ebiten/image.go

821 lines
24 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 (
"fmt"
"image"
"image/color"
"github.com/hajimehoshi/ebiten/internal/buffered"
"github.com/hajimehoshi/ebiten/internal/driver"
"github.com/hajimehoshi/ebiten/internal/graphics"
)
// Image represents a rectangle set of pixels.
// The pixel format is alpha-premultiplied RGBA.
// Image implements image.Image and draw.Image.
//
// Functions of Image never returns error as of 1.5.0, and error values are always nil.
type Image struct {
// addr holds self to check copying.
// See strings.Builder for similar examples.
addr *Image
buffered *buffered.Image
bounds image.Rectangle
original *Image
filter Filter
}
func (i *Image) copyCheck() {
if i.addr != i {
panic("ebiten: illegal use of non-zero Image copied by value")
}
}
// Size returns the size of the image.
func (i *Image) Size() (width, height int) {
s := i.Bounds().Size()
return s.X, s.Y
}
func (i *Image) isDisposed() bool {
return i.buffered == nil
}
func (i *Image) isSubImage() bool {
return i.original != nil
}
// Clear resets the pixels of the image into 0.
//
// When the image is disposed, Clear does nothing.
//
// Clear always returns nil as of 1.5.0.
func (i *Image) Clear() error {
i.Fill(color.Transparent)
return nil
}
// Fill fills the image with a solid color.
//
// When the image is disposed, Fill does nothing.
//
// Fill always returns nil as of 1.5.0.
func (i *Image) Fill(clr color.Color) error {
i.copyCheck()
if i.isDisposed() {
return nil
}
// TODO: Implement this.
if i.isSubImage() {
panic("ebiten: rendering to a sub-image is not implemented (Fill)")
}
i.buffered.Fill(color.RGBAModel.Convert(clr).(color.RGBA))
return nil
}
// DrawImageOptions represents options for DrawImage.
type DrawImageOptions struct {
// GeoM is a geometry matrix to draw.
// The default (zero) value is identify, which draws the image at (0, 0).
GeoM GeoM
// ColorM is a color matrix to draw.
// The default (zero) value is identity, which doesn't change any color.
//
// If Shader is not nil, ColorM is ignored.
ColorM ColorM
// CompositeMode is a composite mode to draw.
// The default (zero) value is regular alpha blending.
CompositeMode CompositeMode
// Filter is a type of texture filter.
// The default (zero) value is FilterDefault.
//
// Filter can also be specified at NewImage* functions, but
// specifying filter at DrawImageOptions is recommended (as of 1.7.0).
//
// If both Filter specified at NewImage* and DrawImageOptions are FilterDefault,
// FilterNearest is used.
// If either is FilterDefault and the other is not, the latter is used.
// Otherwise, Filter specified at DrawImageOptions is used.
//
// If Shader is not nil, Filter is ignored.
Filter Filter
// Shader is a shader.
Shader *Shader
// Uniforms is a set of uniform variables for the shader.
//
// Uniforms is used only when Shader is not nil.
Uniforms []interface{}
// Deprecated: (as of 1.5.0) Use SubImage instead.
ImageParts ImageParts
// Deprecated: (as of 1.1.0) Use SubImage instead.
Parts []ImagePart
// Deprecated: (as of 1.9.0) Use SubImage instead.
SourceRect *image.Rectangle
}
// DrawImage draws the given image on the image i.
//
// DrawImage accepts the options. For details, see the document of
// DrawImageOptions.
//
// For drawing, the pixels of the argument image at the time of this call is
// adopted. Even if the argument image is mutated after this call, the drawing
// result is never affected.
//
// When the image i is disposed, DrawImage does nothing.
// When the given image img is disposed, DrawImage panics.
//
// When the given image is as same as i, DrawImage panics.
//
// DrawImage works more efficiently as batches
// when the successive calls of DrawImages satisfy the below conditions:
//
// * All render targets are same (A in A.DrawImage(B, op))
// * Either all ColorM element values are same or all the ColorM have only
// diagonal ('scale') elements
// * If only (*ColorM).Scale is applied to a ColorM, the ColorM has only
// diagonal elements. The other ColorM functions might modify the other
// elements.
// * All CompositeMode values are same
// * All Filter values are same
// * All Shader values are nil
//
// Even when all the above conditions are satisfied, multiple draw commands can
// be used in really rare cases. Ebiten images usually share an internal
// automatic texture atlas, but when you consume the atlas, or you create a huge
// image, those images cannot be on the same texture atlas. In this case, draw
// commands are separated. The texture atlas size is 4096x4096 so far. Another
// case is when you use an offscreen as a render source. An offscreen doesn't
// share the texture atlas with high probability.
//
// For more performance tips, see https://ebiten.org/documents/performancetips.html
//
// ColorM and Filter are ignored when Shader is not nil.
//
// DrawImage always returns nil as of 1.5.0.
func (i *Image) DrawImage(img *Image, options *DrawImageOptions) error {
i.copyCheck()
if img.isDisposed() {
panic("ebiten: the given image to DrawImage must not be disposed")
}
if i.isDisposed() {
return nil
}
// TODO: Implement this.
if i.isSubImage() {
panic("ebiten: render to a sub-image is not implemented (DrawImage)")
}
// 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
// Parts is deprecated. This implementations is for backward compatibility.
if parts == nil && options.Parts != nil {
parts = imageParts(options.Parts)
}
// ImageParts is deprecated. This implementations is for backward compatibility.
if parts != nil {
l := parts.Len()
for idx := 0; idx < l; idx++ {
sx0, sy0, sx1, sy1 := parts.Src(idx)
dx0, dy0, dx1, dy1 := parts.Dst(idx)
op := &DrawImageOptions{
ColorM: options.ColorM,
CompositeMode: options.CompositeMode,
Filter: options.Filter,
}
op.GeoM.Scale(
float64(dx1-dx0)/float64(sx1-sx0),
float64(dy1-dy0)/float64(sy1-sy0))
op.GeoM.Translate(float64(dx0), float64(dy0))
op.GeoM.Concat(options.GeoM)
i.DrawImage(img.SubImage(image.Rect(sx0, sy0, sx1, sy1)).(*Image), op)
}
return nil
}
bounds := img.Bounds()
// SourceRect is deprecated. This implementation is for backward compatibility.
if options.SourceRect != nil {
bounds = bounds.Intersect(*options.SourceRect)
if bounds.Empty() {
return nil
}
}
mode := driver.CompositeMode(options.CompositeMode)
filter := driver.FilterNearest
if options.Filter != FilterDefault {
filter = driver.Filter(options.Filter)
} else if img.filter != FilterDefault {
filter = driver.Filter(img.filter)
}
a, b, c, d, tx, ty := options.GeoM.elements32()
sx0 := float32(bounds.Min.X)
sy0 := float32(bounds.Min.Y)
sx1 := float32(bounds.Max.X)
sy1 := float32(bounds.Max.Y)
vs := graphics.QuadVertices(sx0, sy0, sx1, sy1, a, b, c, d, tx, ty, 1, 1, 1, 1, filter == driver.FilterScreen)
is := graphics.QuadIndices()
srcs := [graphics.ShaderImageNum]*buffered.Image{img.buffered}
if options.Shader == nil {
i.buffered.DrawTriangles(srcs, vs, is, options.ColorM.impl, mode, filter, driver.AddressUnsafe, driver.Region{}, nil, nil)
return nil
}
i.buffered.DrawTriangles(srcs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, options.Shader.shader, options.Uniforms)
return nil
}
// Vertex represents a vertex passed to DrawTriangles.
type Vertex struct {
// DstX and DstY represents a point on a destination image.
DstX float32
DstY float32
// SrcX and SrcY represents a point on a source image.
// Be careful that SrcX/SrcY coordinates are on the image's bounds.
// This means that a left-upper point of a sub-image might not be (0, 0).
SrcX float32
SrcY float32
// ColorR/ColorG/ColorB/ColorA represents color scaling values.
// 1 means the original source image color is used.
// 0 means a transparent color is used.
