/**
 * @author       Richard Davey <rich@photonstorm.com>
 * @copyright    2020 Photon Storm Ltd.
 * @license      {@link https://opensource.org/licenses/MIT|MIT License}
 */

var Utils = require('../../renderer/webgl/Utils');

/**
 * Renders a stroke outline around the given Shape.
 *
 * @method Phaser.GameObjects.Shape#StrokePathWebGL
 * @since 3.13.0
 * @private
 *
 * @param {Phaser.Renderer.WebGL.WebGLPipeline} pipeline - The WebGL Pipeline used to render this Shape.
 * @param {Phaser.GameObjects.Shape} src - The Game Object shape being rendered in this call.
 * @param {number} alpha - The base alpha value.
 * @param {number} dx - The source displayOriginX.
 * @param {number} dy - The source displayOriginY.
 */
var StrokePathWebGL = function (pipeline, src, alpha, dx, dy)
{
    var strokeTint = pipeline.strokeTint;
    var strokeTintColor = Utils.getTintAppendFloatAlpha(src.strokeColor, src.strokeAlpha * alpha);

    strokeTint.TL = strokeTintColor;
    strokeTint.TR = strokeTintColor;
    strokeTint.BL = strokeTintColor;
    strokeTint.BR = strokeTintColor;

    var path = src.pathData;
    var pathLength = path.length - 1;
    var lineWidth = src.lineWidth;
    var halfLineWidth = lineWidth / 2;

    var px1 = path[0] - dx;
    var py1 = path[1] - dy;

    if (!src.closePath)
    {
        pathLength -= 2;
    }

    for (var i = 2; i < pathLength; i += 2)
    {
        var px2 = path[i] - dx;
        var py2 = path[i + 1] - dy;

        pipeline.batchLine(
            px1,
            py1,
            px2,
            py2,
            halfLineWidth,
            halfLineWidth,
            lineWidth,
            i - 2,
            (src.closePath) ? (i === pathLength - 1) : false
        );

        px1 = px2;
        py1 = py2;
    }
};

module.exports = StrokePathWebGL;