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