ColorR float32
ColorG float32
ColorB float32
ColorA float32
}
// Address represents a sampler address mode.
type Address int
const (
// AddressClampToZero means that out-of-range texture coordinates return 0 (transparent).
AddressClampToZero Address = Address(driver.AddressClampToZero)
// AddressRepeat means that texture coordinates wrap to the other side of the texture.
AddressRepeat Address = Address(driver.AddressRepeat)
// AddressUnsafe means there is no guarantee when the texture coodinates are out of range.
AddressUnsafe Address = Address(driver.AddressUnsafe)
)
// DrawTrianglesOptions represents options for DrawTriangles.
type DrawTrianglesOptions struct {
// ColorM is a color matrix to draw.
// The default (zero) value is identity, which doesn't change any color.
// ColorM is applied before vertex color scale is applied.
//
// If Shader is not nil, ColorM is ignored.
ColorM ColorM
// CompositeMode is a composite mode to draw.
// The default (zero) value is regular alpha blending.
CompositeMode CompositeMode
// Filter is a type of texture filter.
// The default (zero) value is FilterDefault.
//
// If Shader is not nil, Filter is ignored.
Filter Filter
// Address is a sampler address mode.
// The default (zero) value is AddressClampToZero.
//
// If Shader is not nil, Address is ignored.
Address Address
// Shader is a shader.
Shader *Shader
// Uniforms is a set of uniform variables for the shader.
//
// Uniforms is used only when Shader is not nil.
Uniforms []interface{}
}
// MaxIndicesNum is the maximum number of indices for DrawTriangles.
const MaxIndicesNum = graphics.IndicesNum
// DrawTriangles draws triangles with the specified vertices and their indices.
//
// If len(indices) is not multiple of 3, DrawTriangles panics.
//
// If len(indices) is more than MaxIndicesNum, DrawTriangles panics.
//
// The rule in which DrawTriangles works effectively is same as DrawImage's.
//
// When the given image is disposed, DrawTriangles panics.
//
// When the image i is disposed, DrawTriangles does nothing.
//
// img can be nil only when options.Shader is not nil.
func (i *Image) DrawTriangles(vertices []Vertex, indices []uint16, img *Image, options *DrawTrianglesOptions) {
i.copyCheck()
if img != nil && img.isDisposed() {
panic("ebiten: the given image to DrawTriangles must not be disposed")
}
if i.isDisposed() {
return
}
if i.isSubImage() {
panic("ebiten: render to a sub-image is not implemented (DrawTriangles)")
}
if len(indices)%3 != 0 {
panic("ebiten: len(indices) % 3 must be 0")
}
if len(indices) > MaxIndicesNum {
panic("ebiten: len(indices) must be <= MaxIndicesNum")
}
// TODO: Check the maximum value of indices and len(vertices)?
if options == nil {
options = &DrawTrianglesOptions{}
}
if options.Shader != nil && img != nil && img.isSubImage() {
panic("ebiten: rendering a sub-image with a shader is not implemented (DrawTriangles)")
}
mode := driver.CompositeMode(options.CompositeMode)
filter := driver.FilterNearest
if options.Shader == nil {
if options.Filter != FilterDefault {
filter = driver.Filter(options.Filter)
} else if img.filter != FilterDefault {
filter = driver.Filter(img.filter)
}
}
vs := make([]float32, len(vertices)*graphics.VertexFloatNum)
for i, v := range vertices {
vs[i*graphics.VertexFloatNum] = v.DstX
vs[i*graphics.VertexFloatNum+1] = v.DstY
vs[i*graphics.VertexFloatNum+2] = v.SrcX
vs[i*graphics.VertexFloatNum+3] = v.SrcY
vs[i*graphics.VertexFloatNum+4] = v.ColorR
vs[i*graphics.VertexFloatNum+5] = v.ColorG
vs[i*graphics.VertexFloatNum+6] = v.ColorB
vs[i*graphics.VertexFloatNum+7] = v.ColorA
}
is := make([]uint16, len(indices))
copy(is, indices)
var sr driver.Region
if options.Shader == nil && options.Address != AddressUnsafe {
b := img.Bounds()
sr = driver.Region{
X: float32(b.Min.X),
Y: float32(b.Min.Y),
Width: float32(b.Dx()),
Height: float32(b.Dy()),
}
}
var srcs [graphics.ShaderImageNum]*buffered.Image
if img != nil {
srcs[0] = img.buffered
}
if options.Shader == nil {
i.buffered.DrawTriangles(srcs, vs, is, options.ColorM.impl, mode, filter, driver.Address(options.Address), sr, nil, nil)
return
}
i.buffered.DrawTriangles(srcs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, options.Shader.shader, options.Uniforms)
}
// DrawRectShaderOptions represents options for DrawRectShader
//
// This API is experimental.
type DrawRectShaderOptions struct {
// GeoM is a geometry matrix to draw.
// The default (zero) value is identify, which draws the rectangle at (0, 0).
GeoM GeoM
// CompositeMode is a composite mode to draw.
// The default (zero) value is regular alpha blending.
CompositeMode CompositeMode
// Uniforms is a set of uniform variables for the shader.
Uniforms []interface{}
// Images is a set of the source images.
// All the image must be the same size with the rectangle.
Images [4]*Image
}
func init() {
var op DrawRectShaderOptions
if got, want := len(op.Images), graphics.ShaderImageNum; got != want {
panic(fmt.Sprintf("ebiten: len((DrawRectShaderOptions{}).Images) must be %d but %d", want, got))
}
}
// DrawRectShader draws a rectangle with the specified width and height with the specified shader.
//
// When one of the specified image is non-nil and is disposed, DrawRectShader panics.
//
// When the image i is disposed, DrawRectShader does nothing.
//
// This API is experimental.
func (i *Image) DrawRectShader(width, height int, shader *Shader, options *DrawRectShaderOptions) {
i.copyCheck()
if i.isDisposed() {
return
}
// TODO: Implement this.
if i.isSubImage() {
panic("ebiten: rendering to a sub-image is not implemented (DrawRectShader)")
}
if options == nil {
options = &DrawRectShaderOptions{}
}
mode := driver.CompositeMode(options.CompositeMode)
var imgs [graphics.ShaderImageNum]*buffered.Image
for i, img := range options.Images {
if img == nil {
continue
}
if img.isDisposed() {
panic("ebiten: the given image to DrawRectShader must not be disposed")
}
if img.isSubImage() {
// TODO: Implement this.
panic("ebiten: rendering a sub-image is not implemented (DrawRectShader)")
}
if w, h := img.Size(); width != w || height != h {
panic("ebiten: all the source images must be the same size with the rectangle")
}
imgs[i] = img.buffered
}
a, b, c, d, tx, ty := options.GeoM.elements32()
vs := graphics.QuadVertices(0, 0, float32(width), float32(height), a, b, c, d, tx, ty, 1, 1, 1, 1, false)
is := graphics.QuadIndices()
i.buffered.DrawTriangles(imgs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, shader.shader, options.Uniforms)
}
// DrawTrianglesShaderOptions represents options for DrawTrianglesShader
//
// This API is experimental.
type DrawTrianglesShaderOptions struct {
// CompositeMode is a composite mode to draw.
// The default (zero) value is regular alpha blending.
CompositeMode CompositeMode
// Uniforms is a set of uniform variables for the shader.
Uniforms []interface{}
// Images is a set of the source images.
// All the image must be the same size.
Images [4]*Image
}
func init() {
var op DrawTrianglesShaderOptions
if got, want := len(op.Images), graphics.ShaderImageNum; got != want {
panic(fmt.Sprintf("ebiten: len((DrawTrianglesShaderOptions{}).Images) must be %d but %d", want, got))
}
}
// DrawTrianglesShader draws triangles with the specified vertices and their indices with the specified shader.
//
// If len(indices) is not multiple of 3, DrawTrianglesShader panics.
//
// If len(indices) is more than MaxIndicesNum, DrawTrianglesShader panics.
//
// When a specified image is non-nil and is disposed, DrawTrianglesShader panics.
//
// When the image i is disposed, DrawTrianglesShader does nothing.
