all repos — mgba @ abf57aa602513a61dcd4fc4d0b5bcd426090fd0e

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 "gba/renderers/software-private.h"
 10
 11#define SCREEN_SIZE (DS_VIDEO_VERTICAL_PIXELS << 12)
 12
 13DEFINE_VECTOR(DSGXSoftwarePolygonList, struct DSGXSoftwarePolygon);
 14DEFINE_VECTOR(DSGXSoftwareEdgeList, struct DSGXSoftwareEdge);
 15DEFINE_VECTOR(DSGXSoftwareSpanList, struct DSGXSoftwareSpan);
 16
 17static void DSGXSoftwareRendererInit(struct DSGXRenderer* renderer);
 18static void DSGXSoftwareRendererReset(struct DSGXRenderer* renderer);
 19static void DSGXSoftwareRendererDeinit(struct DSGXRenderer* renderer);
 20static void DSGXSoftwareRendererInvalidateTex(struct DSGXRenderer* renderer, int slot);
 21static void DSGXSoftwareRendererSetRAM(struct DSGXRenderer* renderer, struct DSGXVertex* verts, struct DSGXPolygon* polys, unsigned polyCount);
 22static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int y);
 23static void DSGXSoftwareRendererGetScanline(struct DSGXRenderer* renderer, int y, color_t** output);
 24
 25static void _expandColor(uint16_t c15, uint8_t* r, uint8_t* g, uint8_t* b) {
 26	*r = ((c15 << 1) & 0x3E) | 1;
 27	*g = ((c15 >> 4) & 0x3E) | 1;
 28	*b = ((c15 >> 9) & 0x3E) | 1;
 29}
 30
 31static color_t _finishColor(uint8_t r, uint8_t g, uint8_t b) {
 32#ifndef COLOR_16_BIT
 33	color_t rgb = (r << 2) & 0xF8;
 34	rgb |= (g << 10) & 0xF800;
 35	rgb |= (b << 18) & 0xF80000;
 36	return rgb;
 37#else
 38#error Unsupported color depth
 39#endif
 40}
 41
 42static color_t _lookupColor(struct DSGXSoftwareEndpoint* ep, struct DSGXSoftwarePolygon* poly) {
 43	// TODO: Optimize
 44	uint16_t texel;
 45
 46	uint16_t s = ep->s >> 4;
 47	uint16_t t = ep->t >> 4;
 48	if (!DSGXTexParamsIsSRepeat(poly->poly->texParams)) {
 49		if (s < 0) {
 50			s = 0;
 51		} else if (s >= poly->texW) {
 52			s = poly->texW - 1;
 53		}
 54	} else if (DSGXTexParamsIsSMirror(poly->poly->texParams)) {
 55		if (s & poly->texW) {
 56			s = poly->texW - s;
 57		}
 58		s &= poly->texW - 1;
 59	} else {
 60		s &= poly->texW - 1;
 61	}
 62	if (!DSGXTexParamsIsTRepeat(poly->poly->texParams)) {
 63		if (t < 0) {
 64			t = 0;
 65		} else if (s >= poly->texH) {
 66			t = poly->texW - 1;
 67		}
 68	} else if (DSGXTexParamsIsTMirror(poly->poly->texParams)) {
 69		if (t & poly->texH) {
 70			t = poly->texH - t;
 71		}
 72		t &= poly->texH - 1;
 73	} else {
 74		t &= poly->texH - 1;
 75	}
 76
 77	uint16_t texelCoord = s + t * poly->texW;
 78	switch (poly->texFormat) {
 79	case 0:
 80	default:
 81		return _finishColor(ep->cr, ep->cg, ep->cb);
 82	case 1:
 83		return _finishColor(0, 0, 0x3F);
 84	case 2:
 85		return _finishColor(0, 0x3F, 0);
 86	case 3:
 87		texel = ((uint8_t*) poly->texBase)[texelCoord >> 1];
 88		if ((ep->s >> 4) & 0x1) {
 89			texel >>= 4;
 90		}
 91		texel &= 0xF;
 92		break;
 93	case 4:
 94		texel = ((uint8_t*) poly->texBase)[texelCoord];
