Use dep to vendor things

vendor/github.com/faiface/glhf/orphan.go

@@ -0,0 +1,51 @@
+package glhf
+
+import "github.com/go-gl/gl/v3.3-core/gl"
+
+// Init initializes OpenGL by loading function pointers from the active OpenGL context.
+// This function must be manually run inside the main thread (using "github.com/faiface/mainthread"
+// package).
+//
+// It must be called under the presence of an active OpenGL context, e.g., always after calling
+// window.MakeContextCurrent(). Also, always call this function when switching contexts.
+func Init() {
+	err := gl.Init()
+	if err != nil {
+		panic(err)
+	}
+	gl.Enable(gl.BLEND)
+	gl.Enable(gl.SCISSOR_TEST)
+	gl.BlendEquation(gl.FUNC_ADD)
+}
+
+// Clear clears the current framebuffer or window with the given color.
+func Clear(r, g, b, a float32) {
+	gl.ClearColor(r, g, b, a)
+	gl.Clear(gl.COLOR_BUFFER_BIT)
+}
+
+// Bounds sets the drawing bounds in pixels. Drawing outside bounds is always discarted.
+//
+// Calling this function is equivalent to setting viewport and scissor in OpenGL.
+func Bounds(x, y, w, h int) {
+	gl.Viewport(int32(x), int32(y), int32(w), int32(h))
+	gl.Scissor(int32(x), int32(y), int32(w), int32(h))
+}
+
+// BlendFactor represents a source or destination blend factor.
+type BlendFactor int
+
+// Here's the list of all blend factors.
+const (
+	One              = BlendFactor(gl.ONE)
+	Zero             = BlendFactor(gl.ZERO)
+	SrcAlpha         = BlendFactor(gl.SRC_ALPHA)
+	DstAlpha         = BlendFactor(gl.DST_ALPHA)
+	OneMinusSrcAlpha = BlendFactor(gl.ONE_MINUS_SRC_ALPHA)
+	OneMinusDstAlpha = BlendFactor(gl.ONE_MINUS_DST_ALPHA)
+)
+
+// BlendFunc sets the source and destination blend factor.
+func BlendFunc(src, dst BlendFactor) {
+	gl.BlendFunc(uint32(src), uint32(dst))
+}