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 if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
182 video->p->memory.hdmaRemaining = 0x10;
183 video->p->memory.hdmaNext = video->p->cpu->cycles;
184 }
185 break;
186 }
187 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
188 video->p->memory.io[REG_STAT] = video->stat;
189 }
190 if (video->nextMode < video->nextEvent) {
191 video->nextEvent = video->nextMode;
192 }
193 video->eventDiff = 0;
194 }
195 return video->nextEvent;
196}
197
198static void _cleanOAM(struct GBVideo* video, int y) {
199 // TODO: GBC differences
200 // TODO: Optimize
201 video->objMax = 0;
202 int spriteHeight = 8;
203 if (GBRegisterLCDCIsObjSize(video->p->memory.io[REG_LCDC])) {
204 spriteHeight = 16;
205 }
206 int o = 0;
207 int i;
208 for (i = 0; i < 40; ++i) {
209 uint8_t oy = video->oam.obj[i].y;
210 if (y < oy - 16 || y >= oy - 16 + spriteHeight) {
211 continue;
212 }
213 // TODO: Sort
214 video->objThisLine[o] = &video->oam.obj[i];
215 ++o;
216 if (o == 10) {
217 break;
218 }
219 }
220 video->objMax = o;
221}
222
223void GBVideoProcessDots(struct GBVideo* video) {
224 if (video->mode != 3 || video->dotCounter < 0) {
225 return;
226 }
227 int oldX = video->x;
228 video->x = video->dotCounter + video->eventDiff + (video->p->cpu->cycles >> video->p->doubleSpeed);
229 if (video->x > GB_VIDEO_HORIZONTAL_PIXELS) {
230 video->x = GB_VIDEO_HORIZONTAL_PIXELS;
231 }
232 if (video->x == GB_VIDEO_HORIZONTAL_PIXELS) {
233 video->dotCounter = INT_MIN;
234 }
235 if (video->frameskipCounter <= 0) {
236 video->renderer->drawRange(video->renderer, oldX, video->x, video->ly, video->objThisLine, video->objMax);
237 }
238}
239
240void GBVideoWriteLCDC(struct GBVideo* video, GBRegisterLCDC value) {
241 if (!GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && GBRegisterLCDCIsEnable(value)) {
242 video->mode = 2;
243 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
244 video->nextEvent = video->nextMode;
245 video->eventDiff = -video->p->cpu->cycles >> video->p->doubleSpeed;
246 // TODO: Does this read as 0 for 4 T-cycles?
247 video->stat = GBRegisterSTATSetMode(video->stat, 2);
248 video->p->memory.io[REG_STAT] = video->stat;
249 video->ly = 0;
250 video->p->memory.io[REG_LY] = 0;
251
252 if (video->p->cpu->cycles + (video->nextEvent << video->p->doubleSpeed) < video->p->cpu->nextEvent) {
253 video->p->cpu->nextEvent = video->p->cpu->cycles + (video->nextEvent << video->p->doubleSpeed);
254 }
255 return;
256 }
257 if (GBRegisterLCDCIsEnable(video->p->memory.io[REG_LCDC]) && !GBRegisterLCDCIsEnable(value)) {
258 video->mode = 0;
259 video->nextMode = INT_MAX;
260 video->nextEvent = INT_MAX;
261 video->stat = GBRegisterSTATSetMode(video->stat, video->mode);
262 video->p->memory.io[REG_STAT] = video->stat;
263 video->ly = 0;
264 video->p->memory.io[REG_LY] = 0;
265 }
266}
267
268void GBVideoWriteSTAT(struct GBVideo* video, GBRegisterSTAT value) {
269 video->stat = (video->stat & 0x7) | (value & 0x78);
270}
271
272void GBVideoWritePalette(struct GBVideo* video, uint16_t address, uint8_t value) {
273 static const uint16_t dmgPalette[4] = { 0x7FFF, 0x56B5, 0x294A, 0x0000};
274 if (video->p->model < GB_MODEL_CGB) {
275 switch (address) {
276 case REG_BGP:
277 video->palette[0] = dmgPalette[value & 3];
278 video->palette[1] = dmgPalette[(value >> 2) & 3];
279 video->palette[2] = dmgPalette[(value >> 4) & 3];
280 video->palette[3] = dmgPalette[(value >> 6) & 3];
281 video->renderer->writePalette(video->renderer, 0, video->palette[0]);
282 video->renderer->writePalette(video->renderer, 1, video->palette[1]);
283 video->renderer->writePalette(video->renderer, 2, video->palette[2]);
284 video->renderer->writePalette(video->renderer, 3, video->palette[3]);
285 break;
286 case REG_OBP0:
287 video->palette[8 * 4 + 0] = dmgPalette[value & 3];
288 video->palette[8 * 4 + 1] = dmgPalette[(value >> 2) & 3];
289 video->palette[8 * 4 + 2] = dmgPalette[(value >> 4) & 3];
290 video->palette[8 * 4 + 3] = dmgPalette[(value >> 6) & 3];
291 video->renderer->writePalette(video->renderer, 8 * 4 + 0, video->palette[8 * 4 + 0]);
292 video->renderer->writePalette(video->renderer, 8 * 4 + 1, video->palette[8 * 4 + 1]);
293 video->renderer->writePalette(video->renderer, 8 * 4 + 2, video->palette[8 * 4 + 2]);
294 video->renderer->writePalette(video->renderer, 8 * 4 + 3, video->palette[8 * 4 + 3]);
295 break;
296 case REG_OBP1:
297 video->palette[9 * 4 + 0] = dmgPalette[value & 3];
298 video->palette[9 * 4 + 1] = dmgPalette[(value >> 2) & 3];
299 video->palette[9 * 4 + 2] = dmgPalette[(value >> 4) & 3];
300 video->palette[9 * 4 + 3] = dmgPalette[(value >> 6) & 3];
301 video->renderer->writePalette(video->renderer, 9 * 4 + 0, video->palette[9 * 4 + 0]);
302 video->renderer->writePalette(video->renderer, 9 * 4 + 1, video->palette[9 * 4 + 1]);
303 video->renderer->writePalette(video->renderer, 9 * 4 + 2, video->palette[9 * 4 + 2]);
304 video->renderer->writePalette(video->renderer, 9 * 4 + 3, video->palette[9 * 4 + 3]);
305 break;
306 }
307 } else {
308 switch (address) {
309 case REG_BCPD:
310 if (video->bcpIndex & 1) {
311 video->palette[video->bcpIndex >> 1] &= 0x00FF;
312 video->palette[video->bcpIndex >> 1] |= value << 8;
313 } else {
314 video->palette[video->bcpIndex >> 1] &= 0xFF00;
315 video->palette[video->bcpIndex >> 1] |= value;
316 }
317 video->renderer->writePalette(video->renderer, video->bcpIndex >> 1, video->palette[video->bcpIndex >> 1]);
318 if (video->bcpIncrement) {
319 ++video->bcpIndex;
320 video->bcpIndex &= 0x3F;
321 video->p->memory.io[REG_BCPD] = video->palette[video->bcpIndex >> 1];
322 }
323 break;
324 case REG_OCPD:
325 if (video->ocpIndex & 1) {
326 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0x00FF;
327 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value << 8;
328 } else {
329 video->palette[8 * 4 + (video->ocpIndex >> 1)] &= 0xFF00;
330 video->palette[8 * 4 + (video->ocpIndex >> 1)] |= value;
331 }
332 video->renderer->writePalette(video->renderer, 8 * 4 + (video->ocpIndex >> 1), video->palette[8 * 4 + (video->ocpIndex >> 1)]);
333 if (video->ocpIncrement) {
334 ++video->ocpIndex;
335 video->ocpIndex &= 0x3F;
336 video->p->memory.io[REG_OCPD] = video->palette[8 * 4 + (video->ocpIndex >> 1)];
337 }
338 break;
339 }
340 }
341}
342
343void GBVideoSwitchBank(struct GBVideo* video, uint8_t value) {
344 value &= 1;
345 video->vramBank = &video->vram[value * GB_SIZE_VRAM_BANK0];
346 video->vramCurrentBank = value;
347}
348
349static void GBVideoDummyRendererInit(struct GBVideoRenderer* renderer, enum GBModel model) {
350 UNUSED(renderer);
351 UNUSED(model);
352 // Nothing to do
353}
354
355static void GBVideoDummyRendererDeinit(struct GBVideoRenderer* renderer) {
356 UNUSED(renderer);
357 // Nothing to do
358}
359
360static uint8_t GBVideoDummyRendererWriteVideoRegister(struct GBVideoRenderer* renderer, uint16_t address, uint8_t value) {
361 UNUSED(renderer);
362 UNUSED(address);
363 return value;
364}
365
366static void GBVideoDummyRendererWritePalette(struct GBVideoRenderer* renderer, int index, uint16_t value) {
367 UNUSED(renderer);
368 UNUSED(index);
369 UNUSED(value);
370}
371
372static void GBVideoDummyRendererDrawRange(struct GBVideoRenderer* renderer, int startX, int endX, int y, struct GBObj** obj, size_t oamMax) {
373 UNUSED(renderer);
374 UNUSED(endX);
375 UNUSED(startX);
376 UNUSED(y);
377 UNUSED(obj);
378 UNUSED(oamMax);
379 // Nothing to do
380}
381
382static void GBVideoDummyRendererFinishScanline(struct GBVideoRenderer* renderer, int y) {
383 UNUSED(renderer);
384 UNUSED(y);
385 // Nothing to do
386}
387
388static void GBVideoDummyRendererFinishFrame(struct GBVideoRenderer* renderer) {
389 UNUSED(renderer);
390 // Nothing to do
391}
392
393static void GBVideoDummyRendererGetPixels(struct GBVideoRenderer* renderer, unsigned* stride, const void** pixels) {
394 UNUSED(renderer);
395 UNUSED(stride);
396 UNUSED(pixels);
397 // Nothing to do
398}