all repos — mgba @ 0bdf30f650b219c7f17b9a015f63c5cb681a2399

mGBA Game Boy Advance Emulator

src/ds/gx/software.c (view raw)

  1/* Copyright (c) 2013-2017 Jeffrey Pfau
  2 *
  3 * This Source Code Form is subject to the terms of the Mozilla Public
  4 * License, v. 2.0. If a copy of the MPL was not distributed with this
  5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
  6#include <mgba/internal/ds/gx/software.h>
  7
  8#include <mgba-util/memory.h>
  9#include <mgba/internal/ds/io.h>
 10#include "gba/renderers/software-private.h"
 11
 12DEFINE_VECTOR(DSGXSoftwarePolygonList, struct DSGXSoftwarePolygon);
 13DEFINE_VECTOR(DSGXSoftwareEdgeList, struct DSGXSoftwareEdge);
 14
 15static void DSGXSoftwareRendererInit(struct DSGXRenderer* renderer);
 16static void DSGXSoftwareRendererReset(struct DSGXRenderer* renderer);
 17static void DSGXSoftwareRendererDeinit(struct DSGXRenderer* renderer);
 18static void DSGXSoftwareRendererInvalidateTex(struct DSGXRenderer* renderer, int slot);
 19static void DSGXSoftwareRendererSetRAM(struct DSGXRenderer* renderer, struct DSGXVertex* verts, struct DSGXPolygon* polys, unsigned polyCount, bool wSort);
 20static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int y);
 21static void DSGXSoftwareRendererGetScanline(struct DSGXRenderer* renderer, int y, const color_t** output);
 22static void DSGXSoftwareRendererWriteRegister(struct DSGXRenderer* renderer, uint32_t address, uint16_t value);
 23
 24static void _expandColor(uint16_t c15, uint8_t* r, uint8_t* g, uint8_t* b) {
 25	*r = ((c15 << 1) & 0x3E) | 1;
 26	*g = ((c15 >> 4) & 0x3E) | 1;
 27	*b = ((c15 >> 9) & 0x3E) | 1;
 28}
 29
 30static color_t _finishColor(uint8_t r, uint8_t g, uint8_t b, uint8_t a) {
 31#ifndef COLOR_16_BIT
 32	color_t rgba = (r << 2) & 0xFC;
 33	rgba |= (g << 10) & 0xFC00;
 34	rgba |= (b << 18) & 0xFC0000;
 35	rgba |= (a << 26) & 0xF8000000;
 36	return rgba;
 37#else
 38#error Unsupported color depth
 39#endif
 40}
 41
 42static unsigned _mix32(int weightA, unsigned colorA, int weightB, unsigned colorB) {
 43	unsigned c = 0;
 44	unsigned a, b;
 45#ifdef COLOR_16_BIT
 46#error Unsupported color depth
 47#else
 48	a = colorA & 0xFF;
 49	b = colorB & 0xFF;
 50	c |= ((a * weightA + b * weightB) / 32) & 0x1FF;
 51	if (c & 0x00000100) {
 52		c = 0x000000FF;
 53	}
 54
 55	a = colorA & 0xFF00;
 56	b = colorB & 0xFF00;
 57	c |= ((a * weightA + b * weightB) / 32) & 0x1FF00;
 58	if (c & 0x00010000) {
 59		c = (c & 0x000000FF) | 0x0000FF00;
 60	}
 61
 62	a = colorA & 0xFF0000;
 63	b = colorB & 0xFF0000;
 64	c |= ((a * weightA + b * weightB) / 32) & 0x1FF0000;
 65	if (c & 0x01000000) {
 66		c = (c & 0x0000FFFF) | 0x00FF0000;
 67	}
 68#endif
 69	return c;
 70}
 71
 72static unsigned _mixTexels(int weightA, unsigned colorA, int weightB, unsigned colorB) {
 73	unsigned c = 0;
 74	unsigned a, b;
 75	a = colorA & 0x7C1F;
 76	b = colorB & 0x7C1F;
 77	a |= (colorA & 0x3E0) << 16;
 78	b |= (colorB & 0x3E0) << 16;
 79	c = ((a * weightA + b * weightB) / 8);
 80	if (c & 0x04000000) {
 81		c = (c & ~0x07E00000) | 0x03E00000;
 82	}
 83	if (c & 0x0020) {
 84		c = (c & ~0x003F) | 0x001F;
 85	}
 86	if (c & 0x8000) {
 87		c = (c & ~0xF800) | 0x7C00;
 88	}
 89	c = (c & 0x7C1F) | ((c >> 16) & 0x03E0);
 90	return c;
 91}
 92
 93static color_t _lookupColor(struct DSGXSoftwareRenderer* renderer, struct DSGXSoftwareEndpoint* ep, struct DSGXSoftwarePolygon* poly) {
 94	if (!poly->texBase && poly->texFormat) {
