processed.gwi_xl|
000032c0 6f 6f 70 32 64 6f 6e 65 0a 0a 20 20 20 20 20 20 |oop2done.. |
000032d0 20 20 52 53 42 20 20 20 20 20 67 77 69 5f 6d 32 | RSB gwi_m2|
000032e0 2c 20 67 77 69 5f 78 70 2c 20 23 34 0a 20 20 20 |, gwi_xp, #4. |
000032f0 20 20 20 20 20 41 4e 44 20 20 20 20 20 67 77 69 | AND gwi|
00003300 5f 6d 31 2c 20 67 77 69 5f 6d 32 2c 20 23 33 0a |_m1, gwi_m2, #3.|
00003310 20 20 20 20 20 20 20 20 41 44 44 20 20 20 20 20 | ADD |
00003320 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 |gwi_m1, gwi_m1, |
00003330 67 77 69 5f 78 70 0a 20 20 20 20 20 20 20 20 41 |gwi_xp. A|
00003340 44 44 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 |DD gwi_m1, g|
00003350 77 69 5f 6d 31 2c 20 23 31 0a 20 20 20 20 20 20 |wi_m1, #1. |
00003360 20 20 41 44 44 20 20 20 20 20 67 77 69 5f 64 70 | ADD gwi_dp|
00003370 2c 20 67 77 69 5f 64 70 2c 20 67 77 69 5f 6d 31 |, gwi_dp, gwi_m1|
00003380 0a 09 41 44 44 20 20 20 20 20 67 77 69 5f 73 70 |..ADD gwi_sp|
00003390 2c 20 67 77 69 5f 73 70 2c 20 67 77 69 5f 78 70 |, gwi_sp, gwi_xp|
000033a0 2c 20 4c 53 4c 20 23 32 0a 20 20 20 20 20 20 20 |, LSL #2. |
000033b0 20 41 44 44 20 20 20 20 20 67 77 69 5f 73 70 2c | ADD gwi_sp,|
000033c0 20 67 77 69 5f 73 70 2c 20 23 34 09 09 3b 73 74 | gwi_sp, #4..;st|
000033d0 65 70 20 73 70 2c 20 64 70 20 74 6f 20 6e 65 78 |ep sp, dp to nex|
000033e0 74 20 72 6f 77 20 28 74 6f 20 62 65 20 73 63 61 |t row (to be sca|
000033f0 6e 6e 65 64 20 6c 65 66 74 20 74 6f 20 72 69 67 |nned left to rig|
00003400 68 74 29 0a 0a 20 20 20 20 20 20 20 20 4c 44 52 |ht).. LDR|
00003410 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 | gwi_m1, gwi|
00003420 5f 61 6a 0a 20 20 20 20 20 20 20 20 53 55 42 53 |_aj. SUBS|
00003430 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
00003440 6d 31 2c 20 23 31 0a 20 20 20 20 20 20 20 20 53 |m1, #1. S|
00003450 54 52 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 |TR gwi_m1, g|
00003460 77 69 5f 61 6a 0a 20 20 20 20 20 20 20 20 42 4d |wi_aj. BM|
00003470 49 20 20 20 20 20 67 77 69 5f 79 6c 6f 6f 70 64 |I gwi_yloopd|
00003480 6f 6e 65 09 09 09 3b 63 6f 6e 74 69 6e 75 65 20 |one...;continue |
00003490 77 69 74 68 20 6e 65 78 74 20 72 6f 77 2c 20 75 |with next row, u|
000034a0 6e 6c 65 73 73 20 61 6c 6c 20 64 6f 6e 65 0a 0a |nless all done..|
000034b0 20 20 20 20 20 20 20 20 53 55 42 20 20 20 20 20 | SUB |
000034c0 67 77 69 5f 6d 31 2c 20 67 77 69 5f 78 70 2c 20 |gwi_m1, gwi_xp, |
000034d0 23 31 0a 20 20 20 20 20 20 20 20 53 54 52 20 20 |#1. STR |
000034e0 20 20 20 67 77 69 5f 6c 64 65 2c 20 5b 67 77 69 | gwi_lde, [gwi|
000034f0 5f 64 65 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c |_de, gwi_m1, ASL|
00003500 20 23 32 5d 09 3b 62 75 66 66 65 72 20 65 72 72 | #2].;buffer err|
00003510 6f 72 20 66 6f 72 20 66 69 6e 61 6c 20 70 69 78 |or for final pix|
00003520 65 6c 20 6f 6e 20 6c 61 73 74 20 72 6f 77 0a 20 |el on last row. |
