all repos — mgba @ c825c57281734bddefa16c05ec9d61a387029cf5

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/cache-set.h>
  9#include <mgba/internal/arm/macros.h>
 10#include <mgba/internal/gba/io.h>
 11#include <mgba/internal/gba/renderers/cache-set.h>
 12
 13#include <mgba-util/arm-algo.h>
 14#include <mgba-util/memory.h>
 15
 16#define DIRTY_SCANLINE(R, Y) R->scanlineDirty[Y >> 5] |= (1U << (Y & 0x1F))
 17#define CLEAN_SCANLINE(R, Y) R->scanlineDirty[Y >> 5] &= ~(1U << (Y & 0x1F))
 18
 19static void GBAVideoSoftwareRendererInit(struct GBAVideoRenderer* renderer);
 20static void GBAVideoSoftwareRendererDeinit(struct GBAVideoRenderer* renderer);
 21static void GBAVideoSoftwareRendererReset(struct GBAVideoRenderer* renderer);
 22static void GBAVideoSoftwareRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address);
 23static void GBAVideoSoftwareRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam);
 24static void GBAVideoSoftwareRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
 25static uint16_t GBAVideoSoftwareRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
 26static void GBAVideoSoftwareRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
 27static void GBAVideoSoftwareRendererFinishFrame(struct GBAVideoRenderer* renderer);
 28static void GBAVideoSoftwareRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels);
 29static void GBAVideoSoftwareRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels);
 30
 31static void GBAVideoSoftwareRendererUpdateDISPCNT(struct GBAVideoSoftwareRenderer* renderer);
 32static void GBAVideoSoftwareRendererWriteBGCNT(struct GBAVideoSoftwareRenderer* renderer, 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 _drawScanline(struct GBAVideoSoftwareRenderer* renderer, int y);
 40
 41static void _updatePalettes(struct GBAVideoSoftwareRenderer* renderer);
 42
 43static void _breakWindow(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win, int y);
 44static void _breakWindowInner(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win);
 45
 46void GBAVideoSoftwareRendererCreate(struct GBAVideoSoftwareRenderer* renderer) {
 47	renderer->d.init = GBAVideoSoftwareRendererInit;
 48	renderer->d.reset = GBAVideoSoftwareRendererReset;
 49	renderer->d.deinit = GBAVideoSoftwareRendererDeinit;
 50	renderer->d.writeVideoRegister = GBAVideoSoftwareRendererWriteVideoRegister;
 51	renderer->d.writeVRAM = GBAVideoSoftwareRendererWriteVRAM;
 52	renderer->d.writeOAM = GBAVideoSoftwareRendererWriteOAM;
 53	renderer->d.writePalette = GBAVideoSoftwareRendererWritePalette;
 54	renderer->d.drawScanline = GBAVideoSoftwareRendererDrawScanline;
 55	renderer->d.finishFrame = GBAVideoSoftwareRendererFinishFrame;
 56	renderer->d.getPixels = GBAVideoSoftwareRendererGetPixels;
 57	renderer->d.putPixels = GBAVideoSoftwareRendererPutPixels;
 58
 59	renderer->d.disableBG[0] = false;
 60	renderer->d.disableBG[1] = false;
 61	renderer->d.disableBG[2] = false;
 62	renderer->d.disableBG[3] = false;
 63	renderer->d.disableOBJ = false;
 64
 65	renderer->d.highlightBG[0] = false;
 66	renderer->d.highlightBG[1] = false;
 67	renderer->d.highlightBG[2] = false;
 68	renderer->d.highlightBG[3] = false;
 69	int i;
 70	for (i = 0; i < 128; ++i) {
 71		renderer->d.highlightOBJ[i] = false;
 72	}
 73	renderer->d.highlightColor = GBA_COLOR_WHITE;
 74	renderer->d.highlightAmount = 0;
 75
 76	renderer->temporaryBuffer = 0;
 77}
 78
 79static void GBAVideoSoftwareRendererInit(struct GBAVideoRenderer* renderer) {
 80	GBAVideoSoftwareRendererReset(renderer);
 81
 82	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
 83
 84	int y;
 85	for (y = 0; y < GBA_VIDEO_VERTICAL_PIXELS; ++y) {
 86		color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
 87		int x;
 88		for (x = 0; x < GBA_VIDEO_HORIZONTAL_PIXELS; ++x) {
 89			row[x] = GBA_COLOR_WHITE;
 90		}
 91	}
 92}
 93
 94static void GBAVideoSoftwareRendererReset(struct GBAVideoRenderer* renderer) {
 95	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
 96	int i;
 97
 98	softwareRenderer->dispcnt = 0x0080;
 99
100	softwareRenderer->target1Obj = 0;
101	softwareRenderer->target1Bd = 0;
102	softwareRenderer->target2Obj = 0;
103	softwareRenderer->target2Bd = 0;
104	softwareRenderer->blendEffect = BLEND_NONE;
105	for (i = 0; i < 1024; i += 2) {
106		uint16_t entry;
107		LOAD_16(entry, i, softwareRenderer->d.palette);
108		GBAVideoSoftwareRendererWritePalette(renderer, i, entry);
109	}
110	softwareRenderer->blendDirty = false;
111	_updatePalettes(softwareRenderer);
112
113	softwareRenderer->blda = 0;
114	softwareRenderer->bldb = 0;
115	softwareRenderer->bldy = 0;
116
117	softwareRenderer->winN[0] = (struct WindowN) { .control = { .priority = 0 } };
118	softwareRenderer->winN[1] = (struct WindowN) { .control = { .priority = 1 } };
119	softwareRenderer->objwin = (struct WindowControl) { .priority = 2 };
120	softwareRenderer->winout = (struct WindowControl) { .priority = 3 };
121	softwareRenderer->oamDirty = 1;
122	softwareRenderer->oamMax = 0;
123
124	softwareRenderer->mosaic = 0;
125	softwareRenderer->greenswap = false;
126	softwareRenderer->nextY = 0;
127
128	softwareRenderer->objOffsetX = 0;
129	softwareRenderer->objOffsetY = 0;
130
131	memset(softwareRenderer->scanlineDirty, 0xFFFFFFFF, sizeof(softwareRenderer->scanlineDirty));
132	memset(softwareRenderer->cache, 0, sizeof(softwareRenderer->cache));
133	memset(softwareRenderer->nextIo, 0, sizeof(softwareRenderer->nextIo));
134
135	softwareRenderer->lastHighlightAmount = 0;
136
137	for (i = 0; i < 4; ++i) {
138		struct GBAVideoSoftwareBackground* bg = &softwareRenderer->bg[i];
139		bg->index = i;
140		bg->enabled = 0;
141		bg->priority = 0;
142		bg->charBase = 0;
143		bg->mosaic = 0;
144		bg->multipalette = 0;
145		bg->screenBase = 0;
146		bg->overflow = 0;
147		bg->size = 0;
148		bg->target1 = 0;
149		bg->target2 = 0;
150		bg->x = 0;
151		bg->y = 0;
152		bg->refx = 0;
153		bg->refy = 0;
154		bg->dx = 256;
155		bg->dmx = 0;
156		bg->dy = 0;
157		bg->dmy = 256;
158		bg->sx = 0;
159		bg->sy = 0;
160		bg->yCache = -1;
161		bg->offsetX = 0;
162		bg->offsetY = 0;
163	}
164}
165
166static void GBAVideoSoftwareRendererDeinit(struct GBAVideoRenderer* renderer) {
167	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
168	UNUSED(softwareRenderer);
169}
170
171static uint16_t GBAVideoSoftwareRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
172	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
173	if (renderer->cache) {
174		GBAVideoCacheWriteVideoRegister(renderer->cache, address, value);
175	}
176
177	switch (address) {
178	case REG_DISPCNT:
179		value &= 0xFFF7;
180		softwareRenderer->dispcnt = value;
181		GBAVideoSoftwareRendererUpdateDISPCNT(softwareRenderer);
182		break;
183	case REG_GREENSWP:
184		softwareRenderer->greenswap = value & 1;
185		break;
186	case REG_BG0CNT:
187		value &= 0xDFFF;
188		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[0], value);
189		break;
190	case REG_BG1CNT:
191		value &= 0xDFFF;
192		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[1], value);
193		break;
194	case REG_BG2CNT:
195		value &= 0xFFFF;
196		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[2], value);
197		break;
198	case REG_BG3CNT:
199		value &= 0xFFFF;
200		GBAVideoSoftwareRendererWriteBGCNT(softwareRenderer, &softwareRenderer->bg[3], value);
201		break;
202	case REG_BG0HOFS:
203		value &= 0x01FF;
204		softwareRenderer->bg[0].x = value;
205		break;
206	case REG_BG0VOFS:
207		value &= 0x01FF;
208		softwareRenderer->bg[0].y = value;
209		break;
210	case REG_BG1HOFS:
211		value &= 0x01FF;
212		softwareRenderer->bg[1].x = value;
213		break;
214	case REG_BG1VOFS:
215		value &= 0x01FF;
216		softwareRenderer->bg[1].y = value;
217		break;
218	case REG_BG2HOFS:
219		value &= 0x01FF;
220		softwareRenderer->bg[2].x = value;
221		break;
222	case REG_BG2VOFS:
223		value &= 0x01FF;
224		softwareRenderer->bg[2].y = value;
225		break;
226	case REG_BG3HOFS:
227		value &= 0x01FF;
228		softwareRenderer->bg[3].x = value;
229		break;
230	case REG_BG3VOFS:
231		value &= 0x01FF;
232		softwareRenderer->bg[3].y = value;
233		break;
234	case REG_BG2PA:
235		softwareRenderer->bg[2].dx = value;
236		break;
237	case REG_BG2PB:
238		softwareRenderer->bg[2].dmx = value;
239		break;
240	case REG_BG2PC:
241		softwareRenderer->bg[2].dy = value;
242		break;
243	case REG_BG2PD:
244		softwareRenderer->bg[2].dmy = value;
245		break;
246	case REG_BG2X_LO:
247		GBAVideoSoftwareRendererWriteBGX_LO(&softwareRenderer->bg[2], value);
248		if (softwareRenderer->bg[2].sx != softwareRenderer->cache[softwareRenderer->nextY].scale[0][0]) {
249			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
250		}
251		break;
252	case REG_BG2X_HI:
253		GBAVideoSoftwareRendererWriteBGX_HI(&softwareRenderer->bg[2], value);
254		if (softwareRenderer->bg[2].sx != softwareRenderer->cache[softwareRenderer->nextY].scale[0][0]) {
255			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
256		}
257		break;
258	case REG_BG2Y_LO:
259		GBAVideoSoftwareRendererWriteBGY_LO(&softwareRenderer->bg[2], value);
260		if (softwareRenderer->bg[2].sy != softwareRenderer->cache[softwareRenderer->nextY].scale[0][1]) {
261			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
262		}
263		break;
264	case REG_BG2Y_HI:
265		GBAVideoSoftwareRendererWriteBGY_HI(&softwareRenderer->bg[2], value);
266		if (softwareRenderer->bg[2].sy != softwareRenderer->cache[softwareRenderer->nextY].scale[0][1]) {
267			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
268		}
269		break;
270	case REG_BG3PA:
271		softwareRenderer->bg[3].dx = value;
272		break;
273	case REG_BG3PB:
274		softwareRenderer->bg[3].dmx = value;
275		break;
276	case REG_BG3PC:
277		softwareRenderer->bg[3].dy = value;
278		break;
279	case REG_BG3PD:
280		softwareRenderer->bg[3].dmy = value;
281		break;
282	case REG_BG3X_LO:
283		GBAVideoSoftwareRendererWriteBGX_LO(&softwareRenderer->bg[3], value);
284		if (softwareRenderer->bg[3].sx != softwareRenderer->cache[softwareRenderer->nextY].scale[1][0]) {
285			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
286		}
287		break;
288	case REG_BG3X_HI:
289		GBAVideoSoftwareRendererWriteBGX_HI(&softwareRenderer->bg[3], value);
290		if (softwareRenderer->bg[3].sx != softwareRenderer->cache[softwareRenderer->nextY].scale[1][0]) {
291			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
292		}
293		break;
294	case REG_BG3Y_LO:
295		GBAVideoSoftwareRendererWriteBGY_LO(&softwareRenderer->bg[3], value);
296		if (softwareRenderer->bg[3].sy != softwareRenderer->cache[softwareRenderer->nextY].scale[1][1]) {
297			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
298		}
299		break;
300	case REG_BG3Y_HI:
301		GBAVideoSoftwareRendererWriteBGY_HI(&softwareRenderer->bg[3], value);
302		if (softwareRenderer->bg[3].sy != softwareRenderer->cache[softwareRenderer->nextY].scale[1][1]) {
303			DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
304		}
305		break;
306	case REG_BLDCNT:
307		GBAVideoSoftwareRendererWriteBLDCNT(softwareRenderer, value);
308		value &= 0x3FFF;
309		break;
310	case REG_BLDALPHA:
311		softwareRenderer->blda = value & 0x1F;
312		if (softwareRenderer->blda > 0x10) {
313			softwareRenderer->blda = 0x10;
314		}
315		softwareRenderer->bldb = (value >> 8) & 0x1F;
316		if (softwareRenderer->bldb > 0x10) {
317			softwareRenderer->bldb = 0x10;
318		}
319		value &= 0x1F1F;
320		break;
321	case REG_BLDY:
322		value &= 0x1F;
323		if (value > 0x10) {
324			value = 0x10;
325		}
326		if (softwareRenderer->bldy != value) {
327			softwareRenderer->bldy = value;
328			softwareRenderer->blendDirty = true;
329		}
330		break;
331	case REG_WIN0H:
332		softwareRenderer->winN[0].h.end = value;
333		softwareRenderer->winN[0].h.start = value >> 8;
334		if (softwareRenderer->winN[0].h.start > GBA_VIDEO_HORIZONTAL_PIXELS && softwareRenderer->winN[0].h.start > softwareRenderer->winN[0].h.end) {
335			softwareRenderer->winN[0].h.start = 0;
336		}
337		if (softwareRenderer->winN[0].h.end > GBA_VIDEO_HORIZONTAL_PIXELS) {
338			softwareRenderer->winN[0].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
339			if (softwareRenderer->winN[0].h.start > GBA_VIDEO_HORIZONTAL_PIXELS) {
340				softwareRenderer->winN[0].h.start = GBA_VIDEO_HORIZONTAL_PIXELS;
341			}
342		}
343		break;
344	case REG_WIN1H:
345		softwareRenderer->winN[1].h.end = value;
346		softwareRenderer->winN[1].h.start = value >> 8;
347		if (softwareRenderer->winN[1].h.start > GBA_VIDEO_HORIZONTAL_PIXELS && softwareRenderer->winN[1].h.start > softwareRenderer->winN[1].h.end) {
348			softwareRenderer->winN[1].h.start = 0;
349		}
350		if (softwareRenderer->winN[1].h.end > GBA_VIDEO_HORIZONTAL_PIXELS) {
351			softwareRenderer->winN[1].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
352			if (softwareRenderer->winN[1].h.start > GBA_VIDEO_HORIZONTAL_PIXELS) {
353				softwareRenderer->winN[1].h.start = GBA_VIDEO_HORIZONTAL_PIXELS;
354			}
355		}
356		break;
357	case REG_WIN0V:
358		softwareRenderer->winN[0].v.end = value;
359		softwareRenderer->winN[0].v.start = value >> 8;
360		if (softwareRenderer->winN[0].v.start > GBA_VIDEO_VERTICAL_PIXELS && softwareRenderer->winN[0].v.start > softwareRenderer->winN[0].v.end) {
361			softwareRenderer->winN[0].v.start = 0;
362		}
363		if (softwareRenderer->winN[0].v.end > GBA_VIDEO_VERTICAL_PIXELS) {
364			softwareRenderer->winN[0].v.end = GBA_VIDEO_VERTICAL_PIXELS;
365			if (softwareRenderer->winN[0].v.start > GBA_VIDEO_VERTICAL_PIXELS) {
366				softwareRenderer->winN[0].v.start = GBA_VIDEO_VERTICAL_PIXELS;
367			}
368		}
369		break;
370	case REG_WIN1V:
371		softwareRenderer->winN[1].v.end = value;
372		softwareRenderer->winN[1].v.start = value >> 8;
373		if (softwareRenderer->winN[1].v.start > GBA_VIDEO_VERTICAL_PIXELS && softwareRenderer->winN[1].v.start > softwareRenderer->winN[1].v.end) {
374			softwareRenderer->winN[1].v.start = 0;
375		}
376		if (softwareRenderer->winN[1].v.end > GBA_VIDEO_VERTICAL_PIXELS) {
377			softwareRenderer->winN[1].v.end = GBA_VIDEO_VERTICAL_PIXELS;
378			if (softwareRenderer->winN[1].v.start > GBA_VIDEO_VERTICAL_PIXELS) {
379				softwareRenderer->winN[1].v.start = GBA_VIDEO_VERTICAL_PIXELS;
380			}
381		}
382		break;
383	case REG_WININ:
384		value &= 0x3F3F;
385		softwareRenderer->winN[0].control.packed = value;
386		softwareRenderer->winN[1].control.packed = value >> 8;
387		break;
388	case REG_WINOUT:
389		value &= 0x3F3F;
390		softwareRenderer->winout.packed = value;
391		softwareRenderer->objwin.packed = value >> 8;
392		break;
393	case REG_MOSAIC:
394		softwareRenderer->mosaic = value;
395		break;
396	default:
397		mLOG(GBA_VIDEO, GAME_ERROR, "Invalid video register: 0x%03X", address);
398	}
399	softwareRenderer->nextIo[address >> 1] = value;
400	if (softwareRenderer->cache[softwareRenderer->nextY].io[address >> 1] != value) {
401		softwareRenderer->cache[softwareRenderer->nextY].io[address >> 1] = value;
402		DIRTY_SCANLINE(softwareRenderer, softwareRenderer->nextY);
403	}
404	return value;
405}
406
407static void GBAVideoSoftwareRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
408	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
409	if (renderer->cache) {
410		mCacheSetWriteVRAM(renderer->cache, address);
411	}
412	memset(softwareRenderer->scanlineDirty, 0xFFFFFFFF, sizeof(softwareRenderer->scanlineDirty));
413	softwareRenderer->bg[0].yCache = -1;
414	softwareRenderer->bg[1].yCache = -1;
415	softwareRenderer->bg[2].yCache = -1;
416	softwareRenderer->bg[3].yCache = -1;
417}
418
419static void GBAVideoSoftwareRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
420	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
421	UNUSED(oam);
422	softwareRenderer->oamDirty = 1;
423	memset(softwareRenderer->scanlineDirty, 0xFFFFFFFF, sizeof(softwareRenderer->scanlineDirty));
424}
425
426static void GBAVideoSoftwareRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
427	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
428	color_t color = mColorFrom555(value);
429	softwareRenderer->normalPalette[address >> 1] = color;
430	if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
431		softwareRenderer->variantPalette[address >> 1] = _brighten(color, softwareRenderer->bldy);
432	} else if (softwareRenderer->blendEffect == BLEND_DARKEN) {
433		softwareRenderer->variantPalette[address >> 1] = _darken(color, softwareRenderer->bldy);
434	}
435	if (renderer->cache) {
436		mCacheSetWritePalette(renderer->cache, address >> 1, color);
437	}
438	memset(softwareRenderer->scanlineDirty, 0xFFFFFFFF, sizeof(softwareRenderer->scanlineDirty));
439}
440
441static void _breakWindow(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win, int y) {
442	if (win->v.end >= win->v.start) {
443		if (y >= win->v.end) {
444			return;
445		}
446		if (y < win->v.start) {
447			return;
448		}
449	} else if (y >= win->v.end && y < win->v.start) {
450		return;
451	}
452	if (win->h.end > GBA_VIDEO_HORIZONTAL_PIXELS || win->h.end < win->h.start) {
453		struct WindowN splits[2] = { *win, *win };
454		splits[0].h.start = 0;
455		splits[1].h.end = GBA_VIDEO_HORIZONTAL_PIXELS;
456		_breakWindowInner(softwareRenderer, &splits[0]);
457		_breakWindowInner(softwareRenderer, &splits[1]);
458	} else {
459		_breakWindowInner(softwareRenderer, win);
460	}
461}
462
463static void _breakWindowInner(struct GBAVideoSoftwareRenderer* softwareRenderer, struct WindowN* win) {
464	int activeWindow;
465	int startX = 0;
466	if (win->h.end > 0) {
467		for (activeWindow = 0; activeWindow < softwareRenderer->nWindows; ++activeWindow) {
468			if (win->h.start < softwareRenderer->windows[activeWindow].endX) {
469				// Insert a window before the end of the active window
470				struct Window oldWindow = softwareRenderer->windows[activeWindow];
471				if (win->h.start > startX) {
472					// And after the start of the active window
473					int nextWindow = softwareRenderer->nWindows;
474					++softwareRenderer->nWindows;
475					for (; nextWindow > activeWindow; --nextWindow) {
476						softwareRenderer->windows[nextWindow] = softwareRenderer->windows[nextWindow - 1];
477					}
478					softwareRenderer->windows[activeWindow].endX = win->h.start;
479					++activeWindow;
480				}
481				softwareRenderer->windows[activeWindow].control = win->control;
482				softwareRenderer->windows[activeWindow].endX = win->h.end;
483				if (win->h.end >= oldWindow.endX) {
484					// Trim off extra windows we've overwritten
485					for (++activeWindow; softwareRenderer->nWindows > activeWindow + 1 && win->h.end >= softwareRenderer->windows[activeWindow].endX; ++activeWindow) {
486						if (VIDEO_CHECKS && activeWindow >= MAX_WINDOW) {
487							mLOG(GBA_VIDEO, FATAL, "Out of bounds window write will occur");
488							return;
489						}
490						softwareRenderer->windows[activeWindow] = softwareRenderer->windows[activeWindow + 1];
491						--softwareRenderer->nWindows;
492					}
493				} else {
494					++activeWindow;
495					int nextWindow = softwareRenderer->nWindows;
496					++softwareRenderer->nWindows;
497					for (; nextWindow > activeWindow; --nextWindow) {
498						softwareRenderer->windows[nextWindow] = softwareRenderer->windows[nextWindow - 1];
499					}
500					softwareRenderer->windows[activeWindow] = oldWindow;
501				}
502				break;
503			}
504			startX = softwareRenderer->windows[activeWindow].endX;
505		}
506	}
507#ifdef DEBUG
508	if (softwareRenderer->nWindows > MAX_WINDOW) {
509		mLOG(GBA_VIDEO, FATAL, "Out of bounds window write occurred!");
510	}
511#endif
512}
513
514static void GBAVideoSoftwareRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
515	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
516
517	if (y == GBA_VIDEO_VERTICAL_PIXELS - 1) {
518		softwareRenderer->nextY = 0;
519	} else {
520		softwareRenderer->nextY = y + 1;
521	}
522
523	bool dirty = softwareRenderer->scanlineDirty[y >> 5] & (1U << (y & 0x1F));
524	if (memcmp(softwareRenderer->nextIo, softwareRenderer->cache[y].io, sizeof(softwareRenderer->nextIo))) {
525		memcpy(softwareRenderer->cache[y].io, softwareRenderer->nextIo, sizeof(softwareRenderer->nextIo));
526		dirty = true;
527	}
528
529	if (GBARegisterDISPCNTGetMode(softwareRenderer->dispcnt) != 0) {
530		if (softwareRenderer->cache[y].scale[0][0] != softwareRenderer->bg[2].sx ||
531		    softwareRenderer->cache[y].scale[0][1] != softwareRenderer->bg[2].sy ||
532		    softwareRenderer->cache[y].scale[1][0] != softwareRenderer->bg[3].sx ||
533		    softwareRenderer->cache[y].scale[1][1] != softwareRenderer->bg[3].sy) {
534			dirty = true;
535		}
536	}
537	softwareRenderer->cache[y].scale[0][0] = softwareRenderer->bg[2].sx;
538	softwareRenderer->cache[y].scale[0][1] = softwareRenderer->bg[2].sy;
539	softwareRenderer->cache[y].scale[1][0] = softwareRenderer->bg[3].sx;
540	softwareRenderer->cache[y].scale[1][1] = softwareRenderer->bg[3].sy;
541
542	if (!dirty) {
543		if (GBARegisterDISPCNTGetMode(softwareRenderer->dispcnt) != 0) {
544			softwareRenderer->bg[2].sx += softwareRenderer->bg[2].dmx;
545			softwareRenderer->bg[2].sy += softwareRenderer->bg[2].dmy;
546			softwareRenderer->bg[3].sx += softwareRenderer->bg[3].dmx;
547			softwareRenderer->bg[3].sy += softwareRenderer->bg[3].dmy;
548		}
549		return;
550	}
551
552	CLEAN_SCANLINE(softwareRenderer, y);
553
554	color_t* row = &softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * y];
555	if (GBARegisterDISPCNTIsForcedBlank(softwareRenderer->dispcnt)) {
556		int x;
557		for (x = 0; x < GBA_VIDEO_HORIZONTAL_PIXELS; ++x) {
558			row[x] = GBA_COLOR_WHITE;
559		}
560		return;
561	}
562
563	int x;
564	for (x = 0; x < GBA_VIDEO_HORIZONTAL_PIXELS; x += 4) {
565		softwareRenderer->spriteLayer[x] = FLAG_UNWRITTEN;
566		softwareRenderer->spriteLayer[x + 1] = FLAG_UNWRITTEN;
567		softwareRenderer->spriteLayer[x + 2] = FLAG_UNWRITTEN;
568		softwareRenderer->spriteLayer[x + 3] = FLAG_UNWRITTEN;
569	}
570
571	softwareRenderer->windows[0].endX = GBA_VIDEO_HORIZONTAL_PIXELS;
572	softwareRenderer->nWindows = 1;
573	if (GBARegisterDISPCNTIsWin0Enable(softwareRenderer->dispcnt) || GBARegisterDISPCNTIsWin1Enable(softwareRenderer->dispcnt) || GBARegisterDISPCNTIsObjwinEnable(softwareRenderer->dispcnt)) {
574		softwareRenderer->windows[0].control = softwareRenderer->winout;
575		if (GBARegisterDISPCNTIsWin1Enable(softwareRenderer->dispcnt)) {
576			_breakWindow(softwareRenderer, &softwareRenderer->winN[1], y);
577		}
578		if (GBARegisterDISPCNTIsWin0Enable(softwareRenderer->dispcnt)) {
579			_breakWindow(softwareRenderer, &softwareRenderer->winN[0], y);
580		}
581	} else {
582		softwareRenderer->windows[0].control.packed = 0xFF;
583	}
584
585	if (softwareRenderer->lastHighlightAmount != softwareRenderer->d.highlightAmount) {
586		softwareRenderer->lastHighlightAmount = softwareRenderer->d.highlightAmount;
587		if (softwareRenderer->lastHighlightAmount) {
588			softwareRenderer->blendDirty = true;
589		}
590	}
591
592	if (softwareRenderer->blendDirty) {
593		_updatePalettes(softwareRenderer);
594		softwareRenderer->blendDirty = false;
595	}
596	softwareRenderer->forceTarget1 = false;
597
598	int w;
599	x = 0;
600	for (w = 0; w < softwareRenderer->nWindows; ++w) {
601		// TOOD: handle objwin on backdrop
602		uint32_t backdrop = FLAG_UNWRITTEN | FLAG_PRIORITY | FLAG_IS_BACKGROUND;
603		if (!softwareRenderer->target1Bd || softwareRenderer->blendEffect == BLEND_NONE || softwareRenderer->blendEffect == BLEND_ALPHA || !GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
604			backdrop |= softwareRenderer->normalPalette[0];
605		} else {
606			backdrop |= softwareRenderer->variantPalette[0];
607		}
608		int end = softwareRenderer->windows[w].endX;
609		for (; x < end - 3; x += 4) {
610			softwareRenderer->row[x] = backdrop;
611			softwareRenderer->row[x + 1] = backdrop;
612			softwareRenderer->row[x + 2] = backdrop;
613			softwareRenderer->row[x + 3] = backdrop;
614		}
615		for (; x < end; ++x) {
616			softwareRenderer->row[x] = backdrop;
617		}
618	}
619
620	softwareRenderer->bg[0].highlight = softwareRenderer->d.highlightBG[0];
621	softwareRenderer->bg[1].highlight = softwareRenderer->d.highlightBG[1];
622	softwareRenderer->bg[2].highlight = softwareRenderer->d.highlightBG[2];
623	softwareRenderer->bg[3].highlight = softwareRenderer->d.highlightBG[3];
624
625	_drawScanline(softwareRenderer, y);
626
