all repos — mgba @ 4ff24a68d01a102193383f4dcef8910894b23469

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->oamDirty = 1;
112	softwareRenderer->oamMax = 0;
113
114	softwareRenderer->mosaic = 0;
115
116	for (i = 0; i < 4; ++i) {
117		struct GBAVideoSoftwareBackground* bg = &softwareRenderer->bg[i];
118		bg->index = i;
119		bg->enabled = 0;
120		bg->priority = 0;
121		bg->charBase = 0;
122		bg->mosaic = 0;
123		bg->multipalette = 0;
124		bg->screenBase = 0;
125		bg->overflow = 0;
126		bg->size = 0;
127		bg->target1 = 0;
128		bg->target2 = 0;
129		bg->x = 0;
130		bg->y = 0;
131		bg->refx = 0;
132		bg->refy = 0;
133		bg->dx = 256;
134		bg->dmx = 0;
135		bg->dy = 0;
136		bg->dmy = 256;
137		bg->sx = 0;
138		bg->sy = 0;
139	}
140}
141
142static void GBAVideoSoftwareRendererDeinit(struct GBAVideoRenderer* renderer) {
143	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
144	UNUSED(softwareRenderer);
145}
146
147static uint16_t GBAVideoSoftwareRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
148	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
149	switch (address) {
150	case REG_DISPCNT:
151		value &= 0xFFF7;
152		softwareRenderer->dispcnt = value;
153		GBAVideoSoftwareRendererUpdateDISPCNT(softwareRenderer);
154		break;
155	case REG_BG0CNT:
156		value &= 0xDFFF;
157		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[0], value);
158		break;
159	case REG_BG1CNT:
160		value &= 0xDFFF;
161		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[1], value);
162		break;
163	case REG_BG2CNT:
164		value &= 0xFFFF;
165		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[2], value);
166		break;
167	case REG_BG3CNT:
168		value &= 0xFFFF;
169		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[3], value);
170		break;
171	case REG_BG0HOFS:
172		value &= 0x01FF;
173		softwareRenderer->bg[0].x = value;
174		break;
175	case REG_BG0VOFS:
176		value &= 0x01FF;
177		softwareRenderer->bg[0].y = value;
178		break;
179	case REG_BG1HOFS:
180		value &= 0x01FF;
181		softwareRenderer->bg[1].x = value;
182		break;
183	case REG_BG1VOFS:
184		value &= 0x01FF;
185		softwareRenderer->bg[1].y = value;
186		break;
187	case REG_BG2HOFS:
188		value &= 0x01FF;
189		softwareRenderer->bg[2].x = value;
190		break;
191	case REG_BG2VOFS:
192		value &= 0x01FF;
193		softwareRenderer->bg[2].y = value;
194		break;
195	case REG_BG3HOFS:
196		value &= 0x01FF;
197		softwareRenderer->bg[3].x = value;
198		break;
199	case REG_BG3VOFS:
200		value &= 0x01FF;
201		softwareRenderer->bg[3].y = value;
202		break;
203	case REG_BG2PA:
204		GBAVideoSoftwareRendererWriteBGPA(&softwareRenderer->bg[2], value);
205		break;
206	case REG_BG2PB:
207		GBAVideoSoftwareRendererWriteBGPB(&softwareRenderer->bg[2], value);
208		break;
209	case REG_BG2PC:
210		GBAVideoSoftwareRendererWriteBGPC(&softwareRenderer->bg[2], value);
211		break;
212	case REG_BG2PD:
213		GBAVideoSoftwareRendererWriteBGPD(&softwareRenderer->bg[2], value);
214		break;
215	case REG_BG2X_LO:
216		GBAVideoSoftwareRendererWriteBGX_LO(&softwareRenderer->bg[2], value);
217		break;
218	case REG_BG2X_HI:
219		GBAVideoSoftwareRendererWriteBGX_HI(&softwareRenderer->bg[2], value);
220		break;
221	case REG_BG2Y_LO:
222		GBAVideoSoftwareRendererWriteBGY_LO(&softwareRenderer->bg[2], value);
223		break;
224	case REG_BG2Y_HI:
225		GBAVideoSoftwareRendererWriteBGY_HI(&softwareRenderer->bg[2], value);
226		break;
227	case REG_BG3PA:
228		GBAVideoSoftwareRendererWriteBGPA(&softwareRenderer->bg[3], value);
