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!AU_Attack/source/c/engine
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| Tape/disk: | Home » Archimedes archive » Acorn User » AU 1997-10 B.adf » 3D |
| Filename: | !AU_Attack/source/c/engine |
| Read OK: | ✔ |
| File size: | C012 bytes |
| Load address: | 0000 |
| Exec address: | 0000 |
File contents
/*
engine.c : Written by Greg Scott 1997
for Acorn User, as part of the "Virtual
Worlds" series.
Usage of the source code is done at the owners risk, and Acorn User or the author hold no responsibility for damages.
*/
/* AUTHORS NOTE: A lot of the code in here is very complex, and can never be adequately explained. PLEASE PLEASE contact me for more assistance, it is much easier to address personal problems with the ideas than in general.
AUThreeD@aol.com
or contact the Acorn User offices and they will pass it on. Thank you. */
/* ANSI C includes */
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
/* OTHER includes */
#include "our_lib.h"
/* DEFINES */
#define WORLD_WIDTH 64 /* This is the number of walls across in our world */
#define WORLD_HEIGHT 64 /* This is the number of walls down in our world */
#define WALL_WIDTH 64 /* This is the width of each wall in pixels */
#define WALL_HEIGHT 64 /* This is the height of each wall in pixels */
#define WALL_NUMBER 20 /* This defines the number of walls allowed */
#define CELL_X_SIZE 64 /* this is the size in units of each cell */
#define CELL_Y_SIZE 64 /* this is the size in units of each cell */
#define CELL_X_SIZE_FP 6 /* this is used in binary shifting */
#define CELL_Y_SIZE_FP 6 /* this is used in binary shifting */
#define FOUND_WALL 1 /* this flag is used to indicate when an intersection has be found */
#define MAX_DISTANCE 4000 /* this defines the largest distance a ray could travel in the world, used for look up tables */
#define MAX_SCALE 300 /* used for clipping */
#define CLOSEST 50 /* this stores the closest a player can walk into a wall */
/* NEW use of ANGLES variables, they are now not defines but are inputted by the command line at the beginning of main()*/
/* OLD defines have been converted to integers because we now load them in from the command line */
int ANGLE_0,ANGLE_6,ANGLE_30,ANGLE_90,ANGLE_180,ANGLE_270,ANGLE_360,STEP_LENGTH,VERTICAL_SCALE,VIEWVAR,VIEWVART,SCREEN_HEIGHT,SCREEN_WIDTH,DEMO_READ,DEMO_WRITE;
/* GLOBAL variables */
char world[WORLD_HEIGHT+1][WORLD_WIDTH+1];/* This holds our text data file */
char objects[WORLD_HEIGHT+1][WORLD_WIDTH+1]; /* NEW object array (as world)*/
char walls[WALL_NUMBER+1][(WALL_WIDTH*WALL_HEIGHT)+1];
char objgraphics[WALL_NUMBER+1][(WALL_WIDTH*WALL_HEIGHT)+1];
char bar_graphic[16001]; /* this holds the bottom bar on the screen */
/* This holds the wall graphics in a two dimensional array */
/* Note the usage of char and not "int" in both cases. This is because a char is 8 bytes, which gives 256 colours (used in our Mode 13 screen) and also an integer up to 256, when our text file doesn't go over 20 in number! Hence there is no need for an int array in either case. */
char *screen_address; /* this will hold the base of the screen memory which we will manipulate. By altering values in the screen memory, we alter what appears on the screen. Note that this is of type "char *" because it holds the memory address of a byte array - the 256 colour mode 13 screen (well it will do!) */
char *screen_address_bank; /* this is another pointer to the other area of screen memory which we will be using for SCREEN BANKING - avoiding flickering of the screen during animating graphics */
char *screen_address_temp; /* this is a spare pointer for use during the switching of the two above values */
/* these new FIXED POINT INTEGER pointers point to look-up tables used in the ray casting engine. These are explained of in the engine, but the look-ups are generated in aua_tables() */
int *tan_table,*inv_tan_table; /* pointers to tangent look_ups */
int *y_step,*x_step; /* pointers to more complex look_ups */
int *inv_cos_table, /* sin/cos tables (look_ups) */
*inv_sin_table;
int *cos_table; /* cosinal look_up table */
int *recip_table; /* reciprocal table used instead of a */
/* division. See later */
int *coso_table,*sino_table; /* these two tables are for objects */
int *dx_table, /* FIXED POINT tables for moving the */
*dy_table; /* view point very quickly */
int scale_array[320]; /* NEW used to store scale values of each */
/* sliver,for objects later on */
int mirror_array[320]; /* used to flag if a mirror is in use */
/* FUNCTION definitions */
/* this function generates LOOK UP tables - arrays holding pre-calculated trigonometric variables used in the ray casting process */
void aua_tables(void)
{
int ang, /* this is used to hold values while making look-ups */
angt; /* same */
float rad_angle; /* this holds the radians equivalent of the fixed point angle system (0-1920 = 0-360 degrees = 0-6.whatever radians. Next month I'll be changing the system so it becomes 0-1800 instead of 1920, this will allow a slightly smaller screen width, more like Wolfenstein, this will lead to an increase in frame rate. Yes! */
/* dynamically allocated adequate memory for the look-ups */
tan_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
inv_tan_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
y_step = (int *)malloc(sizeof(int) * (ANGLE_360+1));
x_step = (int *)malloc(sizeof(int) * (ANGLE_360+1));
cos_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
inv_cos_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
inv_sin_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
/* new table, for the engine, to avoid using a divide */
recip_table = (int *)malloc(sizeof(int) * (MAX_DISTANCE+1));
/* new tables for moving the view point */
dx_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
dy_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
/* generate them, their use is explained in the ray casting engine */
/* two new tables to use for object plotting */
coso_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
sino_table = (int *)malloc(sizeof(int) * (ANGLE_360+1));
printf("_tables: starting angle loop\n[.");
for(angt=ANGLE_0;angt<=ANGLE_360;angt++)
{
ang=angt;
/* this next line calculates the radian angle to pass to the trig. functions */
rad_angle=(float)((3.272e-4) + ang * 2*3.141592654/ANGLE_360);
tan_table[ang]=(int)(tan(rad_angle)*65536);
inv_tan_table[ang]=(int)((1/tan(rad_angle))*65536);
/* note tha above conversions to fixed point integers */
/* we do the same for these tables, but unfortunately at the asymptotes the numbers become awkwardly large to store in our fixed point representation. Instead of multiplying by 64 we do 8, to make sure that no overflow can occur at this stage. We only need to multiply by another 8 later in the engine, its okay */
if(ang>=ANGLE_0 && ang<ANGLE_180)
{
y_step[ang]=fabs( (8) * (tan_table[ang]) );
}
else
y_step[ang]=-fabs( (8) * (tan_table[ang]) );
if(ang>=ANGLE_90 && ang<ANGLE_270)
{
x_step[ang]=-fabs( (8) * (inv_tan_table[ang]) );
}
else
{
x_step[ang]=fabs( (8) * (inv_tan_table[ang]) );
}
/* conversion to fixed point */
inv_cos_table[ang]=(int)((1/cos(rad_angle))*65536);
inv_sin_table[ang]=(int)((1/sin(rad_angle))*65536);
/* conversion to fixed point of object plotting sine and cosines */
sino_table[ang]=(int)(sin(rad_angle-1.570796327)*65536);
coso_table[ang]=(int)(cos(rad_angle-1.570796327)*65536);
/* work out tables for moving the viewpoint */
dx_table[ang]=(int)(cos(6.28*ang/ANGLE_360)*STEP_LENGTH)*65536;
dy_table[ang]=(int)(sin(6.28*ang/ANGLE_360)*STEP_LENGTH)*65536;
printf(".");
}
/* the cosine table is used to get rid of the "fish bowl effect", explained in the ray caster. Basically we work out cosines for our own span of vision, from -30 degrees to +30 degrees. This means that as we scan from left to right, or vice versa, our rays of light are actually cast out in a cartesian, circular way. Our world is however square, polar, so we have to acknowledge the distortion caused by mixing cartesian and polar coordinates. In this look up we also have a bit of scaling in it, yet more time saving !!! */
for(ang=-ANGLE_30;ang<=ANGLE_30;ang++)
{
/* work out radians to pass to cosine function */
rad_angle=(float)((3.272e-4)+ ang * 2*3.141592654/ANGLE_360);
/*fixed point conversion */
cos_table[ang+ANGLE_30]=(int)(VERTICAL_SCALE/(cos(rad_angle))*65536);
}
printf("......");
/* this creates a reciprocal table, so we don't have to use divides. Multiplying by the reciprocal of a number is the same as dividing by it: After all,
8 / 4 = 2 and 8 * 0.25 (1 over 4) = 2 - they produce the same result */
for(ang=1;ang<MAX_DISTANCE;ang++)
{
/* it is still fixed point though */
recip_table[ang]=(int)(1.0/(float)ang*65536);
}
printf(".]\n");
}
/* this function is the heart of the program, the engine, to generate the first person view */
void aua_raycaster(int view_x,int view_y,int view_angle)
{
/* remember that we are thinking in 2-D, not in 3D when we discuss ideas. Below does not mean "a floor below", it really means "behind", but we say below because we are imagining looking down on the view point to form a 2-D plan */
/* this function, for each column of the 320 pixel width Mode 13 screen, casts out two rays. One ray looks for X, horizontal intersections with walls, and the other tracks intersections with Y, vertical wall boundaries. After all, the only time a collision could occur is on a boundary of a cell, as the wall fills up the entire cell. Expect to see lots of 64's, though remember that this ray caster is very routine, and has not at all been put through my "box of magic". The engine will become much more personalised very soon! */
int cell_x, /* used to store which cell of the walls data the ray is in */
cell_y, /* " */
casting=2, /* used to store if ray casting has finished */
x_hit_type, /* this stores the wall type hit by the x casting ray */
y_hit_type, /* this sotres the wall type (number) hit by the y ray */
x_bound, /* this holds the next x boundary for a possible intersection */
y_bound, /* this holds the next y boundary for a possible intersection */
next_y_cell, /* this is used to figure out the quadrant of the ray (+/-)*/
next_x_cell, /* " */
x_delta, /* this is +'d to the x_bound var. to move to the next boundary */
y_delta, /* this is +'d to the y_bound var. to move to the next boundary */
xi_save, /* this stores where the x casting ray made its intersection */
yi_save, /* this stores where the y casting ray made its intersection */
scale, /* this stores the scale of the sliver to be drawn in each column */
ray, /* this stores the ray number being cast out (0-320)*/
xray, /* this flag is used to show if casting is over */
yray, /* " */
dist_x, /* this holds the distance to the x intersection */
dist_y; /* this holds the distance to the y intersection */
int xi,
yi,
xadd,
yadd; /* these are used to accurately trace and move each ray */
int variables[6], /* this is used to pass variables to a sliver renderer */
clip; /* this could be used later for clipping */
int xtrans_dist, /* these NEW TRANSPARENT variables are used for windows */
ytrans_dist, /* each one will be used later to draw transparent walls */
xtrans_col,
ytrans_col,
xtrans_type,
ytrans_type,
xtrans_done,/* these last two are used as flags to mark if a transpar-*/
ytrans_done;/*ency has been found or not */
int counter=0;
/* firstly, we set up the variables[] we already know, such as screen_address, walls and the screen height we are using. These are all things which our sliver renderer needs to know to plot its column */
variables[0]=(int)screen_address;
/* now we get down to the nitty gritty. Here we subtract 30 degrees from the viewing angle remember that our FOV is 60 degrees which means that we cast from -30 to +30 */
if ( (view_angle-=ANGLE_30) < 0)
{
/* this ensures that we don't go over or under 0/360 degrees! */
view_angle=ANGLE_360 + view_angle;
}
/* now we start the main loop, start at the right of the screen (319), and cast each column one by one to the left */
for (ray=SCREEN_WIDTH-1; ray>=0; ray--)
{
/* for each ray to be cast we actually cast out two rays : one to check for vertical boundary collisions and the other to check for horizontal boundary collisions. Considering that walls fill up each cell, we need only look for intersections on the boundaries. We have to perform seperate cast because just casting one ray complicates the matter and it doesn't give much speed increase, if any. */
/* NEW LINE : We have to check to see if the viewing angle is at the asymptotes, unfortunately the fixed point system cannot store the values held at these angles, so we have to avoid their use. This is not very elegant I know, but it saves a lot of head aches and no one can tell we've done it! */
if(view_angle==ANGLE_0 || view_angle==ANGLE_90 || view_angle ==ANGLE_180 || view_angle==ANGLE_270)view_angle++;
/* SECTION 1 : CALCULATING THE FIRST X and Y INTERSECTIONS*/
/* Once we have done this the following intersections are easy*/
/* The X CASTING RAY : here we test to see if the angle of the ray is facing upwards. We need to know which halfplane we're casting from relative to the y-axis. */
if (view_angle >= ANGLE_0 && view_angle < ANGLE_180)
{
/* if so then we assign variables to that effect. We must compute the first horizontal line that could be intersected with the ray. Note : it will be above the viewer.*/
y_bound = (CELL_Y_SIZE + (view_y & 0xffc0)); /* this line is merely an optimized version of CELL_Y_SIZE + (view_y % 64). I use it many times in this engine. */
y_delta = CELL_Y_SIZE; /* this means that for every movement of the ray, the y boundary moves up one cell, which it would. It is the delta to get to the next horizontal line */
/* next we use the inverse tan function to calculate the initial position of the x boundary searching ray on its first intersection. We have to use tan because it is related to slopes */
/* NEW FIXED POINT CALCULATION of
xi = (float)(inv_tan_table[view_angle] * (y_bound - view_y)) +view_x; */
xi=((y_bound-view_y))*(inv_tan_table[view_angle]);
xi+=(view_x<<16);
/* this means that the quadrant of the ray is not negative, that is the next y boundary will appear above the view point and not below (in terms of looking down on the viewer). This is the cell delta */
next_y_cell = 0;
}
/* if the viewing angle is greater than 180 degrees and less than 270 degrees then we have to do other calculations (lower half plane) */
else
{
/* we know that because the viewing angle is downwards, so then the horizontal intersection has to be BELOW the viewer */
y_bound = (int)(view_y & 0xffc0);
/* because of this we also know that the next Y intersections will be a cell below each other. So the delta for each horizontal intersection will be a cell below the last */
y_delta = -CELL_Y_SIZE;
/* we again use the tangent function, just as before, to calculate the first x intersection with a boundary. */
/* NEW FIXED POINT, I won't show the old lines any more */
