1 static uint32_t SCANEDGE(struct pvertex *v0, struct pvertex *v1, struct pvertex *edge)
4 int32_t x, dx, dy, slope;
6 int r, g, b, dr, dg, db;
7 int32_t rslope, gslope, bslope;
10 int32_t u, v, du, dv, uslope, vslope;
12 int32_t start_idx, end_idx;
15 struct pvertex *tmp = v0;
23 slope = (dx << 8) / dy;
25 r = (v0->r << COLOR_SHIFT);
26 g = (v0->g << COLOR_SHIFT);
27 b = (v0->b << COLOR_SHIFT);
28 dr = (v1->r << COLOR_SHIFT) - r;
29 dg = (v1->g << COLOR_SHIFT) - g;
30 db = (v1->b << COLOR_SHIFT) - b;
31 rslope = (dr << 8) / dy;
32 gslope = (dg << 8) / dy;
33 bslope = (db << 8) / dy;
40 uslope = (du << 8) / dy;
41 vslope = (dv << 8) / dy;
44 start_idx = v0->y >> 8;
47 for(i=start_idx; i<end_idx; i++) {
51 /* we'll store the color in the edge tables with COLOR_SHIFT extra bits of precision */
67 return (uint32_t)start_idx | ((uint32_t)(end_idx - 1) << 16);
70 void POLYFILL(struct pvertex *pv, int nverts)
73 int topidx = 0, botidx = 0, sltop = pfill_fb.height, slbot = 0;
74 struct pvertex *left, *right;
76 /* the following variables are used for interpolating horizontally accros scanlines */
77 #if defined(GOURAUD) || defined(TEXMAP)
81 /* flat version, just pack the color now */
82 color = PACK_RGB16(pv[0].r, pv[0].g, pv[0].b);
85 int32_t r, g, b, dr, dg, db, rslope, gslope, bslope;
88 int32_t u, v, du, dv, uslope, vslope;
91 for(i=1; i<nverts; i++) {
92 if(pv[i].y < pv[topidx].y) topidx = i;
93 if(pv[i].y > pv[botidx].y) botidx = i;
96 left = alloca(pfill_fb.height * sizeof *left);
97 right = alloca(pfill_fb.height * sizeof *right);
99 for(i=0; i<nverts; i++) {
100 int next = NEXTIDX(i);
101 int32_t y0 = pv[i].y;
102 int32_t y1 = pv[next].y;
104 if((y0 >> 8) == (y1 >> 8)) {
107 left[idx].x = pv[i].x < pv[next].x ? pv[i].x : pv[next].x;
108 right[idx].x = pv[i].x < pv[next].x ? pv[next].x : pv[i].x;
111 struct pvertex *edge = y0 > y1 ? left : right;
112 uint32_t res = SCANEDGE(pv + i, pv + next, edge);
113 uint32_t tmp = (res >> 16) & 0xffff;
114 if(tmp > slbot) slbot = tmp;
115 if((tmp = res & 0xffff) < sltop) {
121 /* calculate the slopes of all attributes across the largest span out
122 * of the three: middle, top, or bottom.
125 #if defined(GOURAUD) || defined(TEXMAP)
126 mid = (sltop + slbot) >> 1;
127 dx = right[mid].x - left[mid].x;
128 if((tmp = right[sltop].x - left[sltop].x) > dx) {
132 if((tmp = right[slbot].x - left[slbot].x) > dx) {
136 if(!dx) dx = 256; /* avoid division by zero */
139 dr = right[mid].r - left[mid].r;
140 dg = right[mid].g - left[mid].g;
141 db = right[mid].b - left[mid].b;
142 rslope = (dr << 8) / dx;
143 gslope = (dg << 8) / dx;
144 bslope = (db << 8) / dx;
147 du = right[mid].u - left[mid].u;
148 dv = right[mid].v - left[mid].v;
149 uslope = (du << 8) / dx;
150 vslope = (dv << 8) / dx;
152 #endif /* !defined(HIGH_QUALITY) */
154 /* for each scanline ... */
155 for(i=sltop; i<=slbot; i++) {
160 pixptr = pfill_fb.pixels + i * pfill_fb.width + (x >> 8);
172 #if defined(HIGH_QUALITY) && (defined(GOURAUD) || defined(TEXMAP))
173 if(!(dx = right[i].x - left[i].x)) dx = 256;
176 dr = right[i].r - left[i].r;
177 dg = right[i].g - left[i].g;
178 db = right[i].b - left[i].b;
179 rslope = (dr << 8) / dx;
180 gslope = (dg << 8) / dx;
181 bslope = (db << 8) / dx;
184 du = right[i].u - left[i].u;
185 dv = right[i].v - left[i].v;
186 uslope = (du << 8) / dx;
187 vslope = (dv << 8) / dx;
189 #endif /* HIGH_QUALITY */
191 /* go across the scanline interpolating if necessary */
192 while(x <= right[i].x) {
193 #if defined(GOURAUD) || defined(TEXMAP)
197 /* we upped the color precision to while interpolating the
198 * edges, now drop the extra bits before packing
200 cr = r < 0 ? 0 : (r >> COLOR_SHIFT);
201 cg = g < 0 ? 0 : (g >> COLOR_SHIFT);
202 cb = b < 0 ? 0 : (b >> COLOR_SHIFT);
203 if(cr > 255) cr = 255;
204 if(cg > 255) cg = 255;
205 if(cb > 255) cb = 255;
212 int tx = (u >> (16 - pfill_tex.xshift)) & pfill_tex.xmask;
213 int ty = (v >> (16 - pfill_tex.yshift)) & pfill_tex.ymask;
214 uint16_t texel = pfill_tex.pixels[(ty << pfill_tex.xshift) + tx];
216 /* This is not correct, should be /255, but it's much faster
217 * to shift by 8 (/256), and won't make a huge difference
219 cr = (cr * UNPACK_R16(texel)) >> 8;
220 cg = (cg * UNPACK_G16(texel)) >> 8;
221 cb = (cb * UNPACK_B16(texel)) >> 8;
223 cr = UNPACK_R16(texel);
224 cg = UNPACK_G16(texel);
225 cb = UNPACK_B16(texel);
231 #if defined(GOURAUD) || defined(TEXMAP)
232 color = PACK_RGB16(cr, cg, cb);
235 #ifdef DEBUG_OVERDRAW
236 *pixptr++ += DEBUG_OVERDRAW;