ebiten/graphicscontext.go
2015-02-09 11:02:04 +09:00

91 lines
2.3 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 ebiten
import (
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/graphics/internal/opengl"
"github.com/hajimehoshi/ebiten/internal/ui"
)
func useGLContext(f func(*opengl.Context)) {
ui.ExecOnUIThread(func() {
f(glContext)
})
}
func newGraphicsContext(screenWidth, screenHeight, screenScale int) (*graphicsContext, error) {
c := &graphicsContext{}
if err := c.setSize(screenWidth, screenHeight, screenScale); err != nil {
return nil, err
}
return c, nil
}
type graphicsContext struct {
screen *Image
defaultR *Image
screenScale int
}
func (c *graphicsContext) preUpdate() error {
return c.screen.Clear()
}
func (c *graphicsContext) postUpdate() error {
if err := c.defaultR.Clear(); err != nil {
return err
}
scale := float64(c.screenScale)
options := &DrawImageOptions{}
options.GeoM.Scale(scale, scale)
if err := c.defaultR.DrawImage(c.screen, options); err != nil {
return err
}
return nil
}
func (c *graphicsContext) setSize(screenWidth, screenHeight, screenScale int) error {
if c.defaultR != nil {
c.defaultR.dispose()
}
if c.screen != nil {
c.screen.dispose()
}
var err error
useGLContext(func(g *opengl.Context) {
f, err := graphics.NewZeroFramebuffer(g, screenWidth*screenScale, screenHeight*screenScale)
if err != nil {
return
}
texture, err := graphics.NewTexture(g, screenWidth, screenHeight, g.Nearest)
if err != nil {
return
}
screenF, err := graphics.NewFramebufferFromTexture(g, texture)
if err != nil {
return
}
screen := &Image{framebuffer: screenF, texture: texture}
c.defaultR = &Image{framebuffer: f, texture: nil}
c.screen = screen
c.screenScale = screenScale
})
return err
}