ebiten/graphics/opengl/texture/texture.go
2013-10-27 23:06:14 +09:00

85 lines
2.1 KiB
Go

package texture
// #cgo LDFLAGS: -framework OpenGL
//
// #include <OpenGL/gl.h>
import "C"
import (
gtexture "github.com/hajimehoshi/go-ebiten/graphics/texture"
"image"
"unsafe"
)
type Native C.GLuint
type Filter int
const (
FilterLinear = iota
FilterNearest
)
func createNativeTexture(textureWidth, textureHeight int, pixels []uint8,
filter Filter) Native {
nativeTexture := C.GLuint(0)
C.glGenTextures(1, (*C.GLuint)(&nativeTexture))
if nativeTexture < 0 {
panic("glGenTexture failed")
}
C.glPixelStorei(C.GL_UNPACK_ALIGNMENT, 4)
C.glBindTexture(C.GL_TEXTURE_2D, C.GLuint(nativeTexture))
defer C.glBindTexture(C.GL_TEXTURE_2D, 0)
glFilter := C.GLint(0)
switch filter {
case FilterLinear:
glFilter = C.GL_LINEAR
case FilterNearest:
glFilter = C.GL_NEAREST
default:
panic("not reached")
}
C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MAG_FILTER, glFilter)
C.glTexParameteri(C.GL_TEXTURE_2D, C.GL_TEXTURE_MIN_FILTER, glFilter)
ptr := unsafe.Pointer(nil)
if pixels != nil {
ptr = unsafe.Pointer(&pixels[0])
}
C.glTexImage2D(C.GL_TEXTURE_2D, 0, C.GL_RGBA,
C.GLsizei(textureWidth), C.GLsizei(textureHeight),
0, C.GL_RGBA, C.GL_UNSIGNED_BYTE, ptr)
return Native(nativeTexture)
}
func create(textureWidth, textureHeight int, filter Filter) (
interface{}, error) {
return createNativeTexture(textureWidth, textureHeight,
nil, filter), nil
}
func createFromImage(img *image.NRGBA) (interface{}, error) {
size := img.Bounds().Size()
return createNativeTexture(size.X, size.Y, img.Pix, FilterLinear), nil
}
func New(width, height int, filter Filter) (*gtexture.Texture, error) {
f := func(textureWidth, textureHeight int) (interface{}, error) {
return create(textureWidth, textureHeight, filter)
}
return gtexture.New(width, height, f)
}
func NewEmpty(width, height int) (*gtexture.Texture, error) {
f := func(textureWidth, textureHeight int) (interface{}, error) {
return nil, nil
}
return gtexture.New(width, height, f)
}
func NewFromImage(img image.Image) (*gtexture.Texture, error) {
return gtexture.NewFromImage(img, createFromImage)
}