1 files changed, 115 insertions, 0 deletions
diff --git a/libpsn00b/psxgpu/image.c b/libpsn00b/psxgpu/image.c
new file mode 100644
index 0000000..da51e7d
--- /dev/null
+++ b/libpsn00b/psxgpu/image.c
@@ -0,0 +1,115 @@
+/*
+ * PSn00bSDK GPU library (image and VRAM transfer functions)
+ * (C) 2022 spicyjpeg - MPL licensed
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <psxgpu.h>
+#include <hwregs_c.h>
+
+#define DMA_CHUNK_LENGTH 8
+
+/* VRAM transfer API */
+
+static void _load_store_image(
+	uint32_t	command,
+	int			mode,
+	const RECT	*rect,
+	uint32_t	*data
+) {
+	size_t length = rect->w * rect->h;
+	if (length % 2)
+		printf("psxgpu: can't transfer an odd number of pixels\n");
+
+	length /= 2;
+	if ((length >= DMA_CHUNK_LENGTH) && (length % DMA_CHUNK_LENGTH)) {
+		printf("psxgpu: transfer data length (%d) is not a multiple of %d, rounding\n", length, DMA_CHUNK_LENGTH);
+		length += DMA_CHUNK_LENGTH - 1;
+	}
+
+	DrawSync(0);
+	GPU_GP1 = 0x04000000; // Disable DMA request
+	GPU_GP0 = 0x01000000; // Flush cache
+
+	GPU_GP0 = command;
+	//GPU_GP0 = rect->x | (rect->y << 16);
+	GPU_GP0 = *((const uint32_t *) &(rect->x));
+	//GPU_GP0 = rect->w | (rect->h << 16);
+	GPU_GP0 = *((const uint32_t *) &(rect->w));
+
+	// Enable DMA request, route to GP0 (2) or from GPU_READ (3)
+	GPU_GP1 = 0x04000000 | mode;
+
+	DMA_MADR(2) = (uint32_t) data;
+	if (length < DMA_CHUNK_LENGTH)
+		DMA_BCR(2) = 0x00010000 | length;
+	else
+		DMA_BCR(2) = DMA_CHUNK_LENGTH | ((length / DMA_CHUNK_LENGTH) << 16);
+
+	DMA_CHCR(2) = 0x01000200 | ((mode & 1) ^ 1);
+}
+
+void LoadImage(const RECT *rect, const uint32_t *data) {
+	_load_store_image(0xa0000000, 2, rect, (uint32_t *) data);
+}
+
+void StoreImage(const RECT *rect, uint32_t *data) {
+	_load_store_image(0xc0000000, 3, rect, data);
+}
+
+/* .TIM image parsers */
+
+// This is the only libgs function PSn00bSDK is ever going to implement. The
+// difference from GetTimInfo() is that it copies RECTs rather than merely
+// returning pointers to them, which become useless once the .TIM file is
+// unloaded from main RAM.
+int GsGetTimInfo(const uint32_t *tim, GsIMAGE *info) {
+	if ((*(tim++) & 0xffff) != 0x0010)
+		return 1;
+
+	info->pmode = *(tim++);
+	if (info->pmode & 8) {
+		const uint32_t *palette_end = tim;
+		palette_end += *(tim++) / 4;
+
+		*((uint32_t *) &(info->cx)) = *(tim++);
+		*((uint32_t *) &(info->cw)) = *(tim++);
+		info->clut = (uint32_t *) tim;
+
+		tim = palette_end;
+	} else {
+		info->clut = 0;
+	}
+
+	tim++;
+	*((uint32_t *) &(info->px)) = *(tim++);
+	*((uint32_t *) &(info->pw)) = *(tim++);
+	info->pixel = (uint32_t *) tim;
+
+	return 0;
+}
+
+int GetTimInfo(const uint32_t *tim, TIM_IMAGE *info) {
+	if ((*(tim++) & 0xffff) != 0x0010)
+		return 1;
+
+	info->mode = *(tim++);
+	if (info->mode & 8) {
+		const uint32_t *palette_end = tim;
+		palette_end += *(tim++) / 4;
+
+		info->crect = (RECT *)     tim;
+		info->caddr = (uint32_t *) &tim[2];
+
+		tim = palette_end;
+	} else {
+		info->caddr = 0;
+	}
+
+	tim++;
+	info->prect = (RECT *)     tim;
+	info->paddr = (uint32_t *) &tim[2];
+
+	return 0;
+}