627	if ((softwareRenderer->forceTarget1 || softwareRenderer->bg[0].target1 || softwareRenderer->bg[1].target1 || softwareRenderer->bg[2].target1 || softwareRenderer->bg[3].target1) && softwareRenderer->target2Bd) {
628		x = 0;
629		for (w = 0; w < softwareRenderer->nWindows; ++w) {
630			uint32_t backdrop = 0;
631			if (!softwareRenderer->target1Bd || softwareRenderer->blendEffect == BLEND_NONE || softwareRenderer->blendEffect == BLEND_ALPHA || !GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
632				backdrop |= softwareRenderer->normalPalette[0];
633			} else {
634				backdrop |= softwareRenderer->variantPalette[0];
635			}
636			int end = softwareRenderer->windows[w].endX;
637			for (; x < end; ++x) {
638				uint32_t color = softwareRenderer->row[x];
639				if (color & FLAG_TARGET_1) {
640					softwareRenderer->row[x] = _mix(softwareRenderer->bldb, backdrop, softwareRenderer->blda, color);
641				}
642			}
643		}
644	}
645	if (softwareRenderer->forceTarget1 && (softwareRenderer->blendEffect == BLEND_DARKEN || softwareRenderer->blendEffect == BLEND_BRIGHTEN)) {
646		x = 0;
647		uint32_t mask = FLAG_REBLEND | FLAG_IS_BACKGROUND;
648		uint32_t match = FLAG_REBLEND;
649		if (GBARegisterDISPCNTIsObjwinEnable(softwareRenderer->dispcnt)) {
650			mask |= FLAG_OBJWIN;
651			if (GBAWindowControlIsBlendEnable(softwareRenderer->objwin.packed)) {
652				match |= FLAG_OBJWIN;
653			}
654		}
655		for (w = 0; w < softwareRenderer->nWindows; ++w) {
656			int end = softwareRenderer->windows[w].endX;
657			if (!GBAWindowControlIsBlendEnable(softwareRenderer->windows[w].control.packed)) {
658				x = end;
659				continue;
660			}
661			if (softwareRenderer->blendEffect == BLEND_DARKEN) {
662				for (; x < end; ++x) {
663					uint32_t color = softwareRenderer->row[x];
664					if ((color & mask) == match) {
665						softwareRenderer->row[x] = _darken(color, softwareRenderer->bldy);
666					}
667				}
668			} else if (softwareRenderer->blendEffect == BLEND_BRIGHTEN) {
669				for (; x < end; ++x) {
670					uint32_t color = softwareRenderer->row[x];
671					if ((color & mask) == match) {
672						softwareRenderer->row[x] = _brighten(color, softwareRenderer->bldy);
673					}
674				}
675			}
676		}
677	}
678
679	if (softwareRenderer->greenswap) {
680		for (x = 0; x < GBA_VIDEO_HORIZONTAL_PIXELS; x += 4) {
681			row[x] = softwareRenderer->row[x] & (M_COLOR_RED | M_COLOR_BLUE);
682			row[x] |= softwareRenderer->row[x + 1] & M_COLOR_GREEN;
683			row[x + 1] = softwareRenderer->row[x + 1] & (M_COLOR_RED | M_COLOR_BLUE);
684			row[x + 1] |= softwareRenderer->row[x] & M_COLOR_GREEN;
685			row[x + 2] = softwareRenderer->row[x + 2] & (M_COLOR_RED | M_COLOR_BLUE);
686			row[x + 2] |= softwareRenderer->row[x + 3] & M_COLOR_GREEN;
687			row[x + 3] = softwareRenderer->row[x + 3] & (M_COLOR_RED | M_COLOR_BLUE);
688			row[x + 3] |= softwareRenderer->row[x + 2] & M_COLOR_GREEN;
689
690		}
691	} else {
692#ifdef COLOR_16_BIT
693		for (x = 0; x < GBA_VIDEO_HORIZONTAL_PIXELS; x += 4) {
694			row[x] = softwareRenderer->row[x];
695			row[x + 1] = softwareRenderer->row[x + 1];
696			row[x + 2] = softwareRenderer->row[x + 2];
697			row[x + 3] = softwareRenderer->row[x + 3];
698		}
699#else
700		memcpy(row, softwareRenderer->row, GBA_VIDEO_HORIZONTAL_PIXELS * sizeof(*row));
701#endif
702	}
703}
704
705static void GBAVideoSoftwareRendererFinishFrame(struct GBAVideoRenderer* renderer) {
706	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
707
708	softwareRenderer->nextY = 0;
709	if (softwareRenderer->temporaryBuffer) {
710		mappedMemoryFree(softwareRenderer->temporaryBuffer, GBA_VIDEO_HORIZONTAL_PIXELS * GBA_VIDEO_VERTICAL_PIXELS * 4);
711		softwareRenderer->temporaryBuffer = 0;
712	}
713	softwareRenderer->bg[2].sx = softwareRenderer->bg[2].refx;
714	softwareRenderer->bg[2].sy = softwareRenderer->bg[2].refy;
715	softwareRenderer->bg[3].sx = softwareRenderer->bg[3].refx;
716	softwareRenderer->bg[3].sy = softwareRenderer->bg[3].refy;
717
718	if (softwareRenderer->bg[0].enabled > 0) {
719		softwareRenderer->bg[0].enabled = 3;
720	}
721	if (softwareRenderer->bg[1].enabled > 0) {
722		softwareRenderer->bg[1].enabled = 3;
723	}
724	if (softwareRenderer->bg[2].enabled > 0) {
725		softwareRenderer->bg[2].enabled = 3;
726	}
727	if (softwareRenderer->bg[3].enabled > 0) {
728		softwareRenderer->bg[3].enabled = 3;
729	}
730}
731
732static void GBAVideoSoftwareRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels) {
733	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
734	*stride = softwareRenderer->outputBufferStride;
735	*pixels = softwareRenderer->outputBuffer;
736}
737
738static void GBAVideoSoftwareRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels) {
739	struct GBAVideoSoftwareRenderer* softwareRenderer = (struct GBAVideoSoftwareRenderer*) renderer;
740
741	const color_t* colorPixels = pixels;
742	unsigned i;