00003530 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 | MOV g|
00003540 77 69 5f 69 2c 20 67 77 69 5f 78 70 0a 20 20 20 |wi_i, gwi_xp. |
00003550 20 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 | CMP gwi|
00003560 5f 69 2c 20 23 30 0a 20 20 20 20 20 20 20 20 42 |_i, #0. B|
00003570 4c 45 20 20 20 20 20 67 77 69 5f 78 6c 6f 6f 70 |LE gwi_xloop|
00003580 33 64 6f 6e 65 0a 0a 67 77 69 5f 78 6c 6f 6f 70 |3done..gwi_xloop|
00003590 33 0a 09 4c 44 52 09 67 77 69 5f 6d 31 2c 20 5b |3..LDR.gwi_m1, [|
000035a0 67 77 69 5f 73 70 2c 20 23 30 5d 0a 20 20 20 20 |gwi_sp, #0]. |
000035b0 20 20 20 20 41 4e 44 20 20 20 20 20 67 77 69 5f | AND gwi_|
000035c0 72 2c 20 67 77 69 5f 6d 31 2c 20 23 32 35 35 09 |r, gwi_m1, #255.|
000035d0 3b 66 72 6f 6d 20 68 65 72 65 20 2e 20 2e 20 2e |;from here . . .|
000035e0 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 |. MOV |
000035f0 20 67 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 | gwi_g, gwi_m1, |
00003600 4c 53 52 20 23 38 0a 20 20 20 20 20 20 20 20 41 |LSR #8. A|
00003610 4e 44 20 20 20 20 20 67 77 69 5f 67 2c 20 67 77 |ND gwi_g, gw|
00003620 69 5f 67 2c 20 23 32 35 35 0a 20 20 20 20 20 20 |i_g, #255. |
00003630 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 62 2c | MOV gwi_b,|
00003640 20 67 77 69 5f 6d 31 2c 20 4c 53 52 20 23 31 36 | gwi_m1, LSR #16|
00003650 0a 20 20 20 20 20 20 20 20 41 4e 44 20 20 20 20 |. AND |
00003660 20 67 77 69 5f 62 2c 20 67 77 69 5f 62 2c 20 23 | gwi_b, gwi_b, #|
00003670 32 35 35 09 3b 74 6f 20 68 65 72 65 2c 20 65 78 |255.;to here, ex|
00003680 74 72 61 63 74 20 74 68 72 65 65 20 72 2c 67 20 |tract three r,g |
00003690 26 20 62 20 38 20 62 69 74 20 63 6f 6d 70 6f 6e |& b 8 bit compon|
000036a0 65 6e 74 73 20 69 6e 74 6f 20 5f 72 2c 20 5f 67 |ents into _r, _g|
000036b0 20 26 20 5f 62 0a 0a 20 20 20 20 20 20 20 20 53 | & _b.. S|
000036c0 55 42 20 20 20 20 20 67 77 69 5f 6d 34 2c 20 67 |UB gwi_m4, g|
000036d0 77 69 5f 69 2c 20 23 31 09 09 3b 66 6f 72 20 70 |wi_i, #1..;for p|
000036e0 69 78 65 6c 20 61 62 6f 76 65 20 2e 20 2e 20 2e |ixel above . . .|
000036f0 0a 20 20 20 20 20 20 20 20 4c 44 52 20 20 20 20 |. LDR |
00003700 20 67 77 69 5f 6d 34 2c 20 5b 67 77 69 5f 64 65 | gwi_m4, [gwi_de|
00003710 2c 20 67 77 69 5f 6d 34 2c 20 41 53 4c 20 23 32 |, gwi_m4, ASL #2|
00003720 5d 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |]. MOV |
00003730 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 34 | gwi_m1, gwi_m4|
00003740 2c 20 4c 53 4c 20 23 32 34 0a 20 20 20 20 20 20 |, LSL #24. |
00003750 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 | MOV gwi_m1|
00003760 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 32 |, gwi_m1, ASR #2|
00003770 34 0a 20 20 20 20 20 20 20 20 41 44 44 53 20 20 |4. ADDS |
00003780 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00003790 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c 20 23 32 |, gwi_m1, ASL #2|