 95		break;
 96	case 5:
 97		return _finishColor(0x3F, 0, 0x3F);
 98	case 6:
 99		return _finishColor(0x3F, 0x3F, 0);
100	case 7:
101		return _finishColor(0x3F, 0x3F, 0x3F);
102	}
103	if (DSGXTexParamsIs0Transparent(poly->poly->texParams) && !texel) {
104		return FLAG_UNWRITTEN;
105	}
106	uint8_t r, g, b;
107	texel = poly->palBase[texel];
108	_expandColor(texel, &r, &g, &b);
109	return _finishColor(r, g, b);
110}
111
112static int _edgeSort(const void* a, const void* b) {
113	const struct DSGXSoftwareEdge* ea = a;
114	const struct DSGXSoftwareEdge* eb = b;
115
116	// Sort upside down
117	if (ea->y0 < eb->y0) {
118		return 1;
119	}
120	if (ea->y0 > eb->y0) {
121		return -1;
122	}
123	if (ea->y1 < eb->y1) {
124		return 1;
125	}
126	if (ea->y1 > eb->y1) {
127		return -1;
128	}
129	return 0;
130}
131
132static bool _edgeToSpan(struct DSGXSoftwareSpan* span, const struct DSGXSoftwareEdge* edge, int index, int32_t y) {
133	int32_t height = edge->y1 - edge->y0;
134	int64_t yw = (y << 12) - edge->y0;
135	if (!height) {
136		return false;
137	}
138	// Clamp to bounds
139	if (yw < 0) {
140		yw = 0;
141	} else if (yw > height) {
142		yw = height;
143	}
144	span->ep[index].x = ((int64_t) (edge->x1 - edge->x0) * yw) / height + edge->x0;
145	if (index && span->ep[0].x > span->ep[index].x) {
146		int32_t temp = span->ep[index].x;
147		span->ep[index] = span->ep[0];
148		span->ep[0].x = temp;
149		index = 0;
150	}
151	int32_t w = ((int64_t) (edge->w1 - edge->w0) * yw) / height + edge->w0;
152	span->ep[index].w = w;
153	span->ep[index].cr = (((int32_t) (edge->cr1 * edge->w1 - edge->cr0 * edge->w0) * yw) / height + edge->cr0 * edge->w0) / w;
154	span->ep[index].cg = (((int32_t) (edge->cg1 * edge->w1 - edge->cg0 * edge->w0) * yw) / height + edge->cg0 * edge->w0) / w;
155	span->ep[index].cb = (((int32_t) (edge->cb1 * edge->w1 - edge->cb0 * edge->w0) * yw) / height + edge->cb0 * edge->w0) / w;
156	span->ep[index].s = (((int32_t) (edge->s1 * edge->w1 - edge->s0 * edge->w0) * yw) / height + edge->s0 * edge->w0) / w;
157	span->ep[index].t = (((int32_t) (edge->t1 * edge->w1 - edge->t0 * edge->w0) * yw) / height + edge->t0 * edge->w0) / w;
158
159	return true;
160}
161
162static int _spanSort(const void* a, const void* b) {
163	const struct DSGXSoftwareSpan* sa = a;
164	const struct DSGXSoftwareSpan* sb = b;
165
166	// Sort backwards
167	if (sa->ep[0].x < sb->ep[0].x) {
168		return 1;
169	}
170	if (sa->ep[0].x > sb->ep[0].x) {
171		return -1;
172	}
173	if (sa->ep[0].w < sb->ep[0].w) {
174		return 1;
175	}
176	if (sa->ep[0].w > sb->ep[0].w) {
177		return -1;
178	}
179	return 0;
180}
181
182static void _lerpEndpoint(const struct DSGXSoftwareSpan* span, struct DSGXSoftwareEndpoint* ep, unsigned x) {
183	int64_t width = span->ep[1].x - span->ep[0].x;
184	int64_t xw = ((uint64_t) x << 12) - span->ep[0].x;
185	if (!width) {
186		return; // TODO?
