From cf3894d3e5ece3ff95e8bd7d2c6d0cf0e39b03c4 Mon Sep 17 00:00:00 2001
From: Wouter Wijsman <wwijsman@live.nl>
Date: Fri, 12 Jul 2024 13:22:13 +0200
Subject: [PATCH] Add getStaticVramBuffer getStaticVramTexture

---
 src/gu/Makefile.am |  2 +-
 src/gu/pspgu.h     | 36 ++++++++++++++++++++++++++++++++
 src/gu/vram.c      | 52 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 89 insertions(+), 1 deletion(-)
 create mode 100644 src/gu/vram.c

diff --git a/src/gu/Makefile.am b/src/gu/Makefile.am
index d0f3484b..7e7b257e 100644
--- a/src/gu/Makefile.am
+++ b/src/gu/Makefile.am
@@ -31,5 +31,5 @@ libpspgu_a_SOURCES = callbackFin.c callbackSig.c guInternal.c resetValues.c sceG
 	sceGuSignal.c sceGuSpecular.c sceGuStart.c sceGuStencilFunc.c sceGuStencilOp.c \
 	sceGuSwapBuffers.c sceGuSync.c sceGuTerm.c sceGuTexEnvColor.c sceGuTexFilter.c sceGuTexFlush.c sceGuTexFunc.c \
 	sceGuTexImage.c sceGuTexLevelMode.c sceGuTexMapMode.c sceGuTexMode.c sceGuTexOffset.c sceGuTexProjMapMode.c \
-	sceGuTexScale.c sceGuTexSlope.c sceGuTexSync.c sceGuTexWrap.c sceGuViewport.c
+	sceGuTexScale.c sceGuTexSlope.c sceGuTexSync.c sceGuTexWrap.c sceGuViewport.c vram.c
 
diff --git a/src/gu/pspgu.h b/src/gu/pspgu.h
index d479b08f..530f1a83 100644
--- a/src/gu/pspgu.h
+++ b/src/gu/pspgu.h
@@ -1501,6 +1501,42 @@ void guSwapBuffersBehaviour(int behaviour);
 **/
 void guSwapBuffersCallback(GuSwapBuffersCallback callback);
 
+/**
+  * Allocate a draw buffer in vram
+  *
+  * Available pixel formats are:
+  *   - GU_PSM_5650 - Hicolor, 16-bit
+  *   - GU_PSM_5551 - Hicolor, 16-bit
+  *   - GU_PSM_4444 - Hicolor, 16-bit
+  *   - GU_PSM_8888 - Truecolor, 32-bit
+  *
+  * @param width - Width of the buffer, usually 512 (must be a power of 2)
+  * @param height - Height of the buffer, normally the height of the screen 272 (must be a power of 2)
+  * @param psm - Which pixel format to use
+  * 
+  * @return A pointer to the buffer's relative to vram start (as required by sceGuDispBuffer, sceGuDrawBuffer, sceGuDepthBuffer and sceGuDrawBufferList)
+**/
+void* getStaticVramBuffer(unsigned int width, unsigned int height, unsigned int psm);
+
+/**
+  * Allocate a texture buffer in vram
+  *
+  * Available texture-formats are:
+  *   - GU_PSM_5650 - Hicolor, 16-bit
+  *   - GU_PSM_5551 - Hicolor, 16-bit
+  *   - GU_PSM_4444 - Hicolor, 16-bit
+  *   - GU_PSM_8888 - Truecolor, 32-bit
+  *   - GU_PSM_T4 - Indexed, 4-bit (2 pixels per byte)
+  *   - GU_PSM_T8 - Indexed, 8-bit
+  *
+  * @param width - Width of the buffer (must be a power of 2)
+  * @param height - Height of the buffer (must be a power of 2)
+  * @param psm - Which pixel format to use
+  * 
+  * @return A pointer to the buffer
+**/
+void* getStaticVramTexture(unsigned int width, unsigned int height, unsigned int psm);
+
 /**@}*/
 
 #if defined(__cplusplus)
diff --git a/src/gu/vram.c b/src/gu/vram.c
new file mode 100644
index 00000000..020d5d04
--- /dev/null
+++ b/src/gu/vram.c
@@ -0,0 +1,52 @@
+/*
+ * PSP Software Development Kit - https://github.com/pspdev
+ * -----------------------------------------------------------------------
+ * Licensed under the BSD license, see LICENSE in PSPSDK root for details.
+ *
+ * Copyright (c) 2010 Dan Peori
+ */
+
+#include <pspge.h>
+#include <pspgu.h>
+
+static unsigned int staticOffset = 0;
+
+static unsigned int getMemorySize(unsigned int width, unsigned int height, unsigned int psm)
+{
+	switch (psm)
+	{
+		case GU_PSM_T4:
+			return (width * height) >> 1;
+
+		case GU_PSM_T8:
+			return width * height;
+
+		case GU_PSM_5650:
+		case GU_PSM_5551:
+		case GU_PSM_4444:
+		case GU_PSM_T16:
+			return 2 * width * height;
+
+		case GU_PSM_8888:
+		case GU_PSM_T32:
+			return 4 * width * height;
+
+		default:
+			return 0;
+	}
+}
+
+void* getStaticVramBuffer(unsigned int width, unsigned int height, unsigned int psm)
+{
+	unsigned int memSize = getMemorySize(width,height,psm);
+	void* result = (void*)staticOffset;
+	staticOffset += memSize;
+
+	return result;
+}
+
+void* getStaticVramTexture(unsigned int width, unsigned int height, unsigned int psm)
+{
+	void* result = getStaticVramBuffer(width,height,psm);
+	return (void*)(((unsigned int)result) + ((unsigned int)sceGeEdramGetAddr()));
+}