var Mesh = require('./Mesh');

/**
 * The Plane allows you to draw a texture across several points and them manipulate these points
 *
 *```js
 * for (var i = 0; i < 20; i++) {
 *     points.push(new PIXI.Point(i * 50, 0));
 * };
 * var Plane = new PIXI.Plane(PIXI.Texture.fromImage("snake.png"), points);
 *  ```
 *
 * @class
 * @extends PIXI.mesh.Mesh
 * @memberof PIXI.mesh
 * @param {PIXI.Texture} texture - The texture to use on the Plane.
 * @param {int} segmentsX - The number ox x segments
 * @param {int} segmentsY - The number of y segments
 *
 */
function Plane(texture, segmentsX, segmentsY)
{
    Mesh.call(this, texture);

    /**
     * Tracker for if the Plane is ready to be drawn. Needed because Mesh ctor can
     * call _onTextureUpdated which could call refresh too early.
     *
     * @member {boolean}
     * @private
     */
    this._ready = true;

    this.segmentsX =  segmentsX || 10;
    this.segmentsY = segmentsY || 10;

    this.drawMode = Mesh.DRAW_MODES.TRIANGLES;
    this.refresh();

}


// constructor
Plane.prototype = Object.create( Mesh.prototype );
Plane.prototype.constructor = Plane;
module.exports = Plane;

/**
 * Refreshes
 *
 */
Plane.prototype.refresh = function()
{
    var total = this.segmentsX * this.segmentsY;
    var verts = [];
    var colors = [];
    var uvs = [];
    var indices = [];
    var texture = this.texture;

    var segmentsXSub = this.segmentsX - 1;
    var segmentsYSub = this.segmentsY - 1;
    var i = 0;

    var sizeX = texture.width / segmentsXSub;
    var sizeY = texture.height / segmentsYSub;

    for (i = 0; i < total; i++) {

        var x = (i % this.segmentsX);
        var y = ( (i / this.segmentsX ) | 0 );


        verts.push((x * sizeX),
                   (y * sizeY));

        // this works for rectangular textures. 
        uvs.push(texture._uvs.x0 + (texture._uvs.x1 - texture._uvs.x0) * (x / (this.segmentsX-1)), texture._uvs.y0 + (texture._uvs.y3-texture._uvs.y0) * (y/ (this.segmentsY-1)));
      }

    //  cons

    var totalSub = segmentsXSub * segmentsYSub;

    for (i = 0; i < totalSub; i++) {

        var xpos = i % segmentsXSub;
        var ypos = (i / segmentsXSub ) | 0;


        var  value = (ypos * this.segmentsX) + xpos;
        var  value2 = (ypos * this.segmentsX) + xpos + 1;
        var  value3 = ((ypos+1) * this.segmentsX) + xpos;
        var  value4 = ((ypos+1) * this.segmentsX) + xpos + 1;

        indices.push(value, value2, value3);
        indices.push(value2, value4, value3);
    }


    //console.log(indices)
    this.vertices = new Float32Array(verts);
    this.uvs = new Float32Array(uvs);
    this.colors = new Float32Array(colors);
    this.indices = new Uint16Array(indices);

    this.indexDirty = true;
};

/**
 * Clear texture UVs when new texture is set
 *
 * @private
 */
Plane.prototype._onTextureUpdate = function ()
{
    Mesh.prototype._onTextureUpdate.call(this);

    // wait for the Plane ctor to finish before calling refresh
    if (this._ready) {
        this.refresh();
    }
};