//
// This API is experimental.
func (i *Image) DrawTrianglesShader(vertices []Vertex, indices []uint16, shader *Shader, options *DrawTrianglesShaderOptions) {
i.copyCheck()
if i.isDisposed() {
return
}
if i.isSubImage() {
panic("ebiten: render to a sub-image is not implemented (DrawTrianglesShader)")
}
if len(indices)%3 != 0 {
panic("ebiten: len(indices) % 3 must be 0")
}
if len(indices) > MaxIndicesNum {
panic("ebiten: len(indices) must be <= MaxIndicesNum")
}
if options == nil {
options = &DrawTrianglesShaderOptions{}
}
mode := driver.CompositeMode(options.CompositeMode)
var imgw, imgh int
var imgs [graphics.ShaderImageNum]*buffered.Image
for i, img := range options.Images {
if img == nil {
continue
}
if img.isDisposed() {
panic("ebiten: the given image to DrawTrianglesShader must not be disposed")
}
if img.isSubImage() {
// TODO: Implement this.
panic("ebiten: rendering a sub-image is not implemented (DrawTrianglesShader)")
}
if imgw == 0 || imgh == 0 {
imgw, imgh = img.Size()
} else if w, h := img.Size(); imgw != w || imgh != h {
panic("ebiten: all the source images must be the same size")
}
imgs[i] = img.buffered
}
vs := make([]float32, len(vertices)*graphics.VertexFloatNum)
for i, v := range vertices {
vs[i*graphics.VertexFloatNum] = v.DstX
vs[i*graphics.VertexFloatNum+1] = v.DstY
vs[i*graphics.VertexFloatNum+2] = v.SrcX
vs[i*graphics.VertexFloatNum+3] = v.SrcY
vs[i*graphics.VertexFloatNum+4] = v.ColorR
vs[i*graphics.VertexFloatNum+5] = v.ColorG
vs[i*graphics.VertexFloatNum+6] = v.ColorB
vs[i*graphics.VertexFloatNum+7] = v.ColorA
}
is := make([]uint16, len(indices))
copy(is, indices)
i.buffered.DrawTriangles(imgs, vs, is, nil, mode, driver.FilterNearest, driver.AddressUnsafe, driver.Region{}, shader.shader, options.Uniforms)
}
// SubImage returns an image representing the portion of the image p visible through r.
// The returned value shares pixels with the original image.
//
// The returned value is always *ebiten.Image.
//
// If the image is disposed, SubImage returns nil.
//
// In the current Ebiten implementation, SubImage is available only as a rendering source.
func (i *Image) SubImage(r image.Rectangle) image.Image {
i.copyCheck()
if i.isDisposed() {
return nil
}
r = r.Intersect(i.Bounds())
// Need to check Empty explicitly. See the standard image package implementations.
if r.Empty() {
r = image.ZR
}
// Keep the original image's reference not to dispose that by GC.
var orig = i
if i.isSubImage() {
orig = i.original
}
img := &Image{
buffered: i.buffered,
filter: i.filter,
bounds: r,
original: orig,
}
img.addr = img
return img
}
// Bounds returns the bounds of the image.
func (i *Image) Bounds() image.Rectangle {
if i.isDisposed() {
panic("ebiten: the image is already disposed")
}
return i.bounds
}
// ColorModel returns the color model of the image.
func (i *Image) ColorModel() color.Model {
return color.RGBAModel
}
// At returns the color of the image at (x, y).
//
// At loads pixels from GPU to system memory if necessary, which means that At can be slow.
//
// At always returns a transparent color if the image is disposed.
//
// Note that an important logic should not rely on values returned by At, since
// the returned values can include very slight differences between some machines.
//
// At can't be called outside the main loop (ebiten.Run's updating function) starts (as of version 1.4.0).
func (i *Image) At(x, y int) color.Color {
if i.isDisposed() {
return color.RGBA{}
}
if !image.Pt(x, y).In(i.Bounds()) {
return color.RGBA{}
}
pix, err := i.buffered.Pixels(x, y, 1, 1)
if err != nil {
theUIContext.setError(err)
return color.RGBA{}
}
return color.RGBA{pix[0], pix[1], pix[2], pix[3]}
}
// Set sets the color at (x, y).
//
// Set loads pixels from GPU to system memory if necessary, which means that Set can be slow.
//
// In the current implementation, successive calls of Set invokes loading pixels at most once, so this is efficient.
//
// If the image is disposed, Set does nothing.
func (i *Image) Set(x, y int, clr color.Color) {
i.copyCheck()
if i.isDisposed() {
return
}
if !image.Pt(x, y).In(i.Bounds()) {
return
}
if i.isSubImage() {
i = i.original
}
r, g, b, a := clr.RGBA()
pix := []byte{byte(r >> 8), byte(g >> 8), byte(b >> 8), byte(a >> 8)}
if err := i.buffered.ReplacePixels(pix, x, y, 1, 1); err != nil {
theUIContext.setError(err)
}
}
// Dispose disposes the image data.
// After disposing, most of image functions do nothing and returns meaningless values.
//
// Calling Dispose is not mandatory. GC automatically collects internal resources that no objects refer to.
// However, calling Dispose explicitly is helpful if memory usage matters.
//
// When the image is disposed, Dipose does nothing.
//
// Dipose always return nil as of 1.5.0.
func (i *Image) Dispose() error {
i.copyCheck()
if i.isDisposed() {
return nil
}
if i.isSubImage() {
return nil
}
i.buffered.MarkDisposed()
i.buffered = nil
return nil
}
// ReplacePixels replaces the pixels of the image with p.
//
// The given p must represent RGBA pre-multiplied alpha values.
// len(pix) must equal to 4 * (bounds width) * (bounds height).
//
// ReplacePixels works on a sub-image.
//
// When len(pix) is not appropriate, ReplacePixels panics.
//
// When the image is disposed, ReplacePixels does nothing.
//
// ReplacePixels always returns nil as of 1.5.0.
func (i *Image) ReplacePixels(pixels []byte) error {
i.copyCheck()
if i.isDisposed() {
return nil
}
r := i.Bounds()
// Do not need to copy pixels here.
// * In internal/buffered, pixels are copied when necessary.
// * In internal/shareable, pixels are copied to make its paddings.
if err := i.buffered.ReplacePixels(pixels, r.Min.X, r.Min.Y, r.Dx(), r.Dy()); err != nil {
theUIContext.setError(err)
}
return nil
}
// NewImage returns an empty image.
//
// If width or height is less than 1 or more than device-dependent maximum size, NewImage panics.
//
// filter argument is just for backward compatibility.
// If you are not sure, specify FilterDefault.
//
// Error returned by NewImage is always nil as of 1.5.0.
func NewImage(width, height int, filter Filter) (*Image, error) {
return newImage(width, height, filter, false), nil
}
func newImage(width, height int, filter Filter, volatile bool) *Image {
i := &Image{
buffered: buffered.NewImage(width, height, volatile),
filter: filter,
bounds: image.Rect(0, 0, width, height),
}
i.addr = i
return i
}
// NewImageFromImage creates a new image with the given image (source).
//
// If source's width or height is less than 1 or more than device-dependent maximum size, NewImageFromImage panics.
//
// filter argument is just for backward compatibility.
// If you are not sure, specify FilterDefault.
//
// Error returned by NewImageFromImage is always nil as of 1.5.0.
func NewImageFromImage(source image.Image, filter Filter) (*Image, error) {
size := source.Bounds().Size()
width, height := size.X, size.Y
i := &Image{
buffered: buffered.NewImage(width, height, false),
filter: filter,
bounds: image.Rect(0, 0, width, height),
}
i.addr = i
i.ReplacePixels(imageToBytes(source))
return i, nil
}
func newScreenFramebufferImage(width, height int) *Image {
i := &Image{
buffered: buffered.NewScreenFramebufferImage(width, height),
filter: FilterDefault,
bounds: image.Rect(0, 0, width, height),
}
i.addr = i
return i
}
// MaxImageSize represented the maximum size of an image, but now this constant is deprecated.
//
// Deprecated: (as of 1.7.0) No replacement so far.
//
// TODO: Make this replacement (#541)
var MaxImageSize = 4096