229		break;
230	case REG_BG3PB:
231		GBAVideoSoftwareRendererWriteBGPB(&softwareRenderer->bg[3], value);
232		break;
233	case REG_BG3PC:
234		GBAVideoSoftwareRendererWriteBGPC(&softwareRenderer->bg[3], value);
235		break;
236	case REG_BG3PD:
237		GBAVideoSoftwareRendererWriteBGPD(&softwareRenderer->bg[3], value);
238		break;
239	case REG_BG3X_LO:
240		GBAVideoSoftwareRendererWriteBGX_LO(&softwareRenderer->bg[3], value);
241		break;
242	case REG_BG3X_HI:
243		GBAVideoSoftwareRendererWriteBGX_HI(&softwareRenderer->bg[3], value);
244		break;
245	case REG_BG3Y_LO:
246		GBAVideoSoftwareRendererWriteBGY_LO(&softwareRenderer->bg[3], value);
247		break;
248	case REG_BG3Y_HI:
249		GBAVideoSoftwareRendererWriteBGY_HI(&softwareRenderer->bg[3], value);
250		break;
251	case REG_BLDCNT:
252		GBAVideoSoftwareRendererWriteBLDCNT(softwareRenderer, value);
253		value &= 0x3FFF;
254		break;
255	case REG_BLDALPHA:
256		softwareRenderer->blda = value & 0x1F;
257		if (softwareRenderer->blda > 0x10) {
258			softwareRenderer->blda = 0x10;
259		}
260		softwareRenderer->bldb = (value >> 8) & 0x1F;
261		if (softwareRenderer->bldb > 0x10) {
262			softwareRenderer->bldb = 0x10;
263		}
264		value &= 0x1F1F;
265		break;
266	case REG_BLDY:
267		value &= 0x1F;
268		if (value > 0x10) {
269			value = 0x10;
270		}
271		if (softwareRenderer->bldy != value) {
272			softwareRenderer->bldy = value;
273			softwareRenderer->blendDirty = true;
274		}
275		break;
276	case REG_WIN0H:
277		softwareRenderer->winN[0].h.end = value;
278		softwareRenderer->winN[0].h.start = value >> 8;
279		if (softwareRenderer->winN[0].h.start > VIDEO_HORIZONTAL_PIXELS && softwareRenderer->winN[0].h.start > softwareRenderer->winN[0].h.end) {
280			softwareRenderer->winN[0].h.start = 0;
281		}
282		if (softwareRenderer->winN[0].h.end > VIDEO_HORIZONTAL_PIXELS) {
283			softwareRenderer->winN[0].h.end = VIDEO_HORIZONTAL_PIXELS;
284			if (softwareRenderer->winN[0].h.start > VIDEO_HORIZONTAL_PIXELS) {
285				softwareRenderer->winN[0].h.start = VIDEO_HORIZONTAL_PIXELS;
286			}
287		}
288		break;
289	case REG_WIN1H:
290		softwareRenderer->winN[1].h.end = value;
291		softwareRenderer->winN[1].h.start = value >> 8;
292		if (softwareRenderer->winN[1].h.start > VIDEO_HORIZONTAL_PIXELS && softwareRenderer->winN[1].h.start > softwareRenderer->winN[1].h.end) {
293			softwareRenderer->winN[1].h.start = 0;
294		}
295		if (softwareRenderer->winN[1].h.end > VIDEO_HORIZONTAL_PIXELS) {
296			softwareRenderer->winN[1].h.end = VIDEO_HORIZONTAL_PIXELS;
297			if (softwareRenderer->winN[1].h.start > VIDEO_HORIZONTAL_PIXELS) {
298				softwareRenderer->winN[1].h.start = VIDEO_HORIZONTAL_PIXELS;
299			}
300		}
301		break;
302	case REG_WIN0V:
303		softwareRenderer->winN[0].v.end = value;
304		softwareRenderer->winN[0].v.start = value >> 8;
305		if (softwareRenderer->winN[0].v.start > VIDEO_VERTICAL_PIXELS && softwareRenderer->winN[0].v.start > softwareRenderer->winN[0].v.end) {
306			softwareRenderer->winN[0].v.start = 0;
307		}
308		if (softwareRenderer->winN[0].v.end > VIDEO_VERTICAL_PIXELS) {
309			softwareRenderer->winN[0].v.end = VIDEO_VERTICAL_PIXELS;
310			if (softwareRenderer->winN[0].v.start > VIDEO_VERTICAL_PIXELS) {
311				softwareRenderer->winN[0].v.start = VIDEO_VERTICAL_PIXELS;
312			}
313		}
314		break;
315	case REG_WIN1V:
316		softwareRenderer->winN[1].v.end = value;
317		softwareRenderer->winN[1].v.start = value >> 8;
