src/gba/video.c (view raw)
1/* Copyright (c) 2013-2015 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 "gba/context/sync.h"
9#include "gba/gba.h"
10#include "gba/io.h"
11#include "gba/rr/rr.h"
12#include "gba/serialize.h"
13
14#include "util/memory.h"
15
16static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer);
17static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer);
18static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer);
19static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
20static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address);
21static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
22static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam);
23static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
24static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer);
25static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, const void** pixels);
26
27const int GBAVideoObjSizes[16][2] = {
28 { 8, 8 },
29 { 16, 16 },
30 { 32, 32 },
31 { 64, 64 },
32 { 16, 8 },
33 { 32, 8 },
34 { 32, 16 },
35 { 64, 32 },
36 { 8, 16 },
37 { 8, 32 },
38 { 16, 32 },
39 { 32, 64 },
40 { 0, 0 },
41 { 0, 0 },
42 { 0, 0 },
43 { 0, 0 },
44};
45
46static struct GBAVideoRenderer dummyRenderer = {
47 .init = GBAVideoDummyRendererInit,
48 .reset = GBAVideoDummyRendererReset,
49 .deinit = GBAVideoDummyRendererDeinit,
50 .writeVideoRegister = GBAVideoDummyRendererWriteVideoRegister,
51 .writeVRAM = GBAVideoDummyRendererWriteVRAM,
52 .writePalette = GBAVideoDummyRendererWritePalette,
53 .writeOAM = GBAVideoDummyRendererWriteOAM,
54 .drawScanline = GBAVideoDummyRendererDrawScanline,
55 .finishFrame = GBAVideoDummyRendererFinishFrame,
56 .getPixels = GBAVideoDummyRendererGetPixels
57};
58
59void GBAVideoInit(struct GBAVideo* video) {
60 video->renderer = &dummyRenderer;
61 video->vram = 0;
62 video->frameskip = 0;
63}
64
65void GBAVideoReset(struct GBAVideo* video) {
66 if (video->p->memory.fullBios) {
67 video->vcount = 0;
68 } else {
69 // TODO: Verify exact scanline hardware
70 video->vcount = 0x7E;
71 }
72 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
73
74 video->nextHblank = VIDEO_HDRAW_LENGTH;
75 video->nextEvent = video->nextHblank;
76 video->eventDiff = 0;
77
78 video->nextHblankIRQ = 0;
79 video->nextVblankIRQ = 0;
80 video->nextVcounterIRQ = 0;
81
82 video->frameCounter = 0;
83 video->frameskipCounter = 0;
84
85 if (video->vram) {
86 mappedMemoryFree(video->vram, SIZE_VRAM);
87 }
88 video->vram = anonymousMemoryMap(SIZE_VRAM);
89 video->renderer->vram = video->vram;
90
91 int i;
92 for (i = 0; i < 128; ++i) {
93 STORE_16(0x0200, i * 8 + 0, video->oam.raw);
94 STORE_16(0x0000, i * 8 + 2, video->oam.raw);
95 STORE_16(0x0000, i * 8 + 4, video->oam.raw);
96 STORE_16(0x0000, i * 8 + 6, video->oam.raw);
97 }
98
99 video->renderer->deinit(video->renderer);
100 video->renderer->init(video->renderer);
101}
102
103void GBAVideoDeinit(struct GBAVideo* video) {
104 GBAVideoAssociateRenderer(video, &dummyRenderer);
105 mappedMemoryFree(video->vram, SIZE_VRAM);
106}
107
108void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
109 video->renderer->deinit(video->renderer);
110 video->renderer = renderer;
111 renderer->palette = video->palette;
112 renderer->vram = video->vram;
113 renderer->oam = &video->oam;
114 video->renderer->init(video->renderer);
115}
116
117int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
118 video->nextEvent -= cycles;
119 video->eventDiff += cycles;
120 if (video->nextEvent <= 0) {
121 int32_t lastEvent = video->nextEvent;
122 video->nextHblank -= video->eventDiff;
123 video->nextHblankIRQ -= video->eventDiff;
124 video->nextVcounterIRQ -= video->eventDiff;
125 video->eventDiff = 0;
126 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
127
128 if (GBARegisterDISPSTATIsInHblank(dispstat)) {
129 // End Hblank
130 dispstat = GBARegisterDISPSTATClearInHblank(dispstat);
131 video->nextEvent = video->nextHblank;
132
133 ++video->vcount;
134 if (video->vcount == VIDEO_VERTICAL_TOTAL_PIXELS) {
135 video->vcount = 0;
136 }
137 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
138
139 if (video->vcount == GBARegisterDISPSTATGetVcountSetting(dispstat)) {
140 dispstat = GBARegisterDISPSTATFillVcounter(dispstat);
141 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
142 GBARaiseIRQ(video->p, IRQ_VCOUNTER);
143 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
144 }
145 } else {
146 dispstat = GBARegisterDISPSTATClearVcounter(dispstat);
147 }
148 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
149
150 // Note: state may be recorded during callbacks, so ensure it is consistent!