187	}
188	// Clamp to bounds
189	if (xw < 0) {
190		xw = 0;
191	} else if (xw > width) {
192		xw = width;
193	}
194	int32_t w0 = span->ep[0].w;
195	int32_t w1 = span->ep[1].w;
196	int32_t w = ((int64_t) (w1 - w0) * xw) / width + w0;
197	ep->w = w;
198
199	uint64_t r = ((span->ep[1].cr * (int64_t) w1 - span->ep[0].cr * (int64_t) w0) * xw) / width + span->ep[0].cr * (int64_t) w0;
200	uint64_t g = ((span->ep[1].cg * (int64_t) w1 - span->ep[0].cg * (int64_t) w0) * xw) / width + span->ep[0].cg * (int64_t) w0;
201	uint64_t b = ((span->ep[1].cb * (int64_t) w1 - span->ep[0].cb * (int64_t) w0) * xw) / width + span->ep[0].cb * (int64_t) w0;
202	ep->cr = r / w;
203	ep->cg = g / w;
204	ep->cb = b / w;
205
206	int32_t s = ((span->ep[1].s * (int64_t) w1 - span->ep[0].s * (int64_t) w0) * xw) / width + span->ep[0].s * (int64_t) w0;
207	int32_t t = ((span->ep[1].t * (int64_t) w1 - span->ep[0].t * (int64_t) w0) * xw) / width + span->ep[0].t * (int64_t) w0;
208	ep->s = s / w;
209	ep->t = t / w;
210}
211
212void DSGXSoftwareRendererCreate(struct DSGXSoftwareRenderer* renderer) {
213	renderer->d.init = DSGXSoftwareRendererInit;
214	renderer->d.reset = DSGXSoftwareRendererReset;
215	renderer->d.deinit = DSGXSoftwareRendererDeinit;
216	renderer->d.invalidateTex = DSGXSoftwareRendererInvalidateTex;
217	renderer->d.setRAM = DSGXSoftwareRendererSetRAM;
218	renderer->d.drawScanline = DSGXSoftwareRendererDrawScanline;
219	renderer->d.getScanline = DSGXSoftwareRendererGetScanline;
220}
221
222static void DSGXSoftwareRendererInit(struct DSGXRenderer* renderer) {
223	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
224	DSGXSoftwarePolygonListInit(&softwareRenderer->activePolys, DS_GX_POLYGON_BUFFER_SIZE / 4);
225	DSGXSoftwareEdgeListInit(&softwareRenderer->activeEdges, DS_GX_POLYGON_BUFFER_SIZE);
226	DSGXSoftwareSpanListInit(&softwareRenderer->activeSpans, DS_GX_POLYGON_BUFFER_SIZE / 2);
227	softwareRenderer->bucket = anonymousMemoryMap(sizeof(*softwareRenderer->bucket) * DS_GX_POLYGON_BUFFER_SIZE);
228	softwareRenderer->scanlineCache = anonymousMemoryMap(sizeof(color_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
229}
230
231static void DSGXSoftwareRendererReset(struct DSGXRenderer* renderer) {
232	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
233	softwareRenderer->flushPending = false;
234}
235
236static void DSGXSoftwareRendererDeinit(struct DSGXRenderer* renderer) {
237	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
238	DSGXSoftwarePolygonListDeinit(&softwareRenderer->activePolys);
239	DSGXSoftwareEdgeListDeinit(&softwareRenderer->activeEdges);	
240	DSGXSoftwareSpanListDeinit(&softwareRenderer->activeSpans);
241	mappedMemoryFree(softwareRenderer->bucket, sizeof(*softwareRenderer->bucket) * DS_GX_POLYGON_BUFFER_SIZE);
242	mappedMemoryFree(softwareRenderer->scanlineCache, sizeof(color_t) * DS_VIDEO_VERTICAL_PIXELS * DS_VIDEO_HORIZONTAL_PIXELS);
243}
244
245static void DSGXSoftwareRendererInvalidateTex(struct DSGXRenderer* renderer, int slot) {
246	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
247	// TODO
248}
249
250static void DSGXSoftwareRendererSetRAM(struct DSGXRenderer* renderer, struct DSGXVertex* verts, struct DSGXPolygon* polys, unsigned polyCount) {
251	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
252
253	softwareRenderer->flushPending = true;
254	softwareRenderer->verts = verts;
255	DSGXSoftwarePolygonListClear(&softwareRenderer->activePolys);
256	DSGXSoftwareEdgeListClear(&softwareRenderer->activeEdges);
257	unsigned i;
258	for (i = 0; i < polyCount; ++i) {
259		struct DSGXSoftwarePolygon* poly = DSGXSoftwarePolygonListAppend(&softwareRenderer->activePolys);
