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 GBVideoProcessDots(video);
94 if (video->nextMode <= 0) {
95 int lyc = video->p->memory.io[REG_LYC];
96 switch (video->mode) {
97 case 0:
98 if (video->frameskipCounter <= 0) {
99 video->renderer->finishScanline(video->renderer, video->ly);
100 }
101 ++video->ly;
102 video->p->memory.io[REG_LY] = video->ly;
103 video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->ly);
104 if (video->ly < GB_VIDEO_VERTICAL_PIXELS) {
105 video->nextMode = GB_VIDEO_MODE_2_LENGTH;
106 video->mode = 2;
107 if (GBRegisterSTATIsOAMIRQ(video->stat)) {
108 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
109 }
110 } else {
111 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
112 video->mode = 1;
113 --video->frameskipCounter;
114 if (video->frameskipCounter < 0) {
115 video->renderer->finishFrame(video->renderer);
116 mCoreSyncPostFrame(video->p->sync);
117 video->frameskipCounter = video->frameskip;
118 }
119 GBFrameEnded(video->p);
120 ++video->frameCounter;
121
122 struct mCoreThread* thread = mCoreThreadGet();
123 if (thread && thread->frameCallback) {
124 thread->frameCallback(thread);
125 }
126
127 if (video->p->stream && video->p->stream->postVideoFrame) {
128 const color_t* pixels;
129 unsigned stride;
130 video->renderer->getPixels(video->renderer, &stride, (const void**) &pixels);
131 video->p->stream->postVideoFrame(video->p->stream, pixels, stride);
132 }
133
134 if (GBRegisterSTATIsVblankIRQ(video->stat) || GBRegisterSTATIsOAMIRQ(video->stat)) {
135 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
136 }
137 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_VBLANK);
138 }
139 if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->ly) {
140 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
141 }
142 GBUpdateIRQs(video->p);
143 break;
144 case 1:
145 // TODO: One M-cycle delay
146 ++video->ly;
147 if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS + 1) {
148 video->ly = 0;
149 video->p->memory.io[REG_LY] = video->ly;
150 video->nextMode = GB_VIDEO_MODE_2_LENGTH;
151 video->mode = 2;
152 if (GBRegisterSTATIsOAMIRQ(video->stat)) {
153 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
154 GBUpdateIRQs(video->p);
155 }
156 break;
157 } else if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS) {
158 video->p->memory.io[REG_LY] = 0;
159 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH - 8;
160 } else if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS - 1) {
161 video->p->memory.io[REG_LY] = video->ly;
162 video->nextMode = 8;
163 } else {
164 video->p->memory.io[REG_LY] = video->ly;
165 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
166 }
167
168 video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->p->memory.io[REG_LY]);
169 if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->p->memory.io[REG_LY]) {
170 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
171 GBUpdateIRQs(video->p);
172 }
173 if (video->p->memory.mbcType == GB_MBC7 && video->p->memory.rotation && video->p->memory.rotation->sample) {
174 video->p->memory.rotation->sample(video->p->memory.rotation);
175 }
176 break;
177 case 2:
178 _cleanOAM(video, video->ly);
179 video->dotCounter = 0;
180 video->nextEvent = GB_VIDEO_HORIZONTAL_LENGTH;
181 video->x = 0;
182 video->nextMode = GB_VIDEO_MODE_3_LENGTH_BASE + video->objMax * 12;
183 video->mode = 3;
184 break;
185 case 3:
186 video->nextMode = GB_VIDEO_MODE_0_LENGTH_BASE - video->objMax * 12;
187 video->mode = 0;
188 if (GBRegisterSTATIsHblankIRQ(video->stat)) {
189 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
190 GBUpdateIRQs(video->p);
191 }
192 if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
193 video->p->memory.hdmaRemaining = 0x10;
194 video->p->memory.hdmaNext = video->p->cpu->cycles;
195 }
196 break;
197 }
198 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
