package opengl import ( "github.com/go-gl/gl" "github.com/hajimehoshi/ebiten/graphics" "github.com/hajimehoshi/ebiten/graphics/opengl/internal/shader" "image" "image/draw" ) func adjustImageForTexture(img image.Image) *image.NRGBA { width, height := img.Bounds().Size().X, img.Bounds().Size().Y adjustedImageBounds := image.Rectangle{ image.ZP, image.Point{ shader.AdjustSizeForTexture(width), shader.AdjustSizeForTexture(height), }, } if nrgba, ok := img.(*image.NRGBA); ok && img.Bounds() == adjustedImageBounds { return nrgba } adjustedImage := image.NewNRGBA(adjustedImageBounds) dstBounds := image.Rectangle{ image.ZP, img.Bounds().Size(), } draw.Draw(adjustedImage, dstBounds, img, image.ZP, draw.Src) return adjustedImage } type Texture struct { native gl.Texture width int height int } func createNativeTexture(textureWidth, textureHeight int, pixels []uint8, filter graphics.Filter) gl.Texture { nativeTexture := gl.GenTexture() if nativeTexture < 0 { panic("glGenTexture failed") } gl.PixelStorei(gl.UNPACK_ALIGNMENT, 4) nativeTexture.Bind(gl.TEXTURE_2D) defer gl.Texture(0).Bind(gl.TEXTURE_2D) glFilter := 0 switch filter { case graphics.FilterLinear: glFilter = gl.LINEAR case graphics.FilterNearest: glFilter = gl.NEAREST default: panic("not reached") } gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, glFilter) gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, glFilter) ptr := interface{}(nil) if pixels != nil { ptr = pixels } gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, textureWidth, textureHeight, 0, gl.RGBA, gl.UNSIGNED_BYTE, ptr) return nativeTexture } func createTexture(width, height int, filter graphics.Filter) (*Texture, error) { w := shader.AdjustSizeForTexture(width) h := shader.AdjustSizeForTexture(height) native := createNativeTexture(w, h, nil, filter) return &Texture{native, width, height}, nil } func createTextureFromImage(img image.Image, filter graphics.Filter) (*Texture, error) { adjustedImage := adjustImageForTexture(img) size := adjustedImage.Bounds().Size() native := createNativeTexture(size.X, size.Y, adjustedImage.Pix, filter) return &Texture{native, size.X, size.Y}, nil } func (t *Texture) dispose() { t.native.Delete() }