Re-learning gdi+[95]: tgpimage (15)

By doing this example, I also confirmed that GDI + can directly display transparent pictures in PNG, GIF, and TIF format.

//红色与绿色绕蓝色旋转(r 是弧度)
ColorMatrix: TColorMatrix = (
　(Cos(r),　 Sin(r), 0.0,　0.0,　0.0),
　(-Sin(r),　Cos(r), 0.0,　0.0,　0.0),
　(0.0,　　　0.0,　　1.0,　0.0,　0.0),
　(0.0,　　　0.0,　　0.0,　1.0,　0.0),
　(0.0,　　　0.0,　　0.0,　0.0,　1.0));
//绿色与蓝色绕红色旋转(r 是弧度)
ColorMatrix: TColorMatrix = (
　(0.0,　0.0,　　 0.0,　　 0.0,　0.0),
　(0.0,　Cos(r),　Sin(r),　0.0,　0.0),
　(0.0,　-Sin(r), Cos(r),　0.0,　0.0),
　(0.0,　0.0,　　 0.0,　　 1.0,　0.0),
　(0.0,　0.0,　　 0.0,　　 0.0,　1.0));
//红色与蓝色绕绿色旋转(r 是弧度)
ColorMatrix: TColorMatrix = (
　(Cos(r),　 0.0,　Sin(r),　0.0,　0.0),
　(-Sin(r),　0.0,　Cos(r),　0.0,　0.0),
　(0.0,　　　0.0,　1.0,　　 0.0,　0.0),
　(0.0,　　　0.0,　0.0,　　 1.0,　0.0),
　(0.0,　　　0.0,　0.0,　　 0.0,　1.0));This example effect chart:

Code files:Unit Unit1;
Interface
Uses
Windows, Messages, sysutils, variants, Classes, Graphics, Controls, Forms,
Dialogs, Stdctrls, Comctrls, Extctrls;
Type
TForm1 = Class (Tform)
Trackbar1:ttrackbar;
Radiogroup1:tradiogroup;
Procedure Formcreate (Sender:tobject);
Procedure Formpaint (Sender:tobject);
Procedure Checkbox1click (Sender:tobject);
Procedure Trackbar1change (Sender:tobject);
Procedure Radiogroup1click (Sender:tobject);
End
Var
Form1:tform1;
Implementation
{$R *.DFM}
Uses Gdipobj, GDIPAPI;
Const
Matrix:tcolormatrix = (
(1.0, 0.0, 0.0, 0.0, 0.0),
(0.0, 1.0, 0.0, 0.0, 0.0),
(0.0, 0.0, 1.0, 0.0, 0.0),
(0.0, 0.0, 0.0, 1.0, 0.0),
(0.0, 0.0, 0.0, 0.0, 1.0));
Procedure Tform1.formcreate (Sender:tobject);
Begin
Trackbar1.height: = 23;
Trackbar1.showselrange: = False;
Trackbar1.min: =-180;
Trackbar1.max: = 180;
Trackbar1.position: = 0;
With Radiogroup1.items do
Begin
ADD (' Red and green around Blue spin ');
ADD (' Red and blue around green rotation ');
ADD (' green and blue rotate around red ');
End
Radiogroup1.itemindex: = 0;
DoubleBuffered: = True;
End
Procedure Tform1.formpaint (Sender:tobject);
Var
G:tgpgraphics;
Img:tgpimage;
Imageattributes:tgpimageattributes;
R:single;
Colormatrix:tcolormatrix;
Begin
G: = Tgpgraphics.create (Canvas.handle);
IMG: = tgpimage.create (' c:\temp\test.png ');
ImageAttributes: = tgpimageattributes.create;
R: = trackbar1.position * PI/180; {Radians by angle}
ColorMatrix: = Matrix; {Reply to default value}
Case Radiogroup1.itemindex of
0:begin {red and green rotate around blue}
colormatrix[0,0]: = Cos (R);
colormatrix[0,1]: = Sin (R);
colormatrix[1,0]: =-sin (R);
colormatrix[1,1]: = Cos (R);
End
1:begin {red and blue around green rotation}
colormatrix[0,0]: = Cos (R);
colormatrix[0,2]: = Sin (R);
colormatrix[2,0]: =-sin (R);
colormatrix[2,2]: = Cos (R);
End
2:begin {green and blue rotate around red}
colormatrix[1,1]: = Cos (R);
colormatrix[1,2]: = Sin (R);
colormatrix[2,1]: =-sin (R);
colormatrix[2,2]: = Cos (R);
End
End
Imageattributes.setcolormatrix (ColorMatrix);
G.drawimage (IMG,
Makerect (4, 4, IMG.) GetWidth, IMG. GetHeight),
0,
0,
Img. GetWidth,
Img. GetHeight,
Unitpixel,
ImageAttributes
);
Imageattributes.free;
Img. Free;
G.free;
End
Procedure Tform1.radiogroup1click (Sender:tobject);
Begin
Repaint;
End
Procedure Tform1.trackbar1change (Sender:tobject);
Begin
Repaint;
End
Procedure Tform1.checkbox1click (Sender:tobject);
Begin
Repaint;
End
End.

Form file:object Form1: TForm1
　Left = 0
　Top = 0
　Caption = 'Form1'
　ClientHeight = 290
　ClientWidth = 208
　Color = clBtnFace
　Font.Charset = DEFAULT_CHARSET
　Font.Color = clWindowText
　Font.Height = -11
　Font.Name = 'Tahoma'
　Font.Style = []
　OldCreateOrder = False
　Position = poDesktopCenter
　OnCreate = FormCreate
　OnPaint = FormPaint
　PixelsPerInch = 96
　TextHeight = 13
　object TrackBar1: TTrackBar
　　Left = 3
　　Top = 170
　　Width = 202
　　Height = 22
　　TabOrder = 0
　　OnChange = TrackBar1Change
　end
　object RadioGroup1: TRadioGