From fe69c04f8fe6d229382d1ddd1f8bdb407d256ea2 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sat, 17 Jan 2015 00:56:29 +0900
Subject: [PATCH] Bug fix: Structs containing js.Object can't be compared (for
 now)

---
 internal/graphics/internal/shader/program.go | 2 +-
 internal/opengl/context.go                   | 6 ++++++
 internal/opengl/context_js.go                | 8 +++++++-
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/internal/graphics/internal/shader/program.go b/internal/graphics/internal/shader/program.go
index b6faaae35..f1a52b1a8 100644
--- a/internal/graphics/internal/shader/program.go
+++ b/internal/graphics/internal/shader/program.go
@@ -95,7 +95,7 @@ func (p programFinisher) FinishProgram() {
 }
 
 func useProgramTexture(c *opengl.Context, projectionMatrix []float32, texture opengl.Texture, geo Matrix, color Matrix) programFinisher {
-	if lastProgram != programTexture {
+	if !lastProgram.Equals(programTexture) {
 		c.UseProgram(programTexture)
 		lastProgram = programTexture
 	}
diff --git a/internal/opengl/context.go b/internal/opengl/context.go
index e266a3407..3216481ef 100644
--- a/internal/opengl/context.go
+++ b/internal/opengl/context.go
@@ -26,6 +26,12 @@ type Texture int
 type Framebuffer int
 type Shader int
 type Program int
+
+// TODO: Remove this after the GopherJS bug was fixed (#159)
+func (p Program) Equals(other Program) bool {
+	return p == other
+}
+
 type UniformLocation gl.UniformLocation
 type AttribLocation gl.AttribLocation
 
diff --git a/internal/opengl/context_js.go b/internal/opengl/context_js.go
index 7a84eee35..4bc880a0a 100644
--- a/internal/opengl/context_js.go
+++ b/internal/opengl/context_js.go
@@ -39,6 +39,11 @@ type Program struct {
 	js.Object
 }
 
+// TODO: Remove this after the GopherJS bug was fixed (#159)
+func (p Program) Equals(other Program) bool {
+	return p.Object == other.Object
+}
+
 type UniformLocation struct {
 	js.Object
 }
@@ -151,7 +156,8 @@ var lastFramebuffer Framebuffer
 
 func (c *Context) SetViewport(f Framebuffer, width, height int) error {
 	gl := c.gl
-	if lastFramebuffer != f {
+	// TODO: Fix this after the GopherJS bug was fixed (#159)
+	if lastFramebuffer.Object != f.Object {
 		gl.Flush()
 		lastFramebuffer = f
 	}