xi=((y_bound-view_y))*(inv_tan_table[view_angle]);
xi+=(view_x<<16);
/* and we know also that the quadrant is below the player, so the cell y delta will be negative */
next_y_cell = -1;
}
/* Y RAY : we do similar calculations but this time to calculate the first y intersections */
/* we test to see if the view angle is within the vertical asymptotes of 360 degrees. We need to know which halfplane we're casting from relative to the x-axis. */
if (view_angle < ANGLE_90 || view_angle >= ANGLE_270)
{
/* we can deduce certain things, just as with the x ray. We know that because the view angle is to the right, the next X boundary (which is constant) will be to the RIGHT of the viewer. */
x_bound = (int)(CELL_X_SIZE + (view_x & 0xffc0));
/* notice this recurring optimization of view_x % 64 */
/* and we also know that each vertical cell boundary after the first will be a cell's width away */
x_delta = CELL_X_SIZE;
/* this time we use the tangent function (not the inverse tan) to calculate where the first y boundary intersection will occur). */
/* NEW FIXED POINT */
yi=((x_bound - view_x))*(tan_table[view_angle]);
yi+=(view_y<<16);
/* and we know also that because the view is positive, the next_x_cell delta does not need to be negative */
next_x_cell = 0;
}
/* otherwise, if the viewing angle is towards the other direction...*/
else
{
/* we know that the first x boundary can occur only to the left of the viewer because the ray angle is facing left. So we can do view_x % 64 to calculate the first vertical boundary, this should be becoming obvious */
x_bound = (int)(view_x & 0xffc0);
/* we also know that the delta for the cell will be to the left, each time the ray moves to the next boundary the next vertical intersection will be a cell to the left than the last. */
x_delta = -CELL_X_SIZE;
/* we use the tangental function again to calculate the position on the horizontal intersections */
/* NEW FIXED POINT */
yi=((x_bound - view_x))*(tan_table[view_angle]);
yi+=(view_y<<16);
/* and we also know that the x cell value will be minus, because as the ray moves to another cell, because the ray is going left, the value must be minus. */
next_x_cell = -1;
}
/* Now we have performed the slightly tricky task of the first intersections, we can move on to calculating the next ones. This is more simple, as we know that the intersections can only occur at cell boundaries.*/
/* SECTION 2 : Testing for further intersections */
/* these flags store if casting of both rays is complete */
xray=yray=xtrans_done=ytrans_done=0;
/* X Ray is first */
/* because we are testing for each next intersection, we can figure out more easily the following intersections. */
/* this is a look up table holding the next y intercepts, based on the tangental function and the size of cells. Basically we add this to the ray each time we move it a bit more, searching for a wall at a cell boundary */
/* NEW FIXED POINT, note the shift 3 times to the left, the equivalent of a multiply by 8, this takes no time, and really I don't know why I've done it like this! It works. */
xadd=y_step[view_angle]<<3;
/* start casting the x ray */
while(!xray)
{
/* compute current cell position of the ray to inspect*/
cell_x = ( (x_bound+next_x_cell) >> CELL_X_SIZE_FP);
/* Note we have to shift not only by 6, but also by 16 to convert BACK to normal maths */
cell_y = (int)yi>>22;
/* both of the above examples use binary shifting to achieve a divide by 64. Cell_y computation uses identical techniques to those covered in the magazine. Cell_x is calculated by using the x_bound and next_x_cell values calculated beforehand. */
if(cell_x<0)cell_x=0;if(cell_x>63)cell_x=63;
if(cell_y<0)cell_y=0;if(cell_y>63)cell_y=63;
/* these simple lines ensure that the ray doesn't go out of the world, though they aren't really needed. */
/* we look up in the world file to see if there is a wall at the intersection of our ray */
if ((x_hit_type =world[cell_y][cell_x])!=0)
{
/* or any (extra or different) tile value you wish */
if(x_hit_type==9 || x_hit_type==7 || x_hit_type==10){
/*THEN THE WALL IS TRANSPARENT!!!*/
xtrans_dist=((yi-(view_y<<16))>>8)*(inv_sin_table[view_angle]>>8);
xtrans_type=x_hit_type;
xtrans_col=((int)(yi>>16) & 0x003f);
xtrans_done=FOUND_WALL;
/* we record all required details then continue */
}
else
{
/* if so we calculate the distance to it using the old O-Level technique of using sine and cosine instead of doing the standard PYTHAGORAS technique.*/
/* NEW FIXED POINT calculation, notice that in this next line we have both a conversion TO fixed point (view_y) and also the check against over flow is very apparent, we share the accuracy. See the article for more details */
dist_x = ( (yi - (view_y<<16))>>8) * (inv_sin_table[view_angle]>>8);
/* we also save the exact position of the intersection because we will need it later to add texture mapping. */
/* We save yi after converting it back to normal maths */
yi_save = (int)yi>>16;
/* because the x ray has found a wall, we can stop casting */
xray=FOUND_WALL;
}
}
/* if not, we compute the next possible intersection */
yi +=xadd; /* FIXED POINT ADDITION requires no extra work */
x_bound += x_delta; /* and we also calculate the next horizontal boundary, which we know will be x_delta away, no need for complex workings. */
}
/* SECTION 3 */
/* WE NOW do exactly the same but for the yray, we cast it out, check for a wall, if there is one we take the distance to it etc, if not, we move the ray until a wall it found. */
/* look up the value to add to the ray each time we move it */
/* See above for more information, this is FIXED POINT remember */
yadd=x_step[view_angle]<<3;
/* start casting the ray */
while(!yray)
{
/* compute current cell to inspect */
/* Because XI IS IN FIXED POINT we have to not only divide by 64 but also we have to convert BACK to normal maths */
cell_x = (int)xi>>22;
cell_y = ( (y_bound + next_y_cell) >> CELL_Y_SIZE_FP);
/* these calculations work out which cells the ray is in, ready to check for walls in the world[][] array. They both use binary shifting to perform divide by 64's. */
/* check that the ray has not gone out of the world, though this isn't really necessary */
if(cell_x<0)cell_x=0;if(cell_x>63)cell_x=63;
if(cell_y<0)cell_y=0;if(cell_y>63)cell_y=63;
/* look and see if there is a wall at the current point of intersection */
if ((y_hit_type = world[cell_y][cell_x])!=0)
{
if(y_hit_type==9 || y_hit_type==7 || y_hit_type==10){
/*THEN THE WALL IS TRANSPARENT!!!*/
ytrans_dist=((xi-(view_x<<16))>>8)*(inv_cos_table[view_angle]>>8);
ytrans_type=y_hit_type;
ytrans_col=((int)(xi>>16) & 0x003f);
ytrans_done=FOUND_WALL;
}
/* we record all required details then continue */
else
{
/* Use the old O-Level triangle method of calulating distance using cos, rather than using PYTHAGORAS, which is slower because it uses a square root! */
/* FIXED POINT calculation, just the same as the inv_sin calculation see above. */
dist_y = ( (xi - (view_x<<16))>>8) * (inv_cos_table[view_angle]>>8);
/* save the exact intersection point, we will need it later */
/* Same as aobve, very simple conversion back from FIXED POINT to normal maths */
xi_save = (int)xi>>16;
/* STOP y casting in that case, a wall has been found. */
yray=FOUND_WALL;
}
}
/* if not, move the ray on */
xi+=yadd; /* AGAIN, no extra work is required for FIXED POINT ADDITION */
y_bound += y_delta; /* and move to the next vertical boundary position */
}
/* SECTION 4*/
/* Both rays have been cast, both rays have met a wall, we now need to see which is closer, and then plot it correctly. */
/* find out which wall (x or y) is nearer the viewer. */
/* we have altered this distance checking line to avoid minus distances being selected to draw, which produces large spikes on the screen! Again this is because of fixed point */
if (dist_x < dist_y && dist_x>0 || dist_y<0)
{
/* we need to take into account here, when computing the scale of the vertical strip (sliver) to be drawn, a phenemenon (of sorts) known as the "fish bowl effect". This is caused by mizing of cartesian and polar coordinates. To get rid of it we use the cosine function. I have combined other multiplies of a vertical scaling factor with the cosine transformation to save time. All we eventually be explained. You could replace the line with scale=13312/dist_x++ and see what weird results you get! */
/* NEW NEW NEW : We have fixed point here, and using the reciprocal table (see around) we don't have to do a lengthy divide! Notice how we convert dist_x back to normal to index the recip_table array, and that all accuracy is lost with the cos_table, because all its figures are above zero (see aua_tables) and also that we actually convert the whole answer back to normal maths for scale */
scale = (int)( (cos_table[ray]>>16) * (recip_table[dist_x>>16]) >>16);
/* assign the variables we need to the variables to be passed to the ASM sliver renderer (super fast!) */
if(scale>SCREEN_HEIGHT)
{
scale=SCREEN_HEIGHT-1;
}
variables[2]=scale; /*stores the scale of the strip (height of it)*/
variables[3]=ray; /* we use ray as the x position to plot to (0-319)*/
variables[1]=(int)&walls[x_hit_type][(yi_save & 0x003f)];
variables[4]=(recip_table[scale]<<6);
/* and we call the assembler function (explained at a later date)*/
ourlib_new(&variables[0]);
scale_array[ray]=scale;
}
/* else the dist_y was nearer, everything from above applies */
else
{
/* avoid fish bowl effect and scale properly with FIXED POINT clever bits!, see above */
scale = (int)( (cos_table[ray]>>16) * (recip_table[dist_y>>16]) >> 16);
/* set up variables for our sliver engine, see above */
if(scale>SCREEN_HEIGHT)
{
scale=SCREEN_HEIGHT-1;
}
variables[2]=scale; /*stores the scale of the strip (height of it)*/
variables[3]=ray; /* we use ray as the x position to plot to (0-319)*/
variables[1]=(int)&walls[y_hit_type+1][(xi_save & 0x003f)];
variables[4]=(recip_table[scale]<<6);
/* notice we add one to the wall graphic selection, so the darker tile is used for added variation. See the article for more details of this sort of shading, if you want to call it that! */
/* call our sliver engine */
ourlib_new(&variables[0]);
scale_array[ray]=scale;
}
/* it is here that we draw the overlaying transparent wall */
if(xtrans_done && xtrans_dist<dist_y)
{
scale=(int)((cos_table[ray]>>16) * (recip_table[xtrans_dist>>16])>>16);
if(scale>SCREEN_HEIGHT)scale=SCREEN_HEIGHT-1;
variables[2]=scale;
variables[3]=ray;
variables[4]=(recip_table[scale]<<6);
variables[1]=(int)&walls[xtrans_type][xtrans_col];
/* now call our special function which treats color 0 as a mask */
ourlib_new_mask(variables);
mirror_array[ray]=0;
if(xtrans_type==10)mirror_array[ray]=255;
else scale_array[ray]=scale;
}
else if(ytrans_done && ytrans_dist<dist_x)
{
scale=(int)((cos_table[ray]>>16) * (recip_table[ytrans_dist>>16])>>16);
if(scale>SCREEN_HEIGHT)scale=SCREEN_HEIGHT-1;
variables[2]=scale;
variables[3]=ray;
variables[4]=(recip_table[scale]<<6);
variables[1]=(int)&walls[ytrans_type][ytrans_col];
/* now call our special function which treats color 0 as a mask */
ourlib_new_mask(variables);
mirror_array[ray]=0;
if(ytrans_type==10)mirror_array[ray]=255;
else scale_array[ray]=scale;
}
/* this ray has been finished. Increase the angle of the next ray and start again! */
if (++view_angle>=ANGLE_360)
{
/* this ensures that the ray angle doesn't go over 360 degrees! */
view_angle=0;
}
/* ray loop */
}
/* end ray caster engine */
/* objects*/
}
/* this function grabs all the different walls from a single file */
void aua_graphics(void)
{
int x, /* this is used to store the x coordinate of a point on the screen */
y, /* this is used to store the y coordinate of a point on the screen */
wall_number; /* this will be used to index the walls[x][] char array */
/* first of all we get the graphics file <AUARay$Dir>.graphics onto the screen */
system("*ScreenLoad <AUARay$Dir>.graphics");
/* next we start grabbing each tile, 64 x 64 pixels, into the walls[][] array */
/* we use this large for loop at the ourlib_bitmap_grab function to invidually grab each tile into its own walls[x][] array slot, note that we CAN'T HAVE WALL 0 as this represents a gap in the world! */
ourlib_killcursor(); /* get rid of cursor first */
for(wall_number=1,y=0;y<256;y+=WALL_HEIGHT)for(x=0;x<320;x+=WALL_WIDTH,wall_number++)
{
/* this calls the function ourlib_bitmap_grab (I said it would be handy!) which grabs the area of screen memory marked by the first four parameters, stores it in the byte array pointer in parameter five, reading it all from the screen pointed to by screen_address */
ourlib_bitmap_grab(x,y,x+WALL_WIDTH-1,y+WALL_HEIGHT-1,&walls[wall_number][0],screen_address);
/* this makes sure we don't go over our number of walls limit */
if(wall_number>=WALL_NUMBER)break;
}
/* new stuff load in objects separately */
/* see above for comments (its identical) */
system("*ScreenLoad <AUARay$Dir>.Objgraphic");
ourlib_killcursor();
for(wall_number=1,y=0;y<256;y+=WALL_HEIGHT)for(x=0;x<320;x+=WALL_WIDTH,wall_number++)
{
ourlib_bitmap_grab(x,y,x+63,y+63,&objgraphics[wall_number][0],screen_address);
if(wall_number>WALL_NUMBER)break;
}
/* NEW bottom bar graphics code, here we grab the sprite */
system("*screenload <AUARay$Dir>.Bottombar");
ourlib_bitmap_grab(0,206,319,255,bar_graphic,screen_address);
}
/* this function loads in the data from our world text file and stores it in the world[][] array */
void aua_world(void)
{
FILE *world_file; /* we need a file pointer as we will be loading in text */
int row, /* this will be used to index the world[][] array */
column,counter=0; /* this will be used to index the world[][] array */
char ch; /* this is used to store each number as it is loaded in */
/* open the world file, if it is not there then exit the program */
if(!(world_file=fopen("<AUARay$Dir>.world","r")))exit(1);
/* this program loads in the data from the world file, row by row, column by column using the getc() ANSI function */
for(row=0;row<WORLD_HEIGHT;row++)
{
for(column=0;column<WORLD_WIDTH;column++)
{
while((ch=getc(world_file))==10){} /* this filters out any mess, though not often used! */
if(ch==' ')ch=0; /*this ensures the correct value is stored, if there is a gap in the file, this means a space in the world, a zero */
else ch=ch-'0';
/* this new line will (should!) convert letters into their appropriate number */
if(ch>15)ch-=7;
world[(WORLD_HEIGHT-1)-row][column]=ch; /* this finally stores the value in the correct position */
/*printf("%d",ch); uncomment this line to see the world data loaded in */
}
/*printf("\n"); uncomment this line to see the world data loaded in */
}
/* when all is done, close the file */
fclose(world_file);
/* new part to load in object data, see above for comments */
if(!(world_file=fopen("<AUARay$Dir>.objworld","r"))) exit(1);
for(row=0;row<WORLD_HEIGHT;row++)
{
for(column=0;column<WORLD_WIDTH;column++)
{
while((ch=getc(world_file))==10){}
if(ch==' ')ch=0;
else ch=ch-'0';
if(ch>16)ch-=7;
objects[(WORLD_HEIGHT-1)-row][column]=ch;
}
}
fclose(world_file);
}
/* NEWER MAIN function .