 95		return 0;
 96	}
 97	// TODO: Optimize
 98	uint16_t texel;
 99
100	int16_t s = ep->s >> 4;
101	int16_t t = ep->t >> 4;
102	if (!DSGXTexParamsIsSRepeat(poly->texParams)) {
103		if (s < 0) {
104			s = 0;
105		} else if (s >= poly->texW) {
106			s = poly->texW - 1;
107		}
108	} else if (DSGXTexParamsIsSMirror(poly->texParams)) {
109		if (s & poly->texW) {
110			s = poly->texW - s - 1;
111		}
112		s &= poly->texW - 1;
113	} else {
114		s &= poly->texW - 1;
115	}
116	if (!DSGXTexParamsIsTRepeat(poly->texParams)) {
117		if (t < 0) {
118			t = 0;
119		} else if (t >= poly->texH) {
120			t = poly->texW - 1;
121		}
122	} else if (DSGXTexParamsIsTMirror(poly->texParams)) {
123		if (t & poly->texH) {
124			t = poly->texH - t - 1;
125		}
126		t &= poly->texH - 1;
127	} else {
128		t &= poly->texH - 1;
129	}
130
131	uint16_t texelCoord = s + t * poly->texW;
132	uint8_t ta = 0x1F;
133	uint8_t pa = DSGXPolygonAttrsGetAlpha(poly->polyParams);
134	if (pa) {
135		pa = (pa << 1) + 1;
136	}
137	switch (poly->texFormat) {
138	case 0:
139	default:
140		return _finishColor(ep->cr, ep->cg, ep->cb, pa);
141	case 1:
142		texel = ((uint8_t*) poly->texBase)[texelCoord];
143		ta = (texel >> 5) & 0x7;
144		ta = (ta << 2) + (ta >> 1);
145		texel &= 0x1F;
146		break;
147	case 2:
148		texel = ((uint8_t*) poly->texBase)[texelCoord >> 2];
149		if (texelCoord & 0x3) {
150			texel >>= 2 * texel & 3;
151		}
152		texel &= 0x3;
153		break;
154	case 3:
155		texel = ((uint8_t*) poly->texBase)[texelCoord >> 1];
156		if (texelCoord & 0x1) {
157			texel >>= 4;
158		}
159		texel &= 0xF;
160		break;
161	case 4:
162		texel = ((uint8_t*) poly->texBase)[texelCoord];
163		break;
164	case 5:
165		texelCoord = (s & ~3) + (t & 3) + (t >> 2) * poly->texW;
166		texel = ((uint8_t*) poly->texBase)[texelCoord];
167		texel >>= (s & 3) * 2;
168		texel &= 3;
169		break;
170	case 6:
171		texel = ((uint8_t*) poly->texBase)[texelCoord];
172		ta = (texel >> 3) & 0x1F;
173		texel &= 0x7;
174		break;
175	case 7:
176		texel = poly->texBase[texelCoord];
177		break;
178	}
179	uint8_t r, g, b;
180	unsigned wr, wg, wb, wa;
181	if (poly->texFormat == 5) {
182		if (!renderer->d.tex[1]) {
183			return 0;
184		}
185		uint16_t half = DSGXTexParamsGetVRAMBase(poly->texParams) & 0x8000;
186		uint32_t slot1Base = (DSGXTexParamsGetVRAMBase(poly->texParams) << 1) + (texelCoord >> 2) + half;
187		uint16_t texel2 = renderer->d.tex[1][slot1Base];
188		uint16_t texel2Base = (texel2 & 0x3FFF) << 1;
189		int a = 0x8;
190		int b = 0;
191		switch (texel2 >> 14) {
192		case 0:
193			if (texel == 3) {
194				ta = 0;
195			}
196			texel = poly->palBase[texel + texel2Base];
197			break;
198		case 1:
199			if (texel == 3) {
200				ta = 0;
201			}
202			if (texel != 2) {
203				texel = poly->palBase[texel + texel2Base];
204			} else {
205				texel = poly->palBase[texel2Base];
206				texel2 = poly->palBase[texel2Base + 1];
207				a = 4;
208				b = 4;
209			}
210			break;
211		case 2:
212			texel = poly->palBase[texel + texel2Base];
213			break;
214		case 3:
215			switch (texel) {
216			case 0:
217			case 1:
218				texel = poly->palBase[texel + texel2Base];
219				break;
220			case 2:
221				texel = poly->palBase[texel2Base];
222				texel2 = poly->palBase[texel2Base + 1];
223				a = 5;
224				b = 3;
225				break;
226			case 3:
227				texel = poly->palBase[texel2Base];
228				texel2 = poly->palBase[texel2Base + 1];
229				a = 3;
230				b = 5;
231				break;
232			}
