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
66 video->renderer->deinit(video->renderer);
67 video->renderer->init(video->renderer, video->p->model);
68}
69
70void GBVideoDeinit(struct GBVideo* video) {
71 GBVideoAssociateRenderer(video, &dummyRenderer);
72 mappedMemoryFree(video->vram, GB_SIZE_VRAM);
73}
74
75void GBVideoAssociateRenderer(struct GBVideo* video, struct GBVideoRenderer* renderer) {
76 video->renderer->deinit(video->renderer);
77 video->renderer = renderer;
78 renderer->vram = video->vram;
79 video->renderer->init(video->renderer, video->p->model);
80}
81
82int32_t GBVideoProcessEvents(struct GBVideo* video, int32_t cycles) {
83 video->eventDiff += cycles;
84 if (video->nextEvent != INT_MAX) {
85 video->nextEvent -= cycles;
86 }
87 if (video->nextEvent <= 0) {
88 if (video->nextEvent != INT_MAX) {
89 video->nextMode -= video->eventDiff;
90 }
91 video->nextEvent = INT_MAX;
92 GBVideoProcessDots(video);
93 if (video->nextMode <= 0) {
94 int lyc = video->p->memory.io[REG_LYC];
95 switch (video->mode) {
96 case 0:
97 if (video->frameskipCounter <= 0) {
98 video->renderer->finishScanline(video->renderer, video->ly);
99 }
100 ++video->ly;
101 video->p->memory.io[REG_LY] = video->ly;
102 video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->ly);
103 if (video->ly < GB_VIDEO_VERTICAL_PIXELS) {
104 video->nextMode = GB_VIDEO_MODE_2_LENGTH;
105 video->mode = 2;
106 if (GBRegisterSTATIsOAMIRQ(video->stat)) {
107 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
108 }
109 } else {
110 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
111 video->mode = 1;
112 --video->frameskipCounter;
113 if (video->frameskipCounter < 0) {
114 video->renderer->finishFrame(video->renderer);
115 mCoreSyncPostFrame(video->p->sync);
116 video->frameskipCounter = video->frameskip;
117 }
118 ++video->frameCounter;
119
120 struct mCoreThread* thread = mCoreThreadGet();
121 if (thread && thread->frameCallback) {
122 thread->frameCallback(thread);
123 }
124
125 if (video->p->stream && video->p->stream->postVideoFrame) {
126 const color_t* pixels;
127 unsigned stride;
128 video->renderer->getPixels(video->renderer, &stride, (const void**) &pixels);
129 video->p->stream->postVideoFrame(video->p->stream, pixels, stride);
130 }
131
132 if (GBRegisterSTATIsVblankIRQ(video->stat) || GBRegisterSTATIsOAMIRQ(video->stat)) {
133 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
134 }
135 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_VBLANK);
136 }
137 if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->ly) {
138 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
139 }
140 GBUpdateIRQs(video->p);
141 break;
142 case 1:
143 // TODO: One M-cycle delay
144 ++video->ly;
145 video->stat = GBRegisterSTATSetLYC(video->stat, lyc == video->ly);
146 if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS) {
147 video->ly = 0;
148 video->nextMode = GB_VIDEO_MODE_2_LENGTH;
149 video->mode = 2;
150 if (GBRegisterSTATIsOAMIRQ(video->stat)) {
151 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
152 }
153 } else {
154 video->nextMode = GB_VIDEO_HORIZONTAL_LENGTH;
155 }
156 if (video->ly == GB_VIDEO_VERTICAL_TOTAL_PIXELS - 1) {
157 video->p->memory.io[REG_LY] = 0;
158 } else {
159 video->p->memory.io[REG_LY] = video->ly;
160 }
161 if (GBRegisterSTATIsLYCIRQ(video->stat) && lyc == video->ly) {
162 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
163 }
164 GBUpdateIRQs(video->p);
165 break;
166 case 2:
167 _cleanOAM(video, video->ly);
168 video->dotCounter = 0;
169 video->nextEvent = GB_VIDEO_HORIZONTAL_LENGTH;
170 video->x = 0;
171 video->nextMode = GB_VIDEO_MODE_3_LENGTH_BASE + video->objMax * 8;
172 video->mode = 3;
173 break;
174 case 3:
175 video->nextMode = GB_VIDEO_MODE_0_LENGTH_BASE - video->objMax * 8;
176 video->mode = 0;
177 if (GBRegisterSTATIsHblankIRQ(video->stat)) {
178 video->p->memory.io[REG_IF] |= (1 << GB_IRQ_LCDSTAT);
179 GBUpdateIRQs(video->p);
180 }
181 break;
182 }
183 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
184 video->p->memory.io[REG_STAT] = video->stat;
185 }
186 if (video->nextMode < video->nextEvent) {
187 video->nextEvent = video->nextMode;
188 }
189 video->eventDiff = 0;
190 }
191 return video->nextEvent;
192}
193
194static void _cleanOAM(struct GBVideo* video, int y) {
195 // TODO: GBC differences
196 // TODO: Optimize
197 video->objMax = 0;
198 int spriteHeight = 8;
199 if (GBRegisterLCDCIsObjSize(video->p->memory.io[REG_LCDC])) {
200 spriteHeight = 16;
201 }
202 int o = 0;
203 int i;
204 for (i = 0; i < 40; ++i) {
205 uint8_t oy = video->oam.obj[i].y;
206 if (y < oy - 16 || y >= oy - 16 + spriteHeight) {
207 continue;
208 }
209 // TODO: Sort
210 video->objThisLine[o] = &video->oam.obj[i];
211 ++o;
212 if (o == 10) {
213 break;
214 }
215 }
216 video->objMax = o;
217}
218
219void GBVideoProcessDots(struct GBVideo* video) {
220 if (video->mode != 3 || video->dotCounter < 0) {
221 return;
222 }
223 int oldX = video->x;
224 video->x = video->dotCounter + video->eventDiff + video->p->cpu->cycles;
225 if (video->x > GB_VIDEO_HORIZONTAL_PIXELS) {
226 video->x = GB_VIDEO_HORIZONTAL_PIXELS;
227 }
228 if (video->x == GB_VIDEO_HORIZONTAL_PIXELS) {
229 video->dotCounter = INT_MIN;
230 }
231 if (video->frameskipCounter <= 0) {
232 video->renderer->drawRange(video->renderer, oldX, video->x, video->ly, video->objThisLine, video->objMax);
233 }
234}
235
236void GBVideoWriteLCDC(struct GBVideo* video, GBRegisterLCDC value) {
237 if (!GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && GBRegisterLCDCIsEnable(value)) {
238 video->mode = 2;
239 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
240 video->nextEvent = video->nextMode;
241 video->eventDiff = -video->p->cpu->cycles;
242 // TODO: Does this read as 0 for 4 T-cycles?
243 video->stat = GBRegisterSTATSetMode(video->stat, 2);
244 video->p->memory.io[REG_STAT] = video->stat;
245 video->ly = 0;
246 video->p->memory.io[REG_LY] = 0;
247
248 if (video->p->cpu->cycles + video->nextEvent < video->p->cpu->nextEvent) {
249 video->p->cpu->nextEvent = video->p->cpu->cycles + video->nextEvent;
250 }
251 return;
252 }
253 if (GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && !GBRegisterLCDCIsEnable(value)) {
254 video->mode = 0;
255 video->nextMode = INT_MAX;
256 video->nextEvent = INT_MAX;
257 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
258 video->p->memory.io[REG_STAT] = video->stat;
259 video->ly = 0;
260 video->p->memory.io[REG_LY] = 0;
261 }
262}
263
264void GBVideoWriteSTAT(struct GBVideo* video, GBRegisterSTAT value) {
265 video->stat = (video->stat & 0x7) | (value & 0x78);
266}
267
268void GBVideoWritePalette(struct GBVideo* video, uint16_t address, uint8_t value) {
269 static const uint16_t dmgPalette[4] = { 0x7FFF, 0x294A, 0x14A5, 0x0000};
270 if (video->p->model < GB_MODEL_CGB) {
271 switch (address) {
272 case REG_BGP:
273 video->palette[0] = dmgPalette[value & 3];
274 video->palette[1] = dmgPalette[(value >> 2) & 3];
275 video->palette[2] = dmgPalette[(value >> 4) & 3];
276 video->palette[3] = dmgPalette[(value >> 6) & 3];
277 video->renderer->writePalette(video->renderer, 0, video->palette[0]);
278 video->renderer->writePalette(video->renderer, 1, video->palette[1]);
279 video->renderer->writePalette(video->renderer, 2, video->palette[2]);
280 video->renderer->writePalette(video->renderer, 3, video->palette[3]);
281 break;
282 case REG_OBP0:
283 video->palette[8 * 4 + 0] = dmgPalette[value & 3];
284 video->palette[8 * 4 + 1] = dmgPalette[(value >> 2) & 3];
285 video->palette[8 * 4 + 2] = dmgPalette[(value >> 4) & 3];
