src/gb/video.c (view raw)
1/* Copyright (c) 2013-2016 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 "video.h"
7
8#include "core/sync.h"
9#include "core/thread.h"
10#include "gb/gb.h"
11#include "gb/io.h"
12
13#include "util/memory.h"
14
15static void GBVideoDummyRendererInit(struct GBVideoRenderer* renderer, enum GBModel model);
16static void GBVideoDummyRendererDeinit(struct GBVideoRenderer* renderer);
17static uint8_t GBVideoDummyRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value);
18static void GBVideoDummyRendererWritePalette(struct GBVideoRenderer* renderer, int index, uint16_t value);
19static void GBVideoDummyRendererDrawRange(struct GBVideoRenderer* renderer, int startX, int endX, int y, struct GBObj** obj, size_t oamMax);
20static void GBVideoDummyRendererFinishScanline(struct GBVideoRenderer* renderer, int y);
21static void GBVideoDummyRendererFinishFrame(struct GBVideoRenderer* renderer);
22static void GBVideoDummyRendererGetPixels(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels);
23
24static void _cleanOAM(struct GBVideo* video, int y);
25
26static struct GBVideoRenderer dummyRenderer = {
27 .init = GBVideoDummyRendererInit,
28 .deinit = GBVideoDummyRendererDeinit,
29 .writeVideoRegister = GBVideoDummyRendererWriteVideoRegister,
30 .writePalette = GBVideoDummyRendererWritePalette,
31 .drawRange = GBVideoDummyRendererDrawRange,
32 .finishScanline = GBVideoDummyRendererFinishScanline,
33 .finishFrame = GBVideoDummyRendererFinishFrame,
34 .getPixels = GBVideoDummyRendererGetPixels
35};
36
37void GBVideoInit(struct GBVideo* video) {
38 video->renderer = &dummyRenderer;
39 video->vram = 0;
40 video->frameskip = 0;
41}
42
43void GBVideoReset(struct GBVideo* video) {
44 video->ly = 0;
45 video->mode = 1;
46 video->stat = 1;
47
48 video->nextEvent = INT_MAX;
49 video->eventDiff = 0;
50
51 video->nextMode = INT_MAX;
52 video->dotCounter = INT_MIN;
53
54 video->frameCounter = 0;
55 video->frameskipCounter = 0;
56
57 if (video->vram) {
58 mappedMemoryFree(video->vram, GB_SIZE_VRAM);
59 }
60 video->vram = anonymousMemoryMap(GB_SIZE_VRAM);
61 GBVideoSwitchBank(video, 0);
62 video->renderer->vram = video->vram;
63 memset(&video->oam, 0, sizeof(video->oam));
64 video->renderer->oam = &video->oam;
65 memset(&video->palette, 0, sizeof(video->palette));
66
67 video->renderer->deinit(video->renderer);
68 video->renderer->init(video->renderer, video->p->model);
69}
70
71void GBVideoDeinit(struct GBVideo* video) {
72 GBVideoAssociateRenderer(video, &dummyRenderer);
73 mappedMemoryFree(video->vram, GB_SIZE_VRAM);
74}
75
76void GBVideoAssociateRenderer(struct GBVideo* video, struct GBVideoRenderer* renderer) {
77 video->renderer->deinit(video->renderer);
78 video->renderer = renderer;
79 renderer->vram = video->vram;
80 video->renderer->init(video->renderer, video->p->model);
81}
82
83int32_t GBVideoProcessEvents(struct GBVideo* video, int32_t cycles) {
84 video->eventDiff += cycles;
85 if (video->nextEvent != INT_MAX) {
86 video->nextEvent -= cycles;
87 }
88 if (video->nextEvent <= 0) {
89 if (video->nextEvent != INT_MAX) {
90 video->nextMode -= video->eventDiff;
91 }
92 video->nextEvent = INT_MAX;
93 video->p->memory.io[REG_IF] &= ~(1 << GB_IRQ_LCDSTAT);
94 GBVideoProcessDots(video);
95 if (video->nextMode <= 0) {
96 int lyc = video->p->memory.io[REG_LYC];
97 switch (video->mode) {
98 case 0:
99 if (video->frameskipCounter <= 0) {
100 video->renderer->finishScanline(video->renderer, video->ly);
101 }
102 ++video->ly;
103 video->p->memory.io[REG_LY] = video->ly;
104 video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->ly);
105 if (video->ly < GB_VIDEO_VERTICAL_PIXELS) {
106 video->nextMode = GB_VIDEO_MODE_2_LENGTH;
107 video->mode = 2;
108 if (GBRegisterSTATIsOAMIRQ(video->stat)) {
109 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
110 video->nextEvent = 4;
