ebiten/internal/ui/graphics.go
Hajime Hoshi 3074dca670 internal/ui: add the EBITEN_GRAPHICS_LIBRARY environment variable
The `ebitengl` build tag is gone instead.

Closes #2007
2022-03-24 02:23:37 +09:00

57 lines
1.7 KiB
Go

// Copyright 2022 The Ebiten Authors
//
// 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 ui
import (
"fmt"
"os"
"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver"
)
type graphicsDriverGetter interface {
getAuto() graphicsdriver.Graphics
getOpenGL() graphicsdriver.Graphics
getMetal() graphicsdriver.Graphics
}
func chooseGraphicsDriver(getter graphicsDriverGetter) (graphicsdriver.Graphics, error) {
const envName = "EBITEN_GRAPHICS_LIBRARY"
switch env := os.Getenv(envName); env {
case "", "auto":
if g := getter.getAuto(); g != nil {
return g, nil
}
return nil, fmt.Errorf("ui: no graphics library is available")
case "opengl":
if g := getter.getOpenGL(); g != nil {
return g, nil
}
return nil, fmt.Errorf("ui: %s=%s is specified but OpenGL is not available", envName, env)
case "metal":
if g := getter.getMetal(); g != nil {
return g, nil
}
return nil, fmt.Errorf("ui: %s=%s is specified but Metal is not available", envName, env)
default:
return nil, fmt.Errorf("ui: an unsupported graphics library is specified: %s", env)
}
}
func GraphicsDriverForTesting() graphicsdriver.Graphics {
return theUI.graphicsDriver
}