opengl: Remove BeforeSwapping

I couldn't machines that requre this any longer. Perhaps a bound
framebuffer is always the screen framebuffer before swapping now.

internal/graphicscommand/command.go

@@ -198,13 +198,6 @@ func (q *commandQueue) Flush() {
 	q.nindices = 0
 	q.tmpNumIndices = 0
 	q.nextIndex = 0
-
-	// The bound framebuffer must be the original screen framebuffer before swapping buffers.
-	// Note that swapping might not happen after this function. BeforeSwapping should not be
-	// harmful in any cases.
-	//
-	// TODO: Confirm which machine requires this. Probably BungBungame Photon 2?
-	opengl.GetContext().BeforeSwapping()
 }
 
 // Error returns an OpenGL error for the last command.

internal/opengl/context_desktop.go

@@ -218,10 +218,6 @@ func (c *Context) texSubImage2D(t textureNative, p []byte, x, y, width, height i
 	})
 }
 
-func (c *Context) BeforeSwapping() {
-	c.bindFramebuffer(c.screenFramebuffer)
-}
-
 func (c *Context) newFramebuffer(texture textureNative) (framebufferNative, error) {
 	var framebuffer framebufferNative
 	var f uint32

internal/opengl/context_js.go

@@ -506,7 +506,3 @@ func (c *Context) RestoreContext() {
 		c.loseContext.Call("restoreContext")
 	}
 }
-
-func (c *Context) BeforeSwapping() {
-	// Do nothing
-}

internal/opengl/context_mobile.go

@@ -400,7 +400,3 @@ func (c *Context) Flush() {
 	gl := c.gl
 	gl.Flush()
 }
-
-func (c *Context) BeforeSwapping() {
-	// Do nothing
-}