743	for (i = 0; i < GBA_VIDEO_VERTICAL_PIXELS; ++i) {
744		memmove(&softwareRenderer->outputBuffer[softwareRenderer->outputBufferStride * i], &colorPixels[stride * i], GBA_VIDEO_HORIZONTAL_PIXELS * BYTES_PER_PIXEL);
745	}
746}
747
748static void _enableBg(struct GBAVideoSoftwareRenderer* renderer, int bg, bool active) {
749	int wasActive = renderer->bg[bg].enabled;
750	if (!active) {
751		renderer->bg[bg].enabled = 0;
752	} else if (!wasActive && active) {
753		if (renderer->nextY == 0 || GBARegisterDISPCNTGetMode(renderer->dispcnt) > 2) {
754			// TODO: Investigate in more depth how switching background works in different modes
755			renderer->bg[bg].enabled = 3;
756		} else {
757			renderer->bg[bg].enabled = 1;
758		}
759	}
760}
761
762static void GBAVideoSoftwareRendererUpdateDISPCNT(struct GBAVideoSoftwareRenderer* renderer) {
763	_enableBg(renderer, 0, GBARegisterDISPCNTGetBg0Enable(renderer->dispcnt));
764	_enableBg(renderer, 1, GBARegisterDISPCNTGetBg1Enable(renderer->dispcnt));
765	_enableBg(renderer, 2, GBARegisterDISPCNTGetBg2Enable(renderer->dispcnt));
766	_enableBg(renderer, 3, GBARegisterDISPCNTGetBg3Enable(renderer->dispcnt));
767}
768
769static void GBAVideoSoftwareRendererWriteBGCNT(struct GBAVideoSoftwareRenderer* renderer, struct GBAVideoSoftwareBackground* bg, uint16_t value) {
770	UNUSED(renderer);
771	bg->priority = GBARegisterBGCNTGetPriority(value);
772	bg->charBase = GBARegisterBGCNTGetCharBase(value) << 14;
773	bg->mosaic = GBARegisterBGCNTGetMosaic(value);
774	bg->multipalette = GBARegisterBGCNTGet256Color(value);
775	bg->screenBase = GBARegisterBGCNTGetScreenBase(value) << 11;
776	bg->overflow = GBARegisterBGCNTGetOverflow(value);
777	bg->size = GBARegisterBGCNTGetSize(value);
778	bg->yCache = -1;
779}
780
781static void GBAVideoSoftwareRendererWriteBGX_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
782	bg->refx = (bg->refx & 0xFFFF0000) | value;
783	bg->sx = bg->refx;
784}
785
786static void GBAVideoSoftwareRendererWriteBGX_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
787	bg->refx = (bg->refx & 0x0000FFFF) | (value << 16);
788	bg->refx <<= 4;
789	bg->refx >>= 4;
790	bg->sx = bg->refx;
791}
792
793static void GBAVideoSoftwareRendererWriteBGY_LO(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
794	bg->refy = (bg->refy & 0xFFFF0000) | value;
795	bg->sy = bg->refy;
796}
797
798static void GBAVideoSoftwareRendererWriteBGY_HI(struct GBAVideoSoftwareBackground* bg, uint16_t value) {
799	bg->refy = (bg->refy & 0x0000FFFF) | (value << 16);
800	bg->refy <<= 4;
801	bg->refy >>= 4;
802	bg->sy = bg->refy;
803}
804
805static void GBAVideoSoftwareRendererWriteBLDCNT(struct GBAVideoSoftwareRenderer* renderer, uint16_t value) {
806	enum GBAVideoBlendEffect oldEffect = renderer->blendEffect;
807
808	renderer->bg[0].target1 = GBARegisterBLDCNTGetTarget1Bg0(value);
809	renderer->bg[1].target1 = GBARegisterBLDCNTGetTarget1Bg1(value);
810	renderer->bg[2].target1 = GBARegisterBLDCNTGetTarget1Bg2(value);
811	renderer->bg[3].target1 = GBARegisterBLDCNTGetTarget1Bg3(value);
812	renderer->bg[0].target2 = GBARegisterBLDCNTGetTarget2Bg0(value);
813	renderer->bg[1].target2 = GBARegisterBLDCNTGetTarget2Bg1(value);
814	renderer->bg[2].target2 = GBARegisterBLDCNTGetTarget2Bg2(value);
815	renderer->bg[3].target2 = GBARegisterBLDCNTGetTarget2Bg3(value);
816
817	renderer->blendEffect = GBARegisterBLDCNTGetEffect(value);
818	renderer->target1Obj = GBARegisterBLDCNTGetTarget1Obj(value);
819	renderer->target1Bd = GBARegisterBLDCNTGetTarget1Bd(value);
820	renderer->target2Obj = GBARegisterBLDCNTGetTarget2Obj(value);
821	renderer->target2Bd = GBARegisterBLDCNTGetTarget2Bd(value);
822
823	if (oldEffect != renderer->blendEffect) {
824		renderer->blendDirty = true;
825	}
826}
827
828#define TEST_LAYER_ENABLED(X) \
829	!renderer->d.disableBG[X] && \
830	(renderer->bg[X].enabled == 3 && \
831	(GBAWindowControlIsBg ## X ## Enable(renderer->currentWindow.packed) || \
832	(GBARegisterDISPCNTIsObjwinEnable(renderer->dispcnt) && GBAWindowControlIsBg ## X ## Enable (renderer->objwin.packed))) && \
833	renderer->bg[X].priority == priority)
834
835static void _drawScanline(struct GBAVideoSoftwareRenderer* renderer, int y) {
836	int w;
837	int spriteLayers = 0;
838	if (GBARegisterDISPCNTIsObjEnable(renderer->dispcnt) && !renderer->d.disableOBJ) {
839		if (renderer->oamDirty) {
840			renderer->oamMax = GBAVideoRendererCleanOAM(renderer->d.oam->obj, renderer->sprites, renderer->objOffsetY);
841			renderer->oamDirty = false;
842		}
843		renderer->spriteCyclesRemaining = GBARegisterDISPCNTIsHblankIntervalFree(renderer->dispcnt) ? OBJ_HBLANK_FREE_LENGTH : OBJ_LENGTH;
844		int mosaicV = GBAMosaicControlGetObjV(renderer->mosaic) + 1;
845		int mosaicY = y - (y % mosaicV);
846		int i;
847		for (i = 0; i < renderer->oamMax; ++i) {
848			struct GBAVideoRendererSprite* sprite = &renderer->sprites[i];
