//export hookRequestImage
func hookRequestImage(imageFunc unsafe.Pointer, cid *C.char, cidLen, cwidth, cheight C.int) unsafe.Pointer {
f := *(*func(imgId string, width, height int) image.Image)(imageFunc)
id := unsafeString(cid, cidLen)
width := int(cwidth)
height := int(cheight)
img := f(id, width, height)
var cimage unsafe.Pointer
rect := img.Bounds()
width = rect.Max.X - rect.Min.X
height = rect.Max.Y - rect.Min.Y
cimage = C.newImage(C.int(width), C.int(height))
var cbits []byte
cbitsh := (*reflect.SliceHeader)((unsafe.Pointer)(&cbits))
cbitsh.Data = (uintptr)((unsafe.Pointer)(C.imageBits(cimage)))
cbitsh.Len = width * height * 4 // RGBA
cbitsh.Cap = cbitsh.Len
i := 0
for y := 0; y < height; y++ {
for x := 0; x < width; x++ {
r, g, b, a := img.At(x, y).RGBA()
*(*uint32)(unsafe.Pointer(&cbits[i])) = (a>>8)<<24 | (r>>8)<<16 | (g>>8)<<8 | (b >> 8)
i += 4
}
}
return cimage
}
// Snapshot returns an image with the visible contents of the window.
// The main GUI thread is paused while the data is being acquired.
func (win *Window) Snapshot() image.Image {
// TODO Test this.
var cimage unsafe.Pointer
gui(func() {
cimage = C.windowGrabWindow(win.addr)
})
defer C.delImage(cimage)
// This should be safe to be done out of the main GUI thread.
var cwidth, cheight C.int
C.imageSize(cimage, &cwidth, &cheight)
var cbits []byte
cbitsh := (*reflect.SliceHeader)((unsafe.Pointer)(&cbits))
cbitsh.Data = (uintptr)((unsafe.Pointer)(C.imageBits(cimage)))
cbitsh.Len = int(cwidth * cheight * 8) // RRGGBBAA
cbitsh.Cap = cbitsh.Len
image := image.NewRGBA(image.Rect(0, 0, int(cwidth), int(cheight)))
l := int(cwidth * cheight * 4)
for i := 0; i < l; i += 4 {
var c uint32 = *(*uint32)(unsafe.Pointer(&cbits[i]))
image.Pix[i+0] = byte(c >> 16)
image.Pix[i+1] = byte(c >> 8)
image.Pix[i+2] = byte(c)
image.Pix[i+3] = byte(c >> 24)
}
return image
}