using System;
using System.IO;
using CommonUI.Gemo;


namespace CommonUI.Display
{
    //	------------------------------------------------------------------------------------------
    //	-by zhangyifei
    //	------------------------------------------------------------------------------------------

    public abstract class Driver
    {
        //------------------------------------------------------------------

        private static Driver s_instance = null;
        public static Driver Instance { get { return s_instance; } }
        protected Driver() { s_instance = this; }

        //------------------------------------------------------------------
        #region _Graphics_

        abstract public Image createImage(String resource);
        abstract public void ReloadImage(Image img);

        abstract public Image createImage(Stream stream);

        abstract public Image createImage(byte[] imageData, int imageOffset, int imageLength);

        abstract public Image createRGBImage(uint[] rgba, int width, int height);

        virtual public Image createRGBImage(int width, int height)
        {
            uint[] rgba = new uint[width * height];
            return this.createRGBImage(rgba, width, height);
        }

        abstract public TextLayer createTextLayer(string text, float size, FontStyle style);

        /// <summary>
        /// 测试文本是否换行
        /// </summary>
        /// <param name="text"></param>
        /// <param name="size"></param>
        /// <param name="style"></param>
        /// <param name="borderTime"></param>
        /// <param name="testWidth">测试宽度</param>
        /// <param name="realWidth">[out]实际宽度</param>
        /// <param name="realHeight">[out]实际高度</param>
        /// <returns></returns>
        abstract public bool testTextLineBreak(string text, float size, FontStyle style,
            int borderTime,
            float testWidth,
            out float realWidth,
            out float realHeight);

        /// <summary>
        /// 创建定点缓冲区
        /// </summary>
        /// <param name="capacity"></param>
        /// <returns></returns>
        abstract public VertexBuffer createVertexBuffer(int capacity);

        abstract public void Assert(bool cond, string msg);

        /// <summary>
        /// 检测是否为表情符号
        /// </summary>
        /// <param name="text"></param>
        /// <param name="i"></param>
        /// <param name="len">表情符号所占长度</param>
        /// <returns></returns>
        public virtual bool IsEmoji(string text, int i, out int len)
        {
            if (i + 1 < text.Length)
            {
                int c0 = text[i];
                int c1 = text[i + 1];
                if (c0 >= 0xD800 && c0 <= 0xDBFF)
                {
                    len = 2;
                    return true;
                }
            }
            len = 1;
            return false;
        }

        #endregion
        //------------------------------------------------------------------
    }
}