318		if (softwareRenderer->winN[1].v.start > VIDEO_VERTICAL_PIXELS && softwareRenderer->winN[1].v.start > softwareRenderer->winN[1].v.end) {
319			softwareRenderer->winN[1].v.start = 0;
320		}
321		if (softwareRenderer->winN[1].v.end > VIDEO_VERTICAL_PIXELS) {
322			softwareRenderer->winN[1].v.end = VIDEO_VERTICAL_PIXELS;
323			if (softwareRenderer->winN[1].v.start > VIDEO_VERTICAL_PIXELS) {
324				softwareRenderer->winN[1].v.start = VIDEO_VERTICAL_PIXELS;
325			}
326		}
327		break;
328	case REG_WININ:
329		value &= 0x3F3F;
330		softwareRenderer->winN[0].control.packed = value;
331		softwareRenderer->winN[1].control.packed = value >> 8;
332		break;
333	case REG_WINOUT:
334		value &= 0x3F3F;
335		softwareRenderer->winout.packed = value;
336		softwareRenderer->objwin.packed = value >> 8;
337		break;
338	case REG_MOSAIC:
339		softwareRenderer->mosaic = value;
340		break;
341	case REG_GREENSWP:
342		mLOG(GBA_VIDEO, STUB, "Stub video register write: 0x%03X", address);
343		break;
344	default:
345		mLOG(GBA_VIDEO, GAME_ERROR, "Invalid video register: 0x%03X", address);
346	}
347	return value;
348}
349
350static void GBAVideoSoftwareRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
351	if (renderer->cache) {
352		mTileCacheWriteVRAM(renderer->cache, address);
353	}
354}
355
356static void GBAVideoSoftwareRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
357	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
358	softwareRenderer->oamDirty = 1;
359	UNUSED(oam);
360}
361
362static void GBAVideoSoftwareRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
363	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
364#ifdef COLOR_16_BIT
365#ifdef COLOR_5_6_5
366	unsigned color = 0;
367	color |= (value & 0x001F) << 11;
368	color |= (value & 0x03E0) << 1;
369	color |= (value & 0x7C00) >> 10;
370#else
371	unsigned color = value;
372#endif
373#else
374	unsigned color = 0;
375	color |= (value << 3) & 0xF8;
376	color |= (value << 6) & 0xF800;
377	color |= (value << 9) & 0xF80000;
378	color |= (color >> 5) & 0x070707;
379#endif
380	softwareRenderer->normalPalette[address >> 1] = color;
381	if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
382		softwareRenderer->variantPalette[address >> 1] = _brighten(color, softwareRenderer->bldy);
383	} else if (softwareRenderer->blendEffect == BLEND_DARKEN) {
384		softwareRenderer->variantPalette[address >> 1] = _darken(color, softwareRenderer->bldy);
385	}
386	if (renderer->cache) {
387		mTileCacheWritePalette(renderer->cache, address);
388	}
389}
390
391static void _breakWindow(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win, int y) {
392	if (win->v.end >= win->v.start) {
393		if (y >= win->v.end) {
394			return;
395		}
396		if (y < win->v.start) {
397			return;
398		}
399	} else if (y >= win->v.end && y < win->v.start) {
400		return;
401	}
402	if (win->h.end > VIDEO_HORIZONTAL_PIXELS || win->h.end < win->h.start) {
403		struct WindowN splits[2] = { *win, *win };
404		splits[0].h.start = 0;
405		splits[1].h.end = VIDEO_HORIZONTAL_PIXELS;
406		_breakWindowInner(softwareRenderer, &splits[0]);
407		_breakWindowInner(softwareRenderer, &splits[1]);
408	} else {
409		_breakWindowInner(softwareRenderer, win);
410	}
411}
412
413static void _breakWindowInner(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win) {
414	int activeWindow;
415	int startX = 0;
416	if (win->h.end > 0) {
417		for (activeWindow = 0; activeWindow < softwareRenderer->nWindows; ++activeWindow) {
418			if (win->h.start < softwareRenderer->windows[activeWindow].endX) {