111 }
112 } else {
113 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
114 video->mode = 1;
115 --video->frameskipCounter;
116 if (video->frameskipCounter < 0) {
117 video->renderer->finishFrame(video->renderer);
118 mCoreSyncPostFrame(video->p->sync);
119 video->frameskipCounter = video->frameskip;
120 }
121 GBFrameEnded(video->p);
122 ++video->frameCounter;
123
124 struct mCoreThread* thread = mCoreThreadGet();
125 if (thread && thread->frameCallback) {
126 thread->frameCallback(thread);
127 }
128
129 if (video->p->stream && video->p->stream->postVideoFrame) {
130 const color_t* pixels;
131 unsigned stride;
132 video->renderer->getPixels(video->renderer, &stride, (const void**) &pixels);
133 video->p->stream->postVideoFrame(video->p->stream, pixels, stride);
134 }
135
136 if (GBRegisterSTATIsVblankIRQ(video->stat) || GBRegisterSTATIsOAMIRQ(video->stat)) {
137 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
138 }
139 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_VBLANK);
140 video->nextEvent = 4;
141 }
142 if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->ly) {
143 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
144 video->nextEvent = 4;
145 }
146 GBUpdateIRQs(video->p);
147 break;
148 case 1:
149 // TODO: One M-cycle delay
150 ++video->ly;
151 if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS + 1) {
152 video->ly = 0;
153 video->p->memory.io[REG_LY] = video->ly;
154 video->nextMode = GB_VIDEO_MODE_2_LENGTH;
155 video->mode = 2;
156 if (GBRegisterSTATIsOAMIRQ(video->stat)) {
157 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
158 video->nextEvent = 4;
159 GBUpdateIRQs(video->p);
160 }
161 break;
162 } else if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS) {
163 video->p->memory.io[REG_LY] = 0;
164 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH - 8;
165 } else if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS - 1) {
166 video->p->memory.io[REG_LY] = video->ly;
167 video->nextMode = 8;
168 } else {
169 video->p->memory.io[REG_LY] = video->ly;
170 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
171 }
172
173 video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->p->memory.io[REG_LY]);
174 if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->p->memory.io[REG_LY]) {
175 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
176 video->nextEvent = 4;
177 GBUpdateIRQs(video->p);
178 }
179 if (video->p->memory.mbcType == GB_MBC7 && video->p->memory.rotation && video->p->memory.rotation->sample) {
180 video->p->memory.rotation->sample(video->p->memory.rotation);
181 }
182 break;
183 case 2:
184 _cleanOAM(video, video->ly);
185 video->dotCounter = 0;
186 video->nextEvent = GB_VIDEO_HORIZONTAL_LENGTH;
187 video->x = 0;
188 video->nextMode = GB_VIDEO_MODE_3_LENGTH_BASE + video->objMax * 12;
189 video->mode = 3;
190 break;
191 case 3:
192 video->nextMode = GB_VIDEO_MODE_0_LENGTH_BASE - video->objMax * 12;
193 video->mode = 0;
194 if (GBRegisterSTATIsHblankIRQ(video->stat)) {
195 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
196 video->nextEvent = 4;
197 GBUpdateIRQs(video->p);
198 }
199 if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
200 video->p->memory.hdmaRemaining = 0x10;
201 video->p->memory.hdmaNext = video->p->cpu->cycles;
202 }
203 break;
204 }
205 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
206 video->p->memory.io[REG_STAT] = video->stat;
207 }
208 if (video->nextMode < video->nextEvent) {
209 video->nextEvent = video->nextMode;
210 }
211 video->eventDiff = 0;
212 }
213 return video->nextEvent;
214}
215
216static void _cleanOAM(struct GBVideo* video, int y) {
217 // TODO: GBC differences
218 // TODO: Optimize
219 video->objMax = 0;
220 int spriteHeight = 8;
221 if (GBRegisterLCDCIsObjSize(video->p->memory.io[REG_LCDC])) {
222 spriteHeight = 16;
223 }
224 int o = 0;
