using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Media;


namespace MECF.Framework.UI.Core.DxfScript
{
    /// <summary>
    /// 名称：画布类
    /// 用途：Canvas信息初始化
    /// </summary>
    public partial class GasDxfDocument
    {
        //显示处理
        //初始化尺寸和位置
        private double canvasWidth, canvasHeight;
        private double rate;//dxf文件与屏幕画布的尺寸比例
        private double DefaultSpace = 5;// 默认边缘空间
        private double XSPACE = 10;
        private double YSPACE = 10;
        public double Scale = 1;   //屏幕显示的缩放比例
        public double dragX, dragY;   //拖动的偏移量
        //初始化画布
        private void InitScale()
        {

            // 减去两边的空间以确定实际可用画布大小
            canvasWidth = draw.Width - 2 * DefaultSpace;
            canvasHeight = draw.Height - 2 * DefaultSpace;

            // 检查DXF尺寸是否有效
            if (DxfWidth < 1 || DxfHeight < 1) return;

            // 计算宽度和高度的比例
            double widthRate = canvasWidth / DxfWidth;
            double heightRate = canvasHeight / DxfHeight;

            // 选择较小的比例以确保DXF文件完整显示在画布上
            rate = Math.Min(widthRate, heightRate);

            // 计算空间以使图形居中
            XSPACE = DefaultSpace + (canvasWidth - DxfWidth * rate * Scale) / 2;
            YSPACE = DefaultSpace + (canvasHeight - DxfHeight * rate * Scale) / 2;
        }
        //显示移动结果
        public void DrawMovedImage()
        {
            CreateGraphics();
            draw.LoadDrawing(dragX, dragY);
            CloseGraphics();
        }
        public double ScreenToDxfX(double x)
        {
            return (x - XSPACE - dragX) / (rate * Scale);
        }
        public double ScreenToDxfY(double y)
        {
            return DxfHeight - (y - YSPACE - dragY) / (rate * Scale);
        }
        /// <summary>
        /// 纠正拖拽后产生的位移偏差
        /// </summary>
        public void ModifyDrag()
        {
            var scaleTransform = draw.RenderTransform as ScaleTransform;
            if (scaleTransform == null)
            {
                scaleTransform = new ScaleTransform();
                draw.RenderTransform = scaleTransform;
            }
            double backupDragX = dragX;
            double backupDragY = dragY;
            dragX = 0;
            dragY = 0;
            Draw();
            dragX = backupDragX * scaleTransform.ScaleY;
            dragY = backupDragY * scaleTransform.ScaleY;
            DrawMovedImage();
        }
    }
}