<%@ WebHandler Language="C#" Class="DisplayCut" %>

using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Web;
using System.IO;
using System.Drawing;
using System.Drawing.Imaging;


public class DisplayCut : IHttpHandler
{

    public void ProcessRequest(HttpContext context)
    {
        if (context.Request.QueryString["W"] != null & context.Request.QueryString["H"] != null)
        {
            string CurrentPath = HttpContext.Current.Server.MapPath("~/upload/");

            string FileName = context.Request.QueryString["File"].Trim().Replace("../", "");
            int GetWidth = Convert.ToInt32(context.Request.QueryString["W"].Trim());
            int GetHeight = Convert.ToInt32(context.Request.QueryString["H"].Trim());

            string[] n = Path.GetFileName(FileName).Split('.');
            string picType = n[n.Length - 1].ToLower();
            if (picType == "jpg")
                picType = "jpeg";

            if (picType == "png")
                picType = "jpeg";

            MyWeb.fileSystem fs = new MyWeb.fileSystem();
            
            string FileNameAndPath = CurrentPath + FileName;

            if (!System.IO.File.Exists(FileNameAndPath) | !fs.isPhoto(FileName))
            {
                FileNameAndPath = HttpContext.Current.Server.MapPath("~/App_Script/noimage_us.jpg");
                //顯示無圖片
                picType = "jpeg";
            }

            context.Response.ContentType = "Image/" + picType.ToUpper();
            context.Response.Clear();
            context.Response.Cache.SetExpires(DateTime.Now.AddMinutes(43200));

            //開始處理
            System.IO.FileInfo Original_FileInfo = new System.IO.FileInfo(FileNameAndPath);

            System.Drawing.Image Original_Image = System.Drawing.Image.FromFile(FileNameAndPath);
            //讀取圖片


            int New_Width = Convert.ToInt32(context.Request.QueryString["W"].Trim());
            int New_Height = Convert.ToInt32(context.Request.QueryString["H"].Trim());

            int x = 0;
            int y = 0;

            double temp_w = 1.0;
            double temp_h = 1.0;


            int old_h = Original_Image.Height;
            int old_w = Original_Image.Width;
            int new_h = New_Height;
            int new_w = New_Width;


            if (new_h < old_h)
            {
                temp_w = Convert.ToDouble((Convert.ToDouble(old_h) - Convert.ToDouble(new_h)) / Convert.ToDouble(old_h));
                //寬要縮的比例
            }

            if (new_w < old_w)
            {
                temp_h = Convert.ToDouble(Convert.ToDouble(Convert.ToDouble(old_w) - Convert.ToDouble(new_w)) / Convert.ToDouble(old_w));
                //高要縮的比                        
            }

            if (temp_w != temp_h)
            {
                if (temp_w > temp_h)
                {
                    if (temp_w < 1.0)
                    {
                        New_Width = old_w - ((old_h - new_h) * old_w) / old_h;
                        New_Height = old_h - ((old_h - new_h) * old_h) / old_h;
                    }
                    else
                    {
                        New_Width = old_w - ((old_w - new_w) * old_w) / old_w;
                        New_Height = old_h - ((old_w - new_w) * old_h) / old_w;
                    }
                }
                else
                {
                    if (temp_w < temp_h)
                    {
                        if (temp_h < 1.0)
                        {
                            New_Width = old_w - ((old_w - new_w) * old_w) / old_w;
                            New_Height = old_h - ((old_w - new_w) * old_h) / old_w;
                        }
                        else
                        {
                            New_Width = old_w - ((old_h - new_h) * old_w) / old_h;
                            New_Height = old_h - ((old_h - new_h) * old_h) / old_h;
                        }
                    }
                    else
                    {
                        New_Width = old_w;
                        New_Height = old_h;
                    }
                }
            }
            else
            {
                if (temp_h < 1.0 && temp_w < 1.0)
                {
                    New_Width = old_w - ((old_w - new_w) * old_w) / old_w;
                    New_Height = old_h - ((old_w - new_w) * old_h) / old_w;
                }
                else
                {
                    New_Width = old_w;
                    New_Height = old_h;
                }
            }


