all repos — mgba @ 871c21fb6cf9041b4ac7c7f7074e0b2eb77484fe

mGBA Game Boy Advance Emulator

src/gba/renderers/video-software.c (view raw)

  1/* Copyright (c) 2013-2015 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 "gba/renderers/software-private.h"
  7
  8#include <mgba/core/tile-cache.h>
  9#include <mgba/internal/arm/macros.h>
 10#include <mgba/internal/gba/io.h>
 11
 12#include <mgba-util/arm-algo.h>
 13#include <mgba-util/memory.h>
 14
 15static void GBAVideoSoftwareRendererInit(struct GBAVideoRenderer* renderer);
 16static void GBAVideoSoftwareRendererDeinit(struct GBAVideoRenderer* renderer);
 17static void GBAVideoSoftwareRendererReset(struct GBAVideoRenderer* renderer);
 18static void GBAVideoSoftwareRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address);
 19static void GBAVideoSoftwareRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam);
 20static void GBAVideoSoftwareRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
 21static uint16_t GBAVideoSoftwareRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
 22static void GBAVideoSoftwareRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
 23static void GBAVideoSoftwareRendererFinishFrame(struct GBAVideoRenderer* renderer);
 24static void GBAVideoSoftwareRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels);
 25static void GBAVideoSoftwareRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels);
 26
 27static void GBAVideoSoftwareRendererUpdateDISPCNT(struct GBAVideoSoftwareRenderer* renderer);
 28static void GBAVideoSoftwareRendererWriteBGCNT(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* bg, uint16_t value);
 29static void GBAVideoSoftwareRendererWriteBGPA(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 30static void GBAVideoSoftwareRendererWriteBGPB(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 31static void GBAVideoSoftwareRendererWriteBGPC(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 32static void GBAVideoSoftwareRendererWriteBGPD(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 33static void GBAVideoSoftwareRendererWriteBGX_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 34static void GBAVideoSoftwareRendererWriteBGX_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 35static void GBAVideoSoftwareRendererWriteBGY_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 36static void GBAVideoSoftwareRendererWriteBGY_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value);
 37static void GBAVideoSoftwareRendererWriteBLDCNT(struct GBAVideoSoftwareRenderer* renderer, uint16_t value);
 38
 39static void _cleanOAM(struct GBAVideoSoftwareRenderer* renderer);
 40static void _drawScanline(struct GBAVideoSoftwareRenderer* renderer, int y);
 41
 42static void _updatePalettes(struct GBAVideoSoftwareRenderer* renderer);
 43
 44static void _breakWindow(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win, int y);
 45static void _breakWindowInner(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win);
 46
 47void GBAVideoSoftwareRendererCreate(struct GBAVideoSoftwareRenderer* renderer) {
 48	renderer->d.init = GBAVideoSoftwareRendererInit;
 49	renderer->d.reset = GBAVideoSoftwareRendererReset;
 50	renderer->d.deinit = GBAVideoSoftwareRendererDeinit;
 51	renderer->d.writeVideoRegister = GBAVideoSoftwareRendererWriteVideoRegister;
 52	renderer->d.writeVRAM = GBAVideoSoftwareRendererWriteVRAM;
 53	renderer->d.writeOAM = GBAVideoSoftwareRendererWriteOAM;
 54	renderer->d.writePalette = GBAVideoSoftwareRendererWritePalette;
 55	renderer->d.drawScanline = GBAVideoSoftwareRendererDrawScanline;
 56	renderer->d.finishFrame = GBAVideoSoftwareRendererFinishFrame;
 57	renderer->d.getPixels = GBAVideoSoftwareRendererGetPixels;
 58	renderer->d.putPixels = GBAVideoSoftwareRendererPutPixels;
 59
 60	renderer->d.disableBG[0] = false;
 61	renderer->d.disableBG[1] = false;
 62	renderer->d.disableBG[2] = false;
 63	renderer->d.disableBG[3] = false;
 64	renderer->d.disableOBJ = false;
 65
 66	renderer->temporaryBuffer = 0;
 67}
 68
 69static void GBAVideoSoftwareRendererInit(struct GBAVideoRenderer* renderer) {