419				// Insert a window before the end of the active window
420				struct Window oldWindow = softwareRenderer->windows[activeWindow];
421				if (win->h.start > startX) {
422					// And after the start of the active window
423					int nextWindow = softwareRenderer->nWindows;
424					++softwareRenderer->nWindows;
425					for (; nextWindow > activeWindow; --nextWindow) {
426						softwareRenderer->windows[nextWindow] = softwareRenderer->windows[nextWindow - 1];
427					}
428					softwareRenderer->windows[activeWindow].endX = win->h.start;
429					++activeWindow;
430				}
431				softwareRenderer->windows[activeWindow].control = win->control;
432				softwareRenderer->windows[activeWindow].endX = win->h.end;
433				if (win->h.end >= oldWindow.endX) {
434					// Trim off extra windows we've overwritten
435					for (++activeWindow; softwareRenderer->nWindows > activeWindow + 1 && win->h.end >= softwareRenderer->windows[activeWindow].endX; ++activeWindow) {
436						if (VIDEO_CHECKS && activeWindow >= MAX_WINDOW) {
437							mLOG(GBA_VIDEO, FATAL, "Out of bounds window write will occur");
438							return;
439						}
440						softwareRenderer->windows[activeWindow] = softwareRenderer->windows[activeWindow + 1];
441						--softwareRenderer->nWindows;
442					}
443				} else {
444					++activeWindow;
445					int nextWindow = softwareRenderer->nWindows;
446					++softwareRenderer->nWindows;
447					for (; nextWindow > activeWindow; --nextWindow) {
448						softwareRenderer->windows[nextWindow] = softwareRenderer->windows[nextWindow - 1];
449					}
450					softwareRenderer->windows[activeWindow] = oldWindow;
451				}
452				break;
453			}
454			startX = softwareRenderer->windows[activeWindow].endX;
455		}
456	}
457#ifdef DEBUG
458	if (softwareRenderer->nWindows > MAX_WINDOW) {
459		mLOG(GBA_VIDEO, FATAL, "Out of bounds window write occurred!");
460	}
461#endif
462}
463
464static void _cleanOAM(struct GBAVideoSoftwareRenderer* renderer) {
465	int i;
466	int oamMax = 0;
467	for (i = 0; i < 128; ++i) {
468		struct GBAObj obj;
469		LOAD_16(obj.a, 0, &renderer->d.oam->obj[i].a);
470		LOAD_16(obj.b, 0, &renderer->d.oam->obj[i].b);
471		LOAD_16(obj.c, 0, &renderer->d.oam->obj[i].c);
472		if (GBAObjAttributesAIsTransformed(obj.a) || !GBAObjAttributesAIsDisable(obj.a)) {
473			int height = GBAVideoObjSizes[GBAObjAttributesAGetShape(obj.a) * 4 + GBAObjAttributesBGetSize(obj.b)][1];
474			if (GBAObjAttributesAIsTransformed(obj.a)) {
475				height <<= GBAObjAttributesAGetDoubleSize(obj.a);
476			}
477			if (GBAObjAttributesAGetY(obj.a) < VIDEO_VERTICAL_PIXELS || GBAObjAttributesAGetY(obj.a) + height >= VIDEO_VERTICAL_TOTAL_PIXELS) {
478				renderer->sprites[oamMax].y = GBAObjAttributesAGetY(obj.a);
479				renderer->sprites[oamMax].endY = GBAObjAttributesAGetY(obj.a) + height;
480				renderer->sprites[oamMax].obj = obj;
481				++oamMax;
482			}
483		}
484	}
485	renderer->oamMax = oamMax;
486	renderer->oamDirty = 0;
487}
488
489static void GBAVideoSoftwareRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
490	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
491
492	color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
493	if (GBARegisterDISPCNTIsForcedBlank(softwareRenderer->dispcnt)) {
494		int x;
495		for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; ++x) {
496			row[x] = GBA_COLOR_WHITE;
497		}
498		return;
499	}
500
501	int x;
502	for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; x += 4) {
