src/gba/gba-video.c (view raw)
1/* Copyright (c) 2013-2014 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 "gba-video.h"
7
8#include "gba.h"
9#include "gba-io.h"
10#include "gba-rr.h"
11#include "gba-serialize.h"
12#include "gba-thread.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
26static struct GBAVideoRenderer dummyRenderer = {
27 .init = GBAVideoDummyRendererInit,
28 .reset = GBAVideoDummyRendererReset,
29 .deinit = GBAVideoDummyRendererDeinit,
30 .writeVideoRegister = GBAVideoDummyRendererWriteVideoRegister,
31 .writePalette = GBAVideoDummyRendererWritePalette,
32 .writeOAM = GBAVideoDummyRendererWriteOAM,
33 .drawScanline = GBAVideoDummyRendererDrawScanline,
34 .finishFrame = GBAVideoDummyRendererFinishFrame,
35 .getPixels = GBAVideoDummyRendererGetPixels
36};
37
38void GBAVideoInit(struct GBAVideo* video) {
39 video->renderer = &dummyRenderer;
40 video->vram = 0;
41}
42
43void GBAVideoReset(struct GBAVideo* video) {
44 video->dispstat = 0;
45 video->vcount = 0;
46
47 video->lastHblank = 0;
48 video->nextHblank = VIDEO_HDRAW_LENGTH;
49 video->nextEvent = video->nextHblank;
50 video->eventDiff = video->nextEvent;
51
52 video->nextHblankIRQ = 0;
53 video->nextVblankIRQ = 0;
54 video->nextVcounterIRQ = 0;
55
56 if (video->vram) {
57 mappedMemoryFree(video->vram, SIZE_VRAM);
58 }
59 video->vram = anonymousMemoryMap(SIZE_VRAM);
60 video->renderer->vram = video->vram;
61
62 int i;
63 for (i = 0; i < 128; ++i) {
64 video->oam.raw[i * 4] = 0x0200;
65 video->oam.raw[i * 4 + 1] = 0x0000;
66 video->oam.raw[i * 4 + 2] = 0x0000;
67 video->oam.raw[i * 4 + 3] = 0x0000;
68 }
69
70 video->renderer->deinit(video->renderer);
71 video->renderer->init(video->renderer);
72}
73
74void GBAVideoDeinit(struct GBAVideo* video) {
75 GBAVideoAssociateRenderer(video, &dummyRenderer);
76 mappedMemoryFree(video->vram, SIZE_VRAM);
77}
78
79void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
80 video->renderer->deinit(video->renderer);
81 video->renderer = renderer;
82 renderer->palette = video->palette;
83 renderer->vram = video->vram;
84 renderer->oam = &video->oam;
85 video->renderer->init(video->renderer);
86}
87
88int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
89 video->nextEvent -= cycles;
90 video->eventDiff += cycles;
91 if (video->nextEvent <= 0) {
92 int32_t lastEvent = video->nextEvent;
93 video->lastHblank -= video->eventDiff;
94 video->nextHblank -= video->eventDiff;
95 video->nextHblankIRQ -= video->eventDiff;
96 video->nextVcounterIRQ -= video->eventDiff;
97
98 if (GBARegisterDISPSTATIsInHblank(video->dispstat)) {
99 // End Hblank
100 video->dispstat = GBARegisterDISPSTATClearInHblank(video->dispstat);
101 video->nextEvent = video->nextHblank;
102
103 ++video->vcount;
104 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
105
106 switch (video->vcount) {
107 case VIDEO_VERTICAL_PIXELS:
108 video->dispstat = GBARegisterDISPSTATFillInVblank(video->dispstat);
109 if (GBASyncDrawingFrame(video->p->sync)) {
110 video->renderer->finishFrame(video->renderer);
111 }
112 video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
113 GBAMemoryRunVblankDMAs(video->p, lastEvent);
114 if (GBARegisterDISPSTATIsVblankIRQ(video->dispstat)) {
115 GBARaiseIRQ(video->p, IRQ_VBLANK);
116 }
117 GBASyncPostFrame(video->p->sync);
118 break;
119 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
120 if (video->p->rr) {
121 GBARRNextFrame(video->p->rr);
122 }
123 video->dispstat = GBARegisterDISPSTATClearInVblank(video->dispstat);
124 break;
125 case VIDEO_VERTICAL_TOTAL_PIXELS:
126 video->vcount = 0;
127 video->p->memory.io[REG_VCOUNT >> 1] = 0;
128 break;
129 }
130
131 if (video->vcount == GBARegisterDISPSTATGetVcountSetting(video->dispstat)) {
132 video->dispstat = GBARegisterDISPSTATFillVcounter(video->dispstat);
133 if (GBARegisterDISPSTATIsVcounterIRQ(video->dispstat)) {
134 GBARaiseIRQ(video->p, IRQ_VCOUNTER);
135 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
136 }
137 } else {
138 video->dispstat = GBARegisterDISPSTATClearVcounter(video->dispstat);
139 }
140 } else {
141 // Begin Hblank
142 video->dispstat = GBARegisterDISPSTATFillInHblank(video->dispstat);
