er( gl.FRAMEBUFFER, null );
            //-------------------------------------------------------------------------------

            return this.rgba;
        }

        getKeypoints( rgba, width, height, border = 8 )
        {
            const minX = border;
            const maxX = width - border;
            const minY = border;
            const maxY = height - border;

            const maxKeypoints = Math.ceil( rgba.length / 4 );
            const keypoints = new Array( maxKeypoints );
            