initial raytracing experiment

[dosdemo] / src / scr / raytrace.c

diff --git a/src/scr/raytrace.c b/src/scr/raytrace.c
new file mode 100644 (file)
index 0000000..3d8465f
--- /dev/null
+++ b/src/scr/raytrace.c
@@ -0,0 +1,104 @@
+#include <stdio.h>
+#include <math.h>
+#include "demo.h"
+#include "screen.h"
+#include "gfxutil.h"
+#include "util.h"
+#include "cgmath/cgmath.h"
+#include "rt.h"
+
+static int init(void);
+static void destroy(void);
+static void start(long trans_time);
+static void draw(void);
+
+static struct screen scr = {
+       "raytrace",
+       init,
+       destroy,
+       start,
+       0,
+       draw
+};
+
+static cgm_vec3 raydir[120][160];
+static struct rtscene scn;
+
+struct screen *raytrace_screen(void)
+{
+       return &scr;
+}
+
+static int init(void)
+{
+       int i, j;
+       float z = 1.0f / tan(cgm_deg_to_rad(25.0f));
+
+       for(i=0; i<120; i++) {
+               cgm_vec3 *vptr = raydir[i];
+               float y = 1.0f - (float)i / 60.0f;
+               for(j=0; j<160; j++) {
+                       vptr->x = ((float)j / 80.0f - 1.0f) * 1.333333f;
+                       vptr->y = y;
+                       vptr->z = z;
+                       vptr++;
+               }
+       }
+
+       rt_init(&scn);
+
+       rt_color(1, 0, 0);
+       rt_specular(0.8f, 0.8f, 0.8f);
+       rt_shininess(30.0f);
+       rt_add_sphere(&scn, 0, 0, 0, 1);        /* x,y,z, rad */
+
+       rt_color(0.4, 0.4, 0.4);
+       rt_specular(0, 0, 0);
+       rt_shininess(1);
+       rt_add_plane(&scn, 0, 1, 0, -1);                /* nx,ny,nz, dist */
+
+       rt_color(1, 1, 1);
+       rt_add_light(&scn, -8, 15, -10);
+       return 0;
+}
+
+static void destroy(void)
+{
+       rt_destroy(&scn);
+}
+
+static void start(long start_time)
+{
+}
+
+static void draw(void)
+{
+       int i, j, r, g, b;
+       uint16_t pix, *fbptr = fb_pixels;
+
+       for(i=0; i<120; i++) {
+               for(j=0; j<160; j++) {
+                       cgm_ray ray;
+                       cgm_vec3 col;
+                       ray.dir = raydir[i][j];
+                       cgm_vcons(&ray.origin, 0, 0, -5);
+
+                       if(ray_trace(&ray, &scn, 0, &col)) {
+                               r = cround64(col.x * 255.0f) & 0xff;
+                               g = cround64(col.y * 255.0f) & 0xff;
+                               b = cround64(col.z * 255.0f) & 0xff;
+                               if(r > 255) r = 255;
+                               if(g > 255) g = 255;
+                               if(b > 255) b = 255;
+                               pix = PACK_RGB16(r, g, b);
+                       } else {
+                               pix = 0;
+                       }
+                       fbptr[0] = fbptr[1] = fbptr[320] = fbptr[321] = pix;
+                       fbptr += 2;
+               }
+               fbptr += 320;
+       }
+
+       swap_buffers(0);
+}