git.mutantstargoat.com Git - dosdemo/blob - src/scr/raytrace.c

   1 #include <stdio.h>
   2 #include <math.h>
   3 #include "demo.h"
   4 #include "screen.h"
   5 #include "gfxutil.h"
   6 #include "util.h"
   7 #include "cgmath/cgmath.h"
   8 #include "rt.h"
   9
  10 static int init(void);
  11 static void destroy(void);
  12 static void start(long trans_time);
  13 static void draw(void);
  14
  15 static struct screen scr = {
  16         "raytrace",
  17         init,
  18         destroy,
  19         start,
  20         0,
  21         draw
  22 };
  23
  24 static cgm_vec3 raydir[120][160];
  25 static struct rtscene scn;
  26
  27 struct screen *raytrace_screen(void)
  28 {
  29         return &scr;
  30 }
  31
  32 static int init(void)
  33 {
  34         int i, j;
  35         float z = 1.0f / tan(cgm_deg_to_rad(25.0f));
  36
  37         for(i=0; i<120; i++) {
  38                 cgm_vec3 *vptr = raydir[i];
  39                 float y = 1.0f - (float)i / 60.0f;
  40                 for(j=0; j<160; j++) {
  41                         vptr->x = ((float)j / 80.0f - 1.0f) * 1.333333f;
  42                         vptr->y = y;
  43                         vptr->z = z;
  44                         vptr++;
  45                 }
  46         }
  47
  48         rt_init(&scn);
  49
  50         rt_color(1, 0, 0);
  51         rt_specular(0.8f, 0.8f, 0.8f);
  52         rt_shininess(30.0f);
  53         rt_add_sphere(&scn, 0, 0, 0, 1);        /* x,y,z, rad */
  54
  55         rt_color(0.4, 0.4, 0.4);
  56         rt_specular(0, 0, 0);
  57         rt_shininess(1);
  58         rt_add_plane(&scn, 0, 1, 0, -1);                /* nx,ny,nz, dist */
  59
  60         rt_color(1, 1, 1);
  61         rt_add_light(&scn, -8, 15, -10);
  62         return 0;
  63 }
  64
  65 static void destroy(void)
  66 {
  67         rt_destroy(&scn);
  68 }
  69
  70 static void start(long start_time)
  71 {
  72 }
  73
  74 static void draw(void)
  75 {
  76         int i, j, r, g, b;
  77         uint16_t pix, *fbptr = fb_pixels;
  78
  79         for(i=0; i<120; i++) {
  80                 for(j=0; j<160; j++) {
  81                         cgm_ray ray;
  82                         cgm_vec3 col;
  83                         ray.dir = raydir[i][j];
  84                         cgm_vcons(&ray.origin, 0, 0, -5);
  85
  86                         if(ray_trace(&ray, &scn, 0, &col)) {
  87                                 r = cround64(col.x * 255.0f);
  88                                 g = cround64(col.y * 255.0f);
  89                                 b = cround64(col.z * 255.0f);
  90                                 if(r > 255) r = 255;
  91                                 if(g > 255) g = 255;
  92                                 if(b > 255) b = 255;
  93                                 pix = PACK_RGB16(r, g, b);
  94                         } else {
  95                                 pix = 0;
  96                         }
  97                         fbptr[0] = fbptr[1] = fbptr[320] = fbptr[321] = pix;
  98                         fbptr += 2;
  99                 }
 100                 fbptr += 320;
 101         }
 102
 103         swap_buffers(0);
 104 }