 70	GBAVideoSoftwareRendererReset(renderer);
 71
 72	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
 73
 74	int y;
 75	for (y = 0; y < VIDEO_VERTICAL_PIXELS; ++y) {
 76		color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
 77		int x;
 78		for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; ++x) {
 79			row[x] = GBA_COLOR_WHITE;
 80		}
 81	}
 82}
 83
 84static void GBAVideoSoftwareRendererReset(struct GBAVideoRenderer* renderer) {
 85	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
 86	int i;
 87
 88	softwareRenderer->dispcnt = 0x0080;
 89
 90	softwareRenderer->target1Obj = 0;
 91	softwareRenderer->target1Bd = 0;
 92	softwareRenderer->target2Obj = 0;
 93	softwareRenderer->target2Bd = 0;
 94	softwareRenderer->blendEffect = BLEND_NONE;
 95	for (i = 0; i < 1024; i += 2) {
 96		uint16_t entry;
 97		LOAD_16(entry, i, softwareRenderer->d.palette);
 98		GBAVideoSoftwareRendererWritePalette(renderer, i, entry);
 99	}
100	softwareRenderer->blendDirty = false;
101	_updatePalettes(softwareRenderer);
102
103	softwareRenderer->blda = 0;
104	softwareRenderer->bldb = 0;
105	softwareRenderer->bldy = 0;
106
107	softwareRenderer->winN[0] = (struct WindowN) { .control = { .priority = 0 } };
108	softwareRenderer->winN[1] = (struct WindowN) { .control = { .priority = 1 } };
109	softwareRenderer->objwin = (struct WindowControl) { .priority = 2 };
110	softwareRenderer->winout = (struct WindowControl) { .priority = 3 };
111	softwareRenderer->oamMax = 0;
112
113	softwareRenderer->mosaic = 0;
114
115	for (i = 0; i < 4; ++i) {
116		struct GBAVideoSoftwareBackground* bg = &softwareRenderer->bg[i];
117		bg->index = i;
118		bg->enabled = 0;
119		bg->priority = 0;
120		bg->charBase = 0;
121		bg->mosaic = 0;
122		bg->multipalette = 0;
123		bg->screenBase = 0;
124		bg->overflow = 0;
125		bg->size = 0;
126		bg->target1 = 0;
127		bg->target2 = 0;
128		bg->x = 0;
129		bg->y = 0;
130		bg->refx = 0;
131		bg->refy = 0;
132		bg->dx = 256;
133		bg->dmx = 0;
134		bg->dy = 0;
135		bg->dmy = 256;
136		bg->sx = 0;
137		bg->sy = 0;
138	}
139}
140
141static void GBAVideoSoftwareRendererDeinit(struct GBAVideoRenderer* renderer) {
142	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
143	UNUSED(softwareRenderer);
144}
145
146static uint16_t GBAVideoSoftwareRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
147	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
148	switch (address) {
149	case REG_DISPCNT:
150		softwareRenderer->dispcnt = value;
151		GBAVideoSoftwareRendererUpdateDISPCNT(softwareRenderer);
152		break;
153	case REG_BG0CNT:
154		value &= 0xDFFF;
155		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[0], value);
156		break;
157	case REG_BG1CNT:
158		value &= 0xDFFF;
159		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[1], value);
160		break;
161	case REG_BG2CNT:
162		value &= 0xFFFF;
163		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[2], value);
164		break;
165	case REG_BG3CNT:
166		value &= 0xFFFF;
167		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[3], value);
168		break;
169	case REG_BG0HOFS:
170		value &= 0x01FF;
171		softwareRenderer->bg[0].x = value;
172		break;
173	case REG_BG0VOFS:
174		value &= 0x01FF;
175		softwareRenderer->bg[0].y = value;
176		break;
177	case REG_BG1HOFS:
178		value &= 0x01FF;
179		softwareRenderer->bg[1].x = value;
180		break;
181	case REG_BG1VOFS:
182		value &= 0x01FF;
183		softwareRenderer->bg[1].y = value;
184		break;
185	case REG_BG2HOFS:
186		value &= 0x01FF;
187		softwareRenderer->bg[2].x = value;
188		break;
189	case REG_BG2VOFS:
190		value &= 0x01FF;
191		softwareRenderer->bg[2].y = value;
192		break;
193	case REG_BG3HOFS:
194		value &= 0x01FF;
195		softwareRenderer->bg[3].x = value;
196		break;
197	case REG_BG3VOFS:
198		value &= 0x01FF;
199		softwareRenderer->bg[3].y = value;
200		break;
201	case REG_BG2PA:
202		GBAVideoSoftwareRendererWriteBGPA(&softwareRenderer->bg[2], value);
203		break;
204	case REG_BG2PB:
205		GBAVideoSoftwareRendererWriteBGPB(&softwareRenderer->bg[2], value);
206		break;