000037a0 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 20 |. ADDMI |
000037b0 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
000037c0 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 44 | #15. ADD|
000037d0 20 20 20 20 20 67 77 69 5f 72 2c 20 67 77 69 5f | gwi_r, gwi_|
000037e0 72 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 |r, gwi_m1, ASR #|
000037f0 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |4. MOV |
00003800 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 34 | gwi_m1, gwi_m4|
00003810 2c 20 4c 53 4c 20 23 31 36 0a 20 20 20 20 20 20 |, LSL #16. |
00003820 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 | MOV gwi_m1|
00003830 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 32 |, gwi_m1, ASR #2|
00003840 34 0a 20 20 20 20 20 20 20 20 41 44 44 53 20 20 |4. ADDS |
00003850 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00003860 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c 20 23 32 |, gwi_m1, ASL #2|
00003870 0a 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 20 |. ADDMI |
00003880 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
00003890 20 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 44 | #15. ADD|
000038a0 20 20 20 20 20 67 77 69 5f 67 2c 20 67 77 69 5f | gwi_g, gwi_|
000038b0 67 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 |g, gwi_m1, ASR #|
000038c0 34 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |4. MOV |
000038d0 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 34 | gwi_m1, gwi_m4|
000038e0 2c 20 4c 53 4c 20 23 38 0a 20 20 20 20 20 20 20 |, LSL #8. |
000038f0 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 2c | MOV gwi_m1,|
00003900 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 32 34 | gwi_m1, ASR #24|
00003910 0a 20 20 20 20 20 20 20 20 41 44 44 53 20 20 20 |. ADDS |
00003920 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
00003930 20 67 77 69 5f 6d 31 2c 20 41 53 4c 20 23 32 0a | gwi_m1, ASL #2.|
00003940 20 20 20 20 20 20 20 20 41 44 44 4d 49 20 20 20 | ADDMI |
00003950 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 |gwi_m1, gwi_m1, |
00003960 23 31 35 0a 20 20 20 20 20 20 20 20 41 44 44 20 |#15. ADD |
00003970 20 20 20 20 67 77 69 5f 62 2c 20 67 77 69 5f 62 | gwi_b, gwi_b|
00003980 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 20 23 34 |, gwi_m1, ASR #4|
00003990 09 3b 61 64 64 20 69 6e 20 35 2f 31 36 20 65 72 |.;add in 5/16 er|
000039a0 72 6f 72 0a 0a 20 20 20 20 20 20 20 20 43 4d 50 |ror.. CMP|
000039b0 20 20 20 20 20 67 77 69 5f 69 2c 20 67 77 69 5f | gwi_i, gwi_|
000039c0 78 70 0a 20 20 20 20 20 20 20 20 42 45 51 20 20 |xp. BEQ |
000039d0 20 20 20 67 77 69 5f 78 6c 33 5f 62 31 0a 09 09 | gwi_xl3_b1...|
000039e0 09 09 09 09 3b 69 66 20 6e 6f 74 20 6f 6e 20 6c |....;if not on l|
