ebiten/internal/restorable/image.go

310 lines
7.2 KiB
Go

// Copyright 2016 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 restorable
import (
"errors"
"image"
"image/color"
"github.com/hajimehoshi/ebiten/internal/affine"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/opengl"
)
type drawImageHistoryItem struct {
image *Image
vertices []float32
colorm affine.ColorM
mode opengl.CompositeMode
}
// Image represents an image that can be restored when GL context is lost.
type Image struct {
image *graphics.Image
filter opengl.Filter
// baseImage and baseColor are exclusive.
basePixels []uint8
baseColor color.RGBA
drawImageHistory []*drawImageHistoryItem
stale bool
volatile bool
screen bool
}
func NewImage(width, height int, filter opengl.Filter, volatile bool) (*Image, error) {
img, err := graphics.NewImage(width, height, filter)
if err != nil {
return nil, err
}
return &Image{
image: img,
filter: filter,
volatile: volatile,
}, nil
}
func NewImageFromImage(source *image.RGBA, width, height int, filter opengl.Filter) (*Image, error) {
img, err := graphics.NewImageFromImage(source, width, height, filter)
if err != nil {
// TODO: texture should be removed here?
return nil, err
}
return &Image{
image: img,
filter: filter,
}, nil
}
func NewScreenFramebufferImage(width, height int) (*Image, error) {
img, err := graphics.NewScreenFramebufferImage(width, height)
if err != nil {
return nil, err
}
return &Image{
image: img,
volatile: true,
screen: true,
}, nil
}
func (p *Image) Size() (int, int) {
return p.image.Size()
}
func (p *Image) makeStale() {
p.basePixels = nil
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = true
}
func (p *Image) ClearIfVolatile() error {
if !p.volatile {
return nil
}
p.basePixels = nil
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
if p.image == nil {
panic("not reach")
}
if err := p.image.Fill(color.RGBA{}); err != nil {
return err
}
return nil
}
func (p *Image) Fill(clr color.RGBA) error {
p.basePixels = nil
p.baseColor = clr
p.drawImageHistory = nil
p.stale = false
if err := p.image.Fill(clr); err != nil {
return err
}
return nil
}
func (p *Image) ReplacePixels(pixels []uint8) error {
if err := p.image.ReplacePixels(pixels); err != nil {
return err
}
if p.basePixels == nil {
p.basePixels = make([]uint8, len(pixels))
}
copy(p.basePixels, pixels)
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
return nil
}
func (p *Image) DrawImage(img *Image, vertices []float32, colorm affine.ColorM, mode opengl.CompositeMode) error {
if img.stale || img.volatile {
p.makeStale()
} else {
p.appendDrawImageHistory(img, vertices, colorm, mode)
}
if err := p.image.DrawImage(img.image, vertices, colorm, mode); err != nil {
return err
}
return nil
}
func (p *Image) appendDrawImageHistory(image *Image, vertices []float32, colorm affine.ColorM, mode opengl.CompositeMode) {
if p.stale {
return
}
// All images must be resolved and not stale each after frame.
// So we don't have to care if image is stale or not here.
item := &drawImageHistoryItem{
image: image,
vertices: vertices,
colorm: colorm,
mode: mode,
}
p.drawImageHistory = append(p.drawImageHistory, item)
}
// At returns a color value at (x, y).
//
// Note that this must not be called until context is available.
// This means Pixels members must match with acutal state in VRAM.
func (p *Image) At(x, y int, context *opengl.Context) (color.RGBA, error) {
w, _ := p.image.Size()
idx := 4*x + 4*y*w
if p.basePixels == nil || p.drawImageHistory != nil || p.stale {
if err := p.readPixelsFromVRAM(p.image, context); err != nil {
return color.RGBA{}, err
}
}
r, g, b, a := p.basePixels[idx], p.basePixels[idx+1], p.basePixels[idx+2], p.basePixels[idx+3]
return color.RGBA{r, g, b, a}, nil
}
func (p *Image) MakeStaleIfDependingOn(target *Image) {
if p.stale {
return
}
// TODO: Performance is bad when drawImageHistory is too many.
for _, c := range p.drawImageHistory {
if c.image == target {
p.makeStale()
return
}
}
return
}
func (p *Image) readPixelsFromVRAM(image *graphics.Image, context *opengl.Context) error {
var err error
p.basePixels, err = image.Pixels(context)
if err != nil {
return err
}
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
return nil
}
func (p *Image) ReadPixelsFromVRAMIfStale(context *opengl.Context) error {
if p.volatile {
return nil
}
if !p.stale {
return nil
}
return p.readPixelsFromVRAM(p.image, context)
}
func (p *Image) HasDependency() bool {
if p.stale {
return false
}
return p.drawImageHistory != nil
}
// RestoreImage restores *graphics.Image from the pixels using its state.
func (p *Image) Restore(context *opengl.Context) error {
w, h := p.image.Size()
if p.screen {
// The screen image should also be recreated because framebuffer might
// be changed.
var err error
p.image, err = graphics.NewScreenFramebufferImage(w, h)
if err != nil {
return err
}
p.basePixels = nil
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
return nil
}
if p.volatile {
var err error
p.image, err = graphics.NewImage(w, h, p.filter)
if err != nil {
return err
}
p.basePixels = nil
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
return nil
}
if p.stale {
return errors.New("restorable: pixels must not be stale when restoring")
}
img := image.NewRGBA(image.Rect(0, 0, graphics.NextPowerOf2Int(w), graphics.NextPowerOf2Int(h)))
if p.basePixels != nil {
for j := 0; j < h; j++ {
copy(img.Pix[j*img.Stride:], p.basePixels[j*w*4:(j+1)*w*4])
}
}
gimg, err := graphics.NewImageFromImage(img, w, h, p.filter)
if err != nil {
return err
}
if p.baseColor != (color.RGBA{}) {
if p.basePixels != nil {
panic("not reach")
}
if err := gimg.Fill(p.baseColor); err != nil {
return err
}
}
for _, c := range p.drawImageHistory {
// c.image.image must be already restored.
if c.image.HasDependency() {
panic("not reach")
}
if err := gimg.DrawImage(c.image.image, c.vertices, c.colorm, c.mode); err != nil {
return err
}
}
p.image = gimg
p.basePixels, err = gimg.Pixels(context)
if err != nil {
return err
}
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
return nil
}
func (p *Image) Dispose() error {
if err := p.image.Dispose(); err != nil {
return err
}
p.image = nil
p.basePixels = nil
p.baseColor = color.RGBA{}
p.drawImageHistory = nil
p.stale = false
return nil
}
func (p *Image) IsInvalidated(context *opengl.Context) bool {
return p.image.IsInvalidated(context)
}