207	case REG_BG2PC:
208		GBAVideoSoftwareRendererWriteBGPC(&softwareRenderer->bg[2], value);
209		break;
210	case REG_BG2PD:
211		GBAVideoSoftwareRendererWriteBGPD(&softwareRenderer->bg[2], value);
212		break;
213	case REG_BG2X_LO:
214		GBAVideoSoftwareRendererWriteBGX_LO(&softwareRenderer->bg[2], value);
215		break;
216	case REG_BG2X_HI:
217		GBAVideoSoftwareRendererWriteBGX_HI(&softwareRenderer->bg[2], value);
218		break;
219	case REG_BG2Y_LO:
220		GBAVideoSoftwareRendererWriteBGY_LO(&softwareRenderer->bg[2], value);
221		break;
222	case REG_BG2Y_HI:
223		GBAVideoSoftwareRendererWriteBGY_HI(&softwareRenderer->bg[2], value);
224		break;
225	case REG_BG3PA:
226		GBAVideoSoftwareRendererWriteBGPA(&softwareRenderer->bg[3], value);
227		break;
228	case REG_BG3PB:
229		GBAVideoSoftwareRendererWriteBGPB(&softwareRenderer->bg[3], value);
230		break;
231	case REG_BG3PC:
232		GBAVideoSoftwareRendererWriteBGPC(&softwareRenderer->bg[3], value);
233		break;
234	case REG_BG3PD:
235		GBAVideoSoftwareRendererWriteBGPD(&softwareRenderer->bg[3], value);
236		break;
237	case REG_BG3X_LO:
238		GBAVideoSoftwareRendererWriteBGX_LO(&softwareRenderer->bg[3], value);
239		break;
240	case REG_BG3X_HI:
241		GBAVideoSoftwareRendererWriteBGX_HI(&softwareRenderer->bg[3], value);
242		break;
243	case REG_BG3Y_LO:
244		GBAVideoSoftwareRendererWriteBGY_LO(&softwareRenderer->bg[3], value);
245		break;
246	case REG_BG3Y_HI:
247		GBAVideoSoftwareRendererWriteBGY_HI(&softwareRenderer->bg[3], value);
248		break;
249	case REG_BLDCNT:
250		GBAVideoSoftwareRendererWriteBLDCNT(softwareRenderer, value);
251		value &= 0x3FFF;
252		break;
253	case REG_BLDALPHA:
254		softwareRenderer->blda = value & 0x1F;
255		if (softwareRenderer->blda > 0x10) {
256			softwareRenderer->blda = 0x10;
257		}
258		softwareRenderer->bldb = (value >> 8) & 0x1F;
259		if (softwareRenderer->bldb > 0x10) {
260			softwareRenderer->bldb = 0x10;
261		}
262		value &= 0x1F1F;
263		break;
264	case REG_BLDY:
265		value &= 0x1F;
266		if (value > 0x10) {
267			value = 0x10;
268		}
269		if (softwareRenderer->bldy != value) {
270			softwareRenderer->bldy = value;
271			softwareRenderer->blendDirty = true;
272		}
273		break;
274	case REG_WIN0H:
275		softwareRenderer->winN[0].h.end = value;
276		softwareRenderer->winN[0].h.start = value >> 8;
277		if (softwareRenderer->winN[0].h.start > VIDEO_HORIZONTAL_PIXELS && softwareRenderer->winN[0].h.start > softwareRenderer->winN[0].h.end) {
278			softwareRenderer->winN[0].h.start = 0;
279		}
280		if (softwareRenderer->winN[0].h.end > VIDEO_HORIZONTAL_PIXELS) {
281			softwareRenderer->winN[0].h.end = VIDEO_HORIZONTAL_PIXELS;
282			if (softwareRenderer->winN[0].h.start > VIDEO_HORIZONTAL_PIXELS) {
283				softwareRenderer->winN[0].h.start = VIDEO_HORIZONTAL_PIXELS;
284			}
285		}
286		break;
287	case REG_WIN1H:
288		softwareRenderer->winN[1].h.end = value;
289		softwareRenderer->winN[1].h.start = value >> 8;
290		if (softwareRenderer->winN[1].h.start > VIDEO_HORIZONTAL_PIXELS && softwareRenderer->winN[1].h.start > softwareRenderer->winN[1].h.end) {
291			softwareRenderer->winN[1].h.start = 0;
292		}
293		if (softwareRenderer->winN[1].h.end > VIDEO_HORIZONTAL_PIXELS) {
294			softwareRenderer->winN[1].h.end = VIDEO_HORIZONTAL_PIXELS;
295			if (softwareRenderer->winN[1].h.start > VIDEO_HORIZONTAL_PIXELS) {
296				softwareRenderer->winN[1].h.start = VIDEO_HORIZONTAL_PIXELS;
297			}
298		}
299		break;
300	case REG_WIN0V:
301		softwareRenderer->winN[0].v.end = value;
302		softwareRenderer->winN[0].v.start = value >> 8;
303		if (softwareRenderer->winN[0].v.start > VIDEO_VERTICAL_PIXELS && softwareRenderer->winN[0].v.start > softwareRenderer->winN[0].v.end) {
304			softwareRenderer->winN[0].v.start = 0;
305		}
306		if (softwareRenderer->winN[0].v.end > VIDEO_VERTICAL_PIXELS) {
307			softwareRenderer->winN[0].v.end = VIDEO_VERTICAL_PIXELS;
308			if (softwareRenderer->winN[0].v.start > VIDEO_VERTICAL_PIXELS) {
309				softwareRenderer->winN[0].v.start = VIDEO_VERTICAL_PIXELS;
310			}
311		}
312		break;
313	case REG_WIN1V:
314		softwareRenderer->winN[1].v.end = value;
315		softwareRenderer->winN[1].v.start = value >> 8;
316		if (softwareRenderer->winN[1].v.start > VIDEO_VERTICAL_PIXELS && softwareRenderer->winN[1].v.start > softwareRenderer->winN[1].v.end) {
317			softwareRenderer->winN[1].v.start = 0;
318		}
319		if (softwareRenderer->winN[1].v.end > VIDEO_VERTICAL_PIXELS) {
320			softwareRenderer->winN[1].v.end = VIDEO_VERTICAL_PIXELS;
321			if (softwareRenderer->winN[1].v.start > VIDEO_VERTICAL_PIXELS) {
322				softwareRenderer->winN[1].v.start = VIDEO_VERTICAL_PIXELS;
323			}
324		}
325		break;
326	case REG_WININ:
327		value &= 0x3F3F;
328		softwareRenderer->winN[0].control.packed = value;
329		softwareRenderer->winN[1].control.packed = value >> 8;
330		break;
331	case REG_WINOUT:
332		value &= 0x3F3F;
333		softwareRenderer->winout.packed = value;
334		softwareRenderer->objwin.packed = value >> 8;
335		break;
336	case REG_MOSAIC:
337		softwareRenderer->mosaic = value;
338		break;
339	case REG_GREENSWP:
340		mLOG(GBA_VIDEO, STUB, "Stub video register write: 0x%03X", address);
341		break;
342	default:
343		mLOG(GBA_VIDEO, GAME_ERROR, "Invalid video register: 0x%03X", address);
344	}
345	return value;
346}
347
348static void GBAVideoSoftwareRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
349	if (renderer->cache) {
350		mTileCacheWriteVRAM(renderer->cache, address);
351	}
352}
353
354static void GBAVideoSoftwareRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
355	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
356	softwareRenderer->oamDirty = 1;
357	UNUSED(oam);
358}
359
360static void GBAVideoSoftwareRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
361	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
362	color_t color = mColorFrom555(value);
363	softwareRenderer->normalPalette[address >> 1] = color;
364	if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
365		softwareRenderer->variantPalette[address >> 1] = _brighten(color, softwareRenderer->bldy);
366	} else if (softwareRenderer->blendEffect == BLEND_DARKEN) {
367		softwareRenderer->variantPalette[address >> 1] = _darken(color, softwareRenderer->bldy);
368	}
369	if (renderer->cache) {
370		mTileCacheWritePalette(renderer->cache, address);
371	}
372}
373
374static void _breakWindow(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win, int y) {
375	if (win->v.end >= win->v.start) {
376		if (y >= win->v.end) {
377			return;
378		}
379		if (y < win->v.start) {
380			return;
381		}
382	} else if (y >= win->v.end && y < win->v.start) {
383		return;
384	}
385	if (win->h.end > VIDEO_HORIZONTAL_PIXELS || win->h.end < win->h.start) {
386		struct WindowN splits[2] = { *win, *win };
387		splits[0].h.start = 0;
388		splits[1].h.end = VIDEO_HORIZONTAL_PIXELS;
389		_breakWindowInner(softwareRenderer, &splits[0]);
390		_breakWindowInner(softwareRenderer, &splits[1]);
391	} else {
392		_breakWindowInner(softwareRenderer, win);
393	}
394}
395
396static void _breakWindowInner(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win) {
397	int activeWindow;
398	int startX = 0;
399	if (win->h.end > 0) {
400		for (activeWindow = 0; activeWindow < softwareRenderer->nWindows; ++activeWindow) {
401			if (win->h.start < softwareRenderer->windows[activeWindow].endX) {
402				// Insert a window before the end of the active window
403				struct Window oldWindow = softwareRenderer->windows[activeWindow];
404				if (win->h.start > startX) {
405					// And after the start of the active window
406					int nextWindow = softwareRenderer->nWindows;
407					++softwareRenderer->nWindows;
408					for (; nextWindow > activeWindow; --nextWindow) {
409						softwareRenderer->windows[nextWindow] = softwareRenderer->windows[nextWindow - 1];
410					}
411					softwareRenderer->windows[activeWindow].endX = win->h.start;
412					++activeWindow;
413				}
414				softwareRenderer->windows[activeWindow].control = win->control;
415				softwareRenderer->windows[activeWindow].endX = win->h.end;
416				if (win->h.end >= oldWindow.endX) {
417					// Trim off extra windows we've overwritten