            System.Drawing.Image New_Image = new System.Drawing.Bitmap(GetWidth, GetHeight);
            System.Drawing.Graphics ObjGraphics = System.Drawing.Graphics.FromImage(New_Image);

            MyWeb.global global = new MyWeb.global();

            //相關設定
            ObjGraphics.InterpolationMode = global.InterpolationMode;
            ObjGraphics.SmoothingMode = global.SmoothingMode;
            ObjGraphics.CompositingQuality = global.CompositingQuality;	

            if (picType == "png")
            {
                ObjGraphics.Clear(System.Drawing.Color.Transparent);
                //清空Graphics, 以透明背景色填充
            }
            else
            {
                ObjGraphics.Clear(System.Drawing.Color.White);
                //清空Graphics, 以白色填充
            }

            //在指定位置按指定大小繪制原圖片的片段
            ObjGraphics.DrawImage(Original_Image, new System.Drawing.Rectangle((GetWidth - New_Width) / 2, (GetHeight - New_Height) / 2, New_Width, New_Height), new System.Drawing.Rectangle(x, y, Original_Image.Width, Original_Image.Height), System.Drawing.GraphicsUnit.Pixel);

              if (fs.WatermarkMode == "1")
            {
                FileNameAndPath = HttpContext.Current.Server.MapPath(fs.WatermarkPath);
                System.Drawing.Image Watermark_Image = System.Drawing.Image.FromFile(FileNameAndPath);
                int w_Width = Convert.ToInt32(Math.Round(Convert.ToDouble(GetWidth) * 0.8));
                int w_Height = Convert.ToInt32(Watermark_Image.Height * (Convert.ToDouble(w_Width) / Convert.ToDouble(Watermark_Image.Width)));
                int w_myX = (GetWidth - w_Width) / 2;   //浮水印水平置中
                int w_myY = (GetHeight - w_Height) / 2 + w_Height;   //浮水印水平垂直置中向下偏移一個高度
                var colorMatrix = new ColorMatrix();
                colorMatrix.Matrix33 = (float)Convert.ToSingle(fs.WatermarkPct);
                var imageAttributes = new ImageAttributes();
                imageAttributes.SetColorMatrix(colorMatrix,  ColorMatrixFlag.Default, ColorAdjustType.Bitmap);
                ObjGraphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.AntiAlias;
                ObjGraphics.DrawImage(
                            Watermark_Image,
                            new Rectangle(w_myX, w_myY, w_Width, w_Height),
                            0,
                            0,
                            Watermark_Image.Width,
                            Watermark_Image.Height,
                            GraphicsUnit.Pixel,
                            imageAttributes);
            }


            //下方設定使JPG質量
            System.Drawing.Imaging.EncoderParameters EPS = new System.Drawing.Imaging.EncoderParameters();
            System.Drawing.Imaging.EncoderParameter EP = new System.Drawing.Imaging.EncoderParameter(System.Drawing.Imaging.Encoder.Quality, Convert.ToInt64(global.ImageCompressionQuality));


            EPS.Param[0] = EP;

            System.Drawing.Imaging.ImageCodecInfo[] codecs = System.Drawing.Imaging.ImageCodecInfo.GetImageEncoders();

            System.Drawing.Imaging.ImageCodecInfo ICI = null;


            foreach (System.Drawing.Imaging.ImageCodecInfo codec in codecs)
            {
                if (codec.MimeType.ToLower() == ("image/" + picType).ToLower())
                {
                    ICI = codec;
                }
            }

            New_Image.Save(context.Response.OutputStream, ICI, EPS);


            //Clear
            New_Image.Dispose();
            ObjGraphics.Dispose();
            Original_Image.Dispose();

        }
    }

    public bool IsReusable
    {
        get { return false; }
    }

}