503		softwareRenderer->spriteLayer[x] = FLAG_UNWRITTEN;
504		softwareRenderer->spriteLayer[x + 1] = FLAG_UNWRITTEN;
505		softwareRenderer->spriteLayer[x + 2] = FLAG_UNWRITTEN;
506		softwareRenderer->spriteLayer[x + 3] = FLAG_UNWRITTEN;
507	}
508
509	softwareRenderer->windows[0].endX = VIDEO_HORIZONTAL_PIXELS;
510	softwareRenderer->nWindows = 1;
511	if (GBARegisterDISPCNTIsWin0Enable(softwareRenderer->dispcnt) || GBARegisterDISPCNTIsWin1Enable(softwareRenderer->dispcnt) || GBARegisterDISPCNTIsObjwinEnable(softwareRenderer->dispcnt)) {
512		softwareRenderer->windows[0].control = softwareRenderer->winout;
513		if (GBARegisterDISPCNTIsWin1Enable(softwareRenderer->dispcnt)) {
514			_breakWindow(softwareRenderer, &softwareRenderer->winN[1], y);
515		}
516		if (GBARegisterDISPCNTIsWin0Enable(softwareRenderer->dispcnt)) {
517			_breakWindow(softwareRenderer, &softwareRenderer->winN[0], y);
518		}
519	} else {
520		softwareRenderer->windows[0].control.packed = 0xFF;
521	}
522
523	GBAVideoSoftwareRendererUpdateDISPCNT(softwareRenderer);
524	if (softwareRenderer->blendDirty) {
525		_updatePalettes(softwareRenderer);
526		softwareRenderer->blendDirty = false;
527	}
528
529	int w;
530	x = 0;
531	for (w = 0; w < softwareRenderer->nWindows; ++w) {
532		// TOOD: handle objwin on backdrop
533		uint32_t backdrop = FLAG_UNWRITTEN | FLAG_PRIORITY | FLAG_IS_BACKGROUND;
534		if (!softwareRenderer->target1Bd || softwareRenderer->blendEffect == BLEND_NONE || softwareRenderer->blendEffect == BLEND_ALPHA || !GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
535			backdrop |= softwareRenderer->normalPalette[0];
536		} else {
537			backdrop |= softwareRenderer->variantPalette[0];
538		}
539		int end = softwareRenderer->windows[w].endX;
540		for (; x < end - 3; x += 4) {
541			softwareRenderer->row[x] = backdrop;
542			softwareRenderer->row[x + 1] = backdrop;
543			softwareRenderer->row[x + 2] = backdrop;
544			softwareRenderer->row[x + 3] = backdrop;
545		}
546		for (; x < end; ++x) {
547			softwareRenderer->row[x] = backdrop;
548		}
549	}
550
551	_drawScanline(softwareRenderer, y);
552
553	if (softwareRenderer->target2Bd) {
554		x = 0;
555		for (w = 0; w < softwareRenderer->nWindows; ++w) {
556			uint32_t backdrop = 0;
557			if (!softwareRenderer->target1Bd || softwareRenderer->blendEffect == BLEND_NONE || softwareRenderer->blendEffect == BLEND_ALPHA || !GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
558				backdrop |= softwareRenderer->normalPalette[0];
559			} else {
560				backdrop |= softwareRenderer->variantPalette[0];
561			}
562			int end = softwareRenderer->windows[w].endX;
563			for (; x < end; ++x) {
564				uint32_t color = softwareRenderer->row[x];
565				if (color & FLAG_TARGET_1) {
566					softwareRenderer->row[x] = _mix(softwareRenderer->bldb, backdrop, softwareRenderer->blda, color);
567				}
568			}
569		}
570	}
571	if (softwareRenderer->target1Obj && (softwareRenderer->blendEffect == BLEND_DARKEN || softwareRenderer->blendEffect == BLEND_BRIGHTEN)) {
572		x = 0;
573		uint32_t mask = FLAG_REBLEND | FLAG_TARGET_1 | FLAG_IS_BACKGROUND;
574		uint32_t match = FLAG_REBLEND;
575		if (GBARegisterDISPCNTIsObjwinEnable(softwareRenderer->dispcnt)) {
576			mask |= FLAG_OBJWIN;
577			if (GBAWindowControlIsBlendEnable(softwareRenderer->objwin.packed)) {
578				match |= FLAG_OBJWIN;
579			}
580		}
581		for (w = 0; w < softwareRenderer->nWindows; ++w) {
582			if (!GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
583				continue;
