From 707312b83a79cf83d7b367553b2dee6f8a21a808 Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <post@arntzen-software.no>
Date: Thu, 13 Jun 2019 11:33:19 +0200
Subject: [PATCH] GLSL: Support NV barycentrics.

---
 .../opt/shaders/frag/barycentric-nv.frag      | 19 ++++++++++++++++++
 reference/shaders/frag/barycentric-nv.frag    | 20 +++++++++++++++++++
 shaders/frag/barycentric-nv.frag              | 18 +++++++++++++++++
 spirv_glsl.cpp                                | 20 +++++++++++++++++++
 4 files changed, 77 insertions(+)
 create mode 100644 reference/opt/shaders/frag/barycentric-nv.frag
 create mode 100644 reference/shaders/frag/barycentric-nv.frag
 create mode 100644 shaders/frag/barycentric-nv.frag

diff --git a/reference/opt/shaders/frag/barycentric-nv.frag b/reference/opt/shaders/frag/barycentric-nv.frag
new file mode 100644
index 00000000..cc3b4de2
--- /dev/null
+++ b/reference/opt/shaders/frag/barycentric-nv.frag
@@ -0,0 +1,19 @@
+#version 450
+#extension GL_NV_fragment_shader_barycentric : require
+
+layout(binding = 0, std430) readonly buffer Vertices
+{
+    vec2 uvs[];
+} _19;
+
+layout(location = 0) out vec2 value;
+
+void main()
+{
+    int _23 = 3 * gl_PrimitiveID;
+    int _32 = _23 + 1;
+    int _39 = _23 + 2;
+    value = ((_19.uvs[_23] * gl_BaryCoordNV.x) + (_19.uvs[_32] * gl_BaryCoordNV.y)) + (_19.uvs[_39] * gl_BaryCoordNV.z);
+    value += (((_19.uvs[_23] * gl_BaryCoordNoPerspNV.x) + (_19.uvs[_32] * gl_BaryCoordNoPerspNV.y)) + (_19.uvs[_39] * gl_BaryCoordNoPerspNV.z));
+}
+
diff --git a/reference/shaders/frag/barycentric-nv.frag b/reference/shaders/frag/barycentric-nv.frag
new file mode 100644
index 00000000..12d24bb7
--- /dev/null
+++ b/reference/shaders/frag/barycentric-nv.frag
@@ -0,0 +1,20 @@
+#version 450
+#extension GL_NV_fragment_shader_barycentric : require
+
+layout(binding = 0, std430) readonly buffer Vertices
+{
+    vec2 uvs[];
+} _19;
+
+layout(location = 0) out vec2 value;
+
+void main()
+{
+    int prim = gl_PrimitiveID;
+    vec2 uv0 = _19.uvs[(3 * prim) + 0];
+    vec2 uv1 = _19.uvs[(3 * prim) + 1];
+    vec2 uv2 = _19.uvs[(3 * prim) + 2];
+    value = ((uv0 * gl_BaryCoordNV.x) + (uv1 * gl_BaryCoordNV.y)) + (uv2 * gl_BaryCoordNV.z);
+    value += (((uv0 * gl_BaryCoordNoPerspNV.x) + (uv1 * gl_BaryCoordNoPerspNV.y)) + (uv2 * gl_BaryCoordNoPerspNV.z));
+}
+
diff --git a/shaders/frag/barycentric-nv.frag b/shaders/frag/barycentric-nv.frag
new file mode 100644
index 00000000..34040837
--- /dev/null
+++ b/shaders/frag/barycentric-nv.frag
@@ -0,0 +1,18 @@
+#version 450
+#extension GL_NV_fragment_shader_barycentric : require
+
+layout(location = 0) out vec2 value;
+
+layout(set = 0, binding = 0) readonly buffer Vertices
+{
+	vec2 uvs[];
+};
+      
+void main () {
+	int prim = gl_PrimitiveID;
+	vec2 uv0 = uvs[3 * prim + 0];
+	vec2 uv1 = uvs[3 * prim + 1];
+	vec2 uv2 = uvs[3 * prim + 2];
+    value = gl_BaryCoordNV.x * uv0 + gl_BaryCoordNV.y * uv1 + gl_BaryCoordNV.z * uv2;
+    value += gl_BaryCoordNoPerspNV.x * uv0 + gl_BaryCoordNoPerspNV.y * uv1 + gl_BaryCoordNoPerspNV.z * uv2;
+}
diff --git a/spirv_glsl.cpp b/spirv_glsl.cpp
index b4d888ad..9d1d9943 100644
--- a/spirv_glsl.cpp
+++ b/spirv_glsl.cpp
@@ -6156,6 +6156,26 @@ string CompilerGLSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
 	case BuiltInIncomingRayFlagsNV:
 		return "gl_IncomingRayFlagsNV";
 
+	case BuiltInBaryCoordNV:
+	{
+		if (options.es && options.version < 320)
+			SPIRV_CROSS_THROW("gl_BaryCoordNV requires ESSL 320.");
+		else if (!options.es && options.version < 450)
+			SPIRV_CROSS_THROW("gl_BaryCoordNV requires GLSL 450.");
+		require_extension_internal("GL_NV_fragment_shader_barycentric");
+		return "gl_BaryCoordNV";
+	}
+
+	case BuiltInBaryCoordNoPerspNV:
+	{
+		if (options.es && options.version < 320)
+			SPIRV_CROSS_THROW("gl_BaryCoordNoPerspNV requires ESSL 320.");
+		else if (!options.es && options.version < 450)
+			SPIRV_CROSS_THROW("gl_BaryCoordNoPerspNV requires GLSL 450.");
+		require_extension_internal("GL_NV_fragment_shader_barycentric");
+		return "gl_BaryCoordNoPerspNV";
+	}
+
 	case BuiltInFragStencilRefEXT:
 	{
 		if (!options.es)