X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Fpolyfill.c;h=7bffaa35690460fbdaa12d7e30b9f1337612a936;hb=3616caf014bccbf8814a67cf87ac012a91e7e968;hp=d8facb5a29271e62b29bfb2cbf0a8fc45be21cdf;hpb=921c229affb2b1da97d7be21d5c86ad045a6fcc3;p=dosdemo

diff --git a/src/polyfill.c b/src/polyfill.c
index d8facb5..7bffaa3 100644
--- a/src/polyfill.c
+++ b/src/polyfill.c
@@ -1,14 +1,20 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <alloca.h>
 #include "polyfill.h"
 #include "gfxutil.h"
 #include "demo.h"
 
 void (*fillfunc[])(struct pvertex*, int) = {
 	polyfill_wire,
-	0, 0, 0, 0
+	polyfill_flat,
+	0, 0, 0
 };
 
+struct pimage pimg_fb, pimg_texture;
+
 void polyfill(int mode, struct pvertex *verts, int nverts)
 {
 #ifndef NDEBUG
@@ -23,19 +29,106 @@ void polyfill(int mode, struct pvertex *verts, int nverts)
 
 void polyfill_wire(struct pvertex *verts, int nverts)
 {
-	int i;
+	int i, x0, y0, x1, y1;
 	struct pvertex *v = verts;
 	unsigned short color = ((v->r << 8) & 0xf800) |
 		((v->g << 3) & 0x7e0) | ((v->b >> 3) & 0x1f);
 
-	for(i=0; i<nverts; i++) {
-		int x0, y0, x1, y1;
+	for(i=0; i<nverts - 1; i++) {
 		x0 = v->x >> 8;
 		y0 = v->y >> 8;
 		++v;
 		x1 = v->x >> 8;
 		y1 = v->y >> 8;
-		clip_line(&x0, &y0, &x1, &y1, 0, 0, fb_width, fb_height);
-		draw_line(x0, y0, x1, y1, color);
+		if(clip_line(&x0, &y0, &x1, &y1, 0, 0, pimg_fb.width, pimg_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)) {
+		draw_line(x1, y1, x0, y0, color);
+	}
+}
+
+static void 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;
+	int32_t y;
+	int topidx = 0, botidx = 0, sline;
+	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 {
+			scan_edge(pv + i, pv + next, y0 > y1 ? left : right);
+		}
+	}
+
+	y = pv[topidx].y;
+	while(y < pv[botidx].y) {
+		int32_t x;
+		uint16_t *pixptr;
+
+		sline = y >> 8;
+		x = left[sline].x;
+
+		pixptr = pimg_fb.pixels + sline * pimg_fb.width + (x >> 8);
+
+		while(x <= right[sline].x) {
+			*pixptr++ += 15;
+			x += 256;
+		}
+		y += 256;
+	}
+}
+
+static void scan_edge(struct pvertex *v0, struct pvertex *v1, struct pvertex *edge)
+{
+	int32_t x, y, dx, dy, slope;
+	int 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;
+	idx = v0->y >> 8;
+
+	x = v0->x;
+	y = v0->y;
+	while(y <= v1->y) {
+		edge[idx++].x = x;
+		x += slope;
+		y += 256;
 	}
 }