418					for (++activeWindow; softwareRenderer->nWindows > activeWindow + 1 && win->h.end >= softwareRenderer->windows[activeWindow].endX; ++activeWindow) {
419						if (VIDEO_CHECKS && activeWindow >= MAX_WINDOW) {
420							mLOG(GBA_VIDEO, FATAL, "Out of bounds window write will occur");
421							return;
422						}
423						softwareRenderer->windows[activeWindow] = softwareRenderer->windows[activeWindow + 1];
424						--softwareRenderer->nWindows;
425					}
426				} else {
427					++activeWindow;
428					int nextWindow = softwareRenderer->nWindows;
429					++softwareRenderer->nWindows;
430					for (; nextWindow > activeWindow; --nextWindow) {
431						softwareRenderer->windows[nextWindow] = softwareRenderer->windows[nextWindow - 1];
432					}
433					softwareRenderer->windows[activeWindow] = oldWindow;
434				}
435				break;
436			}
437			startX = softwareRenderer->windows[activeWindow].endX;
438		}
439	}
440#ifdef DEBUG
441	if (softwareRenderer->nWindows > MAX_WINDOW) {
442		mLOG(GBA_VIDEO, FATAL, "Out of bounds window write occurred!");
443	}
444#endif
445}
446
447static void _cleanOAM(struct GBAVideoSoftwareRenderer* renderer) {
448	int i;
449	int oamMax = 0;
450	for (i = 0; i < 128; ++i) {
451		struct GBAObj obj;
452		LOAD_16(obj.a, 0, &renderer->d.oam->obj[i].a);
453		LOAD_16(obj.b, 0, &renderer->d.oam->obj[i].b);
454		LOAD_16(obj.c, 0, &renderer->d.oam->obj[i].c);
455		if (GBAObjAttributesAIsTransformed(obj.a) || !GBAObjAttributesAIsDisable(obj.a)) {
456			int height = GBAVideoObjSizes[GBAObjAttributesAGetShape(obj.a) * 4 + GBAObjAttributesBGetSize(obj.b)][1];
457			if (GBAObjAttributesAIsTransformed(obj.a)) {
458				height <<= GBAObjAttributesAGetDoubleSize(obj.a);
459			}
460			if (GBAObjAttributesAGetY(obj.a) < VIDEO_VERTICAL_PIXELS || GBAObjAttributesAGetY(obj.a) + height >= VIDEO_VERTICAL_TOTAL_PIXELS) {
461				renderer->sprites[oamMax].y = GBAObjAttributesAGetY(obj.a);
462				renderer->sprites[oamMax].endY = GBAObjAttributesAGetY(obj.a) + height;
463				renderer->sprites[oamMax].obj = obj;
464				++oamMax;
465			}
466		}
467	}
468	renderer->oamMax = oamMax;
469	renderer->oamDirty = 0;
470}
471
472static void GBAVideoSoftwareRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
473	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
474
475	color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
476	if (GBARegisterDISPCNTIsForcedBlank(softwareRenderer->dispcnt)) {
477		int x;
478		for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; ++x) {
479			row[x] = GBA_COLOR_WHITE;
480		}
481		return;
482	}
483
484	int x;
485	for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; x += 4) {
486		softwareRenderer->spriteLayer[x] = FLAG_UNWRITTEN;
487		softwareRenderer->spriteLayer[x + 1] = FLAG_UNWRITTEN;
488		softwareRenderer->spriteLayer[x + 2] = FLAG_UNWRITTEN;
489		softwareRenderer->spriteLayer[x + 3] = FLAG_UNWRITTEN;
490	}
491
492	softwareRenderer->windows[0].endX = VIDEO_HORIZONTAL_PIXELS;
493	softwareRenderer->nWindows = 1;
494	if (GBARegisterDISPCNTIsWin0Enable(softwareRenderer->dispcnt) || GBARegisterDISPCNTIsWin1Enable(softwareRenderer->dispcnt) || GBARegisterDISPCNTIsObjwinEnable(softwareRenderer->dispcnt)) {
495		softwareRenderer->windows[0].control = softwareRenderer->winout;
496		if (GBARegisterDISPCNTIsWin1Enable(softwareRenderer->dispcnt)) {
497			_breakWindow(softwareRenderer, &softwareRenderer->winN[1], y);
498		}
499		if (GBARegisterDISPCNTIsWin0Enable(softwareRenderer->dispcnt)) {
500			_breakWindow(softwareRenderer, &softwareRenderer->winN[0], y);
501		}
502	} else {
503		softwareRenderer->windows[0].control.packed = 0xFF;
504	}
505
506	GBAVideoSoftwareRendererUpdateDISPCNT(softwareRenderer);
507	if (softwareRenderer->blendDirty) {
508		_updatePalettes(softwareRenderer);
509		softwareRenderer->blendDirty = false;
510	}
511
512	int w;
513	x = 0;
514	for (w = 0; w < softwareRenderer->nWindows; ++w) {
515		// TOOD: handle objwin on backdrop
516		uint32_t backdrop = FLAG_UNWRITTEN | FLAG_PRIORITY | FLAG_IS_BACKGROUND;