All changes are commented */
void main(int argc,char *argv[])
{
int view_x, /* this holds the viewing x coordinate */
view_y, /* this holds the viewing y coordinate */
view_angle; /* this holds the viewing angle in fixed units 0-1920 */
int
done=0, /* flag to indicate if the user wants to quit */
dx, /* movement variables for the viewer */
dy,
y_cell, /* these NEW variables are used to store the player/viewer*/
x_cell, /* world positions, for calculating viewer hitting walls */
y_sub_cell,
x_sub_cell,
time_start,
time_finish, /* These last few variables are used to work out */
frames=0, /* the frames per sec. of the system, slow for now! */
door_x,
door_y, /* These new variables will be used for door things */
screen_limit;
/* New Object Code ***************** Added Article 5 - good stuff ! */
int object_x,object_y,trans_x,trans_z,screen_x,screen_y1,screen_y2,temp_1,counter,scale,variables[7],index,increment,grid_x,grid_y,object_type,start_x,start_y,stop_x,stop_y,move_x,move_y,tview_x,tview_y,tview_angle;
/* New Object Code Variables Over *************** See Later in Main() */
/* NEW object MOVING code and arrays are now in this function */
/* pattern of movements */
float object_move_increment=0.0000; /* amount to add to index each frame */
float object_move_index=0.0000;
int object_temp_move_index=0;
int object_move_found=0; /* flag to say if moving object found */
/* values to hold moving object */
int object_move_new_x,object_move_new_y; /* new values of object */
/* NEW demo file which can load/store demo information for a walkthrough*/
FILE *demo_file;
/* NEW system of passing, we use the standard argc and argv to supply parameters to the engine. FIRST we must extract them:*/
/* check that correct number of parameters have been passed */
if(argc!=15)
{
/* quit if not */
printf("Error: Incorrect number of parameters passed. _Exiting\n"); exit(1);
/* "beep" (on most machines)*/ putchar('\a');
}
/* use atoi to get it right */
/* INPUT ALL VALUES FROM COMMAND LINE using ATOI and then work out needed*/
/* angle values for the ray casting engine. */
view_x=atoi(argv[1]);
view_y=atoi(argv[2]);
view_angle=atoi(argv[3]);
SCREEN_WIDTH=atoi(argv[4]);
SCREEN_HEIGHT=atoi(argv[5]);
ANGLE_360=atoi(argv[6]);
ANGLE_180=ANGLE_360/2;ANGLE_90=ANGLE_180/2;
ANGLE_6=atoi(argv[9]);
ANGLE_30=(int)ANGLE_90/3;
ANGLE_0=0;
ANGLE_270=ANGLE_90*3;
VERTICAL_SCALE=atoi(argv[7]);
STEP_LENGTH=atoi(argv[8]);
VIEWVAR=atoi(argv[10]);
VIEWVART=atoi(argv[11]);
DEMO_READ=atoi(argv[12]);
DEMO_WRITE=atoi(argv[13]);
object_move_increment=atoi(argv[14]);
/* convert object_inrement properly */
if(object_move_increment==0)object_move_increment=1;
object_move_increment=(float)1/object_move_increment;
screen_limit=(320-SCREEN_WIDTH)>>2;
/* Now we print the information just for the information of the user */
printf("_pre-start: switching to Mode (15) - high res for text.\n");
ourlib_changemode(15);
printf("############## SYSTEM START-UP ###################\n");
printf("_system variables: view_x: %d view_y: %d view_angle: %d\nscreen_width: %d screen_height: %d\nangle_360: %d vertical_scale: %d step_length: %d\nviewvars: %d %d\ndemo_read: %d demo_write: %d object_move_increment: %f\n\n",view_x,view_y,view_angle,SCREEN_WIDTH,SCREEN_HEIGHT,ANGLE_360,VERTICAL_SCALE,STEP_LENGTH,VIEWVAR,VIEWVART,DEMO_READ,DEMO_WRITE,object_move_increment);
if(DEMO_WRITE==1){
if(!(demo_file=fopen("<AUARay$Dir>.demo","w")))exit(1);
printf("_file access: writing to file\n");
}
else if(DEMO_READ==1)
{
if(!(demo_file=fopen("<AUARay$Dir>.demo","r")))exit(1);
printf("_file access: reading demo file\n\n");
}
/* DONE. Now continue as normal with the program */
/* It is here that we see if the DEMOFLAG is set to read/write demos */
/* now we call aua_world to load in the text world file which defines our walls type and layout */
printf("\n_file access: loading in text file <AUARay$Dir>.world\n\n");
aua_world();
/* check to see if the viewer is inside a game cell WALL, which would be bad news! */
if(world[view_y>>6][view_x>>6])
{
printf("\n_error: Bad coordinates given, viewer is IN a WALL!, exiting\n");
exit(1);
}
/* now we call aua_tables to generate some look-up tables for the engine to use, look-ups are explained up at the top of the file next to the global variables */
printf("_main: call aua_tables() (long time on slower machines)\n\n");
/* newer fixed point version */
aua_tables();
/* all is done in terms of input for now. We need to switch to Mode 13 */
printf("_screen: switching to Mode 13\n\n");
/* call ourlib_changemode to switch to mode 13 */
ourlib_changemode(13);
/* call ourlib_findscreen to get the screen base address of mode 13, without the correct address we can't draw anything and the computer could crash */
screen_address=(char *)ourlib_findscreen();
/* NEW LOAD TITLE SCREEN */
system("*ScreenLoad <AUARay$Dir>.title");ourlib_killcursor();
ourlib_wait(200);
/*ourlib_screen_dissolve(screen_address,81920); USE IF WANTED */
/* THEN WAIT THEN SCREENDISSOLVE OUT, see above */
/* now we need to *screenload our graphics file, and grab each individual wall graphic one by one, the function aua_graphics does this */
aua_graphics();
/* NOW we call setup_screens, a small function which helps with banking */
/* With all the data loaded in we shall try and initiate SCREEN BANKS. First we change to MODE 15, so that screen memory becomes available for two times MODE 13 */
ourlib_setup_screens();
ourlib_changemode(15);
/* Now we switch to MODE 13, and get the first screen address */
ourlib_changemode(13);
ourlib_killcursor();
screen_address=(char *)ourlib_findscreen();
/* NEW code to plot the bottom bar on the screen */
ourlib_bitmap_plot(0,206,319,255,bar_graphic,screen_address);
/* Now we switch to the other screen bank and get the other screen address */
ourlib_simpleswitch();
screen_address_bank=(char *)ourlib_findscreen();
ourlib_slowclear(screen_address_bank,81920,0);
ourlib_bitmap_plot(0,206,319,255,bar_graphic,screen_address_bank);
ourlib_killcursor();
/* Switch back to the other screen */
ourlib_simpleswitch();
/* NOW we can call setup background, to tell the screen clearer the colour of the floor and ceilings we want.*/
ourlib_setup_background(208,45);
/* NOW we can start the main loop, exitable only by pressing the Q key. Use the Cursors to move the viewpoint around */
/* We shall also take a reading to work out the frame rate of the system, slow for now */
/* NEW ADJUSTING LINES : we add an offset to both screen memory areas in order to centre the image in the middle of the screen no matter what size */
screen_address+=(320-SCREEN_WIDTH)>>1;
screen_address_bank+=(320-SCREEN_WIDTH)>>1;
ourlib_killcursor(); /* get rid of the cursor flashing away */
time_start=ourlib_gettime();
while(!done) /* the loop will continue until done */
{
ourlib_fastclg_two(screen_address,SCREEN_WIDTH,SCREEN_HEIGHT); /* we call the floor/ceiling function to colour the whole screen */
/* then we call the ray caster to draw over it */
aua_raycaster(view_x,view_y,view_angle);
dx=dy=0;
/* now we test for different key presses and take action accordingly */
if(ourlib_keydown(16)==255)done=1; /* if Q is pressed then quit */
/* LEFT */
if(ourlib_keydown(121)==255)
{
if((view_angle-=ANGLE_6)<ANGLE_0)
view_angle=ANGLE_360;
}
/*RIGHT */
if(ourlib_keydown(25)==255)
{
if((view_angle+=ANGLE_6)>ANGLE_360)
view_angle=ANGLE_0;
}
/* UP and DOWN */
if(ourlib_keydown(57)==255)
{
dx=dx_table[view_angle];
dy=dy_table[view_angle];
}
if(ourlib_keydown(41)==255)
{
dx=-dx_table[view_angle];
dy=-dy_table[view_angle];
}
/* NOW we need to move the player and recalculate the cell the viewer is in, and ALSO check to see if the player has hit a wall */
/* Watch for the conversions of fixed point and things */
/* Player X actually is in normal maths */
view_x= (int)((view_x<<16)+dx)>>16;
view_y= (int)((view_y<<16)+dy)>>16;
/* DEMO HANDLING CODE COMES HERE */
/* Note that this is described briefly in article 5 */
if(DEMO_WRITE || DEMO_READ)
{
tview_x=view_x;
tview_y=view_y;
tview_angle=view_angle;
if(DEMO_WRITE)
{
/* These lines can be used to record the direction of a moving object*/
/*tview_angle=19;
if(view_angle>ANGLE_0 && view_angle<ANGLE_90)tview_angle=19;
if(view_angle>=ANGLE_90 && view_angle<ANGLE_180)tview_angle=17;
if(view_angle>=ANGLE_180 && view_angle<ANGLE_270)tview_angle=15;
if(view_angle>=ANGLE_270 && view_angle<ANGLE_360)tview_angle=10;*/
fprintf(demo_file,"%d %d %d ",tview_x,tview_y,tview_angle);
}
if(DEMO_READ)if((fscanf(demo_file,"%d %d %d ",&tview_x,&tview_y,&tview_angle))==EOF)rewind(demo_file);
view_x=tview_x;
view_y=tview_y;
view_angle=tview_angle;
}
/* NEW OPTIMIZED VERSIONS OF MOVING THE PLAYER */
x_cell = view_x>>6;
y_cell = view_y>>6;
x_sub_cell = view_x & 0x003f;
y_sub_cell = view_y & 0x003f;
/* CHECK to see if player has walked into walls */
if ((dx>>8)>0 ){
if ((world[y_cell][x_cell+1] != 0) && (x_sub_cell>(CELL_X_SIZE-CLOSEST)))
{
view_x-= (x_sub_cell-(CELL_X_SIZE-CLOSEST ));
}
}
else
{
if ( (world[y_cell][x_cell-1] != 0) && (x_sub_cell < (CLOSEST) ) )
{
view_x+= (CLOSEST-x_sub_cell) ;
}
}
if ((dy>>8)>0 ){
if ( (world[(y_cell+1)][x_cell] != 0) &&
(y_sub_cell > (CELL_Y_SIZE-CLOSEST ) ) )
{
view_y-= (y_sub_cell-(CELL_Y_SIZE-CLOSEST ));
}
}
else
{
if ( (world[(y_cell-1)][x_cell] != 0) && (y_sub_cell < (CLOSEST) ) )
{
view_y+= (CLOSEST-y_sub_cell);
}
}
/* NEW DOOR code. A "probe" is sent out in front of the player, if a door tile is found near it then the block is destroyed. */
if(ourlib_keydown(98)==255)
{
/* Use similar techniques to above to find door */
dx=dx_table[view_angle];
dy=dy_table[view_angle];
/* Calculate door x and y, it is in normal maths */
door_x= (int)((view_x<<16)+(dx<<3))>>16;
door_y= (int)((view_y<<16)+(dy<<3))>>16;
/* NEW OPTIMIZED VERSIONS OF FINDIN DOORS */
/* now find the cell we are looking in with the standard equation */
x_cell = (int)door_x>>6;
y_cell = (int)door_y>>6;
/* Check if a doors is present */
if(world[y_cell][x_cell]==7 /* OR WHATEVER YOU LIKE */)
{
world[y_cell][x_cell]=0; /* or alternatively do what you like */
}
}
/* NEW SIMPLE SHOOTER code. You can add as many further tests as you like */
/* Like many additions this month, this is just a simple starter for you all */
if(ourlib_keydown(7)==255)
{
/* Use similar techniques to above to find door */
putchar('\a');
dx=dx_table[view_angle];
dy=dy_table[view_angle];
door_x= (int)((view_x<<16)+(dx<<1))>>16;
door_y= (int)((view_y<<16)+(dy<<1))>>16;
x_cell = (int)door_x>>6;
y_cell = (int)door_y>>6;
/* Check if a object is present */
if(objects[y_cell][x_cell]/* OR WHATEVER YOU LIKE */)
{
objects[y_cell][x_cell]=0; /* or alternatively do what you like */
}
else
{
door_x= (int)((view_x<<16)+(dx<<2))>>16;
door_y= (int)((view_y<<16)+(dy<<2))>>16;
x_cell = (int)door_x>>6;
y_cell = (int)door_y>>6;
/* Check if a object is present */
if(objects[y_cell][x_cell]/* OR WHATEVER YOU LIKE */)
{
objects[y_cell][x_cell]=0; /* or alternatively do what you like */
}
else
{
/* Calculate bullets x and y, it is in normal maths */
door_x= (int)((view_x<<16)+(dx<<3))>>16;
door_y= (int)((view_y<<16)+(dy<<3))>>16;
x_cell = (int)door_x>>6;
y_cell = (int)door_y>>6;
/* Check if a doors is present */
if(objects[y_cell][x_cell]/* OR WHATEVER YOU LIKE */)
{
objects[y_cell][x_cell]=0; /* or alternatively do what you like */
}
}
}
}
/* New Object Code ****************** Added Article 5, good stuff! */
/* This code cycles through the objects and plots them appropriately
if they are visible by the viewer. See ARTICLE 5 for more details.*/
/* Firstly, set up variables we know are going to be used */
variables[0]=(int)screen_address;
variables[2]=SCREEN_HEIGHT;
/* Next we loop through all the visible squares to see if an object has been found */
if(view_angle>ANGLE_0 && view_angle<ANGLE_90)
{
start_x=(view_x>>6)+15;
start_y=(view_y>>6)+15;
stop_x=(view_x>>6)-5;
stop_y=(view_y>>6)-5;
move_x=-1;
move_y=-1;
if(stop_x<0)stop_x=0;if(stop_x>63)stop_x=63;
if(start_x<0)start_x=0;if(start_x>63)start_x=63;
if(stop_y<0)stop_y=0;if(stop_y>63)stop_y=63;
if(start_y<0)start_y=0;if(start_y>63)start_y=63;
}
else if(view_angle>=ANGLE_90 && view_angle<ANGLE_180)
{
start_x=(view_x>>6)-15;
start_y=(view_y>>6)+15;
stop_x=(view_x>>6)+5;
stop_y=(view_y>>6)-5;
move_x=1;
move_y=-1;
if(stop_x<0)stop_x=0;if(stop_x>63)stop_x=63;
if(start_x<0)start_x=0;if(start_x>63)start_x=63;
if(stop_y<0)stop_y=0;if(stop_y>63)stop_y=63;
if(start_y<0)start_y=0;if(start_y>63)start_y=63;
}
else if(view_angle>=ANGLE_180 && view_angle<ANGLE_270)
{
start_x=(view_x>>6)-15;
start_y=(view_y>>6)-15;
stop_x=(view_x>>6)+5;
stop_y=(view_y>>6)+5;
move_x=1;
move_y=1;
if(stop_x<0)stop_x=0;if(stop_x>63)stop_x=63;
if(start_x<0)start_x=0;if(start_x>63)start_x=63;
if(stop_y<0)stop_y=0;if(stop_y>63)stop_y=63;
if(start_y<0)start_y=0;if(start_y>63)start_y=63;
}
else
{
start_x=(view_x>>6)+15;
start_y=(view_y>>6)-15;
stop_x=(view_x>>6)-5;
stop_y=(view_y>>6)+5;
move_x=-1;
move_y=1;
if(stop_x<0)stop_x=0;if(stop_x>63)stop_x=63;
if(start_x<0)start_x=0;if(start_x>63)start_x=63;
if(stop_y<0)stop_y=0;if(stop_y>63)stop_y=63;
if(start_y<0)start_y=0;if(start_y>63)start_y=63;
}
for(grid_x=start_x;grid_x!=stop_x;grid_x+=move_x)for(grid_y=start_y;grid_y!=stop_y;grid_y+=move_y)
{
if(!(object_type=objects[grid_y][grid_x]))continue;
/* An object has been found in this grid square, good!*/
/* in that case we process and plot the object */
/* NEW MOVING OBJECT code. This is actually very simple and can be done in */
/* a _variety_ of ways. This is just one of them, and not the best ;-) */
/*
if(object_type==10 || object_type==15 || object_type==17 || object_type==19)
{
object_x=object_move_x;
object_y=object_move_y;
}
else*/
{
object_x=(grid_x<<6)+32;
object_y=(grid_y<<6)+32;
}
/* now we have to rotate the objects coordinates around the viewer */
/* to establish where it is on the view plane ,using standard rots.*/
trans_x=( (object_x-view_x)*coso_table[view_angle]+(object_y-view_y)*
sino_table[view_angle])>>16;
trans_z=(-(object_x-view_x)*sino_table[view_angle]+(object_y-view_y)*
coso_table[view_angle])>>16;
/* now if the object is infront of the viewer we go further */
if(trans_z<0)continue; /* else we move to next object */
/* we have to work out screen positions now (above and below!) */
temp_1=(((VIEWVART<<5) * recip_table[trans_z]))>>16;
screen_y1=100-temp_1; /* 128 and 160 here indicate origins at the*/
screen_y2=100+temp_1; /* center of the screen ofcourse */
/* the above lines works out the top and bottom of the object */
if((scale=screen_y2-screen_y1)>MAX_SCALE)continue;
screen_x=160 + ( ( VIEWVAR*trans_x * recip_table[trans_z])>>16);
if(scale>(SCREEN_HEIGHT))
{
scale=SCREEN_HEIGHT;
}
variables[5]=screen_y1;
/* above line works out scale from y1 and y2 ready for drawing */
screen_x-=scale>>1;
/* we offset screen_x so then we are at the left of the object */ increment=(int)(recip_table[scale]<<6);
variables[3]=scale;
/* NEW moving object detector checks to see if object is of moving sort */
/* above line prepares more variables for the ourlib function */
/* next we set up fixed point systems to index the object graphic */
/* while we draw it. Instead of floating point this is of course */
index=0;
/* next we use a counter to count if we have finished drawing it. */
counter=scale;
/* initialise a loop to render each sliver one by one */
/* keep going until off the screen or just finished! */
while(screen_x>-64 && screen_x<SCREEN_WIDTH && counter>0)
{
/* NEW mirror code, we have to be careful to make it look good */
if(mirror_array[screen_x]==255 && scale>scale_array[screen_x])
{
variables[1]=(int)&objgraphics[object_type][(int)index>>16];
variables[4]=screen_x;
ourlib_sliver_mask_mirror(variables);
}
else{
/* check to see if object is infront of wall, important! */
if(scale>scale_array[screen_x] && screen_x>screen_limit)
{
/* if so draw this sliver! */
variables[1]=(int)&objgraphics[object_type][(int)index>>16];
variables[4]=screen_x;
ourlib_sliver_mask(variables);
}
} /* add on graphic increment, decrease counter and move to next column */ index+=increment;
counter--;
screen_x++;
}
}
/* Object Code OVER ************* Continue as normal */
/* *************** See Article 5 for more details */
/* NEW moving object : We add a small bit of code to move the object */
/*objects[object_move_y>>6][object_move_x>>6]=0;
object_move_x=object_move[(int)object_move_index];
object_move_y=object_move[(int)object_move_index+1];
objects[object_move_y>>6][object_move_x>>6]=object_move[object_move_index+2];
object_move_index+=3;if(object_move_index>100)object_move_index=0;*/
/* PHEW! Now we can wait for a vysnc and then switch the views/banks over ot produce flicker-free animation */
ourlib_waitvsync();
ourlib_simpleswitch();
/* We also have to switch the memory addresses around so our functions draw to the correct memory */
screen_address_temp=screen_address_bank;
screen_address_bank=screen_address;
screen_address=screen_address_temp;
/* add one to the frames count, we are counting the number of frames generated */
frames++;
}
/* record the time stopped */
time_finish=ourlib_gettime();
/* take a screenshot, using *screen save, and save it inside the directory */
system("*ScreenSave <AUARay$Dir>.scrshot");
if(DEMO_READ || DEMO_WRITE)fclose(demo_file);
/* close down the screens using an ourlib function */
ourlib_closedown_screens();
/* change to mode 15 and bring back the cursor just in case */
ourlib_changemode(15);
ourlib_revivecursor();
/* print the calculation and other info. */