233			break;
234		}
235		if (b) {
236			texel = _mixTexels(a, texel, b, texel2);
237		}
238	} else if (poly->texFormat != 7) {
239		if (poly->texFormat < 5 && poly->texFormat > 1 && DSGXTexParamsIs0Transparent(poly->texParams) && !texel) {
240			return 0;
241		}
242		texel = poly->palBase[texel];
243	}
244	_expandColor(texel, &r, &g, &b);
245	if (ta) {
246		ta = (ta << 1) + 1;
247	}
248	switch (poly->blendFormat) {
249	default:
250	case 0:
251		wr = ((r + 1) * (ep->cr + 1) - 1) >> 6;
252		wg = ((g + 1) * (ep->cg + 1) - 1) >> 6;
253		wb = ((b + 1) * (ep->cb + 1) - 1) >> 6;
254		wa = ((ta + 1) * (pa + 1) - 1) >> 6;
255		return _finishColor(wr, wg, wb, wa);
256	case 1:
257		wr = (r * ta + ep->cr * (63 - ta)) >> 6;
258		wg = (g * ta + ep->cg * (63 - ta)) >> 6;
259		wb = (b * ta + ep->cb * (63 - ta)) >> 6;
260		return _finishColor(wr, wg, wb, pa);
261	case 3:
262		return _finishColor(r, g, b, pa);
263	}
264}
265
266static inline int32_t _interpolate(int32_t x0, int32_t x1, int64_t w0, int64_t w1, int64_t w, int32_t qr) {
267	// 32-bit -> 96-bit
268	int64_t x0b = (w0 & 0xFFFFFFFF) * x0;
269	int64_t x0t = (w0 >> 32) * x0;
270	int64_t x1b = (w1 & 0xFFFFFFFF) * x1;
271	int64_t x1t = (w1 >> 32) * x1;
272	// 96-bit -> 64-bit
273	int64_t xx0 = (x0t << 32) + x0b;
274	int64_t xx1 = (x1t << 32) + x1b;
275	xx1 -= xx0;
276	xx1 >>= 12;
277
278	int64_t qrb = xx1 * qr;
279	qrb += xx0;
280
281	return qrb / w;
282}
283
284static inline int32_t _divideBy(int64_t x, int32_t recip) {
285	int64_t x0 = (x & 0xFFFFFFFF) * recip;
286	int64_t x1 = (x >> 32) * recip;
287	x1 += x0 >> 32;
288	return x1 >> 31;
289}
290
291static bool _edgeToSpan(struct DSGXSoftwareSpan* span, const struct DSGXSoftwareEdge* edge, int index, int32_t y) {
292	int32_t height = edge->y1 - edge->y0;
293	int64_t yw = y - edge->y0;
294	if (!height) {
295		return false;
296	}
297	// Clamp to bounds
298	if (yw < 0) {
299		return false;
300	} else if (yw > height) {
301		return false;
302	}
303
304	span->ep[index].coord[0] = (((int64_t) (edge->x1 - edge->x0) * yw) / height) + edge->x0;
305
306	if (index) {
307		if (span->ep[0].coord[0] == span->ep[index].coord[0]) {
308			return false;
309		}
310		if (span->ep[0].coord[0] > span->ep[index].coord[0]) {
311			int32_t temp = span->ep[index].coord[0];
312			span->ep[index] = span->ep[0];
313			span->ep[0].coord[0] = temp;
314			index = 0;
315		}
316	}
317
318	int64_t w0 = edge->wr0;
319	int64_t w1 = edge->wr1;
320	int64_t w = w1 - w0;
321
322	// Losslessly interpolate two 64-bit values
323	int64_t wb = (w & 0xFFFFFFFF) * yw;
324	int64_t wt = (w >> 32) * yw;
325	int64_t div = wt / height;
326	int64_t rem = wt % height;
327	w = div << 32;
328	wb += rem << 32;
329	div = wb / height;
330	w += div;
331	w += w0;
332
333	span->ep[index].coord[3] = (0x7FFFFFFFFFFFFFFF / w) + 1;
334	span->ep[index].wRecip = w;
335	int32_t qr = (yw << 12) / height;
336
337	span->ep[index].coord[2]  = _interpolate(edge->z0, edge->z1, w0, w1, w, qr);
338	span->ep[index].cr = _interpolate(edge->cr0, edge->cr1, w0, w1, w, qr);
339	span->ep[index].cg = _interpolate(edge->cg0, edge->cg1, w0, w1, w, qr);
340	span->ep[index].cb = _interpolate(edge->cb0, edge->cb1, w0, w1, w, qr);
341	span->ep[index].s  = _interpolate(edge->s0, edge->s1, w0, w1, w, qr);
342	span->ep[index].t  = _interpolate(edge->t0, edge->t1, w0, w1, w, qr);
343
344	return true;
345}
346
347static void _createStep(struct DSGXSoftwareSpan* span) {
