From 1663ad225027d43e939d7c0523138c679a00597d Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 22 Dec 2014 22:49:14 +0900
Subject: [PATCH] Remove shader programColorFinal

---
 .../opengl/internal/shader/drawtexture.go     |  7 +---
 internal/opengl/internal/shader/program.go    | 34 -------------------
 internal/opengl/internal/shader/shader.go     | 30 ++++++----------
 3 files changed, 11 insertions(+), 60 deletions(-)

diff --git a/internal/opengl/internal/shader/drawtexture.go b/internal/opengl/internal/shader/drawtexture.go
index 01740dc08..12dea7410 100644
--- a/internal/opengl/internal/shader/drawtexture.go
+++ b/internal/opengl/internal/shader/drawtexture.go
@@ -47,12 +47,7 @@ func DrawTexture(native gl.Texture, target gl.Texture, projectionMatrix [4][4]fl
 		return
 	}
 	// TODO: Check performance
-	program := gl.Program(0)
-	if 0 < target {
-		program = useProgramColorMatrix(glMatrix(projectionMatrix), geo, color)
-	} else {
-		program = useProgramColorFinal(glMatrix(projectionMatrix), geo)
-	}
+	program := useProgramColorMatrix(glMatrix(projectionMatrix), geo, color)
 
 	gl.ActiveTexture(gl.TEXTURE0)
 	native.Bind(gl.TEXTURE_2D)
diff --git a/internal/opengl/internal/shader/program.go b/internal/opengl/internal/shader/program.go
index e09dea9e6..109010c00 100644
--- a/internal/opengl/internal/shader/program.go
+++ b/internal/opengl/internal/shader/program.go
@@ -29,10 +29,6 @@ var programColorMatrix = program{
 	shaderIds: []shaderId{shaderVertex, shaderColorMatrix},
 }
 
-var programColorFinal = program{
-	shaderIds: []shaderId{shaderVertex, shaderColorFinal},
-}
-
 func (p *program) create() {
 	p.native = gl.CreateProgram()
 	if p.native == 0 {
@@ -59,7 +55,6 @@ func initialize() {
 	}()
 
 	programColorMatrix.create()
-	programColorFinal.create()
 }
 
 func getAttributeLocation(program gl.Program, name string) gl.AttribLocation {
@@ -119,32 +114,3 @@ func useProgramColorMatrix(projectionMatrix [16]float32, geo Matrix, color Matri
 
 	return program.native
 }
-
-func useProgramColorFinal(projectionMatrix [16]float32, geo Matrix) gl.Program {
-	if lastProgram != programColorFinal.native {
-		programColorFinal.native.Use()
-		lastProgram = programColorFinal.native
-	}
-
-	program := programColorFinal
-
-	getUniformLocation(program.native, "projection_matrix").UniformMatrix4fv(false, projectionMatrix)
-
-	a := float32(geo.Element(0, 0))
-	b := float32(geo.Element(0, 1))
-	c := float32(geo.Element(1, 0))
-	d := float32(geo.Element(1, 1))
-	tx := float32(geo.Element(0, 2))
-	ty := float32(geo.Element(1, 2))
-	glModelviewMatrix := [...]float32{
-		a, c, 0, 0,
-		b, d, 0, 0,
-		0, 0, 1, 0,
-		tx, ty, 0, 1,
-	}
-	getUniformLocation(program.native, "modelview_matrix").UniformMatrix4fv(false, glModelviewMatrix)
-
-	getUniformLocation(program.native, "texture").Uniform1i(0)
-
-	return program.native
-}
diff --git a/internal/opengl/internal/shader/shader.go b/internal/opengl/internal/shader/shader.go
index 844ea3fe2..ae45a04b2 100644
--- a/internal/opengl/internal/shader/shader.go
+++ b/internal/opengl/internal/shader/shader.go
@@ -31,9 +31,7 @@ type shaderId int
 
 const (
 	shaderVertex shaderId = iota
-	shaderVertexFinal
 	shaderColorMatrix
-	shaderColorFinal
 )
 
 var shaders = map[shaderId]*shader{
@@ -62,27 +60,19 @@ varying vec2 vertex_out_tex_coord;
 
 void main(void) {
   vec4 color = texture2D(texture, vertex_out_tex_coord);
-  // Un-premultiply alpha
-  color.rgb /= color.a;
-  // Apply the color matrix
-  color = (color_matrix * color) + color_matrix_translation;
-  // Premultiply alpha
-  color = clamp(color, 0.0, 1.0);
-  color.rgb *= color.a;
+
+  if (color_matrix != mat4(1.0) || color_matrix_translation != vec4(0.0)) {
+    // Un-premultiply alpha
+    color.rgb /= color.a;
+    // Apply the color matrix
+    color = (color_matrix * color) + color_matrix_translation;
+    color = clamp(color, 0.0, 1.0);
+    // Premultiply alpha
+    color.rgb *= color.a;
+  }
 
   gl_FragColor = color;
 }
-`,
-	},
-	shaderColorFinal: {
-		shaderType: gl.FRAGMENT_SHADER,
-		source: `
-uniform sampler2D texture;
-varying vec2 vertex_out_tex_coord;
-
-void main(void) {
-  gl_FragColor = texture2D(texture, vertex_out_tex_coord);
-}
 `,
 	},
 }