code: func (t *Texture) Pixels(x, y, w, h int) []uint8 {
  	pixels := make([]uint8, t.width*t.height*4)
  	gl.GetTexImage(
  		gl.TEXTURE_2D,
  		0,
  		gl.RGBA,
  		gl.UNSIGNED_BYTE,
  		gl.Ptr(pixels),
  	)
  	subPixels := make([]uint8, w*h*4)
  	for i := 0; i < h; i++ {
  		row := pixels[(i+y)*t.width*4+x*4 : (i+y)*t.width*4+(x+w)*4]
  		subRow := subPixels[i*w*4 : (i+1)*w*4]
  		copy(subRow, row)
  	}
  	return subPixels
  }
docs: // Pixels returns the content of a sub-region of the Texture as an RGBA byte sequence.