src/gba/gba-video.c (view raw)
1#include "gba-video.h"
2
3#include "gba.h"
4#include "gba-io.h"
5#include "gba-serialize.h"
6#include "gba-thread.h"
7
8#include "util/memory.h"
9
10static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer);
11static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer);
12static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
13static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
14static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer);
15
16static struct GBAVideoRenderer dummyRenderer = {
17 .init = GBAVideoDummyRendererInit,
18 .deinit = GBAVideoDummyRendererDeinit,
19 .writeVideoRegister = GBAVideoDummyRendererWriteVideoRegister,
20 .drawScanline = GBAVideoDummyRendererDrawScanline,
21 .finishFrame = GBAVideoDummyRendererFinishFrame
22};
23
24void GBAVideoInit(struct GBAVideo* video) {
25 video->renderer = &dummyRenderer;
26
27 video->inHblank = 0;
28 video->inVblank = 0;
29 video->vcounter = 0;
30 video->vblankIRQ = 0;
31 video->hblankIRQ = 0;
32 video->vcounterIRQ = 0;
33 video->vcountSetting = 0;
34
35 video->vcount = -1;
36
37 video->lastHblank = 0;
38 video->nextHblank = VIDEO_HDRAW_LENGTH;
39 video->nextEvent = video->nextHblank;
40 video->eventDiff = video->nextEvent;
41
42 video->nextHblankIRQ = 0;
43 video->nextVblankIRQ = 0;
44 video->nextVcounterIRQ = 0;
45
46 video->vram = anonymousMemoryMap(SIZE_VRAM);
47
48 int i;
49 for (i = 0; i < 128; ++i) {
50 video->oam.obj[i].disable = 1;
51 }
52}
53
54void GBAVideoDeinit(struct GBAVideo* video) {
55 GBAVideoAssociateRenderer(video, &dummyRenderer);
56 mappedMemoryFree(video->vram, SIZE_VRAM);
57}
58
59void GBAVideoAssociateRenderer(struct GBAVideo* video, struct GBAVideoRenderer* renderer) {
60 video->renderer->deinit(video->renderer);
61 video->renderer = renderer;
62 renderer->palette = video->palette;
63 renderer->vram = video->vram;
64 renderer->oam = &video->oam;
65 video->renderer->init(video->renderer);
66}
67
68int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
69 video->nextEvent -= cycles;
70 video->eventDiff += cycles;
71 if (video->nextEvent <= 0) {
72 int32_t lastEvent = video->nextEvent;
73 video->lastHblank -= video->eventDiff;
74 video->nextHblank -= video->eventDiff;
75 video->nextHblankIRQ -= video->eventDiff;
76 video->nextVcounterIRQ -= video->eventDiff;
77
78 if (video->inHblank) {
79 // End Hblank
80 video->inHblank = 0;
81 video->nextEvent = video->nextHblank;
82
83 ++video->vcount;
84 video->p->memory.io[REG_VCOUNT >> 1] = video->vcount;
85
86 switch (video->vcount) {
87 case VIDEO_VERTICAL_PIXELS:
88 video->inVblank = 1;
89 if (GBASyncDrawingFrame(video->p->sync)) {
90 video->renderer->finishFrame(video->renderer);
91 }
92 video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
93 GBAMemoryRunVblankDMAs(video->p, lastEvent);
94 if (video->vblankIRQ) {
95 GBARaiseIRQ(video->p, IRQ_VBLANK);
96 }
97 GBASyncPostFrame(video->p->sync);
98 break;
99 case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
100 video->inVblank = 0;
101 break;
102 case VIDEO_VERTICAL_TOTAL_PIXELS:
103 video->vcount = 0;
104 video->p->memory.io[REG_VCOUNT >> 1] = 0;
105 break;
106 }
107
108 video->vcounter = video->vcount == video->vcountSetting;
109 if (video->vcounter && video->vcounterIRQ) {
110 GBARaiseIRQ(video->p, IRQ_VCOUNTER);
111 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
112 }
113
114 if (video->vcount < VIDEO_VERTICAL_PIXELS && GBASyncDrawingFrame(video->p->sync)) {
115 video->renderer->drawScanline(video->renderer, video->vcount);
116 }
117 } else {
118 // Begin Hblank
119 video->inHblank = 1;
120 video->lastHblank = video->nextHblank;
121 video->nextEvent = video->lastHblank + VIDEO_HBLANK_LENGTH;
122 video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
123 video->nextHblankIRQ = video->nextHblank;
124
125 if (video->vcount < VIDEO_VERTICAL_PIXELS) {
126 GBAMemoryRunHblankDMAs(video->p, lastEvent);
