void (*fillfunc[])(struct pvertex*, int) = {
polyfill_wire,
polyfill_flat,
- 0, 0, 0
+ polyfill_gouraud,
+ polyfill_tex,
+ polyfill_tex_gouraud
};
-struct pimage pimg_fb, pimg_texture;
+struct pimage pfill_fb, pfill_tex;
void polyfill(int mode, struct pvertex *verts, int nverts)
{
++v;
x1 = v->x >> 8;
y1 = v->y >> 8;
- if(clip_line(&x0, &y0, &x1, &y1, 0, 0, pimg_fb.width, pimg_fb.height)) {
+ if(clip_line(&x0, &y0, &x1, &y1, 0, 0, pfill_fb.width, pfill_fb.height)) {
draw_line(x0, y0, x1, y1, color);
}
}
x0 = verts[0].x >> 8;
y0 = verts[0].y >> 8;
- if(clip_line(&x1, &y1, &x0, &y0, 0, 0, pimg_fb.width, pimg_fb.height)) {
+ if(clip_line(&x1, &y1, &x0, &y0, 0, 0, pfill_fb.width, pfill_fb.height)) {
draw_line(x1, y1, x0, y0, color);
}
}
-static uint32_t scan_edge(struct pvertex *v0, struct pvertex *v1, struct pvertex *edge);
-
#define NEXTIDX(x) (((x) - 1 + nverts) % nverts)
#define PREVIDX(x) (((x) + 1) % nverts)
-void polyfill_flat(struct pvertex *pv, int nverts)
-{
- int i;
- int topidx = 0, botidx = 0, sltop = pimg_fb.height, slbot = 0;
- struct pvertex *left, *right;
- uint16_t color = PACK_RGB16(pv[0].r, pv[0].g, pv[0].b);
-
- for(i=1; i<nverts; i++) {
- if(pv[i].y < pv[topidx].y) topidx = i;
- if(pv[i].y > pv[botidx].y) botidx = i;
- }
-
- left = (struct pvertex*)alloca(pimg_fb.height * sizeof *left);
- right = (struct pvertex*)alloca(pimg_fb.height * sizeof *right);
- memset(left, 0, pimg_fb.height * sizeof *left);
- memset(right, 0, pimg_fb.height * sizeof *right);
-
- for(i=0; i<nverts; i++) {
- int next = NEXTIDX(i);
- int32_t y0 = pv[i].y;
- int32_t y1 = pv[next].y;
-
- if((y0 >> 8) == (y1 >> 8)) {
- if(y0 > y1) {
- int idx = y0 >> 8;
- left[idx].x = pv[i].x < pv[next].x ? pv[i].x : pv[next].x;
- right[idx].x = pv[i].x < pv[next].x ? pv[next].x : pv[i].x;
- }
- } else {
- struct pvertex *edge = y0 > y1 ? left : right;
- uint32_t res = scan_edge(pv + i, pv + next, edge);
- uint32_t tmp = (res >> 16) & 0xffff;
- if(tmp > slbot) slbot = tmp;
- if((tmp = res & 0xffff) < sltop) {
- sltop = tmp;
- }
- }
- }
-
- for(i=sltop; i<=slbot; i++) {
- int32_t x;
- uint16_t *pixptr;
-
- x = left[i].x;
- pixptr = pimg_fb.pixels + i * pimg_fb.width + (x >> 8);
-
- while(x <= right[i].x) {
-#ifdef DEBUG_POLYFILL
- *pixptr++ += 15;
-#else
- *pixptr++ = color;
-#endif
- x += 256;
- }
- }
-}
-
-static uint32_t scan_edge(struct pvertex *v0, struct pvertex *v1, struct pvertex *edge)
-{
- int i;
- int32_t x, dx, dy, slope;
- int32_t start_idx, end_idx;
-
- if(v0->y > v1->y) {
- struct pvertex *tmp = v0;
- v0 = v1;
- v1 = tmp;
- }
-
- dy = v1->y - v0->y;
- dx = v1->x - v0->x;
- slope = (dx << 8) / dy;
-
- start_idx = v0->y >> 8;
- end_idx = v1->y >> 8;
-
- x = v0->x;
- for(i=start_idx; i<end_idx; i++) {
- edge[i].x = x;
- x += slope;
- }
-
- return (uint32_t)start_idx | ((uint32_t)(end_idx - 1) << 16);
-}
+/* XXX
+ * When HIGH_QUALITY is defined, the rasterizer calculates slopes for attribute
+ * interpolation on each scanline separately; otherwise the slope for each
+ * attribute would be calculated once for the whole polygon, which is faster,
+ * but produces some slight quantization artifacts, due to the limited precision
+ * of fixed-point calculations.
+ */
+#undef HIGH_QUALITY
+
+/* extra bits of precision to use when interpolating colors.
+ * try tweaking this if you notice strange quantization artifacts.
+ */
+#define COLOR_SHIFT 12
+
+
+#define POLYFILL polyfill_flat
+#define SCANEDGE scanedge_flat
+#undef GOURAUD
+#undef TEXMAP
+#include "polytmpl.h"
+#undef POLYFILL
+#undef SCANEDGE
+
+#define POLYFILL polyfill_gouraud
+#define SCANEDGE scanedge_gouraud
+#define GOURAUD
+#undef TEXMAP
+#include "polytmpl.h"
+#undef POLYFILL
+#undef SCANEDGE
+
+#define POLYFILL polyfill_tex
+#define SCANEDGE scanedge_tex
+#undef GOURAUD
+#define TEXMAP
+#include "polytmpl.h"
+#undef POLYFILL
+#undef SCANEDGE
+
+#define POLYFILL polyfill_tex_gouraud
+#define SCANEDGE scanedge_tex_gouraud
+#define GOURAUD
+#define TEXMAP
+#include "polytmpl.h"
+#undef POLYFILL
+#undef SCANEDGE