//////////////////////////////////////////////////////////////////////////////////////
//
//  Copyright (c) 2014-present, Egret Technology.
//  All rights reserved.
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above copyright
//       notice, this list of conditions and the following disclaimer in the
//       documentation and/or other materials provided with the distribution.
//     * Neither the name of the Egret nor the
//       names of its contributors may be used to endorse or promote products
//       derived from this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY EGRET AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
//  OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
//  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
//  IN NO EVENT SHALL EGRET AND CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
//  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;LOSS OF USE, DATA,
//  OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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//  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//////////////////////////////////////////////////////////////////////////////////////

namespace egret.web {

    /**
     * @private  
     */
    export enum WEBGL_ATTRIBUTE_TYPE {
        FLOAT_VEC2 = 0x8B50,
        FLOAT_VEC3 = 0x8B51,
        FLOAT_VEC4 = 0x8B52,
        FLOAT = 0x1406,
        BYTE = 0xffff,
        UNSIGNED_BYTE = 0x1401,
        UNSIGNED_SHORT = 0x1403
    }

    /**
     * @private 
     */
    export class EgretWebGLAttribute {

        private gl:WebGLRenderingContext;

        private name:string;

        private type:WEBGL_ATTRIBUTE_TYPE;

        private size:number;

        public location:number;

        constructor(gl:WebGLRenderingContext, program:WebGLProgram, attributeData:any) {
            this.gl = gl;

            this.name = attributeData.name;

            this.type = attributeData.type;

            this.size = attributeData.size;

            this.location = gl.getAttribLocation(program, this.name);

            this.count = 0;
            this.initCount(gl);
            this.format = gl.FLOAT;
            this.initFormat(gl);
        }

        public count:number;
        private initCount(gl:WebGLRenderingContext):void {
            let type = this.type;

            switch (type) {
                case WEBGL_ATTRIBUTE_TYPE.FLOAT:
                case WEBGL_ATTRIBUTE_TYPE.BYTE:
                case WEBGL_ATTRIBUTE_TYPE.UNSIGNED_BYTE:
                case WEBGL_ATTRIBUTE_TYPE.UNSIGNED_SHORT:
                    this.count = 1;
                    break;
                case WEBGL_ATTRIBUTE_TYPE.FLOAT_VEC2:
                    this.count = 2;
                    break;
                case WEBGL_ATTRIBUTE_TYPE.FLOAT_VEC3:
                    this.count = 3;
                    break;
                case WEBGL_ATTRIBUTE_TYPE.FLOAT_VEC4:
                    this.count = 4;
                    break;
            }
        }

        public format:number;
        private initFormat(gl:WebGLRenderingContext):void {
            let type = this.type;

            switch (type) {
                case WEBGL_ATTRIBUTE_TYPE.FLOAT:
                case WEBGL_ATTRIBUTE_TYPE.FLOAT_VEC2:
                case WEBGL_ATTRIBUTE_TYPE.FLOAT_VEC3:
                case WEBGL_ATTRIBUTE_TYPE.FLOAT_VEC4:
                    this.format = gl.FLOAT;
                    break;
                case WEBGL_ATTRIBUTE_TYPE.UNSIGNED_BYTE:
                    this.format = gl.UNSIGNED_BYTE;
                    break;
                case WEBGL_ATTRIBUTE_TYPE.UNSIGNED_SHORT:
                    this.format = gl.UNSIGNED_SHORT;
                    break;
                case WEBGL_ATTRIBUTE_TYPE.BYTE:
                    this.format = gl.BYTE;
                    break;
            }
        }
    }
}