225 int i;
226 for (i = 0; i < 40; ++i) {
227 uint8_t oy = video->oam.obj[i].y;
228 if (y < oy - 16 || y >= oy - 16 + spriteHeight) {
229 continue;
230 }
231 // TODO: Sort
232 video->objThisLine[o] = &video->oam.obj[i];
233 ++o;
234 if (o == 10) {
235 break;
236 }
237 }
238 video->objMax = o;
239}
240
241void GBVideoProcessDots(struct GBVideo* video) {
242 if (video->mode != 3 || video->dotCounter < 0) {
243 return;
244 }
245 int oldX = video->x;
246 video->x = video->dotCounter + video->eventDiff + (video->p->cpu->cycles >> video->p->doubleSpeed);
247 if (video->x > GB_VIDEO_HORIZONTAL_PIXELS) {
248 video->x = GB_VIDEO_HORIZONTAL_PIXELS;
249 }
250 if (video->x == GB_VIDEO_HORIZONTAL_PIXELS) {
251 video->dotCounter = INT_MIN;
252 }
253 if (video->frameskipCounter <= 0) {
254 video->renderer->drawRange(video->renderer, oldX, video->x, video->ly, video->objThisLine, video->objMax);
255 }
256}
257
258void GBVideoWriteLCDC(struct GBVideo* video, GBRegisterLCDC value) {
259 if (!GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && GBRegisterLCDCIsEnable(value)) {
260 video->mode = 2;
261 video->nextMode = GB_VIDEO_MODE_2_LENGTH - 5; // TODO: Why is this fudge factor needed? Might be related to T-cycles for load/store differing
262 video->nextEvent = video->nextMode;
263 video->eventDiff = -video->p->cpu->cycles >> video->p->doubleSpeed;
264 video->ly = 0;
265 video->p->memory.io[REG_LY] = 0;
266 // TODO: Does this read as 0 for 4 T-cycles?
267 video->stat = GBRegisterSTATSetMode(video->stat, 2);
268 video->stat = GBRegisterSTATSetLYC(video->stat, video->ly == video->p->memory.io[REG_LYC]);
269 if (GBRegisterSTATIsLYCIRQ(video->stat) && video->ly == video->p->memory.io[REG_LYC]) {
270 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
271 video->nextEvent = 4;
272 GBUpdateIRQs(video->p);
273 }
274 video->p->memory.io[REG_STAT] = video->stat;
275
276 if (video->p->cpu->cycles + (video->nextEvent << video->p->doubleSpeed) < video->p->cpu->nextEvent) {
277 video->p->cpu->nextEvent = video->p->cpu->cycles + (video->nextEvent << video->p->doubleSpeed);
278 }
279 return;
280 }
281 if (GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && !GBRegisterLCDCIsEnable(value)) {
282 video->mode = 0;
283 video->nextMode = INT_MAX;
284 video->nextEvent = INT_MAX;
285 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
286 video->p->memory.io[REG_STAT] = video->stat;
287 video->ly = 0;
288 video->p->memory.io[REG_LY] = 0;
289 }
290}
291
292void GBVideoWriteSTAT(struct GBVideo* video, GBRegisterSTAT value) {
293 video->stat = (video->stat & 0x7) | (value & 0x78);
294 if (video->p->model == GB_MODEL_DMG && video->mode == 1) {
295 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
296 video->nextEvent = 4;
297 GBUpdateIRQs(video->p);
298 }
299}
300
301void GBVideoWritePalette(struct GBVideo* video, uint16_t address, uint8_t value) {
302 static const uint16_t dmgPalette[4] = { 0x7FFF, 0x56B5, 0x294A, 0x0000};
303 if (video->p->model < GB_MODEL_CGB) {
304 switch (address) {
305 case REG_BGP:
306 video->palette[0] = dmgPalette[value & 3];
307 video->palette[1] = dmgPalette[(value >> 2) & 3];
308 video->palette[2] = dmgPalette[(value >> 4) & 3];
309 video->palette[3] = dmgPalette[(value >> 6) & 3];
310 video->renderer->writePalette(video->renderer, 0, video->palette[0]);
311 video->renderer->writePalette(video->renderer, 1, video->palette[1]);
312 video->renderer->writePalette(video->renderer, 2, video->palette[2]);
313 video->renderer->writePalette(video->renderer, 3, video->palette[3]);
314 break;
315 case REG_OBP0:
316 video->palette[8 * 4 + 0] = dmgPalette[value & 3];
317 video->palette[8 * 4 + 1] = dmgPalette[(value >> 2) & 3];
318 video->palette[8 * 4 + 2] = dmgPalette[(value >> 4) & 3];
319 video->palette[8 * 4 + 3] = dmgPalette[(value >> 6) & 3];