000039f0 65 66 74 6d 6f 73 74 20 63 6f 6c 75 6d 6e 20 2e |eftmost column .|
00003a00 20 2e 20 2e 0a 20 20 20 20 20 20 20 20 4c 44 52 | . .. LDR|
00003a10 20 20 20 20 20 67 77 69 5f 6d 34 2c 20 5b 67 77 | gwi_m4, [gw|
00003a20 69 5f 64 65 2c 20 67 77 69 5f 69 2c 20 41 53 4c |i_de, gwi_i, ASL|
00003a30 20 23 32 5d 0a 20 20 20 20 20 20 20 20 4d 4f 56 | #2]. MOV|
00003a40 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 | gwi_m1, gwi|
00003a50 5f 6d 34 2c 20 4c 53 4c 20 23 32 34 0a 20 20 20 |_m4, LSL #24. |
00003a60 20 20 20 20 20 4d 4f 56 53 20 20 20 20 67 77 69 | MOVS gwi|
00003a70 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 |_m1, gwi_m1, ASR|
00003a80 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 44 | #24. ADD|
00003a90 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |MI gwi_m1, gwi|
00003aa0 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 |_m1, #15. |
00003ab0 20 41 44 44 20 20 20 20 20 67 77 69 5f 72 2c 20 | ADD gwi_r, |
00003ac0 67 77 69 5f 72 2c 20 67 77 69 5f 6d 31 2c 20 41 |gwi_r, gwi_m1, A|
00003ad0 53 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f |SR #4. MO|
00003ae0 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
00003af0 69 5f 6d 34 2c 20 4c 53 4c 20 23 31 36 0a 20 20 |i_m4, LSL #16. |
00003b00 20 20 20 20 20 20 4d 4f 56 53 20 20 20 20 67 77 | MOVS gw|
00003b10 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00003b20 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 |R #24. AD|
00003b30 44 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |DMI gwi_m1, gw|
00003b40 69 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 |i_m1, #15. |
00003b50 20 20 41 44 44 20 20 20 20 20 67 77 69 5f 67 2c | ADD gwi_g,|
00003b60 20 67 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 | gwi_g, gwi_m1, |
00003b70 41 53 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d |ASR #4. M|
00003b80 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 |OV gwi_m1, g|
00003b90 77 69 5f 6d 34 2c 20 4c 53 4c 20 23 38 0a 20 20 |wi_m4, LSL #8. |
00003ba0 20 20 20 20 20 20 4d 4f 56 53 20 20 20 20 67 77 | MOVS gw|
00003bb0 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00003bc0 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 |R #24. AD|
00003bd0 44 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |DMI gwi_m1, gw|
00003be0 69 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 |i_m1, #15. |
00003bf0 20 20 41 44 44 20 20 20 20 20 67 77 69 5f 62 2c | ADD gwi_b,|
00003c00 20 67 77 69 5f 62 2c 20 67 77 69 5f 6d 31 2c 20 | gwi_b, gwi_m1, |
00003c10 41 53 52 20 23 34 09 3b 61 64 64 20 69 6e 20 31 |ASR #4.;add in 1|
00003c20 2f 31 36 20 65 72 72 6f 72 20 66 6f 72 20 70 69 |/16 error for pi|
00003c30 78 65 6c 20 74 6f 20 61 62 6f 76 65 20 6c 65 66 |xel to above lef|
00003c40 74 0a 0a 20 20 20 20 20 20 20 20 53 54 52 20 20 |t.. STR |