849			int localY = y;
850			renderer->end = 0;
851			if ((y < sprite->y && (sprite->endY - 256 < 0 || y >= sprite->endY - 256)) || y >= sprite->endY) {
852				continue;
853			}
854			if (GBAObjAttributesAIsMosaic(sprite->obj.a) && mosaicV > 1) {
855				localY = mosaicY;
856				if (localY < sprite->y && sprite->y < GBA_VIDEO_VERTICAL_PIXELS) {
857					localY = sprite->y;
858				}
859				if (localY >= (sprite->endY & 0xFF)) {
860					localY = sprite->endY - 1;
861				}
862			}
863			for (w = 0; w < renderer->nWindows; ++w) {
864				renderer->currentWindow = renderer->windows[w].control;
865				renderer->start = renderer->end;
866				renderer->end = renderer->windows[w].endX;
867				// TODO: partial sprite drawing
868				if (!GBAWindowControlIsObjEnable(renderer->currentWindow.packed) && !GBARegisterDISPCNTIsObjwinEnable(renderer->dispcnt)) {
869					continue;
870				}
871
872				int drawn = GBAVideoSoftwareRendererPreprocessSprite(renderer, &sprite->obj, sprite->index, localY);
873				spriteLayers |= drawn << GBAObjAttributesCGetPriority(sprite->obj.c);
874			}
875			renderer->spriteCyclesRemaining -= sprite->cycles;
876			if (renderer->spriteCyclesRemaining <= 0) {
877				break;
878			}
879		}
880	}
881
882	unsigned priority;
883	for (priority = 0; priority < 4; ++priority) {
884		renderer->end = 0;
885		for (w = 0; w < renderer->nWindows; ++w) {
886			renderer->start = renderer->end;
887			renderer->end = renderer->windows[w].endX;
888			renderer->currentWindow = renderer->windows[w].control;
889			if (spriteLayers & (1 << priority)) {
890				GBAVideoSoftwareRendererPostprocessSprite(renderer, priority);
891			}
892			if (TEST_LAYER_ENABLED(0) && GBARegisterDISPCNTGetMode(renderer->dispcnt) < 2) {
893				GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[0], y);
894			}
895			if (TEST_LAYER_ENABLED(1) && GBARegisterDISPCNTGetMode(renderer->dispcnt) < 2) {
896				GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[1], y);
897			}
898			if (TEST_LAYER_ENABLED(2)) {
899				switch (GBARegisterDISPCNTGetMode(renderer->dispcnt)) {
900				case 0:
901					GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[2], y);
902					break;
903				case 1:
904				case 2:
905					GBAVideoSoftwareRendererDrawBackgroundMode2(renderer, &renderer->bg[2], y);
906					break;
907				case 3:
908					GBAVideoSoftwareRendererDrawBackgroundMode3(renderer, &renderer->bg[2], y);
909					break;
910				case 4:
911					GBAVideoSoftwareRendererDrawBackgroundMode4(renderer, &renderer->bg[2], y);
912					break;
913				case 5:
914					GBAVideoSoftwareRendererDrawBackgroundMode5(renderer, &renderer->bg[2], y);
915					break;
916				}
917			}
918			if (TEST_LAYER_ENABLED(3)) {
919				switch (GBARegisterDISPCNTGetMode(renderer->dispcnt)) {
920				case 0:
921					GBAVideoSoftwareRendererDrawBackgroundMode0(renderer, &renderer->bg[3], y);
922					break;
923				case 2:
924					GBAVideoSoftwareRendererDrawBackgroundMode2(renderer, &renderer->bg[3], y);
925					break;
926				}
927			}
928		}
929	}
930	if (GBARegisterDISPCNTGetMode(renderer->dispcnt) != 0) {
931		renderer->bg[2].sx += renderer->bg[2].dmx;
932		renderer->bg[2].sy += renderer->bg[2].dmy;
933		renderer->bg[3].sx += renderer->bg[3].dmx;
934		renderer->bg[3].sy += renderer->bg[3].dmy;
935	}
936
937	if (renderer->bg[0].enabled > 0 && renderer->bg[0].enabled < 3) {
938		++renderer->bg[0].enabled;
939		DIRTY_SCANLINE(renderer, y);
940	}
941	if (renderer->bg[1].enabled > 0 && renderer->bg[1].enabled < 3) {
942		++renderer->bg[1].enabled;
943		DIRTY_SCANLINE(renderer, y);
944	}
945	if (renderer->bg[2].enabled > 0 && renderer->bg[2].enabled < 3) {
946		++renderer->bg[2].enabled;
947		DIRTY_SCANLINE(renderer, y);
948	}
949	if (renderer->bg[3].enabled > 0 && renderer->bg[3].enabled < 3) {
950		++renderer->bg[3].enabled;
951		DIRTY_SCANLINE(renderer, y);
952	}
953}
954
955static void _updatePalettes(struct GBAVideoSoftwareRenderer* renderer) {
956	int i;
957	if (renderer->blendEffect == BLEND_BRIGHTEN) {
958		for (i = 0; i < 512; ++i) {
959			renderer->variantPalette[i] = _brighten(renderer->normalPalette[i], renderer->bldy);
960		}
961	} else if (renderer->blendEffect == BLEND_DARKEN) {
962		for (i = 0; i < 512; ++i) {
963			renderer->variantPalette[i] = _darken(renderer->normalPalette[i], renderer->bldy);
964		}
965	} else {
966		for (i = 0; i < 512; ++i) {
967			renderer->variantPalette[i] = renderer->normalPalette[i];
968		}
969	}
970	unsigned highlightAmount = renderer->d.highlightAmount >> 4;
971
972	if (highlightAmount) {
973		for (i = 0; i < 512; ++i) {
974			renderer->highlightPalette[i] = _mix(0x10 - highlightAmount, renderer->normalPalette[i], highlightAmount, renderer->d.highlightColor);
975			renderer->highlightVariantPalette[i] = _mix(0x10 - highlightAmount, renderer->variantPalette[i], highlightAmount, renderer->d.highlightColor);
976		}
977	}
978}