ebiten/image.go
2016-06-12 01:34:21 +09:00

415 lines
11 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 (
"errors"
"fmt"
"image"
"image/color"
"image/draw"
"runtime"
"sync"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
"github.com/hajimehoshi/ebiten/internal/loop"
"github.com/hajimehoshi/ebiten/internal/ui"
)
var (
imageM sync.Mutex
)
type images struct {
images map[*imageImpl]struct{}
m sync.Mutex
}
var theImages = images{
images: map[*imageImpl]struct{}{},
}
func (i *images) add(img *imageImpl) (*Image, error) {
i.m.Lock()
defer i.m.Unlock()
i.images[img] = struct{}{}
eimg := &Image{img}
runtime.SetFinalizer(eimg, theImages.remove)
return eimg, nil
}
func (i *images) remove(img *Image) {
i.m.Lock()
defer i.m.Unlock()
delete(i.images, img.impl)
}
func (i *images) restorePixels(context *opengl.Context) error {
i.m.Lock()
defer i.m.Unlock()
for img := range i.images {
if err := img.restorePixels(context); err != nil {
return err
}
}
return nil
}
// Image represents an image.
// The pixel format is alpha-premultiplied.
// Image implements image.Image.
type Image struct {
impl *imageImpl
}
// Size returns the size of the image.
//
// This function is concurrent-safe.
func (i *Image) Size() (width, height int) {
return i.impl.width, i.impl.height
}
// Clear resets the pixels of the image into 0.
//
// This function is concurrent-safe.
func (i *Image) Clear() error {
return i.impl.Fill(color.Transparent)
}
// Fill fills the image with a solid color.
//
// This function is concurrent-safe.
func (i *Image) Fill(clr color.Color) error {
return i.impl.Fill(clr)
}
// DrawImage draws the given image on the receiver image.
//
// This method accepts the options.
// The parts of the given image at the parts of the destination.
// After determining parts to draw, this applies the geometry matrix and the color matrix.
//
// Here are the default values:
// ImageParts: (0, 0) - (source width, source height) to (0, 0) - (source width, source height)
// (i.e. the whole source image)
// GeoM: Identity matrix
// ColorM: Identity matrix (that changes no colors)
// CompositeMode: CompositeModeSourceOver (regular alpha blending)
//
// Note that this function returns immediately and actual drawing is done lazily.
//
// This function is concurrent-safe.
func (i *Image) DrawImage(image *Image, options *DrawImageOptions) error {
return i.impl.DrawImage(image, options)
}
// Bounds returns the bounds of the image.
//
// This function is concurrent-safe.
func (i *Image) Bounds() image.Rectangle {
return image.Rect(0, 0, i.impl.width, i.impl.height)
}
// ColorModel returns the color model of the image.
//
// This function is concurrent-safe.
func (i *Image) ColorModel() color.Model {
return color.RGBAModel
}
// At returns the color of the image at (x, y).
//
// This method loads pixels from VRAM to system memory if necessary.
//
// This method can't be called before the main loop (ebiten.Run) starts (as of version 1.4.0-alpha).
//
// This function is concurrent-safe.
func (i *Image) At(x, y int) color.Color {
return i.impl.At(x, y)
}
// Dispose disposes the image data. After disposing, the image becomes invalid.
// This is useful to save memory.
//
// The behavior of any functions for a disposed image is undefined.
//
// This function is concurrent-safe.
func (i *Image) Dispose() error {
return i.impl.Dispose()
}
// ReplacePixels replaces the pixels of the image with p.
//
// The given p must represent RGBA pre-multiplied alpha values. len(p) must equal to 4 * (image width) * (image height).
//
// This function may be slow (as for implementation, this calls glTexSubImage2D).
//
// This function is concurrent-safe.
func (i *Image) ReplacePixels(p []uint8) error {
return i.impl.ReplacePixels(p)
}
type imageImpl struct {
image *graphics.Image
defaultFramebuffer bool
disposed bool
width int
height int
filter Filter
pixels []uint8
}
func (i *imageImpl) Fill(clr color.Color) error {
imageM.Lock()
defer imageM.Unlock()
if i.isDisposed() {
return errors.New("ebiten: image is already disposed")
}
i.pixels = nil
return i.image.Fill(clr)
}
func isWholeNumber(x float64) bool {
return x == float64(int64(x))
}
func (i *imageImpl) DrawImage(image *Image, options *DrawImageOptions) error {
// Calculate vertices before locking because the user can do anything in
// options.ImageParts interface without deadlock (e.g. Call Image functions).
if options == nil {
options = &DrawImageOptions{}
}
parts := options.ImageParts
if parts == nil {
// Check options.Parts for backward-compatibility.
dparts := options.Parts
if dparts != nil {
parts = imageParts(dparts)
} else {
parts = &wholeImage{image.impl.width, image.impl.height}
}
}
quads := &textureQuads{parts: parts, width: image.impl.width, height: image.impl.height}
// TODO: Reuse one vertices instead of making here, but this would need locking.
