From 6e9cd355a5c78c65d20e6b502573d3c17ff8af5d Mon Sep 17 00:00:00 2001
From: StapleButter <thetotalworm@gmail.com>
Date: Tue, 11 Nov 2014 00:12:31 +0100
Subject: [PATCH] Scissor test.

(if calling SetScissorTest right after SetViewport, call FinishDrawing inbetween)
---
 libctru/include/3ds/gpu/gpu.h | 11 +++++++++++
 libctru/source/gpu/gpu.c      | 10 ++++++++++
 2 files changed, 21 insertions(+)

diff --git a/libctru/include/3ds/gpu/gpu.h b/libctru/include/3ds/gpu/gpu.h
index c865867..5700d93 100644
--- a/libctru/include/3ds/gpu/gpu.h
+++ b/libctru/include/3ds/gpu/gpu.h
@@ -65,6 +65,15 @@ typedef enum
 	GPU_GEQUAL = 7
 }GPU_TESTFUNC;
 
+typedef enum
+{
+	GPU_SCISSOR_DISABLE = 0,	// disable scissor test
+	GPU_SCISSOR_INVERT = 1,		// exclude pixels inside the scissor box
+	// 2 is the same as 0
+	GPU_SCISSOR_NORMAL = 3,		// exclude pixels outside of the scissor box
+	
+} GPU_SCISSORMODE;
+
 typedef enum
 {
 	GPU_KEEP = 0, 		// keep destination value
@@ -183,6 +192,8 @@ void GPU_SetUniform(u32 startreg, u32* data, u32 numreg);
 
 void GPU_SetViewport(u32* depthBuffer, u32* colorBuffer, u32 x, u32 y, u32 w, u32 h);
 
+void GPU_SetScissorTest(GPU_SCISSORMODE mode, u32 x, u32 y, u32 w, u32 h);
+
 void GPU_DepthRange(float nearVal, float farVal);
 void GPU_SetAlphaTest(bool enable, GPU_TESTFUNC function, u8 ref);
 void GPU_SetDepthTestAndWriteMask(bool enable, GPU_TESTFUNC function, GPU_WRITEMASK writemask); // GPU_WRITEMASK values can be ORed together
diff --git a/libctru/source/gpu/gpu.c b/libctru/source/gpu/gpu.c
index 8bfde8b..c83a9aa 100644
--- a/libctru/source/gpu/gpu.c
+++ b/libctru/source/gpu/gpu.c
@@ -304,6 +304,16 @@ void GPU_SetViewport(u32* depthBuffer, u32* colorBuffer, u32 x, u32 y, u32 w, u3
 	GPUCMD_Add(0x800F0112, param, 0x00000004);
 }
 
+void GPU_SetScissorTest(GPU_SCISSORMODE mode, u32 x, u32 y, u32 w, u32 h)
+{
+	u32 param[3];
+	
+	param[0x0] = mode;
+	param[0x1] = (y<<16)|(x&0xFFFF);
+	param[0x2] = ((h-1)<<16)|((w-1)&0xFFFF);
+	GPUCMD_Add(0x800F0065, param, 0x00000003);
+}
+
 void GPU_DepthRange(float nearVal, float farVal)
 {
 	GPUCMD_AddSingleParam(0x000F006D, 0x00000001); //?