               checkPixel(signX * 0.750, signY * 0.375, blue);
                checkPixel(signX * 0.375, signY * 0.750, blue);
                checkPixel(signX * 0.750, signY * 0.750, blue);
            }
        }
    }

    const tex = gl.createTexture();
    gl.bindTexture(gl.TEXTURE_2D, tex);
    gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, 2, 2, 0, gl.RGBA, gl.UNSIGNED_BYTE, data);
    gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, ext.MIRROR_CLAMP_TO_EDGE_EXT);
    gl.texParameteri(gl.TEXTURE_2D, gl.T