From 9e161864f625177b6230e969dcf37e2ad145bf14 Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Mon, 22 Feb 2016 03:14:31 +0900
Subject: [PATCH] ui: Bug fix: Make sure current framebuffers rendered (#158)

---
 internal/graphics/opengl/context.go | 4 ++++
 internal/ui/ui_glfw.go              | 5 +++++
 run.go                              | 1 +
 3 files changed, 10 insertions(+)

diff --git a/internal/graphics/opengl/context.go b/internal/graphics/opengl/context.go
index a3f7777f1..0cc12697c 100644
--- a/internal/graphics/opengl/context.go
+++ b/internal/graphics/opengl/context.go
@@ -156,6 +156,10 @@ func (c *Context) TexSubImage2D(p []uint8, width, height int) {
 	gl.TexSubImage2D(mgl.TEXTURE_2D, 0, 0, 0, width, height, mgl.RGBA, mgl.UNSIGNED_BYTE, p)
 }
 
+func (c *Context) BindZeroFramebuffer() {
+	gl.BindFramebuffer(mgl.FRAMEBUFFER, mgl.Framebuffer(ZeroFramebuffer))
+}
+
 func (c *Context) NewFramebuffer(texture Texture) (Framebuffer, error) {
 	f := gl.CreateFramebuffer()
 	gl.BindFramebuffer(mgl.FRAMEBUFFER, f)
diff --git a/internal/ui/ui_glfw.go b/internal/ui/ui_glfw.go
index 0e074091e..d029de338 100644
--- a/internal/ui/ui_glfw.go
+++ b/internal/ui/ui_glfw.go
@@ -157,6 +157,11 @@ func (u *userInterface) setScreenSize(width, height, scale int) bool {
 		return false
 	}
 
+	// To make sure the current existing framebuffers are rendered,
+	// swap buffers here.
+	u.context.BindZeroFramebuffer()
+	u.swapBuffers()
+
 	ch := make(chan struct{})
 	window := u.window
 	window.SetFramebufferSizeCallback(func(w *glfw.Window, width, height int) {
diff --git a/run.go b/run.go
index 5ae950357..84b7193ff 100644
--- a/run.go
+++ b/run.go
@@ -114,6 +114,7 @@ func Run(f func(*Image) error, width, height, scale int, title string) error {
 			return err
 		}
 
+		// Note that the current bound framebuffer must be the default one (0).
 		ui.SwapBuffers()
 
 		// Calc the current FPS.