func findBufferEdges(c *cl.Context, dev *cl.Device, queue *cl.CommandQueue, src image.Image) (image.Image, *cl.Event) {
width := src.Bounds().Dx()
height := src.Bounds().Dy()
srcBuf, err := createBufferFromImage(c, src)
checkFatalError(err)
size := width * height * 4 * 4
dstBuf, err := c.CreateEmptyBuffer(cl.MemWriteOnly, size)
checkFatalError(err)
program := buildProgram(c, dev, "edgedetect.cl")
kernel, err := program.CreateKernel("bufferEdgeDetect")
checkFatalError(err)
err = kernel.SetArg(0, srcBuf)
checkFatalError(err)
err = kernel.SetArg(1, dstBuf)
checkFatalError(err)
err = kernel.SetArg(2, int32(width))
checkFatalError(err)
const edgeSize = 1
kev, err := queue.EnqueueNDRangeKernel(kernel, []int{edgeSize, edgeSize}, []int{width - 2*edgeSize, height - 2*edgeSize}, nil, nil)
checkFatalError(err)
dst := image.NewRGBA(src.Bounds())
_, err = queue.EnqueueReadBufferUint8(dstBuf, true, 0, dst.Pix, nil)
checkFatalError(err)
return dst, kev
}
