       gl.framebufferTexture2D(gl.DRAW_FRAMEBUFFER, gl.COLOR_ATTACHMENT1, gl.TEXTURE_2D, tex_linear0, 0);
        gl.bindTexture(gl.TEXTURE_2D, tex_linear1);
        gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA8, size, size, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
        gl.framebufferTexture2D(gl.DRAW_FRAMEBUFFER, gl.COLOR_ATTACHMENT3, gl.TEXTURE_2D, tex_linear1, 0);
        drawbuffers[1] = gl.COLOR_ATTACHMENT1;
        drawbuffers[3] = gl.COLOR_ATTACHMENT3;
    }

    gl.drawBuffers(drawbuffers);
    wtu.glErro