Add dummy renderer + frame counting infrastructure from GBA.js

src/arm/arm.c

@@ -100,7 +100,7 @@ void ARMReset(struct ARMCore* cpu) {
 	cpu->spsr.packed = 0;
 
 	cpu->cycles = 0;
-	cpu->nextEvent = INT_MAX;
+	cpu->nextEvent = 0;
 
 	cpu->shifterOperand = 0;
 	cpu->shifterCarryOut = 0;

src/gba/gba-video.c

@@ -2,7 +2,23 @@
 
 #include <limits.h>
 
+static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer);
+static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer);
+static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
+static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y);
+static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer);
+
+static struct GBAVideoRenderer dummyRenderer = {
+	.init = GBAVideoDummyRendererInit,
+	.deinit = GBAVideoDummyRendererDeinit,
+	.writeVideoRegister = GBAVideoDummyRendererWriteVideoRegister,
+	.drawScanline = GBAVideoDummyRendererDrawScanline,
+	.finishFrame = GBAVideoDummyRendererFinishFrame
+};
+
 void GBAVideoInit(struct GBAVideo* video) {
+	video->renderer = &dummyRenderer;
+
 	video->inHblank = 0;
 	video->inVblank = 0;
 	video->vcounter = 0;
@@ -23,5 +39,94 @@ void GBAVideoInit(struct GBAVideo* video) {
 }
 
 int32_t GBAVideoProcessEvents(struct GBAVideo* video, int32_t cycles) {
-	return INT_MAX;
+	video->nextEvent -= cycles;
+	if (video->nextEvent <= 0) {
+		video->lastHblank -= video->eventDiff;
+		video->nextHblank -= video->eventDiff;
+		video->nextHblankIRQ -= video->eventDiff;
+		video->nextVcounterIRQ -= video->eventDiff;
+
+		if (video->inHblank) {
+			// End Hblank
+			video->inHblank = 0;
+			video->nextEvent = video->nextHblank;
+
+			++video->vcount;
+
+			switch (video->vcount) {
+			case VIDEO_VERTICAL_PIXELS:
+				video->inVblank = 1;
+				video->renderer->finishFrame(video->renderer);
+				video->nextVblankIRQ = video->nextEvent + VIDEO_TOTAL_LENGTH;
+				//video->cpu.mmu.runVblankDmas();
+				if (video->vblankIRQ) {
+					//video->cpu.irq.raiseIRQ(video->cpu.irq.IRQ_VBLANK);
+				}
+				//video->vblankCallback();
+				break;
+			case VIDEO_VERTICAL_TOTAL_PIXELS - 1:
+				video->inVblank = 0;
+				break;
+			case VIDEO_VERTICAL_TOTAL_PIXELS:
+				video->vcount = 0;
+				//video->renderPath.startDraw();
+				break;
+			}
+
+			video->vcounter = video->vcount == video->vcountSetting;
+			if (video->vcounter && video->vcounterIRQ) {
+				//video->cpu.irq.raiseIRQ(video->cpu.irq.IRQ_VCOUNTER);
+				video->nextVcounterIRQ += VIDEO_TOTAL_LENGTH;
+			}
+
+			if (video->vcount < VIDEO_VERTICAL_PIXELS) {
+				video->renderer->drawScanline(video->renderer, video->vcount);
+			}
+		} else {
+			// Begin Hblank
+			video->inHblank = 1;
+			video->lastHblank = video->nextHblank;
+			video->nextEvent = video->lastHblank + VIDEO_HBLANK_LENGTH;
+			video->nextHblank = video->nextEvent + VIDEO_HDRAW_LENGTH;
+			video->nextHblankIRQ = video->nextHblank;
+
+			if (video->vcount < VIDEO_VERTICAL_PIXELS) {
+				//video->cpu.mmu.runHblankDmas();
+			}
+			if (video->hblankIRQ) {
+				//video->cpu.irq.raiseIRQ(video->cpu.irq.IRQ_HBLANK);
+			}
+		}
+
+		video->eventDiff = video->nextEvent;
+	}
+	return video->nextEvent;
+}
+
+
+static void GBAVideoDummyRendererInit(struct GBAVideoRenderer* renderer) {
+	(void)(renderer);
+	// Nothing to do
+}
+
+static void GBAVideoDummyRendererDeinit(struct GBAVideoRenderer* renderer) {
+	(void)(renderer);
+	// Nothing to do
+}
+static uint16_t GBAVideoDummyRendererWriteVideoRegister(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value) {
+	(void)(renderer);
+	(void)(address);
+	return value;
+}
+
+static void GBAVideoDummyRendererDrawScanline(struct GBAVideoRenderer* renderer, int y) {
+	(void)(renderer);
+	(void)(y);
+	// Nothing to do
+}
+
+static void GBAVideoDummyRendererFinishFrame(struct GBAVideoRenderer* renderer) {
+	(void)(renderer);
+	printf("Drawing a frame\n");
+	// Nothing to do
 }

src/gba/gba-video.h

@@ -26,12 +26,13 @@ struct GBAVideoRenderer {
 	void (*deinit)(struct GBAVideoRenderer* renderer);
 
 	uint16_t (*writeVideoRegister)(struct GBAVideoRenderer* renderer, uint32_t address, uint16_t value);
-	void (*drawScanline)(struct GBAVideoRenderer* video, int y);
-	void (*finishFrame)(struct GBAVideoRenderer* video);
+	void (*drawScanline)(struct GBAVideoRenderer* renderer, int y);
+	void (*finishFrame)(struct GBAVideoRenderer* renderer);
 };
 
 struct GBAVideo {
-	struct GBAVideoRenderer renderer;
+	struct GBA* p;
+	struct GBAVideoRenderer* renderer;
 
 	// DISPSTAT
 	int inHblank;
@@ -49,6 +50,7 @@ struct GBAVideo {
 	int32_t lastHblank;
 	int32_t nextHblank;
 	int32_t nextEvent;
+	int32_t eventDiff;
 
 	int32_t nextHblankIRQ;
 	int32_t nextVblankIRQ;

src/gba/gba.c

@@ -33,6 +33,9 @@ void GBAInit(struct GBA* gba) {
 	GBABoardInit(&gba->board);
 	ARMAssociateBoard(&gba->cpu, &gba->board.d);
 
+	gba->video.p = gba;
+	GBAVideoInit(&gba->video);
+
 	ARMReset(&gba->cpu);
 }