260		struct DSGXSoftwareEdge* edge = DSGXSoftwareEdgeListAppend(&softwareRenderer->activeEdges);
261		poly->poly = &polys[i];
262		poly->texFormat = DSGXTexParamsGetFormat(poly->poly->texParams);
263		poly->texW = 8 << DSGXTexParamsGetSSize(poly->poly->texParams);
264		poly->texH = 8 << DSGXTexParamsGetTSize(poly->poly->texParams);
265		switch (poly->texFormat) {
266		case 0:
267		case 7:
268			poly->texBase = NULL;
269			poly->palBase = NULL;
270			break;
271		default:
272			poly->texBase = &renderer->tex[DSGXTexParamsGetVRAMBase(poly->poly->texParams) >> VRAM_BLOCK_OFFSET][(DSGXTexParamsGetVRAMBase(poly->poly->texParams) << 2) & 0xFFFF];
273			poly->palBase = &renderer->texPal[poly->poly->palBase >> 11][(poly->poly->palBase << 3) & 0x1FFF];
274			break;
275		}
276		edge->polyId = i;
277
278		struct DSGXVertex* v0 = &verts[poly->poly->vertIds[0]];
279		struct DSGXVertex* v1;
280
281		int v;
282		for (v = 1; v < poly->poly->verts; ++v) {
283			v1 = &verts[poly->poly->vertIds[v]];
284			if (v0->vy >= v1->vy) {
285				edge->y0 = SCREEN_SIZE - v0->vy;
286				edge->x0 = v0->vx;
287				edge->w0 = v0->vw;
288				_expandColor(v0->color, &edge->cr0, &edge->cg0, &edge->cb0);
289				edge->s0 = v0->vs;
290				edge->t0 = v0->vt;
291
292				edge->y1 = SCREEN_SIZE - v1->vy;
293				edge->x1 = v1->vx;
294				edge->w1 = v1->vw;
295				_expandColor(v1->color, &edge->cr1, &edge->cg1, &edge->cb1);
296				edge->s1 = v1->vs;
297				edge->t1 = v1->vt;
298			} else {
299				edge->y0 = SCREEN_SIZE - v1->vy;
300				edge->x0 = v1->vx;
301				edge->w0 = v1->vw;
302				_expandColor(v1->color, &edge->cr0, &edge->cg0, &edge->cb0);
303				edge->s0 = v1->vs;
304				edge->t0 = v1->vt;
305
306				edge->y1 = SCREEN_SIZE - v0->vy;
307				edge->x1 = v0->vx;
308				edge->w1 = v0->vw;
309				_expandColor(v0->color, &edge->cr1, &edge->cg1, &edge->cb1);
310				edge->s1 = v0->vs;
311				edge->t1 = v0->vt;
312			}
313
314			edge = DSGXSoftwareEdgeListAppend(&softwareRenderer->activeEdges);
315			edge->polyId = i;
316			v0 = v1;
317		}
318
319		v1 = &verts[poly->poly->vertIds[0]];
320		if (v0->vy >= v1->vy) {
321			edge->y0 = SCREEN_SIZE - v0->vy;
322			edge->x0 = v0->vx;
323			edge->w0 = v0->vw;
324			_expandColor(v0->color, &edge->cr0, &edge->cg0, &edge->cb0);
325			edge->s0 = v0->vs;
326			edge->t0 = v0->vt;
327
328			edge->y1 = SCREEN_SIZE - v1->vy;
329			edge->x1 = v1->vx;
330			edge->w1 = v1->vw;
331			_expandColor(v1->color, &edge->cr1, &edge->cg1, &edge->cb1);
332			edge->s1 = v1->vs;
333			edge->t1 = v1->vt;
334		} else {
335			edge->y0 = SCREEN_SIZE - v1->vy;
336			edge->x0 = v1->vx;
337			edge->w0 = v1->vw;
338			_expandColor(v1->color, &edge->cr0, &edge->cg0, &edge->cb0);
339			edge->s0 = v1->vs;
340			edge->t0 = v1->vt;
341
342			edge->y1 = SCREEN_SIZE - v0->vy;
343			edge->x1 = v0->vx;
344			edge->w1 = v0->vw;
345			_expandColor(v0->color, &edge->cr1, &edge->cg1, &edge->cb1);
346			edge->s1 = v0->vs;
347			edge->t1 = v0->vt;
348		}
349	}
350	qsort(DSGXSoftwareEdgeListGetPointer(&softwareRenderer->activeEdges, 0), DSGXSoftwareEdgeListSize(&softwareRenderer->activeEdges), sizeof(struct DSGXSoftwareEdge), _edgeSort);
351}
352
353static void DSGXSoftwareRendererDrawScanline(struct DSGXRenderer* renderer, int y) {
354	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
355	if (!softwareRenderer->flushPending) {
356		return;
357	}
358	DSGXSoftwareSpanListClear(&softwareRenderer->activeSpans);
359	memset(softwareRenderer->bucket, 0, sizeof(*softwareRenderer->bucket) * DS_GX_POLYGON_BUFFER_SIZE);
360	int i;
361	for (i = DSGXSoftwareEdgeListSize(&softwareRenderer->activeEdges); i; --i) {
362		size_t idx = i - 1;
