ebiten/internal/opengl/gl.go

44 lines
1.1 KiB
Go

// Copyright 2014 Hajime Hoshi
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package opengl
import (
"github.com/go-gl/gl"
)
type Filter int
const (
FilterNearest Filter = gl.NEAREST
FilterLinear = gl.LINEAR
)
func Init() {
gl.Init()
gl.Enable(gl.TEXTURE_2D)
// Textures' pixel formats are alpha premultiplied.
gl.Enable(gl.BLEND)
gl.BlendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA)
}
func Clear(r, g, b, a float64) {
gl.ClearColor(gl.GLclampf(r), gl.GLclampf(g), gl.GLclampf(b), gl.GLclampf(a))
gl.Clear(gl.COLOR_BUFFER_BIT)
}
func Flush() {
gl.Flush()
}