ebiten/graphicscontext.go
2016-07-05 03:01:32 +09:00

170 lines
4.1 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 ebiten
import (
"math"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
)
func newGraphicsContext(f func(*Image) error) *graphicsContext {
return &graphicsContext{
f: f,
}
}
type graphicsContext struct {
f func(*Image) error
offscreen *Image
offscreen2 *Image // TODO: better name
screen *Image
screenScale float64
initialized bool
}
func (c *graphicsContext) SetSize(screenWidth, screenHeight int, screenScale float64) error {
if c.screen != nil {
c.screen.Dispose()
}
if c.offscreen != nil {
c.offscreen.Dispose()
}
offscreen, err := NewImage(screenWidth, screenHeight, FilterNearest)
if err != nil {
return err
}
offscreen.impl.noSave = true
intScreenScale := int(math.Ceil(screenScale))
w := screenWidth * intScreenScale
h := screenHeight * intScreenScale
offscreen2, err := NewImage(w, h, FilterLinear)
if err != nil {
return err
}
offscreen2.impl.noSave = true
w = int(float64(screenWidth) * screenScale)
h = int(float64(screenHeight) * screenScale)
c.screen, err = newImageWithScreenFramebuffer(w, h)
if err != nil {
return err
}
c.screen.impl.noSave = true
c.screen.Clear()
c.offscreen = offscreen
c.offscreen2 = offscreen2
c.screenScale = screenScale
return nil
}
func (c *graphicsContext) needsRestoring(context *opengl.Context) (bool, error) {
// FlushCommands is required because c.offscreen.impl might not have an actual texture.
if err := graphics.FlushCommands(context); err != nil {
return false, err
}
return c.offscreen.impl.isInvalidated(context), nil
}
func (c *graphicsContext) initializeIfNeeded(context *opengl.Context) error {
if !c.initialized {
if err := graphics.Reset(context); err != nil {
return err
}
c.initialized = true
}
r, err := c.needsRestoring(context)
if err != nil {
return err
}
if r {
if err := c.restore(context); err != nil {
return err
}
}
return nil
}
func drawWithFittingScale(dst *Image, src *Image) error {
wd, hd := dst.Size()
ws, hs := src.Size()
sw := float64(wd) / float64(ws)
sh := float64(hd) / float64(hs)
op := &DrawImageOptions{}
op.GeoM.Scale(sw, sh)
if err := dst.DrawImage(src, op); err != nil {
return err
}
return nil
}
func (c *graphicsContext) drawToDefaultRenderTarget(context *opengl.Context) error {
if err := c.screen.Clear(); err != nil {
return err
}
if err := drawWithFittingScale(c.screen, c.offscreen2); err != nil {
return err
}
if err := graphics.FlushCommands(context); err != nil {
return err
}
return nil
}
func (c *graphicsContext) UpdateAndDraw(context *opengl.Context, updateCount int) error {
if err := c.initializeIfNeeded(context); err != nil {
return err
}
for i := 0; i < updateCount; i++ {
if err := c.offscreen.Clear(); err != nil {
return err
}
setRunningSlowly(i < updateCount-1)
if err := c.f(c.offscreen); err != nil {
return err
}
}
if 0 < updateCount {
if err := c.offscreen2.Clear(); err != nil {
return err
}
if err := drawWithFittingScale(c.offscreen2, c.offscreen); err != nil {
return err
}
}
if err := c.drawToDefaultRenderTarget(context); err != nil {
return err
}
if 0 < updateCount {
if err := theImagesForRestoring.savePixels(context); err != nil {
return err
}
}
return nil
}
func (c *graphicsContext) restore(context *opengl.Context) error {
if err := graphics.Reset(context); err != nil {
return err
}
if err := theImagesForRestoring.restore(context); err != nil {
return err
}
return nil
}