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 <mgba/internal/gba/video.h>
7 
8 #include <mgba/core/sync.h>
9 #include <mgba/core/cache-set.h>
10 #include <mgba/internal/arm/macros.h>
11 #include <mgba/internal/gba/dma.h>
12 #include <mgba/internal/gba/gba.h>
13 #include <mgba/internal/gba/io.h>
14 #include <mgba/internal/gba/renderers/cache-set.h>
15 #include <mgba/internal/gba/serialize.h>
16 
17 #include <mgba-util/memory.h>
18 
19 mLOG_DEFINE_CATEGORY(GBA_VIDEO, "GBA Video", "gba.video");
20 
21 static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer);
22 static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer);
23 static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer);
24 static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
25 static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address);
26 static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
27 static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam);
28 static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
29 static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer);
30 static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels);
31 static void GBAVideoDummyRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels);
32 
33 static void _startHblank(struct mTiming*, void* context, uint32_t cyclesLate);
34 static void _startHdraw(struct mTiming*, void* context, uint32_t cyclesLate);
35 
36 MGBA_EXPORT const int GBAVideoObjSizes[16][2] = {
37 	{ 8, 8 },
38 	{ 16, 16 },
39 	{ 32, 32 },
40 	{ 64, 64 },
41 	{ 16, 8 },
42 	{ 32, 8 },
43 	{ 32, 16 },
44 	{ 64, 32 },
45 	{ 8, 16 },
46 	{ 8, 32 },
47 	{ 16, 32 },
48 	{ 32, 64 },
49 	{ 0, 0 },
50 	{ 0, 0 },
51 	{ 0, 0 },
52 	{ 0, 0 },
53 };
54 
55 static struct GBAVideoRenderer dummyRenderer = {
56 	.init = GBAVideoDummyRendererInit,
57 	.reset = GBAVideoDummyRendererReset,
58 	.deinit = GBAVideoDummyRendererDeinit,
59 	.writeVideoRegister = GBAVideoDummyRendererWriteVideoRegister,
60 	.writeVRAM = GBAVideoDummyRendererWriteVRAM,
61 	.writePalette = GBAVideoDummyRendererWritePalette,
62 	.writeOAM = GBAVideoDummyRendererWriteOAM,
63 	.drawScanline = GBAVideoDummyRendererDrawScanline,
64 	.finishFrame = GBAVideoDummyRendererFinishFrame,
65 	.getPixels = GBAVideoDummyRendererGetPixels,
66 	.putPixels = GBAVideoDummyRendererPutPixels,
67 };
68 
GBAVideoInit(struct GBAVideo * video)69 void GBAVideoInit(struct GBAVideo* video) {
70 	video->renderer = &dummyRenderer;
71 	video->renderer->cache = NULL;
72 	video->vram = anonymousMemoryMap(SIZE_VRAM);
73 	video->frameskip = 0;
74 	video->event.name = "GBA Video";
75 	video->event.callback = NULL;
76 	video->event.context = video;
77 	video->event.priority = 8;
78 }
79 
GBAVideoReset(struct GBAVideo * video)80 void GBAVideoReset(struct GBAVideo* video) {
81 	int32_t nextEvent = VIDEO_HDRAW_LENGTH;
82 	if (video->p->memory.fullBios) {
83 		video->vcount = 0;
84 	} else {
85 		// TODO: Verify exact scanline on hardware
86 		video->vcount = 0x7E;
87 		nextEvent = 170;
88 	}
89 	video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
90 
91 	video->event.callback = _startHblank;
92 	mTimingSchedule(&video->p->timing, &video->event, nextEvent);
93 
94 	video->frameCounter = 0;
95 	video->frameskipCounter = 0;
96 	video->renderer->vram = video->vram;
97 
98 	memset(video->palette, 0, sizeof(video->palette));
99 	memset(video->oam.raw, 0, sizeof(video->oam.raw));
100 
101 	video->renderer->reset(video->renderer);
102 }
103 
GBAVideoDeinit(struct GBAVideo * video)104 void GBAVideoDeinit(struct GBAVideo* video) {
105 	video->renderer->deinit(video->renderer);
106 	mappedMemoryFree(video->vram, SIZE_VRAM);
107 }
108 
GBAVideoAssociateRenderer(struct GBAVideo * video,struct GBAVideoRenderer * renderer)109 void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
110 	video->renderer->deinit(video->renderer);
111 	renderer->cache = video->renderer->cache;
112 	video->renderer = renderer;
113 	renderer->palette = video->palette;
114 	renderer->vram = video->vram;
115 	renderer->oam = &video->oam;
116 	video->renderer->init(video->renderer);
117 }
118 
_startHdraw(struct mTiming * timing,void * context,uint32_t cyclesLate)119 void _startHdraw(struct mTiming* timing, void* context, uint32_t cyclesLate) {
120 	struct GBAVideo* video = context;
121 	GBARegisterDISPSTAT dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
122 	dispstat = GBARegisterDISPSTATClearInHblank(dispstat);
123 	video->event.callback = _startHblank;
124 	mTimingSchedule(timing, &video->event, VIDEO_HDRAW_LENGTH - cyclesLate);
125 
126 	++video->vcount;
127 	if (video->vcount == VIDEO_VERTICAL_TOTAL_PIXELS) {
128 		video->vcount = 0;
129 	}
130 	video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
131 
132 	if (video->vcount == GBARegisterDISPSTATGetVcountSetting(dispstat)) {
133 		dispstat = GBARegisterDISPSTATFillVcounter(dispstat);
134 		if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
135 			GBARaiseIRQ(video->p, IRQ_VCOUNTER, cyclesLate);
136 		}
137 	} else {
138 		dispstat = GBARegisterDISPSTATClearVcounter(dispstat);
139 	}
140 	video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
141 
142 	// Note: state may be recorded during callbacks, so ensure it is consistent!
