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 GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
21static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam);
22static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
23static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer);
24static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, void** pixels);
25
26const int GBAVideoObjSizes[16][2] = {
27 { 8, 8 },
28 { 16, 16 },
29 { 32, 32 },
30 { 64, 64 },
31 { 16, 8 },
32 { 32, 8 },
33 { 32, 16 },
34 { 64, 32 },
35 { 8, 16 },
36 { 8, 32 },
37 { 16, 32 },
38 { 32, 64 },
39 { 0, 0 },
40 { 0, 0 },
41 { 0, 0 },
42 { 0, 0 },
43};
44
45static struct GBAVideoRenderer dummyRenderer = {
46 .init = GBAVideoDummyRendererInit,
47 .reset = GBAVideoDummyRendererReset,
48 .deinit = GBAVideoDummyRendererDeinit,
49 .writeVideoRegister = GBAVideoDummyRendererWriteVideoRegister,
50 .writePalette = GBAVideoDummyRendererWritePalette,
51 .writeOAM = GBAVideoDummyRendererWriteOAM,
52 .drawScanline = GBAVideoDummyRendererDrawScanline,
53 .finishFrame = GBAVideoDummyRendererFinishFrame,
54 .getPixels = GBAVideoDummyRendererGetPixels
55};
56
57void GBAVideoInit(struct GBAVideo* video) {
58 video->renderer = &dummyRenderer;
59 video->vram = 0;
60}
61
62void GBAVideoReset(struct GBAVideo* video) {
63 video->vcount = VIDEO_VERTICAL_TOTAL_PIXELS - 1;
64
65 video->lastHblank = 0;
66 video->nextHblank = VIDEO_HDRAW_LENGTH;
67 video->nextEvent = video->nextHblank;
68 video->eventDiff = video->nextEvent;
69
70 video->nextHblankIRQ = 0;
71 video->nextVblankIRQ = 0;
72 video->nextVcounterIRQ = 0;
73
74 video->frameCounter = 0;
75
76 if (video->vram) {
77 mappedMemoryFree(video->vram, SIZE_VRAM);
78 }
79 video->vram = anonymousMemoryMap(SIZE_VRAM);
80 video->renderer->vram = video->vram;
81
82 int i;
83 for (i = 0; i < 128; ++i) {
84 video->oam.raw[i * 4] = 0x0200;
85 video->oam.raw[i * 4 + 1] = 0x0000;
86 video->oam.raw[i * 4 + 2] = 0x0000;
87 video->oam.raw[i * 4 + 3] = 0x0000;
88 }
89
90 video->renderer->deinit(video->renderer);
91 video->renderer->init(video->renderer);
92}
93
94void GBAVideoDeinit(struct GBAVideo* video) {
95 GBAVideoAssociateRenderer(video, &dummyRenderer);
96 mappedMemoryFree(video->vram, SIZE_VRAM);
97}
98
99void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
100 video->renderer->deinit(video->renderer);
101 video->renderer = renderer;
102 renderer->palette = video->palette;
103 renderer->vram = video->vram;
104 renderer->oam = &video->oam;
105 video->renderer->init(video->renderer);
106}
107
108int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
109 video->nextEvent -= cycles;
110 video->eventDiff += cycles;
111 if (video->nextEvent <= 0) {
112 int32_t lastEvent = video->nextEvent;
113 video->lastHblank -= video->eventDiff;
114 video->nextHblank -= video->eventDiff;
115 video->nextHblankIRQ -= video->eventDiff;
116 video->nextVcounterIRQ -= video->eventDiff;
117 video->eventDiff = 0;
118 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
119
120 if (GBARegisterDISPSTATIsInHblank(dispstat)) {
121 // End Hblank
122 dispstat = GBARegisterDISPSTATClearInHblank(dispstat);
123 video->nextEvent = video->nextHblank;
124
125 ++video->vcount;
126 if (video->vcount == VIDEO_VERTICAL_TOTAL_PIXELS) {
127 video->vcount = 0;
128 }
129 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
130
131 if (video->vcount == GBARegisterDISPSTATGetVcountSetting(dispstat)) {
132 dispstat = GBARegisterDISPSTATFillVcounter(dispstat);
133 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
134 GBARaiseIRQ(video->p, IRQ_VCOUNTER);
135 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
136 }
137 } else {
138 dispstat = GBARegisterDISPSTATClearVcounter(dispstat);
139 }
140 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
141
142 // Note: state may be recorded during callbacks, so ensure it is consistent!
