ebiten/image.go
2015-01-05 10:08:54 +09:00

241 lines
6.1 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 (
"github.com/hajimehoshi/ebiten/internal"
"github.com/hajimehoshi/ebiten/internal/graphics"
"github.com/hajimehoshi/ebiten/internal/opengl"
"github.com/hajimehoshi/ebiten/internal/ui"
"image"
"image/color"
)
type innerImage struct {
framebuffer *graphics.Framebuffer
texture *graphics.Texture
}
func newInnerImage(c *opengl.Context, texture *graphics.Texture) (*innerImage, error) {
framebuffer, err := graphics.NewFramebufferFromTexture(c, texture)
if err != nil {
return nil, err
}
return &innerImage{framebuffer, texture}, nil
}
func (i *innerImage) size() (width, height int) {
return i.framebuffer.Size()
}
func (i *innerImage) Clear(c *opengl.Context) error {
return i.Fill(c, color.Transparent)
}
func (i *innerImage) Fill(c *opengl.Context, clr color.Color) error {
r, g, b, a := internal.RGBA(clr)
return i.framebuffer.Fill(c, r, g, b, a)
}
// TODO: Remove this in the future.
type imageParts []ImagePart
func (p imageParts) Len() int {
return len(p)
}
func (p imageParts) Dst(i int) (x0, y0, x1, y1 int) {
dst := &p[i].Dst
return dst.Min.X, dst.Min.Y, dst.Max.X, dst.Max.Y
}
func (p imageParts) Src(i int) (x0, y0, x1, y1 int) {
src := &p[i].Src
return src.Min.X, src.Min.Y, src.Max.X, src.Max.Y
}
type wholeImage struct {
width int
height int
}
func (w *wholeImage) Len() int {
return 1
}
func (w *wholeImage) Dst(i int) (x0, y0, x1, y1 int) {
return 0, 0, w.width, w.height
}
func (w *wholeImage) Src(i int) (x0, y0, x1, y1 int) {
return 0, 0, w.width, w.height
}
func (i *innerImage) drawImage(c *opengl.Context, img *innerImage, options *DrawImageOptions) error {
if options == nil {
options = &DrawImageOptions{}
}
parts := options.ImageParts
if parts == nil {
dparts := options.Parts
if dparts != nil {
parts = imageParts(dparts)
} else {
w, h := img.size()
parts = &wholeImage{w, h}
}
}
w, h := img.size()
quads := &textureQuads{parts: parts, width: w, height: h}
return i.framebuffer.DrawTexture(c, img.texture, quads, &options.GeoM, &options.ColorM)
}
func u(x float32, width int) float32 {
return x / float32(internal.NextPowerOf2Int(width))
}
func v(y float32, height int) float32 {
return y / float32(internal.NextPowerOf2Int(height))
}
type textureQuads struct {
parts ImageParts
width int
height int
}
func (t *textureQuads) Len() int {
return t.parts.Len()
}
func (t *textureQuads) Vertex(i int) (x0, y0, x1, y1 float32) {
ix0, iy0, ix1, iy1 := t.parts.Dst(i)
return float32(ix0), float32(iy0), float32(ix1), float32(iy1)
}
func (t *textureQuads) Texture(i int) (u0, v0, u1, v1 float32) {
x0, y0, x1, y1 := t.parts.Src(i)
w, h := t.width, t.height
return u(float32(x0), w), v(float32(y0), h), u(float32(x1), w), v(float32(y1), h)
}
// Image represents an image.
// The pixel format is alpha-premultiplied.
// Image implements image.Image.
type Image struct {
inner *innerImage
pixels []uint8
}
// Size returns the size of the image.
func (i *Image) Size() (width, height int) {
return i.inner.size()
}
// Clear resets the pixels of the image into 0.
func (i *Image) Clear() (err error) {
i.pixels = nil
ui.Use(func(c *opengl.Context) {
err = i.inner.Clear(c)
})
return
}
// Fill fills the image with a solid color.
func (i *Image) Fill(clr color.Color) (err error) {
i.pixels = nil
ui.Use(func(c *opengl.Context) {
err = i.inner.Fill(c, clr)
})
return
}
// 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)
func (i *Image) DrawImage(image *Image, options *DrawImageOptions) (err error) {
return i.drawImage(image.inner, options)
}
func (i *Image) drawImage(image *innerImage, option *DrawImageOptions) (err error) {
i.pixels = nil
ui.Use(func(c *opengl.Context) {
err = i.inner.drawImage(c, image, option)
})
return
}
// Bounds returns the bounds of the image.
func (i *Image) Bounds() image.Rectangle {
w, h := i.inner.size()
return image.Rect(0, 0, w, h)
}
// 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).
//
// This method loads pixels from GPU to VRAM if necessary.
func (i *Image) At(x, y int) color.Color {
if i.pixels == nil {
ui.Use(func(c *opengl.Context) {
var err error
i.pixels, err = i.inner.texture.Pixels(c)
if err != nil {
panic(err)
}
})
}
w, _ := i.inner.size()
w = internal.NextPowerOf2Int(w)
idx := 4*x + 4*y*w
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}
}
// Deprecated (as of 1.1.0-alpha): Use ImageParts instead.
type ImagePart struct {
Dst image.Rectangle
Src image.Rectangle
}
// An ImageParts represents the parts of the destination image and the parts of the source image.
type ImageParts interface {
Len() int
Dst(i int) (x0, y0, x1, y1 int)
Src(i int) (x0, y0, x1, y1 int)
}
// A DrawImageOptions represents options to render an image on an image.
type DrawImageOptions struct {
ImageParts ImageParts
GeoM GeoM
ColorM ColorM
// Deprecated (as of 1.1.0-alpha): Use ImageParts instead.
Parts []ImagePart
}