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/gba.h"
9#include "gba/io.h"
10#include "gba/serialize.h"
11#include "gba/supervisor/rr.h"
12#include "gba/supervisor/sync.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, 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}
63
64void GBAVideoReset(struct GBAVideo* video) {
65 video->vcount = VIDEO_VERTICAL_TOTAL_PIXELS - 1;
66
67 video->lastHblank = 0;
68 video->nextHblank = VIDEO_HDRAW_LENGTH;
69 video->nextEvent = video->nextHblank;
70 video->eventDiff = 0;
71
72 video->nextHblankIRQ = 0;
73 video->nextVblankIRQ = 0;
74 video->nextVcounterIRQ = 0;
75
76 video->frameCounter = 0;
77
78 if (video->vram) {
79 mappedMemoryFree(video->vram, SIZE_VRAM);
80 }
81 video->vram = anonymousMemoryMap(SIZE_VRAM);
82 video->renderer->vram = video->vram;
83
84 int i;
85 for (i = 0; i < 128; ++i) {
86 video->oam.raw[i * 4] = 0x0200;
87 video->oam.raw[i * 4 + 1] = 0x0000;
88 video->oam.raw[i * 4 + 2] = 0x0000;
89 video->oam.raw[i * 4 + 3] = 0x0000;
90 }
91
92 video->renderer->deinit(video->renderer);
93 video->renderer->init(video->renderer);
94}
95
96void GBAVideoDeinit(struct GBAVideo* video) {
97 GBAVideoAssociateRenderer(video, &dummyRenderer);
98 mappedMemoryFree(video->vram, SIZE_VRAM);
99}
100
101void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
102 video->renderer->deinit(video->renderer);
103 video->renderer = renderer;
104 renderer->palette = video->palette;
105 renderer->vram = video->vram;
106 renderer->oam = &video->oam;
107 video->renderer->init(video->renderer);
108}
109
110int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
111 video->nextEvent -= cycles;
112 video->eventDiff += cycles;
113 if (video->nextEvent <= 0) {
114 int32_t lastEvent = video->nextEvent;
115 video->lastHblank -= video->eventDiff;
116 video->nextHblank -= video->eventDiff;
117 video->nextHblankIRQ -= video->eventDiff;
118 video->nextVcounterIRQ -= video->eventDiff;
119 video->eventDiff = 0;
120 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
121
122 if (GBARegisterDISPSTATIsInHblank(dispstat)) {
123 // End Hblank
124 dispstat = GBARegisterDISPSTATClearInHblank(dispstat);
125 video->nextEvent = video->nextHblank;
126
127 ++video->vcount;
128 if (video->vcount == VIDEO_VERTICAL_TOTAL_PIXELS) {
129 video->vcount = 0;
130 }
131 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
132
133 if (video->vcount == GBARegisterDISPSTATGetVcountSetting(dispstat)) {
134 dispstat = GBARegisterDISPSTATFillVcounter(dispstat);
135 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
136 GBARaiseIRQ(video->p, IRQ_VCOUNTER);
137 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
138 }
139 } else {
140 dispstat = GBARegisterDISPSTATClearVcounter(dispstat);
141 }
142 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
143
144 // Note: state may be recorded during callbacks, so ensure it is consistent!
145 switch (video->vcount) {
146 case 0:
147 GBAFrameStarted(video->p);
148 break;
149 case VIDEO_VERTICAL_PIXELS:
150 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATFillInVblank(dispstat);
151 if (GBASyncDrawingFrame(video->p->sync)) {
152 video->renderer->finishFrame(video->renderer);
153 }
154 video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
155 GBAMemoryRunVblankDMAs(video->p, lastEvent);
156 if (GBARegisterDISPSTATIsVblankIRQ(dispstat)) {
157 GBARaiseIRQ(video->p, IRQ_VBLANK);
158 }
159 GBAFrameEnded(video->p);
160 GBASyncPostFrame(video->p->sync);
161 ++video->frameCounter;
162 break;
163 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
164 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATClearInVblank(dispstat);
165 break;
166 }
167 } else {
168 // Begin Hblank
169 dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
170 video->lastHblank = video->nextHblank;
171 video->nextEvent = video->lastHblank + VIDEO_HBLANK_LENGTH;
172 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
173 video->nextHblankIRQ = video->nextHblank;
174
175 if (video->vcount < VIDEO_VERTICAL_PIXELS && GBASyncDrawingFrame(video->p->sync)) {
176 video->renderer->drawScanline(video->renderer, video->vcount);
177 }
178
179 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
180 GBAMemoryRunHblankDMAs(video->p, lastEvent);
181 }
182 if (GBARegisterDISPSTATIsHblankIRQ(dispstat)) {
183 GBARaiseIRQ(video->p, IRQ_HBLANK);
184 }
185 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
186 }
187 }
188 return video->nextEvent;
189}
190
191void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
192 video->p->memory.io[REG_DISPSTAT >> 1] &= 0x7;
193 video->p->memory.io[REG_DISPSTAT >> 1] |= value;
194
195 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
196
197 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
198 // FIXME: this can be too late if we're in the middle of an Hblank
199 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (GBARegisterDISPSTATGetVcountSetting(dispstat) - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
200 if (video->nextVcounterIRQ < video->nextEvent) {
201 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
202 }
203 }
204}
205
206static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
207 UNUSED(renderer);
208 // Nothing to do
209}
210
211static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
212 UNUSED(renderer);
213 // Nothing to do
214}
215
216static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
217 UNUSED(renderer);
218 // Nothing to do
219}
220
221static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
222 UNUSED(renderer);
223 UNUSED(address);
224 return value;
225}
226
227static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
228 UNUSED(renderer);
229 UNUSED(address);
230 // Nothing to do
231}
232
233static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
234 UNUSED(renderer);
235 UNUSED(address);
236 UNUSED(value);
237 // Nothing to do
238}
239
240static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
241 UNUSED(renderer);
242 UNUSED(oam);
243 // Nothing to do
244}
245
246static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
247 UNUSED(renderer);
248 UNUSED(y);
249 // Nothing to do
250}
251
252static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
253 UNUSED(renderer);
254 // Nothing to do
255}
256
257static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, void** pixels) {
258 UNUSED(renderer);
259 UNUSED(stride);
260 UNUSED(pixels);
261 // Nothing to do
262}
263
264void GBAVideoSerialize(const struct GBAVideo* video, struct GBASerializedState* state) {
265 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
266 memcpy(state->oam, video->oam.raw, SIZE_OAM);
267 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
268 state->video.nextEvent = video->nextEvent;
269 state->video.eventDiff = video->eventDiff;
270 state->video.lastHblank = video->lastHblank;
271 state->video.nextHblank = video->nextHblank;
272 state->video.nextHblankIRQ = video->nextHblankIRQ;
273 state->video.nextVblankIRQ = video->nextVblankIRQ;
274 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
275 state->video.frameCounter = video->frameCounter;
276}
277
278void GBAVideoDeserialize(struct GBAVideo* video, const struct GBASerializedState* state) {
279 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
280 int i;
281 for (i = 0; i < SIZE_OAM; i += 2) {
282 GBAStore16(video->p->cpu, BASE_OAM | i, state->oam[i >> 1], 0);
283 }
284 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
285 GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, state->pram[i >> 1], 0);
286 }
287 video->nextEvent = state->video.nextEvent;
288 video->eventDiff = state->video.eventDiff;
289 video->lastHblank = state->video.lastHblank;
290 video->nextHblank = state->video.nextHblank;
291 video->nextHblankIRQ = state->video.nextHblankIRQ;
292 video->nextVblankIRQ = state->video.nextVblankIRQ;
293 video->nextVcounterIRQ = state->video.nextVcounterIRQ;
294 video->frameCounter = state->video.frameCounter;
295 video->vcount = state->io[REG_VCOUNT >> 1];
296}