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 enum {LASTX = 1, LASTY = 2};
  25
  26 struct tile {
  27         int sz;
  28         unsigned int flags;
  29         struct { int x, y; } cpos[4];   /* corner coordinates */
  30         uint16_t *cptr[4];      /* corner pixels */
  31 };
  32
  33 #define TILESZ          8
  34 #define NUM_TILES       ((320 / TILESZ) * (240 / TILESZ))
  35
  36 static cgm_vec3 raydir[240][320];
  37 static struct tile tiles[NUM_TILES];
  38 static struct rtscene scn;
  39
  40 struct screen *raytrace_screen(void)
  41 {
  42         return &scr;
  43 }
  44
  45 static int init(void)
  46 {
  47         int i, j, k;
  48         float z = 1.0f / tan(cgm_deg_to_rad(25.0f));
  49         struct tile *tptr = tiles;
  50
  51         for(i=0; i<240; i++) {
  52                 cgm_vec3 *vptr = raydir[i];
  53                 float y = 1.0f - (float)i / 120.0f;
  54                 for(j=0; j<320; j++) {
  55                         vptr->x = ((float)j / 160.0f - 1.0f) * 1.333333f;
  56                         vptr->y = y;
  57                         vptr->z = z;
  58                         vptr++;
  59
  60                         if(((j & (TILESZ-1)) | (i & (TILESZ-1))) == 0) {
  61                                 tptr->sz = TILESZ;
  62                                 tptr->flags = 0;
  63                                 if(j + TILESZ >= 320) tptr->flags |= LASTX;
  64                                 if(i + TILESZ >= 240) tptr->flags |= LASTY;
  65
  66                                 tptr->cpos[0].x = j;
  67                                 tptr->cpos[0].y = i;
  68                                 tptr->cpos[1].x = j + (tptr->flags & LASTX ? TILESZ - 1 : TILESZ);
  69                                 tptr->cpos[1].y = i;
  70                                 tptr->cpos[2].x = j;
  71                                 tptr->cpos[2].y = i + (tptr->flags & LASTY ? TILESZ - 1 : TILESZ);
  72                                 tptr->cpos[3].x = tptr->cpos[1].x;
  73                                 tptr->cpos[3].y = tptr->cpos[2].y;
  74
  75                                 for(k=0; k<4; k++) {
  76                                         tptr->cptr[k] = fb_pixels + tptr->cpos[k].y * 320 + tptr->cpos[k].x;
  77                                 }
  78                                 tptr++;
  79                         }
  80                 }
  81         }
  82
  83         rt_init(&scn);
  84
  85         rt_color(1, 0, 0);
  86         rt_specular(0.8f, 0.8f, 0.8f);
  87         rt_shininess(30.0f);
  88         rt_add_sphere(&scn, 0, 0, 0, 1);        /* x,y,z, rad */
  89
  90         rt_color(0.4, 0.4, 0.4);
  91         rt_specular(0, 0, 0);
  92         rt_shininess(1);
  93         rt_add_plane(&scn, 0, 1, 0, -1);                /* nx,ny,nz, dist */
  94
  95         rt_color(1, 1, 1);
  96         rt_add_light(&scn, -8, 15, -10);
  97         return 0;
  98 }
  99
 100 static void destroy(void)
 101 {
 102         rt_destroy(&scn);
 103 }
 104
 105 static void start(long start_time)
 106 {
 107 }
 108
 109 static uint16_t INLINE rend_pixel(int x, int y)
 110 {
 111         int r, g, b;
 112         cgm_ray ray;
 113         cgm_vec3 col;
 114
 115         ray.dir = raydir[y][x];
 116         cgm_vcons(&ray.origin, 0, 0, -5);
 117
 118         if(ray_trace(&ray, &scn, 0, &col)) {
 119                 r = cround64(col.x * 255.0f);
 120                 g = cround64(col.y * 255.0f);
 121                 b = cround64(col.z * 255.0f);
 122                 if(r > 255) r = 255;
 123                 if(g > 255) g = 255;
 124                 if(b > 255) b = 255;
 125                 return PACK_RGB16(r, g, b);
 126         }
 127         return 0;
 128 }
 129
 130 #define FBPTR(x, y)     (fb_pixels + ((y) << 8) + ((y) << 6) + (x))
 131
 132 static void draw(void)
 133 {
 134         int i, j, xbound, ybound;
 135         uint16_t *fbptr;
 136         struct tile *tptr;
 137
 138         tptr = tiles;
 139         for(i=0; i<NUM_TILES; i++) {
 140                 *tptr->cptr[0] = rend_pixel(tptr->cpos[0].x, tptr->cpos[0].y);
 141                 if(tptr->flags & LASTX) {
 142                         *tptr->cptr[1] = rend_pixel(tptr->cpos[1].x, tptr->cpos[1].y);
 143                         if(tptr->flags & LASTY) {
 144                                 *tptr->cptr[3] = rend_pixel(tptr->cpos[3].x, tptr->cpos[3].y);
 145                         }
 146                 }
 147                 if(tptr->flags & LASTY) {
 148                         *tptr->cptr[2] = rend_pixel(tptr->cpos[2].x, tptr->cpos[2].y);
 149                 }
 150                 tptr++;
 151         }
 152
 153         swap_buffers(0);
 154 }