printf("******* FRAMES PER SECOND ********\n%f",(float)frames/(float)((time_finish-time_start)/100));
}
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00000f20 74 20 2a 72 65 63 69 70 5f 74 61 62 6c 65 3b 20 |t *recip_table; |
00000f30 20 20 20 20 20 20 20 20 20 20 20 20 20 2f 2a 20 | /* |
00000f40 72 65 63 69 70 72 6f 63 61 6c 20 74 61 62 6c 65 |reciprocal table|
00000f50 20 75 73 65 64 20 69 6e 73 74 65 61 64 20 6f 66 | used instead of|
00000f60 20 61 20 2a 2f 0a 20 20 20 20 20 20 20 20 20 20 | a */. |
00000f70 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00000f80 20 20 20 20 20 2f 2a 20 64 69 76 69 73 69 6f 6e | /* division|
00000f90 2e 20 53 65 65 20 6c 61 74 65 72 20 2a 2f 0a 69 |. See later */.i|
00000fa0 6e 74 20 2a 63 6f 73 6f 5f 74 61 62 6c 65 2c 2a |nt *coso_table,*|
00000fb0 73 69 6e 6f 5f 74 61 62 6c 65 3b 20 20 20 2f 2a |sino_table; /*|
00000fc0 20 74 68 65 73 65 20 74 77 6f 20 74 61 62 6c 65 | these two table|
00000fd0 73 20 61 72 65 20 66 6f 72 20 6f 62 6a 65 63 74 |s are for object|
00000fe0 73 20 2a 2f 0a 69 6e 74 20 2a 64 78 5f 74 61 62 |s */.int *dx_tab|
00000ff0 6c 65 2c 20 20 20 20 20 20 20 20 20 20 20 20 20 |le, |
00001000 20 20 20 20 2f 2a 20 46 49 58 45 44 20 50 4f 49 | /* FIXED POI|
00001010 4e 54 20 74 61 62 6c 65 73 20 66 6f 72 20 6d 6f |NT tables for mo|
00001020 76 69 6e 67 20 74 68 65 20 2a 2f 0a 20 20 20 20 |ving the */. |
00001030 2a 64 79 5f 74 61 62 6c 65 3b 20 20 20 20 20 20 |*dy_table; |
00001040 20 20 20 20 20 20 20 20 20 20 20 2f 2a 20 76 69 | /* vi|
00001050 65 77 20 70 6f 69 6e 74 20 76 65 72 79 20 71 75 |ew point very qu|
00001060 69 63 6b 6c 79 20 2a 2f 0a 69 6e 74 20 73 63 61 |ickly */.int sca|
00001070 6c 65 5f 61 72 72 61 79 5b 33 32 30 5d 3b 20 20 |le_array[320]; |
00001080 20 20 20 20 20 20 20 20 2f 2a 20 4e 45 57 20 75 | /* NEW u|
00001090 73 65 64 20 74 6f 20 73 74 6f 72 65 20 73 63 61 |sed to store sca|
000010a0 6c 65 20 76 61 6c 75 65 73 20 6f 66 20 65 61 63 |le values of eac|
000010b0 68 20 2a 2f 0a 20 20 20 20 20 20 20 20 20 20 20 |h */. |
000010c0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
000010d0 20 20 20 20 2f 2a 20 73 6c 69 76 65 72 2c 66 6f | /* sliver,fo|
000010e0 72 20 6f 62 6a 65 63 74 73 20 6c 61 74 65 72 20 |r objects later |
000010f0 6f 6e 20 2a 2f 0a 69 6e 74 20 6d 69 72 72 6f 72 |on */.int mirror|
00001100 5f 61 72 72 61 79 5b 33 32 30 5d 3b 20 20 20 20 |_array[320]; |
00001110 20 20 20 20 20 2f 2a 20 75 73 65 64 20 74 6f 20 | /* used to |
00001120 66 6c 61 67 20 69 66 20 61 20 6d 69 72 72 6f 72 |flag if a mirror|
00001130 20 69 73 20 69 6e 20 75 73 65 20 2a 2f 0a 2f 2a | is in use */./*|
00001140 20 46 55 4e 43 54 49 4f 4e 20 64 65 66 69 6e 69 | FUNCTION defini|
00001150 74 69 6f 6e 73 20 2a 2f 0a 0a 2f 2a 20 74 68 69 |tions */../* thi|
00001160 73 20 66 75 6e 63 74 69 6f 6e 20 67 65 6e 65 72 |s function gener|
00001170 61 74 65 73 20 4c 4f 4f 4b 20 55 50 20 74 61 62 |ates LOOK UP tab|
00001180 6c 65 73 20 2d 20 61 72 72 61 79 73 20 68 6f 6c |les - arrays hol|
00001190 64 69 6e 67 20 70 72 65 2d 63 61 6c 63 75 6c 61 |ding pre-calcula|
000011a0 74 65 64 20 74 72 69 67 6f 6e 6f 6d 65 74 72 69 |ted trigonometri|
000011b0 63 20 76 61 72 69 61 62 6c 65 73 20 75 73 65 64 |c variables used|
000011c0 20 69 6e 20 74 68 65 20 72 61 79 20 63 61 73 74 | in the ray cast|
000011d0 69 6e 67 20 70 72 6f 63 65 73 73 20 2a 2f 0a 0a |ing process */..|
000011e0 76 6f 69 64 20 61 75 61 5f 74 61 62 6c 65 73 28 |void aua_tables(|
000011f0 76 6f 69 64 29 0a 7b 0a 0a 69 6e 74 20 61 6e 67 |void).{..int ang|
00001200 2c 20 2f 2a 20 74 68 69 73 20 69 73 20 75 73 65 |, /* this is use|
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00001220 20 77 68 69 6c 65 20 6d 61 6b 69 6e 67 20 6c 6f | while making lo|
00001230 6f 6b 2d 75 70 73 20 2a 2f 0a 20 20 20 20 61 6e |ok-ups */. an|
00001240 67 74 3b 20 2f 2a 20 73 61 6d 65 20 2a 2f 0a 0a |gt; /* same */..|
00001250 66 6c 6f 61 74 20 72 61 64 5f 61 6e 67 6c 65 3b |float rad_angle;|
00001260 20 2f 2a 20 74 68 69 73 20 68 6f 6c 64 73 20 74 | /* this holds t|
00001270 68 65 20 72 61 64 69 61 6e 73 20 65 71 75 69 76 |he radians equiv|
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00001290 65 64 20 70 6f 69 6e 74 20 61 6e 67 6c 65 20 73 |ed point angle s|
000012a0 79 73 74 65 6d 20 28 30 2d 31 39 32 30 20 3d 20 |ystem (0-1920 = |
000012b0 30 2d 33 36 30 20 64 65 67 72 65 65 73 20 3d 20 |0-360 degrees = |
000012c0 30 2d 36 2e 77 68 61 74 65 76 65 72 20 72 61 64 |0-6.whatever rad|
000012d0 69 61 6e 73 2e 20 4e 65 78 74 20 6d 6f 6e 74 68 |ians. Next month|
000012e0 20 49 27 6c 6c 20 62 65 20 63 68 61 6e 67 69 6e | I'll be changin|
000012f0 67 20 74 68 65 20 73 79 73 74 65 6d 20 73 6f 20 |g the system so |
00001300 69 74 20 62 65 63 6f 6d 65 73 20 30 2d 31 38 30 |it becomes 0-180|
00001310 30 20 69 6e 73 74 65 61 64 20 6f 66 20 31 39 32 |0 instead of 192|
00001320 30 2c 20 74 68 69 73 20 77 69 6c 6c 20 61 6c 6c |0, this will all|
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00001360 6c 66 65 6e 73 74 65 69 6e 2c 20 74 68 69 73 20 |lfenstein, this |
00001370 77 69 6c 6c 20 6c 65 61 64 20 74 6f 20 61 6e 20 |will lead to an |
00001380 69 6e 63 72 65 61 73 65 20 69 6e 20 66 72 61 6d |increase in fram|
00001390 65 20 72 61 74 65 2e 20 59 65 73 21 20 2a 2f 0a |e rate. Yes! */.|
000013a0 0a 2f 2a 20 64 79 6e 61 6d 69 63 61 6c 6c 79 20 |./* dynamically |
000013b0 61 6c 6c 6f 63 61 74 65 64 20 61 64 65 71 75 61 |allocated adequa|
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000013d0 65 20 6c 6f 6f 6b 2d 75 70 73 20 2a 2f 0a 74 61 |e look-ups */.ta|
000013e0 6e 5f 74 61 62 6c 65 20 20 20 20 20 3d 20 28 69 |n_table = (i|
000013f0 6e 74 20 2a 29 6d 61 6c 6c 6f 63 28 73 69 7a 65 |nt *)malloc(size|
00001400 6f 66 28 69 6e 74 29 20 2a 20 28 41 4e 47 4c 45 |of(int) * (ANGLE|
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00001420 6e 5f 74 61 62 6c 65 20 3d 20 28 69 6e 74 20 2a |n_table = (int *|
00001430 29 6d 61 6c 6c 6f 63 28 73 69 7a 65 6f 66 28 69 |)malloc(sizeof(i|
00001440 6e 74 29 20 2a 20 28 41 4e 47 4c 45 5f 33 36 30 |nt) * (ANGLE_360|
00001450 2b 31 29 29 3b 0a 0a 79 5f 73 74 65 70 20 20 20 |+1));..y_step |
00001460 20 20 20 20 20 3d 20 28 69 6e 74 20 2a 29 6d 61 | = (int *)ma|
00001470 6c 6c 6f 63 28 73 69 7a 65 6f 66 28 69 6e 74 29 |lloc(sizeof(int)|
00001480 20 2a 20 28 41 4e 47 4c 45 5f 33 36 30 2b 31 29 | * (ANGLE_360+1)|
00001490 29 3b 0a 78 5f 73 74 65 70 20 20 20 20 20 20 20 |);.x_step |
000014a0 20 3d 20 28 69 6e 74 20 20 2a 29 6d 61 6c 6c 6f | = (int *)mallo|
000014b0 63 28 73 69 7a 65 6f 66 28 69 6e 74 29 20 2a 20 |c(sizeof(int) * |
000014c0 28 41 4e 47 4c 45 5f 33 36 30 2b 31 29 29 3b 0a |(ANGLE_360+1));.|
000014d0 0a 63 6f 73 5f 74 61 62 6c 65 20 20 20 20 20 3d |.cos_table =|
000014e0 20 28 69 6e 74 20 20 2a 29 6d 61 6c 6c 6f 63 28 | (int *)malloc(|
000014f0 73 69 7a 65 6f 66 28 69 6e 74 29 20 2a 20 28 41 |sizeof(int) * (A|
00001500 4e 47 4c 45 5f 33 36 30 2b 31 29 29 3b 0a 69 6e |NGLE_360+1));.in|
00001510 76 5f 63 6f 73 5f 74 61 62 6c 65 20 3d 20 28 69 |v_cos_table = (i|
00001520 6e 74 20 20 2a 29 6d 61 6c 6c 6f 63 28 73 69 7a |nt *)malloc(siz|
00001530 65 6f 66 28 69 6e 74 29 20 2a 20 28 41 4e 47 4c |eof(int) * (ANGL|
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00001550 69 6e 5f 74 61 62 6c 65 20 3d 20 28 69 6e 74 20 |in_table = (int |
00001560 20 2a 29 6d 61 6c 6c 6f 63 28 73 69 7a 65 6f 66 | *)malloc(sizeof|
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00001590 61 62 6c 65 2c 20 66 6f 72 20 74 68 65 20 65 6e |able, for the en|
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000015d0 20 28 69 6e 74 20 20 2a 29 6d 61 6c 6c 6f 63 28 | (int *)malloc(|
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000017a0 22 5f 74 61 62 6c 65 73 3a 20 73 74 61 72 74 69 |"_tables: starti|
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00001820 6e 20 61 6e 67 6c 65 20 74 6f 20 70 61 73 73 20 |n angle to pass |
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00001e20 74 6f 20 2b 33 30 20 64 65 67 72 65 65 73 2e 20 |to +30 degrees. |
00001e30 54 68 69 73 20 6d 65 61 6e 73 20 74 68 61 74 20 |This means that |
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00007a30 6c 6c 20 62 65 20 75 73 65 64 20 66 6f 72 20 64 |ll be used for d|
00007a40 6f 6f 72 20 74 68 69 6e 67 73 20 2a 2f 0a 20 20 |oor things */. |
00007a50 20 20 20 20 73 63 72 65 65 6e 5f 6c 69 6d 69 74 | screen_limit|
00007a60 3b 0a 0a 2f 2a 20 4e 65 77 20 4f 62 6a 65 63 74 |;../* New Object|
00007a70 20 43 6f 64 65 20 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a | Code **********|
00007a80 2a 2a 2a 2a 2a 2a 2a 20 41 64 64 65 64 20 41 72 |******* Added Ar|
00007a90 74 69 63 6c 65 20 35 20 2d 20 67 6f 6f 64 20 73 |ticle 5 - good s|