199 video->p->memory.io[REG_STAT] = video->stat;
200 }
201 if (video->nextMode < video->nextEvent) {
202 video->nextEvent = video->nextMode;
203 }
204 video->eventDiff = 0;
205 }
206 return video->nextEvent;
207}
208
209static void _cleanOAM(struct GBVideo* video, int y) {
210 // TODO: GBC differences
211 // TODO: Optimize
212 video->objMax = 0;
213 int spriteHeight = 8;
214 if (GBRegisterLCDCIsObjSize(video->p->memory.io[REG_LCDC])) {
215 spriteHeight = 16;
216 }
217 int o = 0;
218 int i;
219 for (i = 0; i < 40; ++i) {
220 uint8_t oy = video->oam.obj[i].y;
221 if (y < oy - 16 || y >= oy - 16 + spriteHeight) {
222 continue;
223 }
224 // TODO: Sort
225 video->objThisLine[o] = &video->oam.obj[i];
226 ++o;
227 if (o == 10) {
228 break;
229 }
230 }
231 video->objMax = o;
232}
233
234void GBVideoProcessDots(struct GBVideo* video) {
235 if (video->mode != 3 || video->dotCounter < 0) {
236 return;
237 }
238 int oldX = video->x;
239 video->x = video->dotCounter + video->eventDiff + (video->p->cpu->cycles >> video->p->doubleSpeed);
240 if (video->x > GB_VIDEO_HORIZONTAL_PIXELS) {
241 video->x = GB_VIDEO_HORIZONTAL_PIXELS;
242 }
243 if (video->x == GB_VIDEO_HORIZONTAL_PIXELS) {
244 video->dotCounter = INT_MIN;
245 }
246 if (video->frameskipCounter <= 0) {
247 video->renderer->drawRange(video->renderer, oldX, video->x, video->ly, video->objThisLine, video->objMax);
248 }
249}
250
251void GBVideoWriteLCDC(struct GBVideo* video, GBRegisterLCDC value) {
252 if (!GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && GBRegisterLCDCIsEnable(value)) {
253 video->mode = 2;
254 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
255 video->nextEvent = video->nextMode;
256 video->eventDiff = -video->p->cpu->cycles >> video->p->doubleSpeed;
257 // TODO: Does this read as 0 for 4 T-cycles?
258 video->stat = GBRegisterSTATSetMode(video->stat, 2);
259 video->p->memory.io[REG_STAT] = video->stat;
260 video->ly = 0;
261 video->p->memory.io[REG_LY] = 0;
262
263 if (video->p->cpu->cycles + (video->nextEvent << video->p->doubleSpeed) < video->p->cpu->nextEvent) {
264 video->p->cpu->nextEvent = video->p->cpu->cycles + (video->nextEvent << video->p->doubleSpeed);
265 }
266 return;
267 }
268 if (GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && !GBRegisterLCDCIsEnable(value)) {
269 video->mode = 0;
270 video->nextMode = INT_MAX;
271 video->nextEvent = INT_MAX;
272 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
273 video->p->memory.io[REG_STAT] = video->stat;
274 video->ly = 0;
275 video->p->memory.io[REG_LY] = 0;
276 }
277}
278
279void GBVideoWriteSTAT(struct GBVideo* video, GBRegisterSTAT value) {
280 video->stat = (video->stat & 0x7) | (value & 0x78);
281 if (video->p->model == GB_MODEL_DMG && video->mode == 1) {
282 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
283 GBUpdateIRQs(video->p);
284 }
285}
286
287void GBVideoWritePalette(struct GBVideo* video, uint16_t address, uint8_t value) {
288 static const uint16_t dmgPalette[4] = { 0x7FFF, 0x56B5, 0x294A, 0x0000};
289 if (video->p->model < GB_MODEL_CGB) {
290 switch (address) {
291 case REG_BGP:
292 video->palette[0] = dmgPalette[value & 3];
293 video->palette[1] = dmgPalette[(value >> 2) & 3];
294 video->palette[2] = dmgPalette[(value >> 4) & 3];
295 video->palette[3] = dmgPalette[(value >> 6) & 3];
296 video->renderer->writePalette(video->renderer, 0, video->palette[0]);
297 video->renderer->writePalette(video->renderer, 1, video->palette[1]);
298 video->renderer->writePalette(video->renderer, 2, video->palette[2]);
299 video->renderer->writePalette(video->renderer, 3, video->palette[3]);
300 break;
301 case REG_OBP0:
302 video->palette[8 * 4 + 0] = dmgPalette[value & 3];
303 video->palette[8 * 4 + 1] = dmgPalette[(value >> 2) & 3];
304 video->palette[8 * 4 + 2] = dmgPalette[(value >> 4) & 3];
305 video->palette[8 * 4 + 3] = dmgPalette[(value >> 6) & 3];