517		if (!softwareRenderer->target1Bd || softwareRenderer->blendEffect == BLEND_NONE || softwareRenderer->blendEffect == BLEND_ALPHA || !GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
518			backdrop |= softwareRenderer->normalPalette[0];
519		} else {
520			backdrop |= softwareRenderer->variantPalette[0];
521		}
522		int end = softwareRenderer->windows[w].endX;
523		for (; x < end - 3; x += 4) {
524			softwareRenderer->row[x] = backdrop;
525			softwareRenderer->row[x + 1] = backdrop;
526			softwareRenderer->row[x + 2] = backdrop;
527			softwareRenderer->row[x + 3] = backdrop;
528		}
529		for (; x < end; ++x) {
530			softwareRenderer->row[x] = backdrop;
531		}
532	}
533
534	_drawScanline(softwareRenderer, y);
535
536	if (softwareRenderer->target2Bd) {
537		x = 0;
538		for (w = 0; w < softwareRenderer->nWindows; ++w) {
539			uint32_t backdrop = 0;
540			if (!softwareRenderer->target1Bd || softwareRenderer->blendEffect == BLEND_NONE || softwareRenderer->blendEffect == BLEND_ALPHA || !GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
541				backdrop |= softwareRenderer->normalPalette[0];
542			} else {
543				backdrop |= softwareRenderer->variantPalette[0];
544			}
545			int end = softwareRenderer->windows[w].endX;
546			for (; x < end; ++x) {
547				uint32_t color = softwareRenderer->row[x];
548				if (color & FLAG_TARGET_1) {
549					softwareRenderer->row[x] = _mix(softwareRenderer->bldb, backdrop, softwareRenderer->blda, color);
550				}
551			}
552		}
553	}
554	if (softwareRenderer->target1Obj && (softwareRenderer->blendEffect == BLEND_DARKEN || softwareRenderer->blendEffect == BLEND_BRIGHTEN)) {
555		x = 0;
556		for (w = 0; w < softwareRenderer->nWindows; ++w) {
557			if (!GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
558				continue;
559			}
560			int end = softwareRenderer->windows[w].endX;
561			if (softwareRenderer->blendEffect == BLEND_DARKEN) {
562				for (; x < end; ++x) {
563					uint32_t color = softwareRenderer->row[x];
564					if ((color & 0xFF000000) == FLAG_REBLEND) {
565						softwareRenderer->row[x] = _darken(color, softwareRenderer->bldy);
566					}
567				}
568			} else if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
569				for (; x < end; ++x) {
570					uint32_t color = softwareRenderer->row[x];
571					if ((color & 0xFF000000) == FLAG_REBLEND) {
572						softwareRenderer->row[x] = _brighten(color, softwareRenderer->bldy);
573					}
574				}
575			}
576		}
577	}
578
579#ifdef COLOR_16_BIT
580#if defined(__ARM_NEON) && !defined(__APPLE__)
581	_to16Bit(row, softwareRenderer->row, VIDEO_HORIZONTAL_PIXELS);
582#else
583	for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; ++x) {
584		row[x] = softwareRenderer->row[x];
585	}
586#endif
587#else
588	memcpy(row, softwareRenderer->row, VIDEO_HORIZONTAL_PIXELS * sizeof(*row));
589#endif
590}
591
592static void GBAVideoSoftwareRendererFinishFrame(struct GBAVideoRenderer* renderer) {
593	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
594
595	if (softwareRenderer->temporaryBuffer) {
596		mappedMemoryFree(softwareRenderer->temporaryBuffer, VIDEO_HORIZONTAL_PIXELS * VIDEO_VERTICAL_PIXELS * 4);
597		softwareRenderer->temporaryBuffer = 0;
598	}
599	softwareRenderer->bg[2].sx = softwareRenderer->bg[2].refx;
600	softwareRenderer->bg[2].sy = softwareRenderer->bg[2].refy;
601	softwareRenderer->bg[3].sx = softwareRenderer->bg[3].refx;
602	softwareRenderer->bg[3].sy = softwareRenderer->bg[3].refy;
603}
604
605static void GBAVideoSoftwareRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels) {
606	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
607	*stride = softwareRenderer->outputBufferStride;
608	*pixels = softwareRenderer->outputBuffer;
609}
610
611static void GBAVideoSoftwareRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels) {
612	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
613
614	const color_t* colorPixels = pixels;
615	unsigned i;
616	for (i = 0; i < VIDEO_VERTICAL_PIXELS; ++i) {
617		memmove(&softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * i], &colorPixels[stride * i], VIDEO_HORIZONTAL_PIXELS * BYTES_PER_PIXEL);
