foo

[gbajam22] / src / voxscape.c

diff --git a/src/voxscape.c b/src/voxscape.c
index e2e8f4d..6eb5531 100644 (file)
--- a/src/voxscape.c
+++ b/src/voxscape.c
@@ -60,6 +60,7 @@ struct voxscape {
 };
 
 int vox_quality = 1;
+int *projlut;
 
 struct voxscape *vox_create(int xsz, int ysz, uint8_t *himg, uint8_t *cimg)
 {
@@ -191,7 +192,6 @@ void vox_framebuf(struct voxscape *vox, int xres, int yres, void *fb, int horizo
        if(xres != vox->fbwidth) {
                if(!(vox->coltop = iwram_sbrk(xres * sizeof *vox->coltop))) {
                        panic(get_pc(), "vox_framebuf: failed to allocate column table (%d)\n", xres);
-                       return;
                }
        }
        vox->fb = fb;
@@ -224,7 +224,9 @@ void vox_proj(struct voxscape *vox, int fov, int znear, int zfar)
        if(!vox->slicelen) {
                if(!(vox->slicelen = iwram_sbrk(vox->nslices * sizeof *vox->slicelen))) {
                        panic(get_pc(), "vox_proj: failed to allocate slice length table (%d)\n", vox->nslices);
-                       return;
+               }
+               if(!(projlut = iwram_sbrk(vox->nslices * sizeof *projlut))) {
+                       panic(get_pc(), "vox_framebuf: failed to allocate projection table (%d)\n", vox->nslices);
                }
        }
 
@@ -268,6 +270,7 @@ void vox_begin(struct voxscape *vox)
                float theta = (float)vox->fov * M_PI / 360.0f;  /* half angle */
                for(i=0; i<vox->nslices; i++) {
                        vox->slicelen[i] = (int32_t)((vox->znear + i) * tan(theta) * 4.0f * 65536.0f);
+                       projlut[i] = (HSCALE << 8) / (vox->znear + i);
                }
                vox->valid |= SLICELEN;
        }
@@ -280,6 +283,7 @@ void vox_render_slice(struct voxscape *vox, int n)
        int32_t x, y, len, xstep, ystep;
        uint8_t color, last_col;
        uint16_t *fbptr;
+       int proj;
 
        z = vox->znear + n;
 
@@ -290,6 +294,8 @@ void vox_render_slice(struct voxscape *vox, int n)
        x = vox->x - SIN(vox->angle) * z - xstep * (FBWIDTH / 4);
        y = vox->y + COS(vox->angle) * z - ystep * (FBWIDTH / 4);
 
+       /*proj = (HSCALE << 8) / (vox->znear + n);*/
+
        for(i=0; i<FBWIDTH/2; i++) {
                col = i << 1;
                offs = (((y >> 16) & YMASK) << XSHIFT) + ((x >> 16) & XMASK);
@@ -298,7 +304,7 @@ void vox_render_slice(struct voxscape *vox, int n)
                        color = last_col;
                } else {
                        hval = vox->height[offs] - vox->vheight;
-                       hval = hval * HSCALE / (vox->znear + n) + vox->horizon;
+                       hval = ((hval * projlut[n]) >> 8) + vox->horizon;
                        if(hval > FBHEIGHT) hval = FBHEIGHT;
                        color = vox->color[offs];
                        last_offs = offs;