143 switch (video->vcount) {
144 case 0:
145 GBAFrameStarted(video->p);
146 break;
147 case VIDEO_VERTICAL_PIXELS:
148 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATFillInVblank(dispstat);
149 if (GBASyncDrawingFrame(video->p->sync)) {
150 video->renderer->finishFrame(video->renderer);
151 }
152 video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
153 GBAMemoryRunVblankDMAs(video->p, lastEvent);
154 if (GBARegisterDISPSTATIsVblankIRQ(dispstat)) {
155 GBARaiseIRQ(video->p, IRQ_VBLANK);
156 }
157 GBAFrameEnded(video->p);
158 GBASyncPostFrame(video->p->sync);
159 ++video->frameCounter;
160 break;
161 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
162 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATClearInVblank(dispstat);
163 break;
164 }
165 } else {
166 // Begin Hblank
167 dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
168 video->lastHblank = video->nextHblank;
169 video->nextEvent = video->lastHblank + VIDEO_HBLANK_LENGTH;
170 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
171 video->nextHblankIRQ = video->nextHblank;
172
173 if (video->vcount < VIDEO_VERTICAL_PIXELS && GBASyncDrawingFrame(video->p->sync)) {
174 video->renderer->drawScanline(video->renderer, video->vcount);
175 }
176
177 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
178 GBAMemoryRunHblankDMAs(video->p, lastEvent);
179 }
180 if (GBARegisterDISPSTATIsHblankIRQ(dispstat)) {
181 GBARaiseIRQ(video->p, IRQ_HBLANK);
182 }
183 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
184 }
185 }
186 return video->nextEvent;
187}
188
189void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
190 video->p->memory.io[REG_DISPSTAT >> 1] &= 0x7;
191 video->p->memory.io[REG_DISPSTAT >> 1] |= value;
192
193 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
194
195 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
196 // FIXME: this can be too late if we're in the middle of an Hblank
197 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (GBARegisterDISPSTATGetVcountSetting(dispstat) - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
198 if (video->nextVcounterIRQ < video->nextEvent) {
199 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
200 }
201 }
202}
203
204static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
205 UNUSED(renderer);
206 // Nothing to do
207}
208
209static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
210 UNUSED(renderer);
211 // Nothing to do
212}
213
214static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
215 UNUSED(renderer);
216 // Nothing to do
217}
218
219static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
220 UNUSED(renderer);
221 UNUSED(address);
222 return value;
223}
224
225static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
226 UNUSED(renderer);
227 UNUSED(address);
228 UNUSED(value);
229 // Nothing to do
230}
231
232static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
233 UNUSED(renderer);
234 UNUSED(oam);
235 // Nothing to do
236}
237
238static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
239 UNUSED(renderer);
240 UNUSED(y);
241 // Nothing to do
242}
243
244static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
245 UNUSED(renderer);
246 // Nothing to do
247}
248
249static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, void** pixels) {
250 UNUSED(renderer);
251 UNUSED(stride);
252 UNUSED(pixels);
253 // Nothing to do
254}
255
256void GBAVideoSerialize(const struct GBAVideo* video, struct GBASerializedState* state) {
257 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
258 memcpy(state->oam, video->oam.raw, SIZE_OAM);
259 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
260 state->video.nextEvent = video->nextEvent;
261 state->video.eventDiff = video->eventDiff;
262 state->video.lastHblank = video->lastHblank;
263 state->video.nextHblank = video->nextHblank;
264 state->video.nextHblankIRQ = video->nextHblankIRQ;
265 state->video.nextVblankIRQ = video->nextVblankIRQ;
266 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
267 state->video.frameCounter = video->frameCounter;
268}
269
270void GBAVideoDeserialize(struct GBAVideo* video, const struct GBASerializedState* state) {
271 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
272 int i;
273 for (i = 0; i < SIZE_OAM; i += 2) {
274 GBAStore16(video->p->cpu, BASE_OAM | i, state->oam[i >> 1], 0);
275 }
276 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
277 GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, state->pram[i >> 1], 0);
278 }
279 video->nextEvent = state->video.nextEvent;
280 video->eventDiff = state->video.eventDiff;
281 video->lastHblank = state->video.lastHblank;
282 video->nextHblank = state->video.nextHblank;
283 video->nextHblankIRQ = state->video.nextHblankIRQ;
284 video->nextVblankIRQ = state->video.nextVblankIRQ;
285 video->nextVcounterIRQ = state->video.nextVcounterIRQ;
286 video->frameCounter = state->video.frameCounter;
287 video->vcount = state->io[REG_VCOUNT >> 1];
288}