From 731701a2d256efba969cdbaf8712a28aa1a10aad Mon Sep 17 00:00:00 2001
From: Subv <subv2112@gmail.com>
Date: Sun, 19 Aug 2018 00:14:34 -0500
Subject: [PATCH] Shaders: Implemented the gl_FrontFacing input attribute (attr
63).
---
src/video_core/engines/shader_bytecode.h | 3 +++
src/video_core/renderer_opengl/gl_shader_decompiler.cpp | 4 ++++
2 files changed, 7 insertions(+)
diff --git a/src/video_core/engines/shader_bytecode.h b/src/video_core/engines/shader_bytecode.h
index b038a9d922..7e0e4858a1 100644
--- a/src/video_core/engines/shader_bytecode.h
+++ b/src/video_core/engines/shader_bytecode.h
@@ -79,6 +79,9 @@ union Attribute {
// shader, and a tuple of (TessCoord.x, TessCoord.y, TessCoord.z, ~) when inside a Tess Eval
// shader.
TessCoordInstanceIDVertexID = 47,
+ // This attribute contains a tuple of (Unk, Unk, Unk, gl_FrontFacing) when inside a fragment
+ // shader. It is unknown what the other values contain.
+ FrontFacing = 63,
};
union {
diff --git a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
index bb01b3c274..48ddbc687d 100644
--- a/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
+++ b/src/video_core/renderer_opengl/gl_shader_decompiler.cpp
@@ -542,6 +542,10 @@ private:
// shader.
ASSERT(stage == Maxwell3D::Regs::ShaderStage::Vertex);
return "vec4(0, 0, uintBitsToFloat(instance_id.x), uintBitsToFloat(gl_VertexID))";
+ case Attribute::Index::FrontFacing:
+ // TODO(Subv): Find out what the values are for the other elements.
+ ASSERT(stage == Maxwell3D::Regs::ShaderStage::Fragment);
+ return "vec4(0, 0, 0, uintBitsToFloat(gl_FrontFacing ? 1 : 0))";
default:
const u32 index{static_cast<u32>(attribute) -
static_cast<u32>(Attribute::Index::Attribute_0)};