var gl;

async function main() {
    const canvas = document.getElementById("canvas")
    gl = canvas.getContext('webgl')

    if(!gl) {
        console.log("Your browser does not support webgl")
        return
    }

    var ext = gl.getExtension('OES_vertex_array_object');
    if(!ext) {
        console.log("Your browser does not support webgl 2")
        return
    }

    
    
    gl['createVertexArray'] = function() { return ext['createVertexArrayOES'](); };
    gl['deleteVertexArray'] = function(vao) { ext['deleteVertexArrayOES'](vao); };
    gl['bindVertexArray'] = function(vao) { ext['bindVertexArrayOES'](vao); };
    gl['isVertexArray'] = function(vao) { return ext['isVertexArrayOES'](vao); };

    var shader = await Shader.load("shader/simple.vert","shader/simple.frag")

    var triangle = new Mesh(3)
        .store([0.0, 0.5, -0.5, -0.5, 0.5, -0.5], 2)
        .store([1.0, 1.0, 0.0, 0.7, 0.0, 1.0, 0.1, 1.0, 0.6], 3)
        .finish()

    gl.useProgram(shader)
    triangle.bind()
    gl.drawArrays(gl.TRIANGLES, 0, triangle.vertexCount)

}

main()