363		struct DSGXSoftwareEdge* edge = DSGXSoftwareEdgeListGetPointer(&softwareRenderer->activeEdges, idx);
364		if (edge->y1 >> 12 < y) {
365			DSGXSoftwareEdgeListShift(&softwareRenderer->activeEdges, idx, 1);
366			continue;
367		} else if (edge->y0 >> 12 > y) {
368			continue;
369		}
370
371		unsigned poly = edge->polyId;
372		struct DSGXSoftwareSpan* span = softwareRenderer->bucket[poly];
373		if (span && !span->ep[1].w) {
374			_edgeToSpan(span, edge, 1, y);
375			softwareRenderer->bucket[poly] = NULL;
376		} else if (!span) {
377			span = DSGXSoftwareSpanListAppend(&softwareRenderer->activeSpans);
378			memset(&span->ep[1], 0, sizeof(span->ep[1]));
379			span->poly = DSGXSoftwarePolygonListGetPointer(&softwareRenderer->activePolys, poly);
380			if (!_edgeToSpan(span, edge, 0, y)) {
381				// Horizontal line
382				DSGXSoftwareSpanListShift(&softwareRenderer->activeSpans, DSGXSoftwareSpanListSize(&softwareRenderer->activeSpans) - 1, 1);
383			} else {
384				softwareRenderer->bucket[poly] = span;
385			}
386		}
387	}
388	qsort(DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, 0), DSGXSoftwareSpanListSize(&softwareRenderer->activeSpans), sizeof(struct DSGXSoftwareSpan), _spanSort);
389
390	color_t* scanline = &softwareRenderer->scanlineCache[DS_VIDEO_HORIZONTAL_PIXELS * y];
391
392	int nextSpanX = DS_VIDEO_HORIZONTAL_PIXELS;
393	if (DSGXSoftwareSpanListSize(&softwareRenderer->activeSpans)) {
394		nextSpanX = DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, DSGXSoftwareSpanListSize(&softwareRenderer->activeSpans) - 1)->ep[0].x;
395		nextSpanX >>= 12;
396	}
397	for (i = 0; i < DS_VIDEO_HORIZONTAL_PIXELS; ++i) {
398		struct DSGXSoftwareSpan* span = NULL;
399		struct DSGXSoftwareEndpoint ep;
400		int32_t depth = INT32_MIN;
401		scanline[i] = FLAG_UNWRITTEN;
402		if (i >= nextSpanX) {
403			size_t nextSpanId = DSGXSoftwareSpanListSize(&softwareRenderer->activeSpans);
404			span = DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, nextSpanId - 1);
405			while (i > (span->ep[1].x >> 12) || !span->ep[1].x) {
406				DSGXSoftwareSpanListShift(&softwareRenderer->activeSpans, nextSpanId - 1, 1);
407				--nextSpanId;
408				if (!nextSpanId) {
409					nextSpanX = DS_VIDEO_HORIZONTAL_PIXELS;
410					span = NULL;
411					break;
412				}
413				span = DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, nextSpanId - 1);
414				nextSpanX = span->ep[0].x >> 12;
415			}
416			if (i < nextSpanX) {
417				span = NULL;
418			} else {
419				struct DSGXSoftwareSpan* testSpan = DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, nextSpanId - 1);
420				while (i > (testSpan->ep[0].x >> 12)) {
421					if (i <= (testSpan->ep[1].x >> 12)) {
422						_lerpEndpoint(testSpan, &ep, i);
423						color_t color = _lookupColor(&ep, testSpan->poly);
424						if (scanline[i] == FLAG_UNWRITTEN) {
425							scanline[i] = color;
426						}
427						if (ep.w >= depth) {
428							depth = ep.w;
429							span = testSpan;
430							if (color != FLAG_UNWRITTEN) {
431								scanline[i] = color;
432							}
433						}
434					}
435					--nextSpanId;
436					if (!nextSpanId) {
437						break;
438					}
439					testSpan = DSGXSoftwareSpanListGetPointer(&softwareRenderer->activeSpans, nextSpanId - 1);
440				}
441			}
442		}
443	}
444	if (y == DS_VIDEO_VERTICAL_PIXELS - 1) {
445		softwareRenderer->flushPending = false;
446	}
447}
448
449static void DSGXSoftwareRendererGetScanline(struct DSGXRenderer* renderer, int y, color_t** output) {
450	struct DSGXSoftwareRenderer* softwareRenderer = (struct DSGXSoftwareRenderer*) renderer;
451	*output = &softwareRenderer->scanlineCache[DS_VIDEO_HORIZONTAL_PIXELS * y];
452}