00003c50 20 20 20 67 77 69 5f 6c 64 65 2c 20 5b 67 77 69 | gwi_lde, [gwi|
00003c60 5f 64 65 2c 20 67 77 69 5f 69 2c 20 41 53 4c 20 |_de, gwi_i, ASL |
00003c70 23 32 5d 09 3b 62 75 66 66 65 72 20 6c 61 73 74 |#2].;buffer last|
00003c80 20 65 72 72 6f 72 0a 0a 20 20 20 20 20 20 20 20 | error.. |
00003c90 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 |MOV gwi_m1, |
00003ca0 67 77 69 5f 6c 64 65 2c 20 4c 53 4c 20 23 32 34 |gwi_lde, LSL #24|
00003cb0 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 20 |. MOV |
00003cc0 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
00003cd0 20 41 53 52 20 23 32 34 0a 20 20 20 20 20 20 20 | ASR #24. |
00003ce0 20 52 53 42 53 20 20 20 20 67 77 69 5f 6d 31 2c | RSBS gwi_m1,|
00003cf0 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c | gwi_m1, gwi_m1,|
00003d00 20 41 53 4c 20 23 33 0a 20 20 20 20 20 20 20 20 | ASL #3. |
00003d10 41 44 44 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 |ADDMI gwi_m1, |
00003d20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 |gwi_m1, #15. |
00003d30 20 20 20 20 41 44 44 20 20 20 20 20 67 77 69 5f | ADD gwi_|
00003d40 72 2c 20 67 77 69 5f 72 2c 20 67 77 69 5f 6d 31 |r, gwi_r, gwi_m1|
00003d50 2c 20 41 53 52 20 23 34 0a 20 20 20 20 20 20 20 |, ASR #4. |
00003d60 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 2c | MOV gwi_m1,|
00003d70 20 67 77 69 5f 6c 64 65 2c 20 4c 53 4c 20 23 31 | gwi_lde, LSL #1|
00003d80 36 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |6. MOV |
00003d90 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00003da0 2c 20 41 53 52 20 23 32 34 0a 20 20 20 20 20 20 |, ASR #24. |
00003db0 20 20 52 53 42 53 20 20 20 20 67 77 69 5f 6d 31 | RSBS gwi_m1|
00003dc0 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 |, gwi_m1, gwi_m1|
00003dd0 2c 20 41 53 4c 20 23 33 0a 20 20 20 20 20 20 20 |, ASL #3. |
00003de0 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d 31 2c | ADDMI gwi_m1,|
00003df0 20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 20 20 | gwi_m1, #15. |
00003e00 20 20 20 20 20 41 44 44 20 20 20 20 20 67 77 69 | ADD gwi|
00003e10 5f 67 2c 20 67 77 69 5f 67 2c 20 67 77 69 5f 6d |_g, gwi_g, gwi_m|
00003e20 31 2c 20 41 53 52 20 23 34 0a 20 20 20 20 20 20 |1, ASR #4. |
00003e30 20 20 4d 4f 56 20 20 20 20 20 67 77 69 5f 6d 31 | MOV gwi_m1|
00003e40 2c 20 67 77 69 5f 6c 64 65 2c 20 4c 53 4c 20 23 |, gwi_lde, LSL #|
00003e50 38 0a 20 20 20 20 20 20 20 20 4d 4f 56 20 20 20 |8. MOV |
00003e60 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 | gwi_m1, gwi_m1|
00003e70 2c 20 41 53 52 20 23 32 34 0a 20 20 20 20 20 20 |, ASR #24. |
00003e80 20 20 52 53 42 53 20 20 20 20 67 77 69 5f 6d 31 | RSBS gwi_m1|
00003e90 2c 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 |, gwi_m1, gwi_m1|
00003ea0 2c 20 41 53 4c 20 23 33 0a 20 20 20 20 20 20 20 |, ASL #3. |
00003eb0 20 41 44 44 4d 49 20 20 20 67 77 69 5f 6d 31 2c | ADDMI gwi_m1,|