618	}
619}
620
621static void GBAVideoSoftwareRendererUpdateDISPCNT(struct GBAVideoSoftwareRenderer* renderer) {
622	renderer->bg[0].enabled = GBARegisterDISPCNTGetBg0Enable(renderer->dispcnt) && !renderer->d.disableBG[0];
623	renderer->bg[1].enabled = GBARegisterDISPCNTGetBg1Enable(renderer->dispcnt) && !renderer->d.disableBG[1];
624	renderer->bg[2].enabled = GBARegisterDISPCNTGetBg2Enable(renderer->dispcnt) && !renderer->d.disableBG[2];
625	renderer->bg[3].enabled = GBARegisterDISPCNTGetBg3Enable(renderer->dispcnt) && !renderer->d.disableBG[3];
626}
627
628static void GBAVideoSoftwareRendererWriteBGCNT(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* bg, uint16_t value) {
629	UNUSED(renderer);
630	bg->priority = GBARegisterBGCNTGetPriority(value);
631	bg->charBase = GBARegisterBGCNTGetCharBase(value) << 14;
632	bg->mosaic = GBARegisterBGCNTGetMosaic(value);
633	bg->multipalette = GBARegisterBGCNTGet256Color(value);
634	bg->screenBase = GBARegisterBGCNTGetScreenBase(value) << 11;
635	bg->overflow = GBARegisterBGCNTGetOverflow(value);
636	bg->size = GBARegisterBGCNTGetSize(value);
637}
638
639static void GBAVideoSoftwareRendererWriteBGPA(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
640	bg->dx = value;
641}
642
643static void GBAVideoSoftwareRendererWriteBGPB(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
644	bg->dmx = value;
645}
646
647static void GBAVideoSoftwareRendererWriteBGPC(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
648	bg->dy = value;
649}
650
651static void GBAVideoSoftwareRendererWriteBGPD(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
652	bg->dmy = value;
653}
654
655static void GBAVideoSoftwareRendererWriteBGX_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
656	bg->refx = (bg->refx & 0xFFFF0000) | value;
657	bg->sx = bg->refx;
658}
659
660static void GBAVideoSoftwareRendererWriteBGX_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
661	bg->refx = (bg->refx & 0x0000FFFF) | (value << 16);
662	bg->refx <<= 4;
663	bg->refx >>= 4;
664	bg->sx = bg->refx;
665}
666
667static void GBAVideoSoftwareRendererWriteBGY_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
668	bg->refy = (bg->refy & 0xFFFF0000) | value;
669	bg->sy = bg->refy;
670}
671
672static void GBAVideoSoftwareRendererWriteBGY_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
673	bg->refy = (bg->refy & 0x0000FFFF) | (value << 16);
674	bg->refy <<= 4;
675	bg->refy >>= 4;
676	bg->sy = bg->refy;
677}
678
679static void GBAVideoSoftwareRendererWriteBLDCNT(struct GBAVideoSoftwareRenderer* renderer, uint16_t value) {
680	enum BlendEffect oldEffect = renderer->blendEffect;
681
682	renderer->bg[0].target1 = GBARegisterBLDCNTGetTarget1Bg0(value);
683	renderer->bg[1].target1 = GBARegisterBLDCNTGetTarget1Bg1(value);
684	renderer->bg[2].target1 = GBARegisterBLDCNTGetTarget1Bg2(value);
685	renderer->bg[3].target1 = GBARegisterBLDCNTGetTarget1Bg3(value);
686	renderer->bg[0].target2 = GBARegisterBLDCNTGetTarget2Bg0(value);
687	renderer->bg[1].target2 = GBARegisterBLDCNTGetTarget2Bg1(value);
688	renderer->bg[2].target2 = GBARegisterBLDCNTGetTarget2Bg2(value);
689	renderer->bg[3].target2 = GBARegisterBLDCNTGetTarget2Bg3(value);
690
691	renderer->blendEffect = GBARegisterBLDCNTGetEffect(value);
692	renderer->target1Obj = GBARegisterBLDCNTGetTarget1Obj(value);
693	renderer->target1Bd = GBARegisterBLDCNTGetTarget1Bd(value);
694	renderer->target2Obj = GBARegisterBLDCNTGetTarget2Obj(value);
695	renderer->target2Bd = GBARegisterBLDCNTGetTarget2Bd(value);
696
697	if (oldEffect != renderer->blendEffect) {
698		renderer->blendDirty = true;
699	}
700}
701
702#define TEST_LAYER_ENABLED(X) \
703	(renderer->bg[X].enabled && \
704	(GBAWindowControlIsBg ## X ## Enable(renderer->currentWindow.packed) || \
705	(GBARegisterDISPCNTIsObjwinEnable(renderer->dispcnt) && GBAWindowControlIsBg ## X ## Enable (renderer->objwin.packed))) && \
706	renderer->bg[X].priority == priority)
707
708static void _drawScanline(struct GBAVideoSoftwareRenderer* renderer, int y) {
709	int w;
710	renderer->end = 0;