127 }
128 if (video->hblankIRQ) {
129 GBARaiseIRQ(video->p, IRQ_HBLANK);
130 }
131 }
132
133 video->eventDiff = 0;
134 }
135 video->p->memory.io[REG_DISPSTAT >> 1] &= 0xFFF8;
136 video->p->memory.io[REG_DISPSTAT >> 1] |= (video->inVblank) | (video->inHblank << 1) | (video->vcounter << 2);
137 return video->nextEvent;
138}
139
140void GBAVideoWriteDISPSTAT(struct GBAVideo* video, uint16_t value) {
141 union GBARegisterDISPSTAT dispstat;
142 dispstat.packed = value;
143 video->vblankIRQ = dispstat.vblankIRQ;
144 video->hblankIRQ = dispstat.hblankIRQ;
145 video->vcounterIRQ = dispstat.vcounterIRQ;
146 video->vcountSetting = dispstat.vcountSetting;
147
148 if (video->vcounterIRQ) {
149 // FIXME: this can be too late if we're in the middle of an Hblank
150 video->nextVcounterIRQ = video->nextHblank + VIDEO_HBLANK_LENGTH + (video->vcountSetting - video->vcount) * VIDEO_HORIZONTAL_LENGTH;
151 if (video->nextVcounterIRQ < video->nextEvent) {
152 video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
153 }
154 }
155}
156
157static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
158 (void)(renderer);
159 // Nothing to do
160}
161
162static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
163 (void)(renderer);
164 // Nothing to do
165}
166
167static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
168 (void)(renderer);
169 (void)(address);
170 return value;
171}
172
173static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
174 (void)(renderer);
175 (void)(y);
176 // Nothing to do
177}
178
179static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
180 (void)(renderer);
181 // Nothing to do
182}
183
184void GBAVideoSerialize(struct GBAVideo* video, struct GBASerializedState* state) {
185 memcpy(state->vram, video->renderer->vram, SIZE_VRAM);
186 memcpy(state->oam, video->oam.raw, SIZE_OAM);
187 memcpy(state->pram, video->palette, SIZE_PALETTE_RAM);
188 union GBARegisterDISPSTAT dispstat;
189 dispstat.inVblank = video->inVblank;
190 dispstat.inHblank = video->inHblank;
191 dispstat.vcounter = video->vcounter;
192 dispstat.vblankIRQ = video->vblankIRQ;
193 dispstat.hblankIRQ = video->hblankIRQ;
194 dispstat.vcounterIRQ = video->vcounterIRQ;
195 dispstat.vcountSetting = video->vcountSetting;
196 state->io[REG_DISPSTAT >> 1] = dispstat.packed;
197 state->video.nextEvent = video->nextEvent;
198 state->video.eventDiff = video->eventDiff;
199 state->video.lastHblank = video->lastHblank;
200 state->video.nextHblank = video->nextHblank;
201 state->video.nextHblankIRQ = video->nextHblankIRQ;
202 state->video.nextVblankIRQ = video->nextVblankIRQ;
203 state->video.nextVcounterIRQ = video->nextVcounterIRQ;
204}
205
206void GBAVideoDeserialize(struct GBAVideo* video, struct GBASerializedState* state) {
207 memcpy(video->renderer->vram, state->vram, SIZE_VRAM);
208 int i;
209 for (i = 0; i < SIZE_OAM; i += 2) {
210 GBAStore16(&video->p->cpu, BASE_OAM | i, state->oam[i >> 1], 0);
211 }
212 for (i = 0; i < SIZE_PALETTE_RAM; i += 2) {
213 GBAStore16(&video->p->cpu, BASE_PALETTE_RAM | i, state->pram[i >> 1], 0);
214 }
215 union GBARegisterDISPSTAT dispstat;
216 dispstat.packed = state->io[REG_DISPSTAT >> 1];
217 video->inVblank = dispstat.inVblank;
218 video->inHblank = dispstat.inHblank;
219 video->vcounter = dispstat.vcounter;
220 video->vblankIRQ = dispstat.vblankIRQ;
221 video->hblankIRQ = dispstat.hblankIRQ;
222 video->vcounterIRQ = dispstat.vcounterIRQ;
223 video->vcountSetting = dispstat.vcountSetting;
224 video->nextEvent = state->video.nextEvent;
225 video->eventDiff = state->video.eventDiff;
226 video->lastHblank = state->video.lastHblank;
227 video->nextHblank = state->video.nextHblank;
228 video->nextHblankIRQ = state->video.nextHblankIRQ;
229 video->nextVblankIRQ = state->video.nextVblankIRQ;
230 video->nextVcounterIRQ = state->video.nextVcounterIRQ;
231 video->vcount = state->io[REG_VCOUNT >> 1];
232}