ebiten/internal/shareable/shareable.go

368 lines
7.7 KiB
Go

// Copyright 2018 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 shareable
import (
"fmt"
"image"
"image/color"
"runtime"
"github.com/hajimehoshi/ebiten/internal/affine"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/opengl"
"github.com/hajimehoshi/ebiten/internal/packing"
"github.com/hajimehoshi/ebiten/internal/restorable"
"github.com/hajimehoshi/ebiten/internal/sync"
)
type backend struct {
restorable *restorable.Image
// If page is nil, the backend is not shared.
page *packing.Page
}
func (b *backend) TryAlloc(width, height int) (*packing.Node, bool) {
// If the region is allocated without any extention, it's fine.
if n := b.page.Alloc(width, height); n != nil {
return n, true
}
// Simulate the extending the page and calculate the appropriate page size.
page := b.page.Clone()
nExtended := 0
for {
if !page.Extend() {
// The page can't be extended any more. Return as failure.
return nil, false
}
nExtended++
if n := page.Alloc(width, height); n != nil {
break
}
}
for i := 0; i < nExtended; i++ {
b.page.Extend()
}
s := b.page.Size()
newImg := restorable.NewImage(s, s, false)
oldImg := b.restorable
w, h := oldImg.Size()
newImg.DrawImage(oldImg, 0, 0, w, h, nil, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
oldImg.Dispose()
b.restorable = newImg
n := b.page.Alloc(width, height)
if n == nil {
panic("not reached")
}
return n, true
}
var (
// backendsM is a mutex for critical sections of the backend and packing.Node objects.
backendsM sync.Mutex
// theBackends is a set of actually shared images.
theBackends = []*backend{}
)
type Image struct {
width int
height int
disposed bool
backend *backend
// If node is nil, the image is not shared.
node *packing.Node
}
func (i *Image) ensureNotShared() {
if i.backend == nil {
i.allocate(false)
return
}
if i.node == nil {
return
}
x, y, w, h := i.region()
newImg := restorable.NewImage(w, h, false)
newImg.DrawImage(i.backend.restorable, x, y, x+w, y+h, nil, nil, opengl.CompositeModeCopy, graphics.FilterNearest)
i.dispose()
i.backend = &backend{
restorable: newImg,
}
}
func (i *Image) region() (x, y, width, height int) {
if i.backend == nil {
panic("not reached")
}
if i.node == nil {
w, h := i.backend.restorable.Size()
return 0, 0, w, h
}
return i.node.Region()
}
func (i *Image) Size() (width, height int) {
return i.width, i.height
}
func (i *Image) DrawImage(img *Image, sx0, sy0, sx1, sy1 int, geom *affine.GeoM, colorm *affine.ColorM, mode opengl.CompositeMode, filter graphics.Filter) {
backendsM.Lock()
defer backendsM.Unlock()
if img.disposed {
panic("shareable: the drawing source image must not be disposed")
}
if i.disposed {
panic("shareable: the drawing target image must not be disposed")
}
if img.backend == nil {
img.allocate(true)
}
i.ensureNotShared()
// Compare i and img after ensuring i is not shared, or
// i and img might share the same texture even though i != img.
if i.backend.restorable == img.backend.restorable {
panic("shareable: Image.DrawImage: img must be different from the receiver")
}
dx, dy, _, _ := img.region()
sx0 += dx
sy0 += dy
sx1 += dx
sy1 += dy
i.backend.restorable.DrawImage(img.backend.restorable, sx0, sy0, sx1, sy1, geom, colorm, mode, filter)
}
func (i *Image) ReplacePixels(p []byte) {
backendsM.Lock()
defer backendsM.Unlock()
if i.disposed {
panic("shareable: the image must not be disposed")
}
if i.backend == nil {
i.allocate(true)
}
x, y, w, h := i.region()
if l := 4 * w * h; len(p) != l {
panic(fmt.Sprintf("shareable: len(p) was %d but must be %d", len(p), l))
}
i.backend.restorable.ReplacePixels(p, x, y, w, h)
}
func (i *Image) At(x, y int) (color.Color, error) {
backendsM.Lock()
defer backendsM.Unlock()
if i.backend == nil {
return color.RGBA{}, nil
}
ox, oy, w, h := i.region()
if x < 0 || y < 0 || x >= w || y >= h {
return color.RGBA{}, nil
}
clr, err := i.backend.restorable.At(x+ox, y+oy)
return clr, err
}
func (i *Image) Dispose() {
backendsM.Lock()
defer backendsM.Unlock()
i.dispose()
}
func (i *Image) dispose() {
defer func() {
i.disposed = true
i.backend = nil
i.node = nil
runtime.SetFinalizer(i, nil)
}()
if i.disposed {
return
}
if i.backend == nil {
// Not allocated yet.