711	int spriteLayers = 0;
712	if (GBARegisterDISPCNTIsObjEnable(renderer->dispcnt) && !renderer->d.disableOBJ) {
713		if (renderer->oamDirty) {
714			_cleanOAM(renderer);
715		}
716		renderer->spriteCyclesRemaining = GBARegisterDISPCNTIsHblankIntervalFree(renderer->dispcnt) ? OBJ_HBLANK_FREE_LENGTH : OBJ_LENGTH;
717		int mosaicV = GBAMosaicControlGetObjV(renderer->mosaic) + 1;
718		int mosaicY = y - (y % mosaicV);
719		for (w = 0; w < renderer->nWindows; ++w) {
720			renderer->start = renderer->end;
721			renderer->end = renderer->windows[w].endX;
722			renderer->currentWindow = renderer->windows[w].control;
723			if (!GBAWindowControlIsObjEnable(renderer->currentWindow.packed) && !GBARegisterDISPCNTIsObjwinEnable(renderer->dispcnt)) {
724				continue;
725			}
726			int i;
727			int drawn;
728
729			for (i = 0; i < renderer->oamMax; ++i) {
730				int localY = y;
731				if (renderer->spriteCyclesRemaining <= 0) {
732					break;
733				}
734				struct GBAVideoSoftwareSprite* sprite = &renderer->sprites[i];
735				if (GBAObjAttributesAIsMosaic(sprite->obj.a)) {
736					localY = mosaicY;
737				}
738				if ((localY < sprite->y && (sprite->endY - 256 < 0 || localY >= sprite->endY - 256)) || localY >= sprite->endY) {
739					continue;
740				}
741				drawn = GBAVideoSoftwareRendererPreprocessSprite(renderer, &sprite->obj, localY);
742				spriteLayers |= drawn << GBAObjAttributesCGetPriority(sprite->obj.c);
743			}
744		}
745	}
746
747	unsigned priority;
748	for (priority = 0; priority < 4; ++priority) {
749		renderer->end = 0;
750		for (w = 0; w < renderer->nWindows; ++w) {
751			renderer->start = renderer->end;
752			renderer->end = renderer->windows[w].endX;
753			renderer->currentWindow = renderer->windows[w].control;
754			if (spriteLayers & (1 << priority)) {
755				GBAVideoSoftwareRendererPostprocessSprite(renderer, priority);
756			}
757			if (TEST_LAYER_ENABLED(0) && GBARegisterDISPCNTGetMode(renderer->dispcnt) < 2) {
758				GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[0], y);
759			}
760			if (TEST_LAYER_ENABLED(1) && GBARegisterDISPCNTGetMode(renderer->dispcnt) < 2) {
761				GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[1], y);
762			}
763			if (TEST_LAYER_ENABLED(2)) {
764				switch (GBARegisterDISPCNTGetMode(renderer->dispcnt)) {
765				case 0:
766					GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[2], y);
767					break;
768				case 1:
769				case 2:
770					GBAVideoSoftwareRendererDrawBackgroundMode2(renderer, &renderer->bg[2], y);
771					break;
772				case 3:
773					GBAVideoSoftwareRendererDrawBackgroundMode3(renderer, &renderer->bg[2], y);
774					break;
775				case 4:
776					GBAVideoSoftwareRendererDrawBackgroundMode4(renderer, &renderer->bg[2], y);
777					break;
778				case 5:
779					GBAVideoSoftwareRendererDrawBackgroundMode5(renderer, &renderer->bg[2], y);
780					break;
781				}
782			}
783			if (TEST_LAYER_ENABLED(3)) {
784				switch (GBARegisterDISPCNTGetMode(renderer->dispcnt)) {
785				case 0:
786					GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[3], y);
787					break;
788				case 2:
789					GBAVideoSoftwareRendererDrawBackgroundMode2(renderer, &renderer->bg[3], y);
790					break;
791				}
792			}
793		}
794	}
795	if (GBARegisterDISPCNTGetMode(renderer->dispcnt) != 0) {
796		renderer->bg[2].sx += renderer->bg[2].dmx;
797		renderer->bg[2].sy += renderer->bg[2].dmy;
798		renderer->bg[3].sx += renderer->bg[3].dmx;
799		renderer->bg[3].sy += renderer->bg[3].dmy;
800	}
801}
802
803static void _updatePalettes(struct GBAVideoSoftwareRenderer* renderer) {
804	int i;
805	if (renderer->blendEffect == BLEND_BRIGHTEN) {
806		for (i = 0; i < 512; ++i) {
807			renderer->variantPalette[i] = _brighten(renderer->normalPalette[i], renderer->bldy);
808		}
809	} else if (renderer->blendEffect == BLEND_DARKEN) {
810		for (i = 0; i < 512; ++i) {
811			renderer->variantPalette[i] = _darken(renderer->normalPalette[i], renderer->bldy);
812		}
813	} else {
814		for (i = 0; i < 512; ++i) {
815			renderer->variantPalette[i] = renderer->normalPalette[i];
816		}
817	}
818}