143 video->lastHblank = video->nextHblank;
144 video->nextEvent = video->lastHblank + VIDEO_HBLANK_LENGTH;
145 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
146 video->nextHblankIRQ = video->nextHblank;
147
148 if (video->vcount < VIDEO_VERTICAL_PIXELS && GBASyncDrawingFrame(video->p->sync)) {
149 video->renderer->drawScanline(video->renderer, video->vcount);
150 }
151
152 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
153 GBAMemoryRunHblankDMAs(video->p, lastEvent);
154 }
155 if (GBARegisterDISPSTATIsHblankIRQ(video->dispstat)) {
156 GBARaiseIRQ(video->p, IRQ_HBLANK);
157 }
158 }
159
160 video->eventDiff = 0;
161 }
162 video->p->memory.io[REG_DISPSTAT >> 1] &= 0xFFF8;
163 video->p->memory.io[REG_DISPSTAT >> 1] |= video->dispstat & 0x7;
164 return video->nextEvent;
165}
166
167void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
168 video->dispstat &= 0x7;
169 video->dispstat |= value & 0xFFF8;
170
171 if (GBARegisterDISPSTATIsVcounterIRQ(video->dispstat)) {
172 // FIXME: this can be too late if we're in the middle of an Hblank
173 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (GBARegisterDISPSTATGetVcountSetting(video->dispstat) - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
174 if (video->nextVcounterIRQ < video->nextEvent) {
175 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
176 }
177 }
178}
179
180static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
181 UNUSED(renderer);
182 // Nothing to do
183}
184
185static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
186 UNUSED(renderer);
187 // Nothing to do
188}
189
190static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
191 UNUSED(renderer);
192 // Nothing to do
193}
194
195static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
196 UNUSED(renderer);
197 UNUSED(address);
198 return value;
199}
200
201static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
202 UNUSED(renderer);
203 UNUSED(address);
204 UNUSED(value);
205 // Nothing to do
206}
207
208static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
209 UNUSED(renderer);
210 UNUSED(oam);
211 // Nothing to do
212}
213
214static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
215 UNUSED(renderer);
216 UNUSED(y);
217 // Nothing to do
218}
219
220static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
221 UNUSED(renderer);
222 // Nothing to do
223}
224
225static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, void** pixels) {
226 UNUSED(renderer);
227 UNUSED(stride);
228 UNUSED(pixels);
229 // Nothing to do
230}
231
232
233void GBAVideoSerialize(struct GBAVideo* video, struct GBASerializedState* state) {
234 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
235 memcpy(state->oam, video->oam.raw, SIZE_OAM);
236 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
237 state->io[REG_DISPSTAT >> 1] = video->dispstat;
238 state->video.nextEvent = video->nextEvent;
239 state->video.eventDiff = video->eventDiff;
240 state->video.lastHblank = video->lastHblank;
241 state->video.nextHblank = video->nextHblank;
242 state->video.nextHblankIRQ = video->nextHblankIRQ;
243 state->video.nextVblankIRQ = video->nextVblankIRQ;
244 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
245}
246
247void GBAVideoDeserialize(struct GBAVideo* video, struct GBASerializedState* state) {
248 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
249 int i;
250 for (i = 0; i < SIZE_OAM; i += 2) {
251 GBAStore16(video->p->cpu, BASE_OAM | i, state->oam[i >> 1], 0);
252 }
253 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
254 GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, state->pram[i >> 1], 0);
255 }
256 video->dispstat = state->io[REG_DISPSTAT >> 1];
257 video->nextEvent = state->video.nextEvent;
258 video->eventDiff = state->video.eventDiff;
259 video->lastHblank = state->video.lastHblank;
260 video->nextHblank = state->video.nextHblank;
261 video->nextHblankIRQ = state->video.nextHblankIRQ;
262 video->nextVblankIRQ = state->video.nextVblankIRQ;
263 video->nextVcounterIRQ = state->video.nextVcounterIRQ;
264 video->vcount = state->io[REG_VCOUNT >> 1];
265}