306 video->renderer->writePalette(video->renderer, 8 * 4 + 0, video->palette[8 * 4 + 0]);
307 video->renderer->writePalette(video->renderer, 8 * 4 + 1, video->palette[8 * 4 + 1]);
308 video->renderer->writePalette(video->renderer, 8 * 4 + 2, video->palette[8 * 4 + 2]);
309 video->renderer->writePalette(video->renderer, 8 * 4 + 3, video->palette[8 * 4 + 3]);
310 break;
311 case REG_OBP1:
312 video->palette[9 * 4 + 0] = dmgPalette[value & 3];
313 video->palette[9 * 4 + 1] = dmgPalette[(value >> 2) & 3];
314 video->palette[9 * 4 + 2] = dmgPalette[(value >> 4) & 3];
315 video->palette[9 * 4 + 3] = dmgPalette[(value >> 6) & 3];
316 video->renderer->writePalette(video->renderer, 9 * 4 + 0, video->palette[9 * 4 + 0]);
317 video->renderer->writePalette(video->renderer, 9 * 4 + 1, video->palette[9 * 4 + 1]);
318 video->renderer->writePalette(video->renderer, 9 * 4 + 2, video->palette[9 * 4 + 2]);
319 video->renderer->writePalette(video->renderer, 9 * 4 + 3, video->palette[9 * 4 + 3]);
320 break;
321 }
322 } else {
323 switch (address) {
324 case REG_BCPD:
325 if (video->bcpIndex & 1) {
326 video->palette[video->bcpIndex >> 1] &= 0x00FF;
327 video->palette[video->bcpIndex >> 1] |= value << 8;
328 } else {
329 video->palette[video->bcpIndex >> 1] &= 0xFF00;
330 video->palette[video->bcpIndex >> 1] |= value;
331 }
332 video->renderer->writePalette(video->renderer, video->bcpIndex >> 1, video->palette[video->bcpIndex >> 1]);
333 if (video->bcpIncrement) {
334 ++video->bcpIndex;
335 video->bcpIndex &= 0x3F;
336 video->p->memory.io[REG_BCPD] = video->palette[video->bcpIndex >> 1];
337 }
338 break;
339 case REG_OCPD:
340 if (video->ocpIndex & 1) {
341 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0x00FF;
342 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value << 8;
343 } else {
344 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0xFF00;
345 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value;
346 }
347 video->renderer->writePalette(video->renderer, 8 * 4 + (video->ocpIndex >> 1), video->palette[8 * 4 + (video->ocpIndex >> 1)]);
348 if (video->ocpIncrement) {
349 ++video->ocpIndex;
350 video->ocpIndex &= 0x3F;
351 video->p->memory.io[REG_OCPD] = video->palette[8 * 4 + (video->ocpIndex >> 1)];
352 }
353 break;
354 }
355 }
356}
357
358void GBVideoSwitchBank(struct GBVideo* video, uint8_t value) {
359 value &= 1;
360 video->vramBank = &video->vram[value * GB_SIZE_VRAM_BANK0];
361 video->vramCurrentBank = value;
362}
363
364static void GBVideoDummyRendererInit(struct GBVideoRenderer* renderer, enum GBModel model) {
365 UNUSED(renderer);
366 UNUSED(model);
367 // Nothing to do
368}
369
370static void GBVideoDummyRendererDeinit(struct GBVideoRenderer* renderer) {
371 UNUSED(renderer);
372 // Nothing to do
373}
374
375static uint8_t GBVideoDummyRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value) {
376 UNUSED(renderer);
377 UNUSED(address);
378 return value;
379}
380
381static void GBVideoDummyRendererWritePalette(struct GBVideoRenderer* renderer, int index, uint16_t value) {
382 UNUSED(renderer);
383 UNUSED(index);
384 UNUSED(value);
385}
386
387static void GBVideoDummyRendererDrawRange(struct GBVideoRenderer* renderer, int startX, int endX, int y, struct GBObj** obj, size_t oamMax) {
388 UNUSED(renderer);
389 UNUSED(endX);
390 UNUSED(startX);
391 UNUSED(y);
392 UNUSED(obj);
393 UNUSED(oamMax);
394 // Nothing to do
395}
396
397static void GBVideoDummyRendererFinishScanline(struct GBVideoRenderer* renderer, int y) {
398 UNUSED(renderer);
399 UNUSED(y);
400 // Nothing to do
401}
402
403static void GBVideoDummyRendererFinishFrame(struct GBVideoRenderer* renderer) {
404 UNUSED(renderer);
405 // Nothing to do
406}
407
408static void GBVideoDummyRendererGetPixels(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels) {
409 UNUSED(renderer);
410 UNUSED(stride);
411 UNUSED(pixels);
412 // Nothing to do
413}