- xstep = ((COS(vox->angle) >> 8) * len) / vox->fbwidth;
- ystep = ((SIN(vox->angle) >> 8) * len) / vox->fbwidth;
-
- x = vox->x - SIN(vox->angle) * z - xstep * (vox->fbwidth >> 1);
- y = vox->y + COS(vox->angle) * z - ystep * (vox->fbwidth >> 1);
- /* TODO double column */
- for(i=0; i<vox->fbwidth/2; i++) {
- hval = vox_height(vox, x, y) - vox->vheight;
- hval = hval * 160 / (vox->znear + n) + vox->horizon;
- if(hval > vox->fbheight) hval = vox->fbheight;
- if(hval > vox->coltop[i]) {
- color = vox_color(vox, x, y);
- colstart = vox->fbheight - hval;
- colheight = hval - vox->coltop[i];
- fbptr = vox->fb + colstart * vox->fbwidth + i;
+ xstep = (((COS(vox->angle) >> 4) * len) >> 4) / (FBWIDTH / 2);
+ ystep = (((SIN(vox->angle) >> 4) * len) >> 4) / (FBWIDTH / 2);
+
+ x = vox->x - SIN(vox->angle) * z - xstep * (FBWIDTH / 4);
+ y = vox->y + COS(vox->angle) * z - ystep * (FBWIDTH / 4);
+
+ for(i=0; i<FBWIDTH/2; i++) {
+ col = i << 1;
+ offs = (((y >> 16) & YMASK) << XSHIFT) + ((x >> 16) & XMASK);
+ if(offs == last_offs) {
+ hval = last_hval;
+ color = last_col;
+ } else {
+ hval = vox->height[offs] - vox->vheight;
+ hval = hval * HSCALE / (vox->znear + n) + vox->horizon;
+ if(hval > FBHEIGHT) hval = FBHEIGHT;
+ color = vox->color[offs];
+ last_offs = offs;
+ last_hval = hval;
+ last_col = color;
+ }
+ if(hval > vox->coltop[col]) {
+ colstart = FBHEIGHT - hval;
+ colheight = hval - vox->coltop[col];
+ fbptr = vox->fb + colstart * (FBPITCH / 2) + i;