286 video->palette[8 * 4 + 3] = dmgPalette[(value >> 6) & 3];
287 video->renderer->writePalette(video->renderer, 8 * 4 + 0, video->palette[8 * 4 + 0]);
288 video->renderer->writePalette(video->renderer, 8 * 4 + 1, video->palette[8 * 4 + 1]);
289 video->renderer->writePalette(video->renderer, 8 * 4 + 2, video->palette[8 * 4 + 2]);
290 video->renderer->writePalette(video->renderer, 8 * 4 + 3, video->palette[8 * 4 + 3]);
291 break;
292 case REG_OBP1:
293 video->palette[9 * 4 + 0] = dmgPalette[value & 3];
294 video->palette[9 * 4 + 1] = dmgPalette[(value >> 2) & 3];
295 video->palette[9 * 4 + 2] = dmgPalette[(value >> 4) & 3];
296 video->palette[9 * 4 + 3] = dmgPalette[(value >> 6) & 3];
297 video->renderer->writePalette(video->renderer, 9 * 4 + 0, video->palette[9 * 4 + 0]);
298 video->renderer->writePalette(video->renderer, 9 * 4 + 1, video->palette[9 * 4 + 1]);
299 video->renderer->writePalette(video->renderer, 9 * 4 + 2, video->palette[9 * 4 + 2]);
300 video->renderer->writePalette(video->renderer, 9 * 4 + 3, video->palette[9 * 4 + 3]);
301 break;
302 }
303 } else {
304 switch (address) {
305 case REG_BCPD:
306 if (video->bcpIndex & 1) {
307 video->palette[video->bcpIndex >> 1] &= 0x00FF;
308 video->palette[video->bcpIndex >> 1] |= value << 8;
309 } else {
310 video->palette[video->bcpIndex >> 1] &= 0xFF00;
311 video->palette[video->bcpIndex >> 1] |= value;
312 }
313 video->renderer->writePalette(video->renderer, video->bcpIndex >> 1, video->palette[video->bcpIndex >> 1]);
314 if (video->bcpIncrement) {
315 ++video->bcpIndex;
316 video->bcpIndex &= 0x3F;
317 }
318 break;
319 case REG_OCPD:
320 if (video->ocpIndex & 1) {
321 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0x00FF;
322 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value << 8;
323 } else {
324 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0xFF00;
325 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value;
326 }
327 video->renderer->writePalette(video->renderer, 8 * 4 + (video->ocpIndex >> 1), video->palette[8 * 4 + (video->ocpIndex >> 1)]);
328 if (video->ocpIncrement) {
329 ++video->ocpIndex;
330 video->ocpIndex &= 0x3F;
331 }
332 break;
333 }
334 }
335}
336
337void GBVideoSwitchBank(struct GBVideo* video, uint8_t value) {
338 value &= 1;
339 video->vramBank = &video->vram[value * GB_SIZE_VRAM_BANK0];
340 video->vramCurrentBank = value;
341}
342
343static void GBVideoDummyRendererInit(struct GBVideoRenderer* renderer, enum GBModel model) {
344 UNUSED(renderer);
345 UNUSED(model);
346 // Nothing to do
347}
348
349static void GBVideoDummyRendererDeinit(struct GBVideoRenderer* renderer) {
350 UNUSED(renderer);
351 // Nothing to do
352}
353
354static uint8_t GBVideoDummyRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value) {
355 UNUSED(renderer);
356 UNUSED(address);
357 return value;
358}
359
360static void GBVideoDummyRendererWritePalette(struct GBVideoRenderer* renderer, int index, uint16_t value) {
361 UNUSED(renderer);
362 UNUSED(index);
363 UNUSED(value);
364}
365
366static void GBVideoDummyRendererDrawRange(struct GBVideoRenderer* renderer, int startX, int endX, int y, struct GBObj** obj, size_t oamMax) {
367 UNUSED(renderer);
368 UNUSED(endX);
369 UNUSED(startX);
370 UNUSED(y);
371 UNUSED(obj);
372 UNUSED(oamMax);
373 // Nothing to do
374}
375
376static void GBVideoDummyRendererFinishScanline(struct GBVideoRenderer* renderer, int y) {
377 UNUSED(renderer);
378 UNUSED(y);
379 // Nothing to do
380}
381
382static void GBVideoDummyRendererFinishFrame(struct GBVideoRenderer* renderer) {
383 UNUSED(renderer);
384 // Nothing to do
385}
386
387static void GBVideoDummyRendererGetPixels(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels) {
388 UNUSED(renderer);
389 UNUSED(stride);
390 UNUSED(pixels);
391 // Nothing to do
392}