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->lastHblank = 0;
75 video->nextHblank = VIDEO_HDRAW_LENGTH;
76 video->nextEvent = video->nextHblank;
77 video->eventDiff = 0;
78
79 video->nextHblankIRQ = 0;
80 video->nextVblankIRQ = 0;
81 video->nextVcounterIRQ = 0;
82
83 video->frameCounter = 0;
84 video->frameskipCounter = 0;
85
86 if (video->vram) {
87 mappedMemoryFree(video->vram, SIZE_VRAM);
88 }
89 video->vram = anonymousMemoryMap(SIZE_VRAM);
90 video->renderer->vram = video->vram;
91
92 int i;
93 for (i = 0; i < 128; ++i) {
94 video->oam.raw[i * 4] = 0x0200;
95 video->oam.raw[i * 4 + 1] = 0x0000;
96 video->oam.raw[i * 4 + 2] = 0x0000;
97 video->oam.raw[i * 4 + 3] = 0x0000;
98 }
99
100 video->renderer->deinit(video->renderer);
101 video->renderer->init(video->renderer);
102}
103
104void GBAVideoDeinit(struct GBAVideo* video) {
105 GBAVideoAssociateRenderer(video, &dummyRenderer);
106 mappedMemoryFree(video->vram, SIZE_VRAM);
107}
108
109void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
110 video->renderer->deinit(video->renderer);
111 video->renderer = renderer;
112 renderer->palette = video->palette;
113 renderer->vram = video->vram;
114 renderer->oam = &video->oam;
115 video->renderer->init(video->renderer);
116}
117
118int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
119 video->nextEvent -= cycles;
120 video->eventDiff += cycles;
121 if (video->nextEvent <= 0) {
122 int32_t lastEvent = video->nextEvent;
123 video->lastHblank -= video->eventDiff;
124 video->nextHblank -= video->eventDiff;
125 video->nextHblankIRQ -= video->eventDiff;
126 video->nextVcounterIRQ -= video->eventDiff;
127 video->eventDiff = 0;
128 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
129
130 if (GBARegisterDISPSTATIsInHblank(dispstat)) {
131 // End Hblank
132 dispstat = GBARegisterDISPSTATClearInHblank(dispstat);
133 video->nextEvent = video->nextHblank;
134
135 ++video->vcount;
136 if (video->vcount == VIDEO_VERTICAL_TOTAL_PIXELS) {
137 video->vcount = 0;
138 }
139 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
140
141 if (video->vcount == GBARegisterDISPSTATGetVcountSetting(dispstat)) {
142 dispstat = GBARegisterDISPSTATFillVcounter(dispstat);
143 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
144 GBARaiseIRQ(video->p, IRQ_VCOUNTER);
145 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
146 }
147 } else {
148 dispstat = GBARegisterDISPSTATClearVcounter(dispstat);
149 }
150 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
151
152 // Note: state may be recorded during callbacks, so ensure it is consistent!
153 switch (video->vcount) {
154 case 0:
155 GBAFrameStarted(video->p);
156 break;
157 case VIDEO_VERTICAL_PIXELS:
158 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATFillInVblank(dispstat);
159 if (video->frameskipCounter <= 0) {
160 video->renderer->finishFrame(video->renderer);
161 }
162 video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
163 GBAMemoryRunVblankDMAs(video->p, lastEvent);
164 if (GBARegisterDISPSTATIsVblankIRQ(dispstat)) {
165 GBARaiseIRQ(video->p, IRQ_VBLANK);
166 }
167 GBAFrameEnded(video->p);
168 --video->frameskipCounter;
169 if (video->frameskipCounter < 0) {
170 video->frameskipCounter = video->frameskip;
171 }
172 ++video->frameCounter;
173 break;
174 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
175 video->p->memory.io[REG_DISPSTAT >> 1] = GBARegisterDISPSTATClearInVblank(dispstat);
176 break;
177 }
178 } else {
179 // Begin Hblank
180 dispstat = GBARegisterDISPSTATFillInHblank(dispstat);
181 video->lastHblank = video->nextHblank;
182 video->nextEvent = video->lastHblank + VIDEO_HBLANK_LENGTH;
183 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
184 video->nextHblankIRQ = video->nextHblank;
185
186 if (video->vcount < VIDEO_VERTICAL_PIXELS && video->frameskipCounter <= 0) {
187 video->renderer->drawScanline(video->renderer, video->vcount);
188 }
189
190 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
191 GBAMemoryRunHblankDMAs(video->p, lastEvent);
192 }
193 if (GBARegisterDISPSTATIsHblankIRQ(dispstat)) {
194 GBARaiseIRQ(video->p, IRQ_HBLANK);
195 }
196 video->p->memory.io[REG_DISPSTAT >> 1] = dispstat;
197 }
198 }
199 return video->nextEvent;
200}
201
202void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
203 video->p->memory.io[REG_DISPSTAT >> 1] &= 0x7;
204 video->p->memory.io[REG_DISPSTAT >> 1] |= value;
205
206 uint16_t dispstat = video->p->memory.io[REG_DISPSTAT >> 1];
207
208 if (GBARegisterDISPSTATIsVcounterIRQ(dispstat)) {
209 // FIXME: this can be too late if we're in the middle of an Hblank
210 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (GBARegisterDISPSTATGetVcountSetting(dispstat) - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
211 if (video->nextVcounterIRQ < video->nextEvent) {
212 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
213 }
214 }
215}
216
217static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
218 UNUSED(renderer);
219 // Nothing to do
220}
221
222static void GBAVideoDummyRendererReset(struct GBAVideoRenderer* renderer) {
223 UNUSED(renderer);
224 // Nothing to do
225}
226
227static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
228 UNUSED(renderer);
229 // Nothing to do
230}
231
232static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
233 UNUSED(renderer);
234 UNUSED(address);
235 return value;
236}
237
238static void GBAVideoDummyRendererWriteVRAM(struct GBAVideoRenderer* renderer, uint32_t address) {
239 UNUSED(renderer);
240 UNUSED(address);
241 // Nothing to do
242}
243
244static void GBAVideoDummyRendererWritePalette(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
245 UNUSED(renderer);
246 UNUSED(address);
247 UNUSED(value);
248 // Nothing to do
249}
250
251static void GBAVideoDummyRendererWriteOAM(struct GBAVideoRenderer* renderer, uint32_t oam) {
252 UNUSED(renderer);
253 UNUSED(oam);
254 // Nothing to do
255}
256
257static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
258 UNUSED(renderer);
259 UNUSED(y);
260 // Nothing to do
261}
262
263static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
264 UNUSED(renderer);
265 // Nothing to do
266}
267
268static void GBAVideoDummyRendererGetPixels(struct GBAVideoRenderer* renderer, unsigned* stride, const void** pixels) {
269 UNUSED(renderer);
270 UNUSED(stride);
271 UNUSED(pixels);
272 // Nothing to do
273}
274
275void GBAVideoSerialize(const struct GBAVideo* video, struct GBASerializedState* state) {
276 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
277 memcpy(state->oam, video->oam.raw, SIZE_OAM);
278 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
279 state->video.nextEvent = video->nextEvent;
280 state->video.eventDiff = video->eventDiff;
281 state->video.lastHblank = video->lastHblank;
282 state->video.nextHblank = video->nextHblank;
283 state->video.nextHblankIRQ = video->nextHblankIRQ;
284 state->video.nextVblankIRQ = video->nextVblankIRQ;
285 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
286 state->video.frameCounter = video->frameCounter;
287}
288
289void GBAVideoDeserialize(struct GBAVideo* video, const struct GBASerializedState* state) {
290 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
291 int i;
292 for (i = 0; i < SIZE_OAM; i += 2) {
293 GBAStore16(video->p->cpu, BASE_OAM | i, state->oam[i >> 1], 0);
294 }
295 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
296 GBAStore16(video->p->cpu, BASE_PALETTE_RAM | i, state->pram[i >> 1], 0);
297 }
298 video->nextEvent = state->video.nextEvent;
299 video->eventDiff = state->video.eventDiff;
300 video->lastHblank = state->video.lastHblank;
301 video->nextHblank = state->video.nextHblank;
302 video->nextHblankIRQ = state->video.nextHblankIRQ;
303 video->nextVblankIRQ = state->video.nextVblankIRQ;
304 video->nextVcounterIRQ = state->video.nextVcounterIRQ;
305 video->frameCounter = state->video.frameCounter;
306 video->vcount = state->io[REG_VCOUNT >> 1];
307}