348	int32_t width = (span->ep[1].coord[0] - span->ep[0].coord[0]) >> 7;
349
350	span->ep[0].stepW = span->ep[0].wRecip;
351	span->ep[0].stepZ = span->ep[0].coord[2] * span->ep[0].wRecip;
352	span->ep[0].stepR = span->ep[0].cr * span->ep[0].wRecip;
353	span->ep[0].stepG = span->ep[0].cg * span->ep[0].wRecip;
354	span->ep[0].stepB = span->ep[0].cb * span->ep[0].wRecip;
355	span->ep[0].stepS = span->ep[0].s  * span->ep[0].wRecip;
356	span->ep[0].stepT = span->ep[0].t  * span->ep[0].wRecip;
357
358	span->ep[1].stepW = span->ep[1].wRecip;
359	span->ep[1].stepZ = span->ep[1].coord[2] * span->ep[1].wRecip;
360	span->ep[1].stepR = span->ep[1].cr * span->ep[1].wRecip;
361	span->ep[1].stepG = span->ep[1].cg * span->ep[1].wRecip;
362	span->ep[1].stepB = span->ep[1].cb * span->ep[1].wRecip;
363	span->ep[1].stepS = span->ep[1].s  * span->ep[1].wRecip;
364	span->ep[1].stepT = span->ep[1].t  * span->ep[1].wRecip;
365
366	if (!width) {
367		return;
368	}
369	span->step.coord[0] = span->ep[1].coord[0] - span->ep[0].coord[0];
370	span->step.stepW = ((span->ep[1].stepW - span->ep[0].stepW) / width) << 5;
371	span->step.stepZ = ((span->ep[1].stepZ - span->ep[0].stepZ) / width) << 5;
372	span->step.stepR = ((span->ep[1].stepR - span->ep[0].stepR) / width) << 5;
373	span->step.stepG = ((span->ep[1].stepG - span->ep[0].stepG) / width) << 5;
374	span->step.stepB = ((span->ep[1].stepB - span->ep[0].stepB) / width) << 5;
375	span->step.stepS = ((span->ep[1].stepS - span->ep[0].stepS) / width) << 5;
376	span->step.stepT = ((span->ep[1].stepT - span->ep[0].stepT) / width) << 5;
377}
378
379static void _stepEndpoint(struct DSGXSoftwareSpan* span) {
380	int32_t nextX = (span->ep[0].coord[0] & ~0xFFF) + 0x1000;
381	span->ep[0].coord[0] = nextX;
382
383	span->ep[0].wRecip += span->step.stepW;
384	span->ep[0].coord[3] = (0x7FFFFFFFFFFFFFFF / span->ep[0].wRecip) + 1;
385
386	span->ep[0].stepZ += span->step.stepZ;
387	span->ep[0].coord[2] = _divideBy(span->ep[0].stepZ, span->ep[0].coord[3]);
388
389	span->ep[0].stepR += span->step.stepR;
390	span->ep[0].stepG += span->step.stepG;
391	span->ep[0].stepB += span->step.stepB;
392	span->ep[0].stepS += span->step.stepS;
393	span->ep[0].stepT += span->step.stepT;
394}
395
396static void _resolveEndpoint(struct DSGXSoftwareSpan* span) {
397	span->ep[0].cr = _divideBy(span->ep[0].stepR, span->ep[0].coord[3]);
398	span->ep[0].cg = _divideBy(span->ep[0].stepG, span->ep[0].coord[3]);
399	span->ep[0].cb = _divideBy(span->ep[0].stepB, span->ep[0].coord[3]);
400	span->ep[0].s = _divideBy(span->ep[0].stepS, span->ep[0].coord[3]);
401	span->ep[0].t = _divideBy(span->ep[0].stepT, span->ep[0].coord[3]);
402}
403
404void DSGXSoftwareRendererCreate(struct DSGXSoftwareRenderer* renderer) {
405	renderer->d.init = DSGXSoftwareRendererInit;
406	renderer->d.reset = DSGXSoftwareRendererReset;
407	renderer->d.deinit = DSGXSoftwareRendererDeinit;
408	renderer->d.invalidateTex = DSGXSoftwareRendererInvalidateTex;
409	renderer->d.setRAM = DSGXSoftwareRendererSetRAM;
410	renderer->d.drawScanline = DSGXSoftwareRendererDrawScanline;
411	renderer->d.getScanline = DSGXSoftwareRendererGetScanline;
412	renderer->d.writeRegister = DSGXSoftwareRendererWriteRegister;
413}
414
415static void DSGXSoftwareRendererInit(struct DSGXRenderer* renderer) {
416	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
417	DSGXSoftwarePolygonListInit(&softwareRenderer->activePolys, DS_GX_POLYGON_BUFFER_SIZE / 4);