143 	switch (video->vcount) {
144 	case 0:
145 		GBAFrameStarted(video->p);
146 		break;
147 	case GBA_VIDEO_VERTICAL_PIXELS:
148 		video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATFillInVblank(dispstat);
149 		if (video->frameskipCounter <= 0) {
150 			video->renderer->finishFrame(video->renderer);
151 		}
152 		GBADMARunVblank(video->p, -cyclesLate);
153 		if (GBARegisterDISPSTATIsVblankIRQ(dispstat)) {
154 			GBARaiseIRQ(video->p, IRQ_VBLANK, cyclesLate);
155 		}
156 		GBAFrameEnded(video->p);
157 		mCoreSyncPostFrame(video->p->sync);
158 		--video->frameskipCounter;
159 		if (video->frameskipCounter < 0) {
160 			video->frameskipCounter = video->frameskip;
161 		}
162 		++video->frameCounter;
163 		break;
164 	case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
165 		video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATClearInVblank(dispstat);
166 		break;
167 	}
168 }
169 
_startHblank(struct mTiming * timing,void * context,uint32_t cyclesLate)170 void _startHblank(struct mTiming* timing, void* context, uint32_t cyclesLate) {
171 	struct GBAVideo* video = context;
172 	GBARegisterDISPSTAT dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
173 	dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
174 	video->event.callback = _startHdraw;
175 	mTimingSchedule(timing, &video->event, VIDEO_HBLANK_LENGTH - cyclesLate);
176 
177 	// Begin Hblank
178 	dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
179 	if (video->vcount < GBA_VIDEO_VERTICAL_PIXELS && video->frameskipCounter <= 0) {
180 		video->renderer->drawScanline(video->renderer, video->vcount);
181 	}
182 
183 	if (video->vcount < GBA_VIDEO_VERTICAL_PIXELS) {
184 		GBADMARunHblank(video->p, -cyclesLate);
185 	}
186 	if (video->vcount >= 2 && video->vcount < GBA_VIDEO_VERTICAL_PIXELS + 2) {
187 		GBADMARunDisplayStart(video->p, -cyclesLate);
188 	}
189 	if (GBARegisterDISPSTATIsHblankIRQ(dispstat)) {
190 		GBARaiseIRQ(video->p, IRQ_HBLANK, cyclesLate);
191 	}
192 	video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
193 }
194 
GBAVideoWriteDISPSTAT(struct GBAVideo * video,uint16_t value)195 void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
196 	video->p->memory.io[REG_DISPSTAT >> 1] &= 0x7;
197 	video->p->memory.io[REG_DISPSTAT >> 1] |= value;
198 	// TODO: Does a VCounter IRQ trigger on write?
