PS1: Manually handle resetting GPU and VSync

misc/ps1/ps1defs.h

@@ -41,6 +41,7 @@ enum gp0_rectcmd_flags {
 };
 
 enum gp1_cmd_type {
+	GP1_CMD_RESET_GPU        = 0x00000000,
 	GP1_CMD_DISPLAY_ACTIVE   = 0x03000000,
 	GP1_CMD_DMA_MODE         = 0x04000000,
 	GP1_CMD_DISPLAY_ADDRESS  = 0x05000000,

src/Graphics_PS1.c

@@ -14,7 +14,52 @@
 #include "../misc/ps1/ps1defs.h"
 // Based off https://github.com/Lameguy64/PSn00bSDK/blob/master/examples/beginner/hello/main.c
 
+#define wait_while(cond) while (cond) { __asm__ volatile(""); }
 
+
+/*########################################################################################################################*
+*------------------------------------------------------GPU management-----------------------------------------------------*
+*#########################################################################################################################*/
+static volatile cc_uint32 vblank_count;
+
+static void vblank_handler(void) { vblank_count++; }
+
+#define DMA_IDX_GPU (DMA_GPU * 4)
+#define DMA_IDX_OTC (DMA_OTC * 4)
+
+void Gfx_ResetGPU(void) {
+	int needs_exit = EnterCriticalSection();
+	InterruptCallback(IRQ_VBLANK, &vblank_handler);
+	if (needs_exit) ExitCriticalSection();
+
+	GPU_GP1 = GP1_CMD_RESET_GPU;
+	ChangeClearPAD(0);
+
+	// Enable GPU and OTC DMA channels at priority 3
+	DMA_DPCR |= (0xB << DMA_IDX_GPU) | (0xB << DMA_IDX_OTC);
+
+	// Stop pending DMA
+	DMA_CHCR(DMA_GPU) = CHRC_MODE_SLICE | CHRC_FROM_RAM;
+	DMA_CHCR(DMA_OTC) = CHRC_MODE_SLICE;
+}
+
+void Gfx_VSync(void) {
+	cc_uint32 counter = vblank_count;
+
+	for (int i = 0; i < 0x100000; i++) 
+	{
+		if (counter != vblank_count) return;
+	}
+
+	// VSync IRQ may be swallowed by BIOS, try to undo that
+	Platform_LogConst("VSync timed out");
+	ChangeClearPAD(0);
+}
+
+
+/*########################################################################################################################*
+*------------------------------------------------------Render buffers-----------------------------------------------------*
+*#########################################################################################################################*/
 // Length of the ordering table, i.e. the range Z coordinates can have, 0-15 in
 // this case. Larger values will allow for more granularity with depth (useful
 // when drawing a complex 3D scene) at the expense of RAM usage and performance.
@@ -24,8 +69,6 @@
 // crashes due to too many primitives being drawn, increase this value.
 #define BUFFER_LENGTH 32768
 
-#define wait_while(cond) while (cond) { __asm__ volatile(""); }
-
 struct EnvPrimities {
 	uint32_t tag;
 	uint32_t tpage_code[1];
@@ -51,7 +94,6 @@ static uint8_t*  next_packet_end;
 static int       active_buffer;
 static RenderBuffer* cur_buffer;
 static void* lastPoly;
-static cc_bool cullingEnabled, noMemWarned;
 
 static void BuildContext(RenderBuffer* buf) {
 	struct EnvPrimities* prim = &buf->env;
@@ -105,7 +147,13 @@ static void SetupContexts(int w, int h) {
 	OnBufferUpdated();
 }
 
+
+/*########################################################################################################################*
+*----------------------------------------------------------General--------------------------------------------------------*
+*#########################################################################################################################*/
 static GfxResourceID white_square;
+static cc_bool cullingEnabled;
+
 void Gfx_RestoreState(void) {
 	InitDefaultResources();
 	
@@ -907,7 +955,7 @@ void Gfx_EndFrame(void) {
 		Platform_LogConst("OUT OF VERTEX RAM");
 	}
 	WaitUntilFinished();
-	VSync(0);
+	Gfx_VSync();
 
 	RenderBuffer* draw_buffer = &buffers[active_buffer];
 	RenderBuffer* disp_buffer = &buffers[active_buffer ^ 1];

src/Platform_PS1.c

@@ -246,8 +246,11 @@ cc_result Socket_CheckWritable(cc_socket s, cc_bool* writable) {
 /*########################################################################################################################*
 *--------------------------------------------------------Platform---------------------------------------------------------*
 *#########################################################################################################################*/
+extern void Gfx_ResetGPU(void);
+
 void Platform_Init(void) {
-	ResetGraph(0);
+	ResetCallback();
+	Gfx_ResetGPU();
 	Stopwatch_Init();
 }
 

src/Window_PS1.c

@@ -24,9 +24,12 @@
 static cc_bool launcherMode;
 struct _DisplayData DisplayInfo;
 struct cc_window WindowInfo;
-static DISPENV disp;
+static int gpu_video_mode;
+
+void Window_PreInit(void) {
+	gpu_video_mode = (GPU_GP1 >> 20) & 1;
+}
 
-void Window_PreInit(void) { }
 void Window_Init(void) {
 	DisplayInfo.Width  = SCREEN_XRES;
 	DisplayInfo.Height = SCREEN_YRES;
@@ -49,7 +52,7 @@ void Window_Init(void) {
 void Window_Free(void) { }
 
 static void InitScreen(void) {
-	int vid  = GetVideoMode();
+	int vid  = gpu_video_mode;
 	int mode = (vid << 3) | GP1_HOR_RES_320 | GP1_VER_RES_240;
 	int yMid = vid ? 0xA3 : 0x88; // PAL has more vertical lines
 
@@ -82,9 +85,10 @@ static void ClearScreen(void)
 	GPU_GP0 = GP0_CMD_FILL_XY(0, 0);
 	GPU_GP0 = GP0_CMD_FILL_WH(320, 200);
 }
+extern void Gfx_ResetGPU(void);
 
 void Window_Create2D(int width, int height) {
-	ResetGraph(0);
+	Gfx_ResetGPU();
 	launcherMode = true;
 
 	InitScreen();
@@ -92,7 +96,7 @@ void Window_Create2D(int width, int height) {
 }
 
 void Window_Create3D(int width, int height) { 
-	ResetGraph(0);
+	Gfx_ResetGPU();
 	launcherMode = false;
 
 	InitScreen();