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