return
}
if i.node == nil {
i.backend.restorable.Dispose()
return
}
i.backend.page.Free(i.node)
if !i.backend.page.IsEmpty() {
// As this part can be reused, this should be cleared explicitly.
x0, y0, x1, y1 := i.region()
i.backend.restorable.ReplacePixels(nil, x0, y0, x1, y1)
return
}
i.backend.restorable.Dispose()
index := -1
for idx, sh := range theBackends {
if sh == i.backend {
index = idx
break
}
}
if index == -1 {
panic("not reached")
}
theBackends = append(theBackends[:index], theBackends[index+1:]...)
}
func (i *Image) IsInvalidated() (bool, error) {
backendsM.Lock()
defer backendsM.Unlock()
v, err := i.backend.restorable.IsInvalidated()
return v, err
}
func NewImage(width, height int) *Image {
// Actual allocation is done lazily.
return &Image{
width: width,
height: height,
}
}
func (i *Image) allocate(shareable bool) {
if i.backend != nil {
panic("not reached")
}
const (
initSize = 1024
maxSize = 4096
)
if !shareable || i.width > maxSize || i.height > maxSize {
i.backend = &backend{
restorable: restorable.NewImage(i.width, i.height, false),
}
return
}
for _, b := range theBackends {
if n, ok := b.TryAlloc(i.width, i.height); ok {
i.backend = b
i.node = n
return
}
}
size := initSize
for i.width > size || i.height > size {
if size == maxSize {
panic("not reached")
}
size *= 2
}
b := &backend{
restorable: restorable.NewImage(size, size, false),
page: packing.NewPage(size, maxSize),
}
theBackends = append(theBackends, b)
n := b.page.Alloc(i.width, i.height)
if n == nil {
panic("not reached")
}
i.backend = b
i.node = n
runtime.SetFinalizer(i, (*Image).Dispose)
return
}
func NewVolatileImage(width, height int) *Image {
backendsM.Lock()
defer backendsM.Unlock()
r := restorable.NewImage(width, height, true)
i := &Image{
width: width,
height: height,
backend: &backend{
restorable: r,
},
}
runtime.SetFinalizer(i, (*Image).Dispose)
return i
}
func NewScreenFramebufferImage(width, height int) *Image {
backendsM.Lock()
defer backendsM.Unlock()
r := restorable.NewScreenFramebufferImage(width, height)
i := &Image{
width: width,
height: height,
backend: &backend{
restorable: r,
},
}
runtime.SetFinalizer(i, (*Image).Dispose)
return i
}
func InitializeGLState() error {
backendsM.Lock()
defer backendsM.Unlock()
return restorable.InitializeGLState()
}
func ResolveStaleImages() error {
backendsM.Lock()
defer backendsM.Unlock()
return restorable.ResolveStaleImages()
}
func IsRestoringEnabled() bool {
// As IsRestoringEnabled is an immutable state, no need to lock here.
return restorable.IsRestoringEnabled()
}
func Restore() error {
backendsM.Lock()
defer backendsM.Unlock()
return restorable.Restore()
}
func Images() ([]image.Image, error) {
backendsM.Lock()
defer backendsM.Unlock()
return restorable.Images()
}