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 video->frameskipCounter = video->frameskip;
169 }
170 ++video->frameCounter;
171 break;
172 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
173 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATClearInVblank(dispstat);
174 break;
175 }
176 } else {
177 // Begin Hblank
178 dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
179 video->nextEvent = video->nextHblank + VIDEO_HBLANK_LENGTH;
180 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
181 video->nextHblankIRQ = video->nextHblank;
182
183 if (video->vcount < VIDEO_VERTICAL_PIXELS && video->frameskipCounter <= 0) {
184 video->renderer->drawScanline(video->renderer, video->vcount);
185 }
186
187 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
188 GBAMemoryRunHblankDMAs(video->p, lastEvent);
189 }
190 if (GBARegisterDISPSTATIsHblankIRQ(dispstat)) {
191 GBARaiseIRQ(video->p, IRQ_HBLANK);
192 }
193 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
194 }
195 }
196 return video->nextEvent;
197}
198
199void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
200 video->p->memory.io[REG_DISPSTAT >> 1] &= 0x7;
201 video->p->memory.io[REG_DISPSTAT >> 1] |= value;
202
203 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
204
205 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
206 // FIXME: this can be too late if we're in the middle of an Hblank
207 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (GBARegisterDISPSTATGetVcountSetting(dispstat) - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
208 if (video->nextVcounterIRQ < video->nextEvent) {
209 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
210 }
211 }
212}
213
214static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
215 UNUSED(renderer);
216 // Nothing to do
217}
218
219static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
220 UNUSED(renderer);
221 // Nothing to do
222}
223
224static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
225 UNUSED(renderer);
226 // Nothing to do
227}
228
229static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
230 UNUSED(renderer);
231 UNUSED(address);
232 return value;
233}
234
235static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
236 UNUSED(renderer);
237 UNUSED(address);
238 // Nothing to do
239}
240
241static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
242 UNUSED(renderer);
243 UNUSED(address);
244 UNUSED(value);
245 // Nothing to do
246}
247
248static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
249 UNUSED(renderer);
250 UNUSED(oam);
251 // Nothing to do
252}
253
254static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
255 UNUSED(renderer);
256 UNUSED(y);
257 // Nothing to do
258}
259
260static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
261 UNUSED(renderer);
262 // Nothing to do
263}
264
265static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, const void** pixels) {
266 UNUSED(renderer);
267 UNUSED(stride);
268 UNUSED(pixels);
269 // Nothing to do
270}
271
272void GBAVideoSerialize(const struct GBAVideo* video, struct GBASerializedState* state) {
273 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
274 memcpy(state->oam, video->oam.raw, SIZE_OAM);
275 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
276 state->video.nextEvent = video->nextEvent;
277 state->video.eventDiff = video->eventDiff;
278 state->video.lastHblank = video->nextHblank - VIDEO_HBLANK_LENGTH;
279 state->video.nextHblank = video->nextHblank;
280 state->video.nextHblankIRQ = video->nextHblankIRQ;
281 state->video.nextVblankIRQ = video->nextVblankIRQ;
282 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
283 state->video.frameCounter = video->frameCounter;
284}
285
286void GBAVideoDeserialize(struct GBAVideo* video, const struct GBASerializedState* state) {
287 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
288 uint16_t value;
289 int i;
290 for (i = 0; i < SIZE_OAM; i += 2) {
291 LOAD_16(value, i, state->oam);
292 GBAStore16(video->p->cpu, BASE_OAM | i, value, 0);
293 }
294 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
295 LOAD_16(value, i, state->pram);
296 GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, value, 0);
297 }
298 video->nextEvent = state->video.nextEvent;
299 video->eventDiff = state->video.eventDiff;
300 video->nextHblank = state->video.nextHblank;
301 video->nextHblankIRQ = state->video.nextHblankIRQ;
302 video->nextVblankIRQ = state->video.nextVblankIRQ;
303 video->nextVcounterIRQ = state->video.nextVcounterIRQ;
304 video->frameCounter = state->video.frameCounter;
305 video->vcount = state->io[REG_VCOUNT >> 1];
306}