00003ec0 20 67 77 69 5f 6d 31 2c 20 23 31 35 0a 20 20 20 | gwi_m1, #15. |
00003ed0 20 20 20 20 20 41 44 44 20 20 20 20 20 67 77 69 | ADD gwi|
00003ee0 5f 62 2c 20 67 77 69 5f 62 2c 20 67 77 69 5f 6d |_b, gwi_b, gwi_m|
00003ef0 31 2c 20 41 53 52 20 23 34 09 3b 26 20 61 64 64 |1, ASR #4.;& add|
00003f00 20 69 6e 20 37 2f 31 36 20 65 72 72 6f 72 20 66 | in 7/16 error f|
00003f10 6f 72 20 70 69 78 65 6c 20 74 6f 20 6c 65 66 74 |or pixel to left|
00003f20 0a 0a 67 77 69 5f 78 6c 33 5f 62 31 0a 20 20 20 |..gwi_xl3_b1. |
00003f30 20 20 20 20 20 43 4d 50 20 20 20 20 20 67 77 69 | CMP gwi|
00003f40 5f 69 2c 20 23 31 0a 20 20 20 20 20 20 20 20 42 |_i, #1. B|
00003f50 45 51 20 20 20 20 20 67 77 69 5f 78 6c 33 5f 62 |EQ gwi_xl3_b|
00003f60 32 0a 09 09 09 09 09 09 3b 69 66 20 6e 6f 74 20 |2.......;if not |
00003f70 6f 6e 20 66 61 72 20 72 69 67 68 74 20 2e 20 2e |on far right . .|
00003f80 20 2e 0a 20 20 20 20 20 20 20 20 53 55 42 20 20 | .. SUB |
00003f90 20 20 20 67 77 69 5f 6d 32 2c 20 67 77 69 5f 69 | gwi_m2, gwi_i|
00003fa0 2c 20 23 32 0a 20 20 20 20 20 20 20 20 4c 44 52 |, #2. LDR|
00003fb0 20 20 20 20 20 67 77 69 5f 6d 34 2c 20 5b 67 77 | gwi_m4, [gw|
00003fc0 69 5f 64 65 2c 20 67 77 69 5f 6d 32 2c 20 41 53 |i_de, gwi_m2, AS|
00003fd0 4c 20 23 32 5d 0a 20 20 20 20 20 20 20 20 4d 4f |L #2]. MO|
00003fe0 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
00003ff0 69 5f 6d 34 2c 20 4c 53 4c 20 23 32 34 0a 20 20 |i_m4, LSL #24. |
00004000 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 | MOV gw|
00004010 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00004020 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 |R #24. AD|
00004030 44 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |DS gwi_m1, gw|
00004040 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00004050 4c 20 23 31 0a 20 20 20 20 20 20 20 20 41 44 44 |L #1. ADD|
00004060 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |MI gwi_m1, gwi|
00004070 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 |_m1, #15. |
00004080 20 41 44 44 20 20 20 20 20 67 77 69 5f 72 2c 20 | ADD gwi_r, |
00004090 67 77 69 5f 72 2c 20 67 77 69 5f 6d 31 2c 20 41 |gwi_r, gwi_m1, A|
000040a0 53 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f |SR #4. MO|
000040b0 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
000040c0 69 5f 6d 34 2c 20 4c 53 4c 20 23 31 36 0a 20 20 |i_m4, LSL #16. |
000040d0 20 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 | MOV gw|
000040e0 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
000040f0 52 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 |R #24. AD|
00004100 44 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |DS gwi_m1, gw|
00004110 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |i_m1, gwi_m1, AS|
00004120 4c 20 23 31 0a 20 20 20 20 20 20 20 20 41 44 44 |L #1. ADD|
