func RenderAdvanced(x, y, dx, dy, rot float64, flip bool) {
if textureList != 0 {
var run, op mathgl.Mat4
run.Identity()
op.Translation(float32(x), float32(y), 0)
run.Multiply(&op)
op.Translation(float32(dx/2), float32(dy/2), 0)
run.Multiply(&op)
op.RotationZ(float32(rot))
run.Multiply(&op)
if flip {
op.Translation(float32(-dx/2), float32(-dy/2), 0)
run.Multiply(&op)
op.Scaling(float32(dx), float32(dy), 1)
run.Multiply(&op)
} else {
op.Translation(float32(dx/2), float32(-dy/2), 0)
run.Multiply(&op)
op.Scaling(float32(-dx), float32(dy), 1)
run.Multiply(&op)
}
gl.PushMatrix()
gl.MultMatrixf(&run[0])
gl.Enable(gl.TEXTURE_2D)
gl.CallList(textureList)
gl.PopMatrix()
}
}
func Render(x, y, dx, dy float64) {
var run, op mathgl.Mat4
run.Identity()
op.Translation(float32(x), float32(y), 0)
run.Multiply(&op)
op.Scaling(float32(dx), float32(dy), 1)
run.Multiply(&op)
gl.PushMatrix()
gl.Enable(gl.TEXTURE_2D)
gl.MultMatrixf(&run[0])
gl.CallList(textureList)
gl.PopMatrix()
}