584			}
585			int end = softwareRenderer->windows[w].endX;
586			if (softwareRenderer->blendEffect == BLEND_DARKEN) {
587				for (; x < end; ++x) {
588					uint32_t color = softwareRenderer->row[x];
589					if ((color & mask) == match) {
590						softwareRenderer->row[x] = _darken(color, softwareRenderer->bldy);
591					}
592				}
593			} else if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
594				for (; x < end; ++x) {
595					uint32_t color = softwareRenderer->row[x];
596					if ((color & mask) == match) {
597						softwareRenderer->row[x] = _brighten(color, softwareRenderer->bldy);
598					}
599				}
600			}
601		}
602	}
603
604#ifdef COLOR_16_BIT
605#if defined(__ARM_NEON) && !defined(__APPLE__)
606	_to16Bit(row, softwareRenderer->row, VIDEO_HORIZONTAL_PIXELS);
607#else
608	for (x = 0; x < VIDEO_HORIZONTAL_PIXELS; ++x) {
609		row[x] = softwareRenderer->row[x];
610	}
611#endif
612#else
613	memcpy(row, softwareRenderer->row, VIDEO_HORIZONTAL_PIXELS * sizeof(*row));
614#endif
615}
616
617static void GBAVideoSoftwareRendererFinishFrame(struct GBAVideoRenderer* renderer) {
618	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
619
620	if (softwareRenderer->temporaryBuffer) {
621		mappedMemoryFree(softwareRenderer->temporaryBuffer, VIDEO_HORIZONTAL_PIXELS * VIDEO_VERTICAL_PIXELS * 4);
622		softwareRenderer->temporaryBuffer = 0;
623	}
624	softwareRenderer->bg[2].sx = softwareRenderer->bg[2].refx;
625	softwareRenderer->bg[2].sy = softwareRenderer->bg[2].refy;
626	softwareRenderer->bg[3].sx = softwareRenderer->bg[3].refx;
627	softwareRenderer->bg[3].sy = softwareRenderer->bg[3].refy;
628}
629
630static void GBAVideoSoftwareRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels) {
631	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
632	*stride = softwareRenderer->outputBufferStride;
633	*pixels = softwareRenderer->outputBuffer;
634}
635
636static void GBAVideoSoftwareRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels) {
637	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
638
639	const color_t* colorPixels = pixels;
640	unsigned i;
641	for (i = 0; i < VIDEO_VERTICAL_PIXELS; ++i) {
642		memmove(&softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * i], &colorPixels[stride * i], VIDEO_HORIZONTAL_PIXELS * BYTES_PER_PIXEL);
643	}
644}
645
646static void GBAVideoSoftwareRendererUpdateDISPCNT(struct GBAVideoSoftwareRenderer* renderer) {
647	renderer->bg[0].enabled = GBARegisterDISPCNTGetBg0Enable(renderer->dispcnt) && !renderer->d.disableBG[0];
648	renderer->bg[1].enabled = GBARegisterDISPCNTGetBg1Enable(renderer->dispcnt) && !renderer->d.disableBG[1];
649	renderer->bg[2].enabled = GBARegisterDISPCNTGetBg2Enable(renderer->dispcnt) && !renderer->d.disableBG[2];
650	renderer->bg[3].enabled = GBARegisterDISPCNTGetBg3Enable(renderer->dispcnt) && !renderer->d.disableBG[3];
651}
652
653static void GBAVideoSoftwareRendererWriteBGCNT(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* bg, uint16_t value) {
654	UNUSED(renderer);
655	bg->priority = GBARegisterBGCNTGetPriority(value);
656	bg->charBase = GBARegisterBGCNTGetCharBase(value) << 14;
657	bg->mosaic = GBARegisterBGCNTGetMosaic(value);
658	bg->multipalette = GBARegisterBGCNTGet256Color(value);
659	bg->screenBase = GBARegisterBGCNTGetScreenBase(value) << 11;
660	bg->overflow = GBARegisterBGCNTGetOverflow(value);
661	bg->size = GBARegisterBGCNTGetSize(value);
662}
663
664static void GBAVideoSoftwareRendererWriteBGPA(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
665	bg->dx = value;
666}
667
668static void GBAVideoSoftwareRendererWriteBGPB(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
669	bg->dmx = value;
670}
671
672static void GBAVideoSoftwareRendererWriteBGPC(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
673	bg->dy = value;
674}
675
676static void GBAVideoSoftwareRendererWriteBGPD(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
677	bg->dmy = value;
678}
679
680static void GBAVideoSoftwareRendererWriteBGX_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
681	bg->refx = (bg->refx & 0xFFFF0000) | value;
682	bg->sx = bg->refx;
683}
684
685static void GBAVideoSoftwareRendererWriteBGX_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
686	bg->refx = (bg->refx & 0x0000FFFF) | (value << 16);
687	bg->refx <<= 4;
688	bg->refx >>= 4;
689	bg->sx = bg->refx;
690}
691
692static void GBAVideoSoftwareRendererWriteBGY_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
693	bg->refy = (bg->refy & 0xFFFF0000) | value;
694	bg->sy = bg->refy;
695}
696
697static void GBAVideoSoftwareRendererWriteBGY_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
698	bg->refy = (bg->refy & 0x0000FFFF) | (value << 16);
699	bg->refy <<= 4;
700	bg->refy >>= 4;
701	bg->sy = bg->refy;
702}
703
704static void GBAVideoSoftwareRendererWriteBLDCNT(struct GBAVideoSoftwareRenderer* renderer, uint16_t value) {
705	enum BlendEffect oldEffect = renderer->blendEffect;
706
707	renderer->bg[0].target1 = GBARegisterBLDCNTGetTarget1Bg0(value);
708	renderer->bg[1].target1 = GBARegisterBLDCNTGetTarget1Bg1(value);
709	renderer->bg[2].target1 = GBARegisterBLDCNTGetTarget1Bg2(value);
710	renderer->bg[3].target1 = GBARegisterBLDCNTGetTarget1Bg3(value);
711	renderer->bg[0].target2 = GBARegisterBLDCNTGetTarget2Bg0(value);
712	renderer->bg[1].target2 = GBARegisterBLDCNTGetTarget2Bg1(value);
713	renderer->bg[2].target2 = GBARegisterBLDCNTGetTarget2Bg2(value);
714	renderer->bg[3].target2 = GBARegisterBLDCNTGetTarget2Bg3(value);
715
716	renderer->blendEffect = GBARegisterBLDCNTGetEffect(value);
717	renderer->target1Obj = GBARegisterBLDCNTGetTarget1Obj(value);
718	renderer->target1Bd = GBARegisterBLDCNTGetTarget1Bd(value);
719	renderer->target2Obj = GBARegisterBLDCNTGetTarget2Obj(value);
720	renderer->target2Bd = GBARegisterBLDCNTGetTarget2Bd(value);
721
722	if (oldEffect != renderer->blendEffect) {
723		renderer->blendDirty = true;
724	}
725}
726
727#define TEST_LAYER_ENABLED(X) \
728	(renderer->bg[X].enabled && \
729	(GBAWindowControlIsBg ## X ## Enable(renderer->currentWindow.packed) || \
730	(GBARegisterDISPCNTIsObjwinEnable(renderer->dispcnt) && GBAWindowControlIsBg ## X ## Enable (renderer->objwin.packed))) && \
731	renderer->bg[X].priority == priority)
732
733static void _drawScanline(struct GBAVideoSoftwareRenderer* renderer, int y) {
734	int w;
735	renderer->end = 0;
736	int spriteLayers = 0;
737	if (GBARegisterDISPCNTIsObjEnable(renderer->dispcnt) && !renderer->d.disableOBJ) {
738		if (renderer->oamDirty) {
739			_cleanOAM(renderer);
740		}
741		renderer->spriteCyclesRemaining = GBARegisterDISPCNTIsHblankIntervalFree(renderer->dispcnt) ? OBJ_HBLANK_FREE_LENGTH : OBJ_LENGTH;
742		int mosaicV = GBAMosaicControlGetObjV(renderer->mosaic) + 1;
743		int mosaicY = y - (y % mosaicV);
744		for (w = 0; w < renderer->nWindows; ++w) {
745			renderer->start = renderer->end;
746			renderer->end = renderer->windows[w].endX;
747			renderer->currentWindow = renderer->windows[w].control;