418	DSGXSoftwareEdgeListInit(&softwareRenderer->activeEdges, 16);
419	softwareRenderer->scanlineCache = anonymousMemoryMap(sizeof(color_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
420	softwareRenderer->depthBuffer = anonymousMemoryMap(sizeof(int32_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
421	softwareRenderer->stencilBuffer = anonymousMemoryMap(sizeof(uint8_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
422}
423
424static void DSGXSoftwareRendererReset(struct DSGXRenderer* renderer) {
425	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
426	softwareRenderer->clearColor = 0;
427	softwareRenderer->clearStencil = 0;
428}
429
430static void DSGXSoftwareRendererDeinit(struct DSGXRenderer* renderer) {
431	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
432	DSGXSoftwarePolygonListDeinit(&softwareRenderer->activePolys);
433	DSGXSoftwareEdgeListDeinit(&softwareRenderer->activeEdges);	
434	mappedMemoryFree(softwareRenderer->scanlineCache, sizeof(color_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
435	mappedMemoryFree(softwareRenderer->depthBuffer, sizeof(int32_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
436	mappedMemoryFree(softwareRenderer->stencilBuffer, sizeof(uint8_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
437}
438
439static void DSGXSoftwareRendererInvalidateTex(struct DSGXRenderer* renderer, int slot) {
440	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
441	// TODO
442}
443
444static void _preparePoly(struct DSGXRenderer* renderer, struct DSGXVertex* verts, struct DSGXSoftwarePolygon* poly) {
445	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
446	struct DSGXSoftwareEdge* edge = DSGXSoftwareEdgeListAppend(&softwareRenderer->activeEdges);
447	poly->texParams = poly->poly->texParams;
448	poly->polyParams = poly->poly->polyParams;
449	poly->texFormat = DSGXTexParamsGetFormat(poly->texParams);
450	poly->blendFormat = DSGXPolygonAttrsGetMode(poly->polyParams);
451	poly->texW = 8 << DSGXTexParamsGetSSize(poly->texParams);
452	poly->texH = 8 << DSGXTexParamsGetTSize(poly->texParams);
453	if (!renderer->tex[DSGXTexParamsGetVRAMBase(poly->texParams) >> VRAM_BLOCK_OFFSET]) {
454		poly->texBase = NULL;
455		poly->palBase = NULL;
456	} else {
457		switch (poly->texFormat) {
458		case 0:
459			poly->texBase = NULL;
460			poly->palBase = NULL;
461			break;
462		case 2:
463			poly->texBase = &renderer->tex[DSGXTexParamsGetVRAMBase(poly->poly->texParams) >> VRAM_BLOCK_OFFSET][(DSGXTexParamsGetVRAMBase(poly->poly->texParams) << 2) & 0xFFFF];
464			poly->palBase = &renderer->texPal[poly->poly->palBase >> 11][(poly->poly->palBase << 2) & 0x1FFF];
465			break;
466		default:
467			poly->texBase = &renderer->tex[DSGXTexParamsGetVRAMBase(poly->poly->texParams) >> VRAM_BLOCK_OFFSET][(DSGXTexParamsGetVRAMBase(poly->poly->texParams) << 2) & 0xFFFF];
468			poly->palBase = &renderer->texPal[poly->poly->palBase >> 10][(poly->poly->palBase << 3) & 0x1FFF];
469			break;
470		}
471	}
472	edge->polyId = poly->polyId;
473	poly->minY = DS_VIDEO_VERTICAL_PIXELS - 1;
474	poly->maxY = 0;
475
476	struct DSGXVertex* v0 = &verts[poly->poly->vertIds[0]];
477	struct DSGXVertex* v1;
478
479	int32_t v0w = v0->viewCoord[3];
480	if (!v0w) {
481		v0w = 1;
482	}
483
484	int32_t v0x = (v0->viewCoord[0] + v0w) * (int64_t) (renderer->viewportWidth << 12) / (v0w * 2) + (renderer->viewportX << 12);
485	int32_t v0y = (-v0->viewCoord[1] + v0w) * (int64_t) (renderer->viewportHeight << 12) / (v0w * 2) + (renderer->viewportY << 12);
486	if (poly->minY > v0y >> 12) {
487		poly->minY = v0y >> 12;
488	}
489	if (poly->maxY < v0y >> 12) {
490		poly->maxY = v0y >> 12;
491	}
492
493	int v;
494	for (v = 1; v < poly->poly->verts; ++v) {
495		v1 = &verts[poly->poly->vertIds[v]];
496
497		int32_t v1w = v1->viewCoord[3];
498		if (!v1w) {
499			v1w = 1;
500		}
501		int32_t v1x = (v1->viewCoord[0] + v1w) * (int64_t) (renderer->viewportWidth << 12) / (v1w * 2) + (renderer->viewportX << 12);
502		int32_t v1y = (-v1->viewCoord[1] + v1w) * (int64_t) (renderer->viewportHeight << 12) / (v1w * 2) + (renderer->viewportY << 12);
503		if (poly->minY > v1y >> 12) {
504			poly->minY = v1y >> 12;
505		}
506		if (poly->maxY < v1y >> 12) {
507			poly->maxY = v1y >> 12;
508		}
509
510		if (v0y <= v1y) {
511			edge->y0 = v0y;
512			edge->x0 = v0x;
513			edge->z0 = v0->viewCoord[2];
514			edge->w0 = v0w;
515			_expandColor(v0->color, &edge->cr0, &edge->cg0, &edge->cb0);
516			edge->s0 = v0->vs;
517			edge->t0 = v0->vt;
518
519			edge->y1 = v1y;
520			edge->x1 = v1x;
521			edge->z1 = v1->viewCoord[2];
522			edge->w1 = v1w;
523			_expandColor(v1->color, &edge->cr1, &edge->cg1, &edge->cb1);
524			edge->s1 = v1->vs;
525			edge->t1 = v1->vt;
526		} else {
527			edge->y0 = v1y;
528			edge->x0 = v1x;
529			edge->z0 = v1->viewCoord[2];
530			edge->w0 = v1w;
531			_expandColor(v1->color, &edge->cr0, &edge->cg0, &edge->cb0);
532			edge->s0 = v1->vs;
533			edge->t0 = v1->vt;
534
535			edge->y1 = v0y;
536			edge->x1 = v0x;
537			edge->z1 = v0->viewCoord[2];
538			edge->w1 = v0w;
539			_expandColor(v0->color, &edge->cr1, &edge->cg1, &edge->cb1);
540			edge->s1 = v0->vs;
541			edge->t1 = v0->vt;
542		}
543		edge->wr0 = 0x7FFFFFFFFFFFFFFF / edge->w0;
544		edge->wr1 = 0x7FFFFFFFFFFFFFFF / edge->w1;
545
546		edge = DSGXSoftwareEdgeListAppend(&softwareRenderer->activeEdges);
547		edge->polyId = poly->polyId;
548		v0 = v1;
549		v0x = v1x;
550		v0y = v1y;
551		v0w = v1w;
552	}
553
554	v1 = &verts[poly->poly->vertIds[0]];
555
556	int32_t v1w = v1->viewCoord[3];
557	if (!v1w) {
558		v1w = 1;
559	}
560	int32_t v1x = (v1->viewCoord[0] + v1w) * (int64_t) (renderer->viewportWidth << 12) / (v1w * 2) + (renderer->viewportX << 12);
561	int32_t v1y = (-v1->viewCoord[1] + v1w) * (int64_t) (renderer->viewportHeight << 12) / (v1w * 2) + (renderer->viewportY << 12);
562
563	if (poly->minY > v1y >> 12) {
564		poly->minY = v1y >> 12;
565	}
566	if (poly->maxY < v1y >> 12) {
567		poly->maxY = v1y >> 12;
568	}
569
570	if (v0y <= v1y) {
571		edge->y0 = v0y;
572		edge->x0 = v0x;
573		edge->z0 = v0->viewCoord[2];
574		edge->w0 = v0w;
575		_expandColor(v0->color, &edge->cr0, &edge->cg0, &edge->cb0);
576		edge->s0 = v0->vs;
577		edge->t0 = v0->vt;
578
579		edge->y1 = v1y;
580		edge->x1 = v1x;
581		edge->z1 = v1->viewCoord[2];
582		edge->w1 = v1w;
583		_expandColor(v1->color, &edge->cr1, &edge->cg1, &edge->cb1);
584		edge->s1 = v1->vs;
585		edge->t1 = v1->vt;
586	} else {
587		edge->y0 = v1y;
588		edge->x0 = v1x;
589		edge->z0 = v1->viewCoord[2];
590		edge->w0 = v1w;
591		_expandColor(v1->color, &edge->cr0, &edge->cg0, &edge->cb0);
592		edge->s0 = v1->vs;
593		edge->t0 = v1->vt;
594
595		edge->y1 = v0y;
596		edge->x1 = v0x;
597		edge->z1 = v0->viewCoord[2];
598		edge->w1 = v0w;
599		_expandColor(v0->color, &edge->cr1, &edge->cg1, &edge->cb1);
600		edge->s1 = v0->vs;
601		edge->t1 = v0->vt;
602	}
603	edge->wr0 = 0x7FFFFFFFFFFFFFFF / edge->w0;
604	edge->wr1 = 0x7FFFFFFFFFFFFFFF / edge->w1;
605
606	if (poly->maxY >= DS_VIDEO_VERTICAL_PIXELS) {
607		poly->maxY = DS_VIDEO_VERTICAL_PIXELS - 1;
608	}
609	if (poly->minY < 0) {
610		poly->minY = 0;
611	}
612}
613
614static void _drawSpan(struct DSGXSoftwareRenderer* softwareRenderer, struct DSGXSoftwareSpan* span, int y) {
615	color_t* scanline = &softwareRenderer->scanlineCache[DS_VIDEO_HORIZONTAL_PIXELS * y];
616	int32_t* depth = &softwareRenderer->depthBuffer[DS_VIDEO_HORIZONTAL_PIXELS * y];
617	uint8_t* stencil = &softwareRenderer->stencilBuffer[DS_VIDEO_HORIZONTAL_PIXELS * y];
618	int32_t x = span->ep[0].coord[0] >> 12;
619	if (x < 0) {
620		x = 0;
621	}
622	unsigned stencilValue = span->polyId;
623	if (span->poly->blendFormat == 3) {
624		stencilValue |= 0x40;
625	}
626	for (; x < (span->ep[1].coord[0] >> 12) && x < DS_VIDEO_HORIZONTAL_PIXELS; ++x) {
627		if (span->ep[0].coord[softwareRenderer->sort] < depth[x]) {
628			_resolveEndpoint(span);
629			color_t color = _lookupColor(softwareRenderer, &span->ep[0], span->poly);
630			unsigned a = color >> 27;
631			unsigned current = scanline[x];
632			unsigned b = current >> 27;
633			unsigned ab = a;
634			unsigned s = stencilValue;
635			if (b > ab) {
636				ab = b;
637			}
638			if (a == 0x1F) {
639				if (!(s & 0x40) || (s & 0x3F && !(stencil[x] & 0x40))) {
640					depth[x] = span->ep[0].coord[softwareRenderer->sort];
641					scanline[x] = color;
642					s &= ~0x40;
643				}
644				stencil[x] = s;
645			} else if (a) {
646				// TODO: Disable alpha?
647				if (b) {
648					color = _mix32(a, color, 0x1F - a, current);
649					color |= ab << 27;
650				}
651				if (stencil[x] != s) {
652					if (!(s & 0x40) || (s & 0x3F && !(stencil[x] & 0x40))) {
653						if (DSGXPolygonAttrsIsUpdateDepth(span->poly->poly->polyParams)) {
654							depth[x] = span->ep[0].coord[softwareRenderer->sort];
655						}
656						scanline[x] = color;
657						s &= ~0x40;
658					}
659					stencil[x] = s;
660				}
661			}
662		}
663		_stepEndpoint(span);
664	}
665}
666
667static void DSGXSoftwareRendererSetRAM(struct DSGXRenderer* renderer, struct DSGXVertex* verts, struct DSGXPolygon* polys, unsigned polyCount, bool wSort) {
668	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
669
670	softwareRenderer->sort = wSort ? 3 : 2;
671	softwareRenderer->verts = verts;
672	DSGXSoftwarePolygonListClear(&softwareRenderer->activePolys);
673	size_t i;
674	// Pass 1: Opaque
675	for (i = 0; i < polyCount; ++i) {
676		struct DSGXSoftwarePolygon* poly = NULL;
677		switch (DSGXTexParamsGetFormat(polys[i].texParams)) {
678		default:
679			if (DSGXPolygonAttrsGetAlpha(polys[i].polyParams) == 0x1F) {
680				poly = DSGXSoftwarePolygonListAppend(&softwareRenderer->activePolys);
681				break;
682			}
683		case 1:
684		case 6:
685			break;
686		}
687		if (!poly) {
688			continue;
689		}
690		poly->poly = &polys[i];
691		poly->polyId = DSGXSoftwarePolygonListSize(&softwareRenderer->activePolys) - 1;
692	}
693	// Pass 2: Translucent
694	for (i = 0; i < polyCount; ++i) {
695		struct DSGXSoftwarePolygon* poly = NULL;
696		switch (DSGXTexParamsGetFormat(polys[i].texParams)) {
697		default:
698			if (DSGXPolygonAttrsGetAlpha(polys[i].polyParams) == 0x1F) {
699				break;
700			}
701		case 1:
702		case 6:
703			poly = DSGXSoftwarePolygonListAppend(&softwareRenderer->activePolys);
704			break;
705		}
706		if (!poly) {
707			continue;
708		}
709		poly->poly = &polys[i];
710		poly->polyId = DSGXSoftwarePolygonListSize(&softwareRenderer->activePolys) - 1;
711	}
712
713	color_t clearColor = softwareRenderer->clearColor;
714	uint16_t clearStencil = softwareRenderer->clearStencil;
715
716	for (i = 0; i < DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS ; i += 4) {
717		softwareRenderer->depthBuffer[i] = INT32_MAX;
718		softwareRenderer->depthBuffer[i + 1] = INT32_MAX;
719		softwareRenderer->depthBuffer[i + 2] = INT32_MAX;
720		softwareRenderer->depthBuffer[i + 3] = INT32_MAX;
721		softwareRenderer->scanlineCache[i] = clearColor;
722		softwareRenderer->scanlineCache[i + 1] = clearColor;
723		softwareRenderer->scanlineCache[i + 2] = clearColor;
724		softwareRenderer->scanlineCache[i + 3] = clearColor;
725		softwareRenderer->stencilBuffer[i] = clearStencil;
726		softwareRenderer->stencilBuffer[i + 1] = clearStencil;
727		softwareRenderer->stencilBuffer[i + 2] = clearStencil;
728		softwareRenderer->stencilBuffer[i + 3] = clearStencil;
729	}
730	softwareRenderer->flushPending = true;
731}
732
733static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int y) {
734	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
735	if (!softwareRenderer->flushPending || y) {
736		return;
737	}
738
739	size_t p;
740	for (p = 0; p < DSGXSoftwarePolygonListSize(&softwareRenderer->activePolys); ++p) {
741		struct DSGXSoftwarePolygon* poly = DSGXSoftwarePolygonListGetPointer(&softwareRenderer->activePolys, p);
742		DSGXSoftwareEdgeListClear(&softwareRenderer->activeEdges);
743		_preparePoly(renderer, softwareRenderer->verts, poly);
744		int y;
745		for (y = poly->minY; y <= poly->maxY; ++y) {
746			struct DSGXSoftwareSpan span = {
747				.poly = poly,
748				.polyId = DSGXPolygonAttrsGetId(poly->polyParams),
749			};
750			size_t i;
751			for (i = 0; i < DSGXSoftwareEdgeListSize(&softwareRenderer->activeEdges); ++i) {
752				struct DSGXSoftwareEdge* edge = DSGXSoftwareEdgeListGetPointer(&softwareRenderer->activeEdges, i);
753				if (edge->y1 < (y << 12)) {
754					continue;
755				} else if (edge->y0 > (y << 12)) {
756					continue;
757				}
758
759				if (span.ep[0].coord[3]) {
760					if (_edgeToSpan(&span, edge, 1, y << 12)) {
761						_createStep(&span);
762						_drawSpan(softwareRenderer, &span, y);
763					}
764				} else if (!_edgeToSpan(&span, edge, 0, y << 12)) {
765					// Horizontal line
766					continue;
767				}
768			}
769		}
770	}
771	softwareRenderer->flushPending = false;
772}
773
774static void DSGXSoftwareRendererGetScanline(struct DSGXRenderer* renderer, int y, const color_t** output) {
775	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
776	*output = &softwareRenderer->scanlineCache[DS_VIDEO_HORIZONTAL_PIXELS * y];
777}
778
779static void DSGXSoftwareRendererWriteRegister(struct DSGXRenderer* renderer, uint32_t address, uint16_t value) {
780	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
781	switch (address) {
782	case DS9_REG_CLEAR_COLOR_LO:
783		softwareRenderer->clearColor &= 0xFF000000;
784		softwareRenderer->clearColor |= (value & 0x001F) << 3;
785		softwareRenderer->clearColor |= (value & 0x03E0) << 6;
786		softwareRenderer->clearColor |= (value & 0x7C00) << 9;
787		break;
788	case DS9_REG_CLEAR_COLOR_HI:
789		softwareRenderer->clearColor &= 0x00FFFFFF;
790		softwareRenderer->clearColor |= (value & 0x001F) << 27;
791		softwareRenderer->clearStencil = (value & 0x3F00) >> 8;
792		break;
793	}
794}