Text Transformation in GDI+（二）

现在我们改变一下变换顺序，顺序为Translate -> Rotate -> Scale，使用Append

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace MatrixOrderDemo
{
    class MatrixOrderDemo:Form
    {
        static void Main(string[] args)
        {
            Application.Run(new MatrixOrderDemo());
        }
        public MatrixOrderDemo()
        {
            Text = "转换顺序测试";
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = CreateGraphics();
            g.Clear(this.BackColor);

            Rectangle rect =
                new Rectangle(20,20,100,100);
            Brush brush = new SolidBrush(Color.Red);

            //此为绘制方格网
            for (int i = 0; i < ClientSize.Width; i +=10)
            {
                for (int j = 0; j < ClientSize.Height; j +=10)
                {
                    g.DrawLine(new Pen(Color.Gray),new Point(i,0),new Point(i,ClientSize.Height));
                    g.DrawLine(new Pen(Color.Gray),new Point(0,j),new Point(ClientSize.Width,j));
                }
            }
            //g.DrawLine(new Pen(Color.Green),new PointF(14.14f,0),new PointF(14.14f,28.28f));
            //g.DrawLine(new Pen(Color.Green),new PointF(0,28.28f),new PointF(14.14f,28.28f));

            g.FillRectangle(brush,rect);

            g.TranslateTransform(150.0f, 50.0f, System.Drawing.Drawing2D.MatrixOrder.Append);
            //g.ScaleTransform(1.5f,0.5f);
            //g.RotateTransform(45.0f,System.Drawing.Drawing2D.MatrixOrder.Append);
            
            g.FillRectangle(brush,rect);

            //此为验证的矩形
            Rectangle rect1 =
                new Rectangle(20, 20, 100, 100);
            g.FillRectangle(new SolidBrush(Color.Green), rect1);

            brush.Dispose();
            g.Dispose();
        }
    }
}

 

 

 第43行代码运用了TranslateTransform，从实际运行效果来看，绿色正方形的开状没有发生变化，绿色正方向左上角点的坐标为（170，70）；符合20+150=170，20+50=70；

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace MatrixOrderDemo
{
    class MatrixOrderDemo:Form
    {
        static void Main(string[] args)
        {
            Application.Run(new MatrixOrderDemo());
        }
        public MatrixOrderDemo()
        {
            Text = "转换顺序测试";
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = CreateGraphics();
            g.Clear(this.BackColor);

            Rectangle rect =
                new Rectangle(20,20,100,100);
            Brush brush = new SolidBrush(Color.Red);

            //此为绘制方格网
            for (int i = 0; i < ClientSize.Width; i +=10)
            {
                for (int j = 0; j < ClientSize.Height; j +=10)
                {
                    g.DrawLine(new Pen(Color.Gray),new Point(i,0),new Point(i,ClientSize.Height));
                    g.DrawLine(new Pen(Color.Gray),new Point(0,j),new Point(ClientSize.Width,j));
                }
            }
            //g.DrawLine(new Pen(Color.Green),new PointF(14.14f,0),new PointF(14.14f,28.28f));
            //g.DrawLine(new Pen(Color.Green),new PointF(0,28.28f),new PointF(14.14f,28.28f));

            g.FillRectangle(brush,rect);

            g.TranslateTransform(150.0f, 50.0f, System.Drawing.Drawing2D.MatrixOrder.Append);
            g.ScaleTransform(1.5f,0.5f);
            //g.RotateTransform(45.0f,System.Drawing.Drawing2D.MatrixOrder.Append);
            
            g.FillRectangle(brush,rect);

            //此为验证的矩形
            Rectangle rect1 =
                new Rectangle(20, 20, 100, 100);
            g.FillRectangle(new SolidBrush(Color.Green), rect1);

            brush.Dispose();
            g.Dispose();
        }
    }
}

 

 上述代码启用第44行，使用ScaleTransform进行缩放；从上图可以看出绿色矩形的形状已经由长度100扩大了1.5倍后，变为了150长；高度100缩小了0.5倍后，变为了50高。绿色矩形的左上角坐标为（180，60），可以推断出自定义坐标经过移动（150，50）后，再进行ScaleTransform缩放，则仅仅是对于自定义坐标中的实体进行了缩放或扩大，也就是说世界坐标系没有变化，坐标（20，20），长宽为100的实体绿色正方形在自定义坐标系中横坐标扩大1.5倍，为30（注意：这是自定义坐标系中的坐标），纵坐标缩小0.5倍，为10（这也是自定义坐标系中的坐标），结合第一步中的平移（150，50），则最终绿色矩形呈现出来的左上角坐标是：横轴150+30=180；纵轴50+10=60；

 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace MatrixOrderDemo
{
    class MatrixOrderDemo:Form
    {
        static void Main(string[] args)
        {
            Application.Run(new MatrixOrderDemo());
        }
        public MatrixOrderDemo()
        {
            Text = "转换顺序测试";
        }
        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = CreateGraphics();
            g.Clear(this.BackColor);

            Rectangle rect =
                new Rectangle(20,20,100,100);
            Brush brush = new SolidBrush(Color.Red);

            //此为绘制方格网
            for (int i = 0; i < ClientSize.Width; i +=10)
            {
                for (int j = 0; j < ClientSize.Height; j +=10)
                {
                    g.DrawLine(new Pen(Color.Gray),new Point(i,0),new Point(i,ClientSize.Height));
                    g.DrawLine(new Pen(Color.Gray),new Point(0,j),new Point(ClientSize.Width,j));
                }
            }
            g.DrawLine(new Pen(Color.Purple), new PointF(84.8528f, 0), new PointF(84.8528f, 169.7056f));
            g.DrawLine(new Pen(Color.Purple), new PointF(0, 169.7056f), new PointF(84.8528f, 169.7056f));

            g.FillRectangle(brush,rect);

            g.TranslateTransform(150.0f, 50.0f, System.Drawing.Drawing2D.MatrixOrder.Append);
            g.ScaleTransform(1.5f,0.5f);
            g.RotateTransform(45.0f,System.Drawing.Drawing2D.MatrixOrder.Append);
            
            g.FillRectangle(brush,rect);

            //此为验证的矩形
            Rectangle rect1 =
                new Rectangle(20, 20, 100, 100);
            g.FillRectangle(new SolidBrush(Color.Green), rect1);

            brush.Dispose();
            g.Dispose();
        }
    }
}

上述代码使用RotateTransform顺时针旋转45度；此旋转的基础仍然是以世界坐标系（0，0）为原点进行旋转；以上一示例中绿色矩形的左上角坐标为（180，60）顺时针旋转45度进行验证，具体计算公式如下：

x1=180*cos45-60*sin45 = 84.8528;

y1=180*sin45+60*cos45=169.7056;

程序运行如下（注：代码中特意增加了两行验证代码，如图中紫色横线和紫色竖线所示）：