748			if (!GBAWindowControlIsObjEnable(renderer->currentWindow.packed) && !GBARegisterDISPCNTIsObjwinEnable(renderer->dispcnt)) {
749				continue;
750			}
751			int i;
752			int drawn;
753
754			for (i = 0; i < renderer->oamMax; ++i) {
755				int localY = y;
756				if (renderer->spriteCyclesRemaining <= 0) {
757					break;
758				}
759				struct GBAVideoSoftwareSprite* sprite = &renderer->sprites[i];
760				if (GBAObjAttributesAIsMosaic(sprite->obj.a)) {
761					localY = mosaicY;
762				}
763				if ((localY < sprite->y && (sprite->endY - 256 < 0 || localY >= sprite->endY - 256)) || localY >= sprite->endY) {
764					continue;
765				}
766				drawn = GBAVideoSoftwareRendererPreprocessSprite(renderer, &sprite->obj, localY);
767				spriteLayers |= drawn << GBAObjAttributesCGetPriority(sprite->obj.c);
768			}
769		}
770	}
771
772	unsigned priority;
773	for (priority = 0; priority < 4; ++priority) {
774		renderer->end = 0;
775		for (w = 0; w < renderer->nWindows; ++w) {
776			renderer->start = renderer->end;
777			renderer->end = renderer->windows[w].endX;
778			renderer->currentWindow = renderer->windows[w].control;
779			if (spriteLayers & (1 << priority)) {
780				GBAVideoSoftwareRendererPostprocessSprite(renderer, priority);
781			}
782			if (TEST_LAYER_ENABLED(0) && GBARegisterDISPCNTGetMode(renderer->dispcnt) < 2) {
783				GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[0], y);
784			}
785			if (TEST_LAYER_ENABLED(1) && GBARegisterDISPCNTGetMode(renderer->dispcnt) < 2) {
786				GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[1], y);
787			}
788			if (TEST_LAYER_ENABLED(2)) {
789				switch (GBARegisterDISPCNTGetMode(renderer->dispcnt)) {
790				case 0:
791					GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[2], y);
792					break;
793				case 1:
794				case 2:
795					GBAVideoSoftwareRendererDrawBackgroundMode2(renderer, &renderer->bg[2], y);
796					break;
797				case 3:
798					GBAVideoSoftwareRendererDrawBackgroundMode3(renderer, &renderer->bg[2], y);
799					break;
800				case 4:
801					GBAVideoSoftwareRendererDrawBackgroundMode4(renderer, &renderer->bg[2], y);
802					break;
803				case 5:
804					GBAVideoSoftwareRendererDrawBackgroundMode5(renderer, &renderer->bg[2], y);
805					break;
806				}
807			}
808			if (TEST_LAYER_ENABLED(3)) {
809				switch (GBARegisterDISPCNTGetMode(renderer->dispcnt)) {
810				case 0:
811					GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[3], y);
812					break;
813				case 2:
814					GBAVideoSoftwareRendererDrawBackgroundMode2(renderer, &renderer->bg[3], y);
815					break;
816				}
817			}
818		}
819	}
820	if (GBARegisterDISPCNTGetMode(renderer->dispcnt) != 0) {
821		renderer->bg[2].sx += renderer->bg[2].dmx;
822		renderer->bg[2].sy += renderer->bg[2].dmy;
823		renderer->bg[3].sx += renderer->bg[3].dmx;
824		renderer->bg[3].sy += renderer->bg[3].dmy;
825	}
826}
827
828static void _updatePalettes(struct GBAVideoSoftwareRenderer* renderer) {
829	int i;
830	if (renderer->blendEffect == BLEND_BRIGHTEN) {
831		for (i = 0; i < 512; ++i) {
832			renderer->variantPalette[i] = _brighten(renderer->normalPalette[i], renderer->bldy);
833		}
834	} else if (renderer->blendEffect == BLEND_DARKEN) {
835		for (i = 0; i < 512; ++i) {
836			renderer->variantPalette[i] = _darken(renderer->normalPalette[i], renderer->bldy);
837		}
838	} else {
839		for (i = 0; i < 512; ++i) {
840			renderer->variantPalette[i] = renderer->normalPalette[i];
841		}
842	}
843}