00007aa0 74 75 66 66 20 21 20 2a 2f 0a 69 6e 74 20 6f 62 |tuff ! */.int ob|
00007ab0 6a 65 63 74 5f 78 2c 6f 62 6a 65 63 74 5f 79 2c |ject_x,object_y,|
00007ac0 74 72 61 6e 73 5f 78 2c 74 72 61 6e 73 5f 7a 2c |trans_x,trans_z,|
00007ad0 73 63 72 65 65 6e 5f 78 2c 73 63 72 65 65 6e 5f |screen_x,screen_|
00007ae0 79 31 2c 73 63 72 65 65 6e 5f 79 32 2c 74 65 6d |y1,screen_y2,tem|
00007af0 70 5f 31 2c 63 6f 75 6e 74 65 72 2c 73 63 61 6c |p_1,counter,scal|
00007b00 65 2c 76 61 72 69 61 62 6c 65 73 5b 37 5d 2c 69 |e,variables[7],i|
00007b10 6e 64 65 78 2c 69 6e 63 72 65 6d 65 6e 74 2c 67 |ndex,increment,g|
00007b20 72 69 64 5f 78 2c 67 72 69 64 5f 79 2c 6f 62 6a |rid_x,grid_y,obj|
00007b30 65 63 74 5f 74 79 70 65 2c 73 74 61 72 74 5f 78 |ect_type,start_x|
00007b40 2c 73 74 61 72 74 5f 79 2c 73 74 6f 70 5f 78 2c |,start_y,stop_x,|
00007b50 73 74 6f 70 5f 79 2c 6d 6f 76 65 5f 78 2c 6d 6f |stop_y,move_x,mo|
00007b60 76 65 5f 79 2c 74 76 69 65 77 5f 78 2c 74 76 69 |ve_y,tview_x,tvi|
00007b70 65 77 5f 79 2c 74 76 69 65 77 5f 61 6e 67 6c 65 |ew_y,tview_angle|
00007b80 3b 0a 2f 2a 20 4e 65 77 20 4f 62 6a 65 63 74 20 |;./* New Object |
00007b90 43 6f 64 65 20 56 61 72 69 61 62 6c 65 73 20 4f |Code Variables O|
00007ba0 76 65 72 20 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a |ver ************|
00007bb0 2a 2a 2a 20 53 65 65 20 4c 61 74 65 72 20 69 6e |*** See Later in|
00007bc0 20 4d 61 69 6e 28 29 20 2a 2f 0a 2f 2a 20 4e 45 | Main() */./* NE|
00007bd0 57 20 6f 62 6a 65 63 74 20 4d 4f 56 49 4e 47 20 |W object MOVING |
00007be0 63 6f 64 65 20 61 6e 64 20 61 72 72 61 79 73 20 |code and arrays |
00007bf0 61 72 65 20 6e 6f 77 20 69 6e 20 74 68 69 73 20 |are now in this |
00007c00 66 75 6e 63 74 69 6f 6e 20 2a 2f 0a 0a 20 2f 2a |function */.. /*|
00007c10 20 70 61 74 74 65 72 6e 20 6f 66 20 6d 6f 76 65 | pattern of move|
00007c20 6d 65 6e 74 73 20 2a 2f 0a 66 6c 6f 61 74 20 6f |ments */.float o|
00007c30 62 6a 65 63 74 5f 6d 6f 76 65 5f 69 6e 63 72 65 |bject_move_incre|
00007c40 6d 65 6e 74 3d 30 2e 30 30 30 30 3b 20 20 20 20 |ment=0.0000; |
00007c50 20 20 20 20 20 20 20 20 20 20 20 2f 2a 20 61 6d | /* am|
00007c60 6f 75 6e 74 20 74 6f 20 61 64 64 20 74 6f 20 69 |ount to add to i|
00007c70 6e 64 65 78 20 65 61 63 68 20 66 72 61 6d 65 20 |ndex each frame |
00007c80 2a 2f 0a 66 6c 6f 61 74 20 6f 62 6a 65 63 74 5f |*/.float object_|
00007c90 6d 6f 76 65 5f 69 6e 64 65 78 3d 30 2e 30 30 30 |move_index=0.000|
00007ca0 30 3b 0a 69 6e 74 20 6f 62 6a 65 63 74 5f 74 65 |0;.int object_te|
00007cb0 6d 70 5f 6d 6f 76 65 5f 69 6e 64 65 78 3d 30 3b |mp_move_index=0;|
00007cc0 0a 69 6e 74 20 6f 62 6a 65 63 74 5f 6d 6f 76 65 |.int object_move|
00007cd0 5f 66 6f 75 6e 64 3d 30 3b 20 20 20 20 20 20 20 |_found=0; |
00007ce0 20 20 20 20 20 2f 2a 20 66 6c 61 67 20 74 6f 20 | /* flag to |
00007cf0 73 61 79 20 69 66 20 6d 6f 76 69 6e 67 20 6f 62 |say if moving ob|
00007d00 6a 65 63 74 20 66 6f 75 6e 64 20 2a 2f 0a 20 20 |ject found */. |
00007d10 20 2f 2a 20 76 61 6c 75 65 73 20 74 6f 20 68 6f | /* values to ho|
00007d20 6c 64 20 6d 6f 76 69 6e 67 20 6f 62 6a 65 63 74 |ld moving object|
00007d30 20 2a 2f 0a 69 6e 74 20 6f 62 6a 65 63 74 5f 6d | */.int object_m|
00007d40 6f 76 65 5f 6e 65 77 5f 78 2c 6f 62 6a 65 63 74 |ove_new_x,object|
00007d50 5f 6d 6f 76 65 5f 6e 65 77 5f 79 3b 20 2f 2a 20 |_move_new_y; /* |
00007d60 6e 65 77 20 76 61 6c 75 65 73 20 6f 66 20 6f 62 |new values of ob|
00007d70 6a 65 63 74 20 2a 2f 0a 0a 2f 2a 20 4e 45 57 20 |ject */../* NEW |
00007d80 64 65 6d 6f 20 66 69 6c 65 20 77 68 69 63 68 20 |demo file which |
00007d90 63 61 6e 20 6c 6f 61 64 2f 73 74 6f 72 65 20 64 |can load/store d|
00007da0 65 6d 6f 20 69 6e 66 6f 72 6d 61 74 69 6f 6e 20 |emo information |
00007db0 66 6f 72 20 61 20 77 61 6c 6b 74 68 72 6f 75 67 |for a walkthroug|
00007dc0 68 2a 2f 0a 0a 46 49 4c 45 20 2a 64 65 6d 6f 5f |h*/..FILE *demo_|
00007dd0 66 69 6c 65 3b 0a 0a 2f 2a 20 4e 45 57 20 73 79 |file;../* NEW sy|
00007de0 73 74 65 6d 20 6f 66 20 70 61 73 73 69 6e 67 2c |stem of passing,|
00007df0 20 77 65 20 75 73 65 20 74 68 65 20 73 74 61 6e | we use the stan|
00007e00 64 61 72 64 20 61 72 67 63 20 61 6e 64 20 61 72 |dard argc and ar|
00007e10 67 76 20 74 6f 20 73 75 70 70 6c 79 20 70 61 72 |gv to supply par|
00007e20 61 6d 65 74 65 72 73 20 74 6f 20 74 68 65 20 65 |ameters to the e|
00007e30 6e 67 69 6e 65 2e 20 46 49 52 53 54 20 77 65 20 |ngine. FIRST we |
00007e40 6d 75 73 74 20 65 78 74 72 61 63 74 20 74 68 65 |must extract the|
00007e50 6d 3a 2a 2f 0a 0a 2f 2a 20 63 68 65 63 6b 20 74 |m:*/../* check t|
00007e60 68 61 74 20 63 6f 72 72 65 63 74 20 6e 75 6d 62 |hat correct numb|
00007e70 65 72 20 6f 66 20 70 61 72 61 6d 65 74 65 72 73 |er of parameters|
00007e80 20 68 61 76 65 20 62 65 65 6e 20 70 61 73 73 65 | have been passe|
00007e90 64 20 2a 2f 0a 0a 69 66 28 61 72 67 63 21 3d 31 |d */..if(argc!=1|
00007ea0 35 29 0a 7b 0a 2f 2a 20 71 75 69 74 20 69 66 20 |5).{./* quit if |
00007eb0 6e 6f 74 20 2a 2f 0a 70 72 69 6e 74 66 28 22 45 |not */.printf("E|
00007ec0 72 72 6f 72 3a 20 49 6e 63 6f 72 72 65 63 74 20 |rror: Incorrect |
00007ed0 6e 75 6d 62 65 72 20 6f 66 20 70 61 72 61 6d 65 |number of parame|
00007ee0 74 65 72 73 20 70 61 73 73 65 64 2e 20 5f 45 78 |ters passed. _Ex|
00007ef0 69 74 69 6e 67 5c 6e 22 29 3b 20 65 78 69 74 28 |iting\n"); exit(|
00007f00 31 29 3b 0a 2f 2a 20 22 62 65 65 70 22 20 28 6f |1);./* "beep" (o|
00007f10 6e 20 6d 6f 73 74 20 6d 61 63 68 69 6e 65 73 29 |n most machines)|
00007f20 2a 2f 20 70 75 74 63 68 61 72 28 27 5c 61 27 29 |*/ putchar('\a')|
00007f30 3b 0a 7d 0a 2f 2a 20 75 73 65 20 61 74 6f 69 20 |;.}./* use atoi |
00007f40 74 6f 20 67 65 74 20 69 74 20 72 69 67 68 74 20 |to get it right |
00007f50 2a 2f 0a 2f 2a 20 49 4e 50 55 54 20 41 4c 4c 20 |*/./* INPUT ALL |
00007f60 56 41 4c 55 45 53 20 46 52 4f 4d 20 43 4f 4d 4d |VALUES FROM COMM|
00007f70 41 4e 44 20 4c 49 4e 45 20 75 73 69 6e 67 20 41 |AND LINE using A|
00007f80 54 4f 49 20 61 6e 64 20 74 68 65 6e 20 77 6f 72 |TOI and then wor|
00007f90 6b 20 6f 75 74 20 6e 65 65 64 65 64 2a 2f 0a 2f |k out needed*/./|
00007fa0 2a 20 61 6e 67 6c 65 20 76 61 6c 75 65 73 20 66 |* angle values f|
00007fb0 6f 72 20 74 68 65 20 72 61 79 20 63 61 73 74 69 |or the ray casti|
00007fc0 6e 67 20 65 6e 67 69 6e 65 2e 20 2a 2f 0a 76 69 |ng engine. */.vi|
00007fd0 65 77 5f 78 3d 61 74 6f 69 28 61 72 67 76 5b 31 |ew_x=atoi(argv[1|
00007fe0 5d 29 3b 0a 76 69 65 77 5f 79 3d 61 74 6f 69 28 |]);.view_y=atoi(|
00007ff0 61 72 67 76 5b 32 5d 29 3b 0a 76 69 65 77 5f 61 |argv[2]);.view_a|
00008000 6e 67 6c 65 3d 61 74 6f 69 28 61 72 67 76 5b 33 |ngle=atoi(argv[3|
00008010 5d 29 3b 0a 53 43 52 45 45 4e 5f 57 49 44 54 48 |]);.SCREEN_WIDTH|
00008020 3d 61 74 6f 69 28 61 72 67 76 5b 34 5d 29 3b 0a |=atoi(argv[4]);.|
00008030 53 43 52 45 45 4e 5f 48 45 49 47 48 54 3d 61 74 |SCREEN_HEIGHT=at|
00008040 6f 69 28 61 72 67 76 5b 35 5d 29 3b 0a 41 4e 47 |oi(argv[5]);.ANG|
00008050 4c 45 5f 33 36 30 3d 61 74 6f 69 28 61 72 67 76 |LE_360=atoi(argv|
00008060 5b 36 5d 29 3b 0a 41 4e 47 4c 45 5f 31 38 30 3d |[6]);.ANGLE_180=|
00008070 41 4e 47 4c 45 5f 33 36 30 2f 32 3b 41 4e 47 4c |ANGLE_360/2;ANGL|
00008080 45 5f 39 30 3d 41 4e 47 4c 45 5f 31 38 30 2f 32 |E_90=ANGLE_180/2|
00008090 3b 0a 41 4e 47 4c 45 5f 36 3d 61 74 6f 69 28 61 |;.ANGLE_6=atoi(a|
000080a0 72 67 76 5b 39 5d 29 3b 0a 41 4e 47 4c 45 5f 33 |rgv[9]);.ANGLE_3|
000080b0 30 3d 28 69 6e 74 29 41 4e 47 4c 45 5f 39 30 2f |0=(int)ANGLE_90/|
000080c0 33 3b 0a 41 4e 47 4c 45 5f 30 3d 30 3b 0a 41 4e |3;.ANGLE_0=0;.AN|
000080d0 47 4c 45 5f 32 37 30 3d 41 4e 47 4c 45 5f 39 30 |GLE_270=ANGLE_90|
000080e0 2a 33 3b 0a 56 45 52 54 49 43 41 4c 5f 53 43 41 |*3;.VERTICAL_SCA|
000080f0 4c 45 3d 61 74 6f 69 28 61 72 67 76 5b 37 5d 29 |LE=atoi(argv[7])|
00008100 3b 0a 53 54 45 50 5f 4c 45 4e 47 54 48 3d 61 74 |;.STEP_LENGTH=at|
00008110 6f 69 28 61 72 67 76 5b 38 5d 29 3b 0a 56 49 45 |oi(argv[8]);.VIE|
00008120 57 56 41 52 3d 61 74 6f 69 28 61 72 67 76 5b 31 |WVAR=atoi(argv[1|
00008130 30 5d 29 3b 0a 56 49 45 57 56 41 52 54 3d 61 74 |0]);.VIEWVART=at|
00008140 6f 69 28 61 72 67 76 5b 31 31 5d 29 3b 0a 44 45 |oi(argv[11]);.DE|
00008150 4d 4f 5f 52 45 41 44 3d 61 74 6f 69 28 61 72 67 |MO_READ=atoi(arg|
00008160 76 5b 31 32 5d 29 3b 0a 44 45 4d 4f 5f 57 52 49 |v[12]);.DEMO_WRI|
00008170 54 45 3d 61 74 6f 69 28 61 72 67 76 5b 31 33 5d |TE=atoi(argv[13]|
00008180 29 3b 0a 6f 62 6a 65 63 74 5f 6d 6f 76 65 5f 69 |);.object_move_i|
00008190 6e 63 72 65 6d 65 6e 74 3d 61 74 6f 69 28 61 72 |ncrement=atoi(ar|
000081a0 67 76 5b 31 34 5d 29 3b 0a 2f 2a 20 63 6f 6e 76 |gv[14]);./* conv|
000081b0 65 72 74 20 6f 62 6a 65 63 74 5f 69 6e 72 65 6d |ert object_inrem|
000081c0 65 6e 74 20 70 72 6f 70 65 72 6c 79 20 2a 2f 0a |ent properly */.|
