From 316e502f4be0c74b28bd30db9168876045bf528d Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 16 May 2020 23:29:01 +0900
Subject: [PATCH] shaderir: Add predefined macros

---
 internal/shaderir/glsl.go    |  4 ++++
 internal/shaderir/ir_test.go | 10 ++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/internal/shaderir/glsl.go b/internal/shaderir/glsl.go
index 9ef4f6f3b..6874a0894 100644
--- a/internal/shaderir/glsl.go
+++ b/internal/shaderir/glsl.go
@@ -53,16 +53,20 @@ func (p *Program) Glsl() string {
 
 	// Vertex func
 	if len(p.VertexFunc.Block.Stmts) > 0 {
+		lines = append(lines, "#if defined(COMPILING_VERTEX_SHADER)")
 		lines = append(lines, "void main(void) {")
 		lines = append(lines, p.glslBlock(&p.VertexFunc.Block, 0, 0)...)
 		lines = append(lines, "}")
+		lines = append(lines, "#endif")
 	}
 
 	// Fragment func
 	if len(p.FragmentFunc.Block.Stmts) > 0 {
+		lines = append(lines, "#if defined(COMPILING_FRAGMENT_SHADER)")
 		lines = append(lines, "void main(void) {")
 		lines = append(lines, p.glslBlock(&p.FragmentFunc.Block, 0, 0)...)
 		lines = append(lines, "}")
+		lines = append(lines, "#endif")
 	}
 
 	var stLines []string
diff --git a/internal/shaderir/ir_test.go b/internal/shaderir/ir_test.go
index 226911871..9eb7e6d21 100644
--- a/internal/shaderir/ir_test.go
+++ b/internal/shaderir/ir_test.go
@@ -562,11 +562,13 @@ attribute float A1;
 attribute vec2 A2;
 varying float V0;
 varying vec2 V1;
+#if defined(COMPILING_VERTEX_SHADER)
 void main(void) {
 	gl_Position = A0;
 	V0 = A1;
 	V1 = A2;
-}`,
+}
+#endif`,
 		},
 		{
 			Name: "FragmentFunc",
@@ -628,11 +630,14 @@ attribute float A1;
 attribute vec2 A2;
 varying float V0;
 varying vec2 V1;
+#if defined(COMPILING_VERTEX_SHADER)
 void main(void) {
 	gl_Position = A0;
 	V0 = A1;
 	V1 = A2;
 }
+#endif
+#if defined(COMPILING_FRAGMENT_SHADER)
 void main(void) {
 	vec2 l0;
 	vec4 l1;
@@ -640,7 +645,8 @@ void main(void) {
 	l2 = V0;
 	l0 = V1;
 	l1 = gl_FragCoord;
-}`,
+}
+#endif`,
 		},
 	}
 	for _, tc := range tests {