Function draw$2

libs/mapv/mapv.js:1484–1539

(gl, data, options)

var fs_s = ['precision mediump float;', 'uniform vec4 u_FragColor;', 'void main() {', 'gl_FragColor = u_FragColor;', '}'].join('');

function draw$2(gl, data, options) {

    if (!data) {
        return;
    }

    var program = initShaders(gl, vs_s, fs_s);

    gl.enable(gl.BLEND);
    gl.blendFunc(gl.SRC_ALPHA, gl.ONE);

    //gl.clearColor(0.0, 0.0, 1.0, 1.0);
    gl.clear(gl.COLOR_BUFFER_BIT);

    var halfCanvasWidth = gl.canvas.width / 2;
    var halfCanvasHeight = gl.canvas.height / 2;

    // Create a buffer object
    var vertexBuffer = gl.createBuffer();
    // Bind the buffer object to target
    gl.bindBuffer(gl.ARRAY_BUFFER, vertexBuffer);

    var a_Position = gl.getAttribLocation(program, 'a_Position');
    // Assign the buffer object to a_Position variable
    gl.vertexAttribPointer(a_Position, 2, gl.FLOAT, false, 0, 0);

    // Enable the assignment to a_Position variable
    gl.enableVertexAttribArray(a_Position);

    var uFragColor = gl.getUniformLocation(program, 'u_FragColor');

    var colored = getColorData(options.strokeStyle || 'red');

    gl.uniform4f(uFragColor, colored[0] / 255, colored[1] / 255, colored[2] / 255, colored[3] / 255);

    gl.lineWidth(options.lineWidth || 1);

    for (var i = 0, len = data.length; i < len; i++) {
        var _geometry = data[i].geometry._coordinates;

        var verticesData = [];

        for (var j = 0; j < _geometry.length; j++) {
            var item = _geometry[j];

            var x = (item[0] - halfCanvasWidth) / halfCanvasWidth;
            var y = (halfCanvasHeight - item[1]) / halfCanvasHeight;
            verticesData.push(x, y);
        }

        var vertices = new Float32Array(verticesData);
        // Write date into the buffer object
        gl.bufferData(gl.ARRAY_BUFFER, vertices, gl.STATIC_DRAW);
        gl.drawArrays(gl.LINE_STRIP, 0, _geometry.length);
    }
}

var line = {