00004130 4d 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |MI gwi_m1, gwi|
00004140 5f 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 |_m1, #15. |
00004150 20 41 44 44 20 20 20 20 20 67 77 69 5f 67 2c 20 | ADD gwi_g, |
00004160 67 77 69 5f 67 2c 20 67 77 69 5f 6d 31 2c 20 41 |gwi_g, gwi_m1, A|
00004170 53 52 20 23 34 0a 20 20 20 20 20 20 20 20 4d 4f |SR #4. MO|
00004180 56 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |V gwi_m1, gw|
00004190 69 5f 6d 34 2c 20 4c 53 4c 20 23 38 0a 20 20 20 |i_m4, LSL #8. |
000041a0 20 20 20 20 20 4d 4f 56 20 20 20 20 20 67 77 69 | MOV gwi|
000041b0 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 52 |_m1, gwi_m1, ASR|
000041c0 20 23 32 34 0a 20 20 20 20 20 20 20 20 41 44 44 | #24. ADD|
000041d0 53 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 |S gwi_m1, gwi|
000041e0 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 41 53 4c |_m1, gwi_m1, ASL|
000041f0 20 23 31 0a 20 20 20 20 20 20 20 20 41 44 44 4d | #1. ADDM|
00004200 49 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f |I gwi_m1, gwi_|
00004210 6d 31 2c 20 23 31 35 0a 20 20 20 20 20 20 20 20 |m1, #15. |
00004220 41 44 44 20 20 20 20 20 67 77 69 5f 62 2c 20 67 |ADD gwi_b, g|
00004230 77 69 5f 62 2c 20 67 77 69 5f 6d 31 2c 20 41 53 |wi_b, gwi_m1, AS|
00004240 52 20 23 34 09 3b 61 64 64 20 69 6e 20 33 2f 31 |R #4.;add in 3/1|
00004250 36 20 65 72 72 6f 72 20 66 6f 72 20 70 69 78 65 |6 error for pixe|
00004260 6c 20 74 6f 20 61 62 6f 76 65 20 72 69 67 68 74 |l to above right|
00004270 0a 0a 67 77 69 5f 78 6c 33 5f 62 32 0a 0a 20 20 |..gwi_xl3_b2.. |
00004280 20 20 20 20 20 20 67 77 69 5f 73 65 67 31 09 09 | gwi_seg1..|
00004290 09 3b 77 72 69 74 65 20 64 65 73 74 69 6e 61 74 |.;write destinat|
000042a0 69 6f 6e 20 70 69 78 65 6c 20 26 20 63 61 6c 63 |ion pixel & calc|
000042b0 20 69 74 73 20 65 72 72 6f 72 0a 0a 20 20 20 20 | its error.. |
000042c0 20 20 20 20 41 44 44 20 20 20 20 20 67 77 69 5f | ADD gwi_|
000042d0 64 70 2c 20 67 77 69 5f 64 70 2c 20 23 31 0a 20 |dp, gwi_dp, #1. |
000042e0 20 20 20 20 20 20 20 41 44 44 20 20 20 20 20 67 | ADD g|
000042f0 77 69 5f 73 70 2c 20 67 77 69 5f 73 70 2c 20 23 |wi_sp, gwi_sp, #|
00004300 34 0a 20 20 20 20 20 20 20 20 53 55 42 53 20 20 |4. SUBS |
00004310 20 20 67 77 69 5f 69 2c 20 67 77 69 5f 69 2c 20 | gwi_i, gwi_i, |
00004320 23 31 0a 20 20 20 20 20 20 20 20 42 47 54 20 20 |#1. BGT |
00004330 20 20 20 67 77 69 5f 78 6c 6f 6f 70 33 09 09 3b | gwi_xloop3..;|
00004340 63 6f 6e 74 69 6e 75 65 20 74 69 6c 6c 20 61 6c |continue till al|
00004350 6c 20 6f 66 20 6c 65 66 74 20 74 6f 20 72 69 67 |l of left to rig|
00004360 68 74 20 72 6f 77 20 70 72 6f 63 65 73 73 65 64 |ht row processed|
00004370 0a 67 77 69 5f 78 6c 6f 6f 70 33 64 6f 6e 65 0a |.gwi_xloop3done.|
00004380 0a 20 20 20 20 20 20 20 20 52 53 42 20 20 20 20 |. RSB |
00004390 20 67 77 69 5f 6d 32 2c 20 67 77 69 5f 78 70 2c | gwi_m2, gwi_xp,|
