exp/shiny: fix usage of TexImage2D after breaking change

CL 133155 adds the internalFormat parameter to TexImage2D. Fix
the two usages of TexImage2D in this repository.

Change-Id: Id529c755f47202d10f8aeec0f85f8f4e0d6fcfd1
Reviewed-on: https://go-review.googlesource.com/133175
Reviewed-by: Nigel Tao <nigeltao@golang.org>
diff --git a/shiny/driver/gldriver/screen.go b/shiny/driver/gldriver/screen.go
index 3100ebc..f6f18f1 100644
--- a/shiny/driver/gldriver/screen.go
+++ b/shiny/driver/gldriver/screen.go
@@ -99,7 +99,7 @@
 	}
 
 	glctx.BindTexture(gl.TEXTURE_2D, t.id)
-	glctx.TexImage2D(gl.TEXTURE_2D, 0, size.X, size.Y, gl.RGBA, gl.UNSIGNED_BYTE, nil)
+	glctx.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, size.X, size.Y, gl.RGBA, gl.UNSIGNED_BYTE, nil)
 	glctx.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
 	glctx.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
 	glctx.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)
diff --git a/shiny/widget/glwidget/glwidget.go b/shiny/widget/glwidget/glwidget.go
index c80ea6e..b63677b 100644
--- a/shiny/widget/glwidget/glwidget.go
+++ b/shiny/widget/glwidget/glwidget.go
@@ -62,7 +62,7 @@
 	w.tex = w.Ctx.CreateTexture()
 	w.Ctx.BindTexture(gl.TEXTURE_2D, w.tex)
 
-	w.Ctx.TexImage2D(gl.TEXTURE_2D, 0, maxWidth, maxHeight, gl.RGBA, gl.UNSIGNED_BYTE, nil)
+	w.Ctx.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, maxWidth, maxHeight, gl.RGBA, gl.UNSIGNED_BYTE, nil)
 	w.Ctx.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR)
 	w.Ctx.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR)
 	w.Ctx.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE)