Fix VSync(), assert(), warnings and some examples

2 files changed, 7 insertions, 6 deletions

diff --git a/libpsn00b/psxgpu/common.c b/libpsn00b/psxgpu/common.c
index c52ab8a..537f672 100644
--- a/libpsn00b/psxgpu/common.c
+++ b/libpsn00b/psxgpu/common.c
@@ -133,12 +133,13 @@ int VSync(int mode) {
 		return delta;
 	if (mode < 0)
 		return _vblank_counter;
-	if (!mode)
-		mode = 1; // VSync(0) = wait for one vblank
 
-	// Wait for at least one vertical blank event since the last call to
-	// VSync() to occur.
-	for (uint32_t target = _last_vblank + mode; _vblank_counter < target;) {
+	// Wait for the specified number of vertical blank events since the last
+	// call to VSync() to occur (if mode >= 2) or just for a single vertical
+	// blank (if mode = 0).
+	uint32_t target = mode ? (_last_vblank + mode) : (_vblank_counter + 1);
+
+	while (_vblank_counter < target) {
 		uint32_t status = GPU_GP1;
 		_vsync_halt_func();
 
diff --git a/libpsn00b/psxgpu/image.c b/libpsn00b/psxgpu/image.c
index 61ac484..ba5c445 100644
--- a/libpsn00b/psxgpu/image.c
+++ b/libpsn00b/psxgpu/image.c
@@ -53,7 +53,7 @@ static void _dma_transfer(const RECT *rect, uint32_t *data, int write) {
 	// Enable DMA request, route to GP0 (2) or from GPU_READ (3)
 	GPU_GP1 = 0x04000002 | (write ^ 1);
 
-	while (DMA_CHCR(DMA_GPU) & (1 << 24))
+	while ((DMA_CHCR(DMA_GPU) & (1 << 24)) || !(GPU_GP1 & (1 << 28)))
 		__asm__ volatile("");
 
 	DMA_MADR(DMA_GPU) = (uint32_t) data;