000043a0 20 23 34 0a 20 20 20 20 20 20 20 20 41 4e 44 20 | #4. AND |
000043b0 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
000043c0 6d 32 2c 20 23 33 0a 20 20 20 20 20 20 20 20 41 |m2, #3. A|
000043d0 44 44 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 |DD gwi_m1, g|
000043e0 77 69 5f 6d 31 2c 20 67 77 69 5f 78 70 0a 20 20 |wi_m1, gwi_xp. |
000043f0 20 20 20 20 20 20 53 55 42 20 20 20 20 20 67 77 | SUB gw|
00004400 69 5f 6d 31 2c 20 67 77 69 5f 6d 31 2c 20 23 31 |i_m1, gwi_m1, #1|
00004410 0a 20 20 20 20 20 20 20 20 41 44 44 20 20 20 20 |. ADD |
00004420 20 67 77 69 5f 64 70 2c 20 67 77 69 5f 64 70 2c | gwi_dp, gwi_dp,|
00004430 20 67 77 69 5f 6d 31 0a 09 41 44 44 20 20 20 20 | gwi_m1..ADD |
00004440 20 67 77 69 5f 73 70 2c 20 67 77 69 5f 73 70 2c | gwi_sp, gwi_sp,|
00004450 20 67 77 69 5f 78 70 2c 20 4c 53 4c 20 23 32 0a | gwi_xp, LSL #2.|
00004460 20 20 20 20 20 20 20 20 53 55 42 20 20 20 20 20 | SUB |
00004470 67 77 69 5f 73 70 2c 20 67 77 69 5f 73 70 2c 20 |gwi_sp, gwi_sp, |
00004480 23 34 09 3b 73 74 65 70 20 64 70 2c 20 73 70 20 |#4.;step dp, sp |
00004490 74 6f 20 73 74 61 72 74 20 6f 66 20 6e 65 78 74 |to start of next|
000044a0 20 72 69 67 68 74 2d 74 6f 2d 6c 65 66 74 20 72 | right-to-left r|
000044b0 6f 77 0a 0a 20 20 20 20 20 20 20 20 4c 44 52 20 |ow.. LDR |
000044c0 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f | gwi_m1, gwi_|
000044d0 61 6a 0a 20 20 20 20 20 20 20 20 53 55 42 53 20 |aj. SUBS |
000044e0 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 69 5f 6d | gwi_m1, gwi_m|
000044f0 31 2c 20 23 31 0a 20 20 20 20 20 20 20 20 53 54 |1, #1. ST|
00004500 52 20 20 20 20 20 67 77 69 5f 6d 31 2c 20 67 77 |R gwi_m1, gw|
00004510 69 5f 61 6a 0a 20 20 20 20 20 20 20 20 42 50 4c |i_aj. BPL|
00004520 20 20 20 20 20 67 77 69 5f 79 6c 6f 6f 70 09 09 | gwi_yloop..|
00004530 3b 26 20 72 65 70 65 61 74 2c 20 75 6e 74 69 6c |;& repeat, until|
00004540 20 61 6c 6c 20 72 6f 77 73 20 64 6f 6e 65 0a 0a | all rows done..|
00004550 67 77 69 5f 79 6c 6f 6f 70 64 6f 6e 65 0a 20 20 |gwi_yloopdone. |
00004560 20 20 20 20 20 20 3b 61 6c 6c 20 64 6f 6e 65 0a | ;all done.|
00004570 20 20 20 20 20 20 20 20 4c 44 52 20 20 20 20 20 | LDR |
00004580 73 70 2c 20 67 77 69 5f 61 73 70 0a 20 20 20 20 |sp, gwi_asp. |
00004590 20 20 20 20 4c 44 52 20 20 20 20 20 66 70 2c 20 | LDR fp, |
000045a0 67 77 69 5f 61 66 70 0a 20 20 20 20 20 20 20 20 |gwi_afp. |
000045b0 4c 44 52 20 20 20 20 20 73 6c 2c 20 67 77 69 5f |LDR sl, gwi_|
000045c0 61 73 6c 0a 20 20 20 20 20 20 20 20 4c 44 4d 45 |asl. LDME|
000045d0 41 20 20 20 66 70 2c 20 7b 72 34 2d 72 39 2c 20 |A fp, {r4-r9, |
000045e0 66 70 2c 20 73 70 2c 20 70 63 7d 5e 09 3b 67 65 |fp, sp, pc}^.;ge|
000045f0 74 20 6f 75 74 20 6f 66 20 68 65 72 65 21 0a 0a |t out of here!..|
00004600 0a 0a 20 20 20 20 20 20 20 20 45 4e 44 0a |.. END.|
0000460e 
.