commit 44f634ba28d81247df92186fd5c8c344e5463ff1
author Andrew Gerrand <adg@golang.org> Wed Dec 02 09:54:46 2015 +1100
committer Andrew Gerrand <adg@golang.org> Thu Jan 07 02:45:44 2016 +0000
tree c883a649e8eddca11f5e1116872db980d904c5b7
parent 0a85ca5e8507167b3b4357677a2b24bee9e106f4

exp/gl/glutil: set blend mode when drawing sprites

Change-Id: Ib8a3dc3b08c8d64f2d461f943c8ebab75578a127
Reviewed-on: https://go-review.googlesource.com/17320
Reviewed-by: Nigel Tao <nigeltao@golang.org>

exp/gl/glutil/glimage.go

diff --git a/exp/gl/glutil/glimage.go b/exp/gl/glutil/glimage.go
index 55aba42..ca41c07 100644
--- a/exp/gl/glutil/glimage.go
+++ b/exp/gl/glutil/glimage.go
@@ -169,6 +169,9 @@
 	glimage := img.images
 	glctx := img.images.glctx
 
+	glctx.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
+	glctx.Enable(gl.BLEND)
+
 	// TODO(crawshaw): Adjust viewport for the top bar on android?
 	glctx.UseProgram(glimage.program)
 	{
@@ -288,6 +291,8 @@
 
 	glctx.DisableVertexAttribArray(glimage.pos)
 	glctx.DisableVertexAttribArray(glimage.inUV)
+
+	glctx.Disable(gl.BLEND)
 }
 
 var quadXYCoords = f32.Bytes(binary.LittleEndian,