151 switch (video->vcount) {
152 case 0:
153 GBAFrameStarted(video->p);
154 break;
155 case VIDEO_VERTICAL_PIXELS:
156 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATFillInVblank(dispstat);
157 if (video->frameskipCounter <= 0) {
158 video->renderer->finishFrame(video->renderer);
159 }
160 video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
161 GBAMemoryRunVblankDMAs(video->p, lastEvent);
162 if (GBARegisterDISPSTATIsVblankIRQ(dispstat)) {
163 GBARaiseIRQ(video->p, IRQ_VBLANK);
164 }
165 GBAFrameEnded(video->p);
166 --video->frameskipCounter;
167 if (video->frameskipCounter < 0) {
168 GBASyncPostFrame(video->p->sync);
169 video->frameskipCounter = video->frameskip;
170 }
171 ++video->frameCounter;
172 break;
173 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
174 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATClearInVblank(dispstat);
175 break;
176 }
177 } else {
178 // Begin Hblank
179 dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
180 video->nextEvent = video->nextHblank + VIDEO_HBLANK_LENGTH;
181 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
182 video->nextHblankIRQ = video->nextHblank;
183
184 if (video->vcount < VIDEO_VERTICAL_PIXELS && video->frameskipCounter <= 0) {
185 video->renderer->drawScanline(video->renderer, video->vcount);
186 }
187
188 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
189 GBAMemoryRunHblankDMAs(video->p, lastEvent);
190 }
191 if (GBARegisterDISPSTATIsHblankIRQ(dispstat)) {
192 GBARaiseIRQ(video->p, IRQ_HBLANK);
193 }
194 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
195 }
196 }
197 return video->nextEvent;
198}
199
200void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
201 video->p->memory.io[REG_DISPSTAT >> 1] &= 0x7;
202 video->p->memory.io[REG_DISPSTAT >> 1] |= value;
203
204 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
205
206 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
207 // FIXME: this can be too late if we're in the middle of an Hblank
208 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (GBARegisterDISPSTATGetVcountSetting(dispstat) - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
209 if (video->nextVcounterIRQ < video->nextEvent) {
210 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
211 }
212 }
213}
214
215static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
216 UNUSED(renderer);
217 // Nothing to do
218}
219
220static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
221 UNUSED(renderer);
222 // Nothing to do
223}
224
225static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
226 UNUSED(renderer);
227 // Nothing to do
228}
229
230static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
231 UNUSED(renderer);
232 UNUSED(address);
233 return value;
234}
235
236static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
237 UNUSED(renderer);
238 UNUSED(address);
239 // Nothing to do
240}
241
242static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
243 UNUSED(renderer);
244 UNUSED(address);
245 UNUSED(value);
246 // Nothing to do
247}
248
249static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
250 UNUSED(renderer);
251 UNUSED(oam);
252 // Nothing to do
253}
254
255static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
256 UNUSED(renderer);
257 UNUSED(y);
258 // Nothing to do
259}
260
261static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
262 UNUSED(renderer);
263 // Nothing to do
264}
265
266static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, const void** pixels) {
267 UNUSED(renderer);
268 UNUSED(stride);
269 UNUSED(pixels);
270 // Nothing to do
271}
272
273void GBAVideoSerialize(const struct GBAVideo* video, struct GBASerializedState* state) {
274 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
275 memcpy(state->oam, video->oam.raw, SIZE_OAM);
276 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
277 state->video.nextEvent = video->nextEvent;
278 state->video.eventDiff = video->eventDiff;
279 state->video.lastHblank = video->nextHblank - VIDEO_HBLANK_LENGTH;
280 state->video.nextHblank = video->nextHblank;
281 state->video.nextHblankIRQ = video->nextHblankIRQ;
282 state->video.nextVblankIRQ = video->nextVblankIRQ;
283 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
284 state->video.frameCounter = video->frameCounter;
285}
286
287void GBAVideoDeserialize(struct GBAVideo* video, const struct GBASerializedState* state) {
288 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
289 uint16_t value;
290 int i;
291 for (i = 0; i < SIZE_OAM; i += 2) {
292 LOAD_16(value, i, state->oam);
293 GBAStore16(video->p->cpu, BASE_OAM | i, value, 0);
294 }
295 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
296 LOAD_16(value, i, state->pram);
297 GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, value, 0);
298 }
299 LOAD_32(video->nextEvent, 0, &state->video.nextEvent);
300 LOAD_32(video->eventDiff, 0, &state->video.eventDiff);
301 LOAD_32(video->nextHblank, 0, &state->video.nextHblank);
302 LOAD_32(video->nextHblankIRQ, 0, &state->video.nextHblankIRQ);
303 LOAD_32(video->nextVblankIRQ, 0, &state->video.nextVblankIRQ);
304 LOAD_32(video->nextVcounterIRQ, 0, &state->video.nextVcounterIRQ);
305 LOAD_32(video->frameCounter, 0, &state->video.frameCounter);
306 LOAD_16(video->vcount, REG_VCOUNT, state->io);
307}