vertices := make([]int16, parts.Len()*16)
n := quads.vertices(vertices)
if n == 0 {
return nil
}
if i == image.impl {
return errors.New("ebiten: Image.DrawImage: image should be different from the receiver")
}
imageM.Lock()
defer imageM.Unlock()
if i.isDisposed() {
return errors.New("ebiten: image is already disposed")
}
i.pixels = nil
geom := &options.GeoM
colorm := &options.ColorM
mode := opengl.CompositeMode(options.CompositeMode)
if err := i.image.DrawImage(image.impl.image, vertices[:16*n], geom, colorm, mode); err != nil {
return err
}
return nil
}
func (i *imageImpl) At(x, y int) color.Color {
if !loop.IsRunning() {
panic("ebiten: At can't be called when the GL context is not initialized (this panic happens as of version 1.4.0-alpha)")
}
imageM.Lock()
defer imageM.Unlock()
if i.isDisposed() {
return color.Transparent
}
if i.pixels == nil {
var err error
i.pixels, err = i.image.Pixels(ui.GLContext())
if err != nil {
panic(err)
}
}
idx := 4*x + 4*y*i.width
r, g, b, a := i.pixels[idx], i.pixels[idx+1], i.pixels[idx+2], i.pixels[idx+3]
return color.RGBA{r, g, b, a}
}
func (i *imageImpl) restorePixels(context *opengl.Context) error {
imageM.Lock()
defer imageM.Unlock()
if i.defaultFramebuffer {
return nil
}
if i.disposed {
return nil
}
// TODO: As the texture is already disposed, is it correct to delete it here?
if err := i.image.Dispose(); err != nil {
return err
}
// TODO: Recalc i.pixels here
img := image.NewRGBA(image.Rect(0, 0, i.width, i.height))
for j := 0; j < i.height; j++ {
copy(img.Pix[j*img.Stride:], i.pixels[j*i.width*4:(j+1)*i.width*4])
}
var err error
i.image, err = graphics.NewImageFromImage(img, glFilter(context, i.filter))
if err != nil {
return err
}
return nil
}
func (i *imageImpl) Dispose() error {
imageM.Lock()
defer imageM.Unlock()
if i.isDisposed() {
return errors.New("ebiten: image is already disposed")
}
if err := i.image.Dispose(); err != nil {
return err
}
i.image = nil
i.disposed = true
i.pixels = nil
runtime.SetFinalizer(i, nil)
return nil
}
func (i *imageImpl) isDisposed() bool {
return i.disposed
}
func (i *imageImpl) ReplacePixels(p []uint8) error {
if l := 4 * i.width * i.height; len(p) != l {
return fmt.Errorf("ebiten: p's length must be %d", l)
}
imageM.Lock()
defer imageM.Unlock()
// TODO: Copy p?
i.pixels = nil
if i.isDisposed() {
return errors.New("ebiten: image is already disposed")
}
return i.image.ReplacePixels(p)
}
// A DrawImageOptions represents options to render an image on an image.
type DrawImageOptions struct {
ImageParts ImageParts
GeoM GeoM
ColorM ColorM
CompositeMode CompositeMode
// Deprecated (as of 1.1.0-alpha): Use ImageParts instead.
Parts []ImagePart
}
// NewImage returns an empty image.
//
// NewImage generates a new texture and a new framebuffer.
//
// This function is concurrent-safe.
func NewImage(width, height int, filter Filter) (*Image, error) {
image := &imageImpl{
width: width,
height: height,
filter: filter,
}
eimg, err := theImages.add(image)
if err != nil {
return nil, err
}
imageM.Lock()
defer imageM.Unlock()
image.image, err = graphics.NewImage(width, height, glFilter(ui.GLContext(), filter))
if err != nil {
return nil, err
}
runtime.SetFinalizer(image, (*imageImpl).Dispose)
if err := image.image.Fill(color.Transparent); err != nil {
return nil, err
}
return eimg, nil
}
// NewImageFromImage creates a new image with the given image (source).
//
// NewImageFromImage generates a new texture and a new framebuffer.
//
// This function is concurrent-safe.
func NewImageFromImage(source image.Image, filter Filter) (*Image, error) {
size := source.Bounds().Size()
w, h := size.X, size.Y
// TODO: Return error when the image is too big!
img := &imageImpl{
width: w,
height: h,
filter: filter,
}
eimg, err := theImages.add(img)
if err != nil {
return nil, err
}
// Don't lock while manipulating an image.Image interface.
rgbaImg, ok := source.(*image.RGBA)
if !ok {
origImg := source
newImg := image.NewRGBA(origImg.Bounds())
draw.Draw(newImg, newImg.Bounds(), origImg, origImg.Bounds().Min, draw.Src)
rgbaImg = newImg
}
imageM.Lock()
defer imageM.Unlock()
img.image, err = graphics.NewImageFromImage(rgbaImg, glFilter(ui.GLContext(), filter))
if err != nil {
// TODO: texture should be removed here?
return nil, err
}
runtime.SetFinalizer(img, (*imageImpl).Dispose)
return eimg, nil
}
func newImageWithZeroFramebuffer(width, height int) (*Image, error) {
img, err := newImageWithZeroFramebufferImpl(width, height)
if err != nil {
return nil, err
}
return img, nil
}
func newImageWithZeroFramebufferImpl(width, height int) (*Image, error) {
imageM.Lock()
defer imageM.Unlock()
i, err := graphics.NewZeroFramebufferImage(width, height)
if err != nil {
return nil, err
}
img := &imageImpl{
image: i,
width: width,
height: height,
defaultFramebuffer: true,
}
eimg, err := theImages.add(img)
if err != nil {
return nil, err
}
runtime.SetFinalizer(img, (*imageImpl).Dispose)
return eimg, nil
}