320 video->renderer->writePalette(video->renderer, 8 * 4 + 0, video->palette[8 * 4 + 0]);
321 video->renderer->writePalette(video->renderer, 8 * 4 + 1, video->palette[8 * 4 + 1]);
322 video->renderer->writePalette(video->renderer, 8 * 4 + 2, video->palette[8 * 4 + 2]);
323 video->renderer->writePalette(video->renderer, 8 * 4 + 3, video->palette[8 * 4 + 3]);
324 break;
325 case REG_OBP1:
326 video->palette[9 * 4 + 0] = dmgPalette[value & 3];
327 video->palette[9 * 4 + 1] = dmgPalette[(value >> 2) & 3];
328 video->palette[9 * 4 + 2] = dmgPalette[(value >> 4) & 3];
329 video->palette[9 * 4 + 3] = dmgPalette[(value >> 6) & 3];
330 video->renderer->writePalette(video->renderer, 9 * 4 + 0, video->palette[9 * 4 + 0]);
331 video->renderer->writePalette(video->renderer, 9 * 4 + 1, video->palette[9 * 4 + 1]);
332 video->renderer->writePalette(video->renderer, 9 * 4 + 2, video->palette[9 * 4 + 2]);
333 video->renderer->writePalette(video->renderer, 9 * 4 + 3, video->palette[9 * 4 + 3]);
334 break;
335 }
336 } else {
337 switch (address) {
338 case REG_BCPD:
339 if (video->bcpIndex & 1) {
340 video->palette[video->bcpIndex >> 1] &= 0x00FF;
341 video->palette[video->bcpIndex >> 1] |= value << 8;
342 } else {
343 video->palette[video->bcpIndex >> 1] &= 0xFF00;
344 video->palette[video->bcpIndex >> 1] |= value;
345 }
346 video->renderer->writePalette(video->renderer, video->bcpIndex >> 1, video->palette[video->bcpIndex >> 1]);
347 if (video->bcpIncrement) {
348 ++video->bcpIndex;
349 video->bcpIndex &= 0x3F;
350 video->p->memory.io[REG_BCPD] = video->palette[video->bcpIndex >> 1];
351 }
352 break;
353 case REG_OCPD:
354 if (video->ocpIndex & 1) {
355 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0x00FF;
356 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value << 8;
357 } else {
358 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0xFF00;
359 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value;
360 }
361 video->renderer->writePalette(video->renderer, 8 * 4 + (video->ocpIndex >> 1), video->palette[8 * 4 + (video->ocpIndex >> 1)]);
362 if (video->ocpIncrement) {
363 ++video->ocpIndex;
364 video->ocpIndex &= 0x3F;
365 video->p->memory.io[REG_OCPD] = video->palette[8 * 4 + (video->ocpIndex >> 1)];
366 }
367 break;
368 }
369 }
370}
371
372void GBVideoSwitchBank(struct GBVideo* video, uint8_t value) {
373 value &= 1;
374 video->vramBank = &video->vram[value * GB_SIZE_VRAM_BANK0];
375 video->vramCurrentBank = value;
376}
377
378static void GBVideoDummyRendererInit(struct GBVideoRenderer* renderer, enum GBModel model) {
379 UNUSED(renderer);
380 UNUSED(model);
381 // Nothing to do
382}
383
384static void GBVideoDummyRendererDeinit(struct GBVideoRenderer* renderer) {
385 UNUSED(renderer);
386 // Nothing to do
387}
388
389static uint8_t GBVideoDummyRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value) {
390 UNUSED(renderer);
391 UNUSED(address);
392 return value;
393}
394
395static void GBVideoDummyRendererWritePalette(struct GBVideoRenderer* renderer, int index, uint16_t value) {
396 UNUSED(renderer);
397 UNUSED(index);
398 UNUSED(value);
399}
400
401static void GBVideoDummyRendererDrawRange(struct GBVideoRenderer* renderer, int startX, int endX, int y, struct GBObj** obj, size_t oamMax) {
402 UNUSED(renderer);
403 UNUSED(endX);
404 UNUSED(startX);
405 UNUSED(y);
406 UNUSED(obj);
407 UNUSED(oamMax);
408 // Nothing to do
409}
410
411static void GBVideoDummyRendererFinishScanline(struct GBVideoRenderer* renderer, int y) {
412 UNUSED(renderer);
413 UNUSED(y);
414 // Nothing to do
415}
416
417static void GBVideoDummyRendererFinishFrame(struct GBVideoRenderer* renderer) {
418 UNUSED(renderer);
419 // Nothing to do
420}
421
422static void GBVideoDummyRendererGetPixels(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels) {
423 UNUSED(renderer);
424 UNUSED(stride);
425 UNUSED(pixels);
426 // Nothing to do
427}