199 }
200 
GBAVideoDummyRendererInit(struct GBAVideoRenderer * renderer)201 static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
202 	UNUSED(renderer);
203 	// Nothing to do
204 }
205 
GBAVideoDummyRendererReset(struct GBAVideoRenderer * renderer)206 static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
207 	UNUSED(renderer);
208 	// Nothing to do
209 }
210 
GBAVideoDummyRendererDeinit(struct GBAVideoRenderer * renderer)211 static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
212 	UNUSED(renderer);
213 	// Nothing to do
214 }
215 
GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer * renderer,uint32_t address,uint16_t value)216 static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
217 	if (renderer->cache) {
218 		GBAVideoCacheWriteVideoRegister(renderer->cache, address, value);
219 	}
220 	switch (address) {
221 	case REG_DISPCNT:
222 		value &= 0xFFF7;
223 		break;
224 	case REG_BG0CNT:
225 	case REG_BG1CNT:
226 		value &= 0xDFFF;
227 		break;
228 	case REG_BG2CNT:
229 	case REG_BG3CNT:
230 		value &= 0xFFFF;
231 		break;
232 	case REG_BG0HOFS:
233 	case REG_BG0VOFS:
234 	case REG_BG1HOFS:
235 	case REG_BG1VOFS:
236 	case REG_BG2HOFS:
237 	case REG_BG2VOFS:
238 	case REG_BG3HOFS:
239 	case REG_BG3VOFS:
240 		value &= 0x01FF;
241 		break;
242 	case REG_BLDCNT:
243 		value &= 0x3FFF;
244 		break;
245 	case REG_BLDALPHA:
246 		value &= 0x1F1F;
247 		break;
248 	case REG_WININ:
249 	case REG_WINOUT:
250 		value &= 0x3F3F;
251 		break;
252 	default:
253 		break;
254 	}
255 	return value;
256 }
257 
GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer * renderer,uint32_t address)258 static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
259 	if (renderer->cache) {
260 		mCacheSetWriteVRAM(renderer->cache, address);
261 	}
262 }
263 
GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer * renderer,uint32_t address,uint16_t value)264 static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
265 	if (renderer->cache) {
266 		mCacheSetWritePalette(renderer->cache, address >> 1, mColorFrom555(value));
267 	}
268 }
269 
GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer * renderer,uint32_t oam)270 static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
271 	UNUSED(renderer);
272 	UNUSED(oam);
273 	// Nothing to do
274 }
275 
GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer * renderer,int y)276 static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
277 	UNUSED(renderer);
278 	UNUSED(y);
279 	// Nothing to do
280 }
281 
GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer * renderer)282 static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
283 	UNUSED(renderer);
284 	// Nothing to do
285 }
286 
GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer * renderer,size_t * stride,const void ** pixels)287 static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, size_t* stride, const void** pixels) {
288 	UNUSED(renderer);
289 	UNUSED(stride);
290 	UNUSED(pixels);
291 	// Nothing to do
292 }
293 
GBAVideoDummyRendererPutPixels(struct GBAVideoRenderer * renderer,size_t stride,const void * pixels)294 static void GBAVideoDummyRendererPutPixels(struct GBAVideoRenderer* renderer, size_t stride, const void* pixels) {
295 	UNUSED(renderer);
296 	UNUSED(stride);
297 	UNUSED(pixels);
298 	// Nothing to do
299 }
300 
GBAVideoSerialize(const struct GBAVideo * video,struct GBASerializedState * state)301 void GBAVideoSerialize(const struct GBAVideo* video, struct GBASerializedState* state) {
302 	memcpy(state->vram, video->vram, SIZE_VRAM);
303 	memcpy(state->oam, video->oam.raw, SIZE_OAM);
304 	memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
305 	STORE_32(video->event.when - mTimingCurrentTime(&video->p->timing), 0, &state->video.nextEvent);
306 	STORE_32(video->frameCounter, 0, &state->video.frameCounter);
307 }
308 
GBAVideoDeserialize(struct GBAVideo * video,const struct GBASerializedState * state)309 void GBAVideoDeserialize(struct GBAVideo* video, const struct GBASerializedState* state) {
310 	memcpy(video->vram, state->vram, SIZE_VRAM);
311 	uint16_t value;
312 	int i;
313 	for (i = 0; i < SIZE_OAM; i += 2) {
314 		LOAD_16(value, i, state->oam);
315 		GBAStore16(video->p->cpu, BASE_OAM | i, value, 0);
316 	}
317 	for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
318 		LOAD_16(value, i, state->pram);
319 		GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, value, 0);
320 	}
321 	LOAD_32(video->frameCounter, 0, &state->video.frameCounter);
322 
323 	uint32_t when;
324 	LOAD_32(when, 0, &state->video.nextEvent);
325 	GBARegisterDISPSTAT dispstat = state->io[REG_DISPSTAT >> 1];
326 	if (GBARegisterDISPSTATIsInHblank(dispstat)) {
327 		video->event.callback = _startHdraw;
328 	} else {
329 		video->event.callback = _startHblank;
330 	}
331 	mTimingSchedule(&video->p->timing, &video->event, when);
332 
333 	LOAD_16(video->vcount, REG_VCOUNT, state->io);
334 	video->renderer->reset(video->renderer);
335 }
336