ebiten/internal/graphics/texture.go
2016-02-27 02:35:05 +09:00

98 lines
2.7 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 graphics
import (
"errors"
"github.com/hajimehoshi/ebiten/internal/graphics/opengl"
"image"
"image/draw"
)
func adjustImageForTexture(img image.Image) *image.RGBA {
width, height := img.Bounds().Size().X, img.Bounds().Size().Y
adjustedImageBounds := image.Rectangle{
image.ZP,
image.Point{
int(NextPowerOf2Int32(int32(width))),
int(NextPowerOf2Int32(int32(height))),
},
}
if adjustedImage, ok := img.(*image.RGBA); ok && img.Bounds() == adjustedImageBounds {
return adjustedImage
}
adjustedImage := image.NewRGBA(adjustedImageBounds)
dstBounds := image.Rectangle{
image.ZP,
img.Bounds().Size(),
}
draw.Draw(adjustedImage, dstBounds, img, image.ZP, draw.Src)
return adjustedImage
}
type Texture struct {
native opengl.Texture
width int
height int
}
func (t *Texture) Size() (width, height int) {
return t.width, t.height
}
func NewTexture(c *opengl.Context, width, height int, filter opengl.Filter) (*Texture, error) {
w := int(NextPowerOf2Int32(int32(width)))
h := int(NextPowerOf2Int32(int32(height)))
if w < 4 {
return nil, errors.New("width must be equal or more than 4.")
}
if h < 4 {
return nil, errors.New("height must be equal or more than 4.")
}
native, err := c.NewTexture(w, h, nil, filter)
if err != nil {
return nil, err
}
return &Texture{native, width, height}, nil
}
func NewTextureFromImage(c *opengl.Context, img image.Image, filter opengl.Filter) (*Texture, error) {
origSize := img.Bounds().Size()
if origSize.X < 4 {
return nil, errors.New("width must be equal or more than 4.")
}
if origSize.Y < 4 {
return nil, errors.New("height must be equal or more than 4.")
}
adjustedImage := adjustImageForTexture(img)
size := adjustedImage.Bounds().Size()
native, err := c.NewTexture(size.X, size.Y, adjustedImage.Pix, filter)
if err != nil {
return nil, err
}
return &Texture{native, origSize.X, origSize.Y}, nil
}
func (t *Texture) Dispose(c *opengl.Context) {
c.DeleteTexture(t.native)
}
func (t *Texture) ReplacePixels(c *opengl.Context, p []uint8) error {
c.BindTexture(t.native)
c.TexSubImage2D(p, t.width, t.height)
return nil
}