000081d0 69 66 28 6f 62 6a 65 63 74 5f 6d 6f 76 65 5f 69 |if(object_move_i|
000081e0 6e 63 72 65 6d 65 6e 74 3d 3d 30 29 6f 62 6a 65 |ncrement==0)obje|
000081f0 63 74 5f 6d 6f 76 65 5f 69 6e 63 72 65 6d 65 6e |ct_move_incremen|
00008200 74 3d 31 3b 0a 6f 62 6a 65 63 74 5f 6d 6f 76 65 |t=1;.object_move|
00008210 5f 69 6e 63 72 65 6d 65 6e 74 3d 28 66 6c 6f 61 |_increment=(floa|
00008220 74 29 31 2f 6f 62 6a 65 63 74 5f 6d 6f 76 65 5f |t)1/object_move_|
00008230 69 6e 63 72 65 6d 65 6e 74 3b 0a 0a 73 63 72 65 |increment;..scre|
00008240 65 6e 5f 6c 69 6d 69 74 3d 28 33 32 30 2d 53 43 |en_limit=(320-SC|
00008250 52 45 45 4e 5f 57 49 44 54 48 29 3e 3e 32 3b 0a |REEN_WIDTH)>>2;.|
00008260 2f 2a 20 4e 6f 77 20 77 65 20 70 72 69 6e 74 20 |/* Now we print |
00008270 74 68 65 20 69 6e 66 6f 72 6d 61 74 69 6f 6e 20 |the information |
00008280 6a 75 73 74 20 66 6f 72 20 74 68 65 20 69 6e 66 |just for the inf|
00008290 6f 72 6d 61 74 69 6f 6e 20 6f 66 20 74 68 65 20 |ormation of the |
000082a0 75 73 65 72 20 2a 2f 0a 70 72 69 6e 74 66 28 22 |user */.printf("|
000082b0 5f 70 72 65 2d 73 74 61 72 74 3a 20 73 77 69 74 |_pre-start: swit|
000082c0 63 68 69 6e 67 20 74 6f 20 4d 6f 64 65 20 28 31 |ching to Mode (1|
000082d0 35 29 20 2d 20 68 69 67 68 20 72 65 73 20 66 6f |5) - high res fo|
000082e0 72 20 74 65 78 74 2e 5c 6e 22 29 3b 0a 6f 75 72 |r text.\n");.our|
000082f0 6c 69 62 5f 63 68 61 6e 67 65 6d 6f 64 65 28 31 |lib_changemode(1|
00008300 35 29 3b 0a 70 72 69 6e 74 66 28 22 23 23 23 23 |5);.printf("####|
00008310 23 23 23 23 23 23 23 23 23 23 20 53 59 53 54 45 |########## SYSTE|
00008320 4d 20 53 54 41 52 54 2d 55 50 20 23 23 23 23 23 |M START-UP #####|
00008330 23 23 23 23 23 23 23 23 23 23 23 23 23 23 5c 6e |##############\n|
00008340 22 29 3b 0a 70 72 69 6e 74 66 28 22 5f 73 79 73 |");.printf("_sys|
00008350 74 65 6d 20 76 61 72 69 61 62 6c 65 73 3a 20 76 |tem variables: v|
00008360 69 65 77 5f 78 3a 20 25 64 20 76 69 65 77 5f 79 |iew_x: %d view_y|
00008370 3a 20 25 64 20 76 69 65 77 5f 61 6e 67 6c 65 3a |: %d view_angle:|
00008380 20 25 64 5c 6e 73 63 72 65 65 6e 5f 77 69 64 74 | %d\nscreen_widt|
00008390 68 3a 20 25 64 20 73 63 72 65 65 6e 5f 68 65 69 |h: %d screen_hei|
000083a0 67 68 74 3a 20 25 64 5c 6e 61 6e 67 6c 65 5f 33 |ght: %d\nangle_3|
000083b0 36 30 3a 20 25 64 20 76 65 72 74 69 63 61 6c 5f |60: %d vertical_|
000083c0 73 63 61 6c 65 3a 20 25 64 20 73 74 65 70 5f 6c |scale: %d step_l|
000083d0 65 6e 67 74 68 3a 20 25 64 5c 6e 76 69 65 77 76 |ength: %d\nviewv|
000083e0 61 72 73 3a 20 25 64 20 25 64 5c 6e 64 65 6d 6f |ars: %d %d\ndemo|
000083f0 5f 72 65 61 64 3a 20 25 64 20 64 65 6d 6f 5f 77 |_read: %d demo_w|
00008400 72 69 74 65 3a 20 25 64 20 6f 62 6a 65 63 74 5f |rite: %d object_|
00008410 6d 6f 76 65 5f 69 6e 63 72 65 6d 65 6e 74 3a 20 |move_increment: |
00008420 25 66 5c 6e 5c 6e 22 2c 76 69 65 77 5f 78 2c 76 |%f\n\n",view_x,v|
00008430 69 65 77 5f 79 2c 76 69 65 77 5f 61 6e 67 6c 65 |iew_y,view_angle|
00008440 2c 53 43 52 45 45 4e 5f 57 49 44 54 48 2c 53 43 |,SCREEN_WIDTH,SC|
00008450 52 45 45 4e 5f 48 45 49 47 48 54 2c 41 4e 47 4c |REEN_HEIGHT,ANGL|
00008460 45 5f 33 36 30 2c 56 45 52 54 49 43 41 4c 5f 53 |E_360,VERTICAL_S|
00008470 43 41 4c 45 2c 53 54 45 50 5f 4c 45 4e 47 54 48 |CALE,STEP_LENGTH|
00008480 2c 56 49 45 57 56 41 52 2c 56 49 45 57 56 41 52 |,VIEWVAR,VIEWVAR|
00008490 54 2c 44 45 4d 4f 5f 52 45 41 44 2c 44 45 4d 4f |T,DEMO_READ,DEMO|
000084a0 5f 57 52 49 54 45 2c 6f 62 6a 65 63 74 5f 6d 6f |_WRITE,object_mo|
000084b0 76 65 5f 69 6e 63 72 65 6d 65 6e 74 29 3b 0a 0a |ve_increment);..|
000084c0 0a 69 66 28 44 45 4d 4f 5f 57 52 49 54 45 3d 3d |.if(DEMO_WRITE==|
000084d0 31 29 7b 0a 69 66 28 21 28 64 65 6d 6f 5f 66 69 |1){.if(!(demo_fi|
000084e0 6c 65 3d 66 6f 70 65 6e 28 22 3c 41 55 41 52 61 |le=fopen("<AUARa|
000084f0 79 24 44 69 72 3e 2e 64 65 6d 6f 22 2c 22 77 22 |y$Dir>.demo","w"|
00008500 29 29 29 65 78 69 74 28 31 29 3b 0a 70 72 69 6e |)))exit(1);.prin|
00008510 74 66 28 22 5f 66 69 6c 65 20 61 63 63 65 73 73 |tf("_file access|
00008520 3a 20 77 72 69 74 69 6e 67 20 74 6f 20 66 69 6c |: writing to fil|
00008530 65 5c 6e 22 29 3b 0a 7d 0a 65 6c 73 65 20 69 66 |e\n");.}.else if|
00008540 28 44 45 4d 4f 5f 52 45 41 44 3d 3d 31 29 0a 7b |(DEMO_READ==1).{|
00008550 0a 20 20 69 66 28 21 28 64 65 6d 6f 5f 66 69 6c |. if(!(demo_fil|
00008560 65 3d 66 6f 70 65 6e 28 22 3c 41 55 41 52 61 79 |e=fopen("<AUARay|
00008570 24 44 69 72 3e 2e 64 65 6d 6f 22 2c 22 72 22 29 |$Dir>.demo","r")|
00008580 29 29 65 78 69 74 28 31 29 3b 0a 20 20 70 72 69 |))exit(1);. pri|
00008590 6e 74 66 28 22 5f 66 69 6c 65 20 61 63 63 65 73 |ntf("_file acces|
000085a0 73 3a 20 72 65 61 64 69 6e 67 20 64 65 6d 6f 20 |s: reading demo |
000085b0 66 69 6c 65 5c 6e 5c 6e 22 29 3b 0a 7d 0a 0a 2f |file\n\n");.}../|
000085c0 2a 20 44 4f 4e 45 2e 20 4e 6f 77 20 63 6f 6e 74 |* DONE. Now cont|
000085d0 69 6e 75 65 20 61 73 20 6e 6f 72 6d 61 6c 20 77 |inue as normal w|
000085e0 69 74 68 20 74 68 65 20 70 72 6f 67 72 61 6d 20 |ith the program |
000085f0 2a 2f 0a 2f 2a 20 49 74 20 69 73 20 68 65 72 65 |*/./* It is here|
00008600 20 74 68 61 74 20 77 65 20 73 65 65 20 69 66 20 | that we see if |
00008610 74 68 65 20 44 45 4d 4f 46 4c 41 47 20 69 73 20 |the DEMOFLAG is |
00008620 73 65 74 20 74 6f 20 72 65 61 64 2f 77 72 69 74 |set to read/writ|
00008630 65 20 64 65 6d 6f 73 20 2a 2f 0a 0a 0a 0a 2f 2a |e demos */..../*|
00008640 20 6e 6f 77 20 77 65 20 63 61 6c 6c 20 61 75 61 | now we call aua|
00008650 5f 77 6f 72 6c 64 20 74 6f 20 6c 6f 61 64 20 69 |_world to load i|
00008660 6e 20 74 68 65 20 74 65 78 74 20 77 6f 72 6c 64 |n the text world|
00008670 20 66 69 6c 65 20 77 68 69 63 68 20 64 65 66 69 | file which defi|
00008680 6e 65 73 20 6f 75 72 20 77 61 6c 6c 73 20 74 79 |nes our walls ty|
00008690 70 65 20 61 6e 64 20 6c 61 79 6f 75 74 20 2a 2f |pe and layout */|
000086a0 0a 0a 70 72 69 6e 74 66 28 22 5c 6e 5f 66 69 6c |..printf("\n_fil|
000086b0 65 20 61 63 63 65 73 73 3a 20 6c 6f 61 64 69 6e |e access: loadin|
000086c0 67 20 69 6e 20 74 65 78 74 20 66 69 6c 65 20 3c |g in text file <|
000086d0 41 55 41 52 61 79 24 44 69 72 3e 2e 77 6f 72 6c |AUARay$Dir>.worl|
000086e0 64 5c 6e 5c 6e 22 29 3b 0a 61 75 61 5f 77 6f 72 |d\n\n");.aua_wor|
000086f0 6c 64 28 29 3b 0a 0a 2f 2a 20 63 68 65 63 6b 20 |ld();../* check |
00008700 74 6f 20 73 65 65 20 69 66 20 74 68 65 20 76 69 |to see if the vi|
00008710 65 77 65 72 20 69 73 20 69 6e 73 69 64 65 20 61 |ewer is inside a|
00008720 20 67 61 6d 65 20 63 65 6c 6c 20 57 41 4c 4c 2c | game cell WALL,|
00008730 20 77 68 69 63 68 20 77 6f 75 6c 64 20 62 65 20 | which would be |
00008740 62 61 64 20 6e 65 77 73 21 20 2a 2f 0a 0a 69 66 |bad news! */..if|
00008750 28 77 6f 72 6c 64 5b 76 69 65 77 5f 79 3e 3e 36 |(world[view_y>>6|
00008760 5d 5b 76 69 65 77 5f 78 3e 3e 36 5d 29 0a 7b 0a |][view_x>>6]).{.|
00008770 20 20 70 72 69 6e 74 66 28 22 5c 6e 5f 65 72 72 | printf("\n_err|
00008780 6f 72 3a 20 42 61 64 20 63 6f 6f 72 64 69 6e 61 |or: Bad coordina|
00008790 74 65 73 20 67 69 76 65 6e 2c 20 76 69 65 77 65 |tes given, viewe|
000087a0 72 20 69 73 20 49 4e 20 61 20 57 41 4c 4c 21 2c |r is IN a WALL!,|
000087b0 20 65 78 69 74 69 6e 67 5c 6e 22 29 3b 0a 20 20 | exiting\n");. |
000087c0 65 78 69 74 28 31 29 3b 0a 7d 0a 0a 2f 2a 20 6e |exit(1);.}../* n|
000087d0 6f 77 20 77 65 20 63 61 6c 6c 20 61 75 61 5f 74 |ow we call aua_t|
000087e0 61 62 6c 65 73 20 74 6f 20 67 65 6e 65 72 61 74 |ables to generat|
000087f0 65 20 73 6f 6d 65 20 6c 6f 6f 6b 2d 75 70 20 74 |e some look-up t|
00008800 61 62 6c 65 73 20 66 6f 72 20 74 68 65 20 65 6e |ables for the en|
00008810 67 69 6e 65 20 74 6f 20 75 73 65 2c 20 6c 6f 6f |gine to use, loo|
00008820 6b 2d 75 70 73 20 61 72 65 20 65 78 70 6c 61 69 |k-ups are explai|
00008830 6e 65 64 20 75 70 20 61 74 20 74 68 65 20 74 6f |ned up at the to|
00008840 70 20 6f 66 20 74 68 65 20 66 69 6c 65 20 6e 65 |p of the file ne|
00008850 78 74 20 74 6f 20 74 68 65 20 67 6c 6f 62 61 6c |xt to the global|
00008860 20 76 61 72 69 61 62 6c 65 73 20 2a 2f 0a 0a 70 | variables */..p|
00008870 72 69 6e 74 66 28 22 5f 6d 61 69 6e 3a 20 63 61 |rintf("_main: ca|
00008880 6c 6c 20 61 75 61 5f 74 61 62 6c 65 73 28 29 20 |ll aua_tables() |
00008890 28 6c 6f 6e 67 20 74 69 6d 65 20 6f 6e 20 73 6c |(long time on sl|
000088a0 6f 77 65 72 20 6d 61 63 68 69 6e 65 73 29 5c 6e |ower machines)\n|
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00009800 39 3b 0a 20 20 69 66 28 76 69 65 77 5f 61 6e 67 |9;. if(view_ang|
00009810 6c 65 3e 3d 41 4e 47 4c 45 5f 39 30 20 26 26 20 |le>=ANGLE_90 && |
00009820 76 69 65 77 5f 61 6e 67 6c 65 3c 41 4e 47 4c 45 |view_angle<ANGLE|
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00009840 3d 31 37 3b 0a 20 20 69 66 28 76 69 65 77 5f 61 |=17;. if(view_a|
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00009860 26 26 20 76 69 65 77 5f 61 6e 67 6c 65 3c 41 4e |&& view_angle<AN|
00009870 47 4c 45 5f 32 37 30 29 74 76 69 65 77 5f 61 6e |GLE_270)tview_an|
00009880 67 6c 65 3d 31 35 3b 0a 20 20 69 66 28 76 69 65 |gle=15;. if(vie|
00009890 77 5f 61 6e 67 6c 65 3e 3d 41 4e 47 4c 45 5f 32 |w_angle>=ANGLE_2|
000098a0 37 30 20 26 26 20 76 69 65 77 5f 61 6e 67 6c 65 |70 && view_angle|
000098b0 3c 41 4e 47 4c 45 5f 33 36 30 29 74 76 69 65 77 |<ANGLE_360)tview|
000098c0 5f 61 6e 67 6c 65 3d 31 30 3b 2a 2f 0a 0a 20 20 |_angle=10;*/.. |
000098d0 66 70 72 69 6e 74 66 28 64 65 6d 6f 5f 66 69 6c |fprintf(demo_fil|
000098e0 65 2c 22 25 64 20 25 64 20 25 64 20 22 2c 74 76 |e,"%d %d %d ",tv|
000098f0 69 65 77 5f 78 2c 74 76 69 65 77 5f 79 2c 74 76 |iew_x,tview_y,tv|
00009900 69 65 77 5f 61 6e 67 6c 65 29 3b 0a 0a 7d 0a 69 |iew_angle);..}.i|
00009910 66 28 44 45 4d 4f 5f 52 45 41 44 29 69 66 28 28 |f(DEMO_READ)if((|
00009920 66 73 63 61 6e 66 28 64 65 6d 6f 5f 66 69 6c 65 |fscanf(demo_file|
00009930 2c 22 25 64 20 25 64 20 25 64 20 22 2c 26 74 76 |,"%d %d %d ",&tv|
00009940 69 65 77 5f 78 2c 26 74 76 69 65 77 5f 79 2c 26 |iew_x,&tview_y,&|
00009950 74 76 69 65 77 5f 61 6e 67 6c 65 29 29 3d 3d 45 |tview_angle))==E|
00009960 4f 46 29 72 65 77 69 6e 64 28 64 65 6d 6f 5f 66 |OF)rewind(demo_f|
00009970 69 6c 65 29 3b 0a 76 69 65 77 5f 78 3d 74 76 69 |ile);.view_x=tvi|
00009980 65 77 5f 78 3b 0a 76 69 65 77 5f 79 3d 74 76 69 |ew_x;.view_y=tvi|
00009990 65 77 5f 79 3b 0a 76 69 65 77 5f 61 6e 67 6c 65 |ew_y;.view_angle|
000099a0 3d 74 76 69 65 77 5f 61 6e 67 6c 65 3b 0a 7d 0a |=tview_angle;.}.|
000099b0 2f 2a 20 4e 45 57 20 4f 50 54 49 4d 49 5a 45 44 |/* NEW OPTIMIZED|
000099c0 20 56 45 52 53 49 4f 4e 53 20 4f 46 20 4d 4f 56 | VERSIONS OF MOV|
000099d0 49 4e 47 20 54 48 45 20 50 4c 41 59 45 52 20 2a |ING THE PLAYER *|
000099e0 2f 0a 0a 20 78 5f 63 65 6c 6c 20 3d 20 76 69 65 |/.. x_cell = vie|
000099f0 77 5f 78 3e 3e 36 3b 0a 20 79 5f 63 65 6c 6c 20 |w_x>>6;. y_cell |
00009a00 3d 20 76 69 65 77 5f 79 3e 3e 36 3b 0a 0a 20 78 |= view_y>>6;.. x|
00009a10 5f 73 75 62 5f 63 65 6c 6c 20 3d 20 76 69 65 77 |_sub_cell = view|
00009a20 5f 78 20 26 20 30 78 30 30 33 66 3b 0a 20 79 5f |_x & 0x003f;. y_|
00009a30 73 75 62 5f 63 65 6c 6c 20 3d 20 76 69 65 77 5f |sub_cell = view_|
00009a40 79 20 26 20 30 78 30 30 33 66 3b 0a 0a 2f 2a 20 |y & 0x003f;../* |
00009a50 43 48 45 43 4b 20 74 6f 20 73 65 65 20 69 66 20 |CHECK to see if |
00009a60 70 6c 61 79 65 72 20 68 61 73 20 77 61 6c 6b 65 |player has walke|
00009a70 64 20 69 6e 74 6f 20 77 61 6c 6c 73 20 2a 2f 0a |d into walls */.|
00009a80 20 69 66 20 28 28 64 78 3e 3e 38 29 3e 30 20 29 | if ((dx>>8)>0 )|
00009a90 7b 0a 20 69 66 20 28 28 77 6f 72 6c 64 5b 79 5f |{. if ((world[y_|
00009aa0 63 65 6c 6c 5d 5b 78 5f 63 65 6c 6c 2b 31 5d 20 |cell][x_cell+1] |
00009ab0 21 3d 20 30 29 20 20 26 26 20 28 78 5f 73 75 62 |!= 0) && (x_sub|
00009ac0 5f 63 65 6c 6c 3e 28 43 45 4c 4c 5f 58 5f 53 49 |_cell>(CELL_X_SI|
00009ad0 5a 45 2d 43 4c 4f 53 45 53 54 29 29 29 0a 20 20 |ZE-CLOSEST))). |
00009ae0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 7b 0a | {.|
00009af0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
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00009b20 45 2d 43 4c 4f 53 45 53 54 20 29 29 3b 0a 20 20 |E-CLOSEST ));. |
00009b30 20 20 20 20 20 20 20 20 20 20 20 20 20 20 7d 0a | }.|
00009b40 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009b50 7d 0a 20 65 6c 73 65 0a 20 7b 0a 20 69 66 20 28 |}. else. {. if (|
00009b60 20 28 77 6f 72 6c 64 5b 79 5f 63 65 6c 6c 5d 5b | (world[y_cell][|
00009b70 78 5f 63 65 6c 6c 2d 31 5d 20 21 3d 20 30 29 20 |x_cell-1] != 0) |
00009b80 20 26 26 20 28 78 5f 73 75 62 5f 63 65 6c 6c 20 | && (x_sub_cell |
00009b90 3c 20 28 43 4c 4f 53 45 53 54 29 20 29 20 29 0a |< (CLOSEST) ) ).|
00009ba0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009bb0 7b 0a 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |{. |
00009bc0 20 20 76 69 65 77 5f 78 2b 3d 20 28 43 4c 4f 53 | view_x+= (CLOS|
00009bd0 45 53 54 2d 78 5f 73 75 62 5f 63 65 6c 6c 29 20 |EST-x_sub_cell) |
00009be0 3b 0a 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |;. |
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00009c30 20 20 26 26 0a 20 20 20 20 20 20 20 20 20 20 20 | &&. |
00009c40 20 20 20 20 20 28 79 5f 73 75 62 5f 63 65 6c 6c | (y_sub_cell|
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00009c70 20 20 20 20 20 20 20 20 20 20 20 20 20 20 7b 0a | {.|
00009c80 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
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00009cb0 45 2d 43 4c 4f 53 45 53 54 20 29 29 3b 0a 20 20 |E-CLOSEST ));. |
00009cc0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 7d 0a | }.|
00009cd0 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
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00009d30 29 0a 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |). |
00009d40 20 20 7b 0a 20 20 20 20 20 20 20 20 20 20 20 20 | {. |
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00009d80 20 20 20 7d 0a 20 7d 0a 0a 0a 0a 2f 2a 20 4e 45 | }. }..../* NE|
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00009e30 20 73 69 6d 69 6c 61 72 20 74 65 63 68 6e 69 71 | similar techniq|
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00009f20 20 4f 50 54 49 4d 49 5a 45 44 20 56 45 52 53 49 | OPTIMIZED VERSI|
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00009fc0 0a 0a 2f 2a 20 43 68 65 63 6b 20 69 66 20 61 20 |../* Check if a |
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0000a060 7d 0a 7d 0a 0a 0a 2f 2a 20 4e 45 57 20 53 49 4d |}.}.../* NEW SIM|
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0000a090 20 6d 61 6e 79 20 66 75 72 74 68 65 72 20 74 65 | many further te|
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0000a0b0 2a 2f 0a 2f 2a 20 4c 69 6b 65 20 6d 61 6e 79 20 |*/./* Like many |
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0000a2f0 3e 31 36 3b 0a 20 64 6f 6f 72 5f 79 3d 20 28 69 |>16;. door_y= (i|
0000a300 6e 74 29 28 28 76 69 65 77 5f 79 3c 3c 31 36 29 |nt)((view_y<<16)|
0000a310 2b 28 64 79 3c 3c 32 29 29 3e 3e 31 36 3b 0a 0a |+(dy<<2))>>16;..|
0000a320 20 78 5f 63 65 6c 6c 20 3d 20 28 69 6e 74 29 64 | x_cell = (int)d|
0000a330 6f 6f 72 5f 78 3e 3e 36 3b 0a 20 79 5f 63 65 6c |oor_x>>6;. y_cel|
0000a340 6c 20 3d 20 28 69 6e 74 29 64 6f 6f 72 5f 79 3e |l = (int)door_y>|
0000a350 3e 36 3b 0a 2f 2a 20 43 68 65 63 6b 20 69 66 20 |>6;./* Check if |
0000a360 61 20 6f 62 6a 65 63 74 20 69 73 20 70 72 65 73 |a object is pres|
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0000a3d0 61 6c 74 65 72 6e 61 74 69 76 65 6c 79 20 64 6f |alternatively do|
0000a3e0 20 77 68 61 74 20 79 6f 75 20 6c 69 6b 65 20 2a | what you like *|
0000a3f0 2f 0a 7d 0a 65 6c 73 65 0a 7b 0a 0a 2f 2a 20 43 |/.}.else.{../* C|
0000a400 61 6c 63 75 6c 61 74 65 20 62 75 6c 6c 65 74 73 |alculate bullets|
0000a410 20 78 20 61 6e 64 20 79 2c 20 69 74 20 69 73 20 | x and y, it is |
0000a420 69 6e 20 6e 6f 72 6d 61 6c 20 6d 61 74 68 73 20 |in normal maths |
0000a430 2a 2f 0a 20 64 6f 6f 72 5f 78 3d 20 28 69 6e 74 |*/. door_x= (int|
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0000a460 6f 72 5f 79 3d 20 28 69 6e 74 29 28 28 76 69 65 |or_y= (int)((vie|
0000a470 77 5f 79 3c 3c 31 36 29 2b 28 64 79 3c 3c 33 29 |w_y<<16)+(dy<<3)|
0000a480 29 3e 3e 31 36 3b 0a 0a 20 78 5f 63 65 6c 6c 20 |)>>16;.. x_cell |
0000a490 3d 20 28 69 6e 74 29 64 6f 6f 72 5f 78 3e 3e 36 |= (int)door_x>>6|
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0000a500 41 54 45 56 45 52 20 59 4f 55 20 4c 49 4b 45 20 |ATEVER YOU LIKE |
0000a510 2a 2f 29 0a 7b 0a 6f 62 6a 65 63 74 73 5b 79 5f |*/).{.objects[y_|
0000a520 63 65 6c 6c 5d 5b 78 5f 63 65 6c 6c 5d 3d 30 3b |cell][x_cell]=0;|
0000a530 20 2f 2a 20 6f 72 20 61 6c 74 65 72 6e 61 74 69 | /* or alternati|
0000a540 76 65 6c 79 20 64 6f 20 77 68 61 74 20 79 6f 75 |vely do what you|
0000a550 20 6c 69 6b 65 20 2a 2f 0a 7d 0a 0a 7d 0a 0a 7d | like */.}..}..}|
0000a560 0a 0a 0a 0a 0a 0a 7d 0a 0a 0a 0a 2f 2a 20 4e 65 |......}..../* Ne|
0000a570 77 20 4f 62 6a 65 63 74 20 43 6f 64 65 20 2a 2a |w Object Code **|
0000a580 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a 2a |****************|
0000a590 20 41 64 64 65 64 20 41 72 74 69 63 6c 65 20 35 | Added Article 5|
0000a5a0 2c 20 67 6f 6f 64 20 73 74 75 66 66 21 20 20 20 |, good stuff! |
0000a5b0 2a 2f 0a 2f 2a 20 54 68 69 73 20 63 6f 64 65 20 |*/./* This code |
0000a5c0 63 79 63 6c 65 73 20 74 68 72 6f 75 67 68 20 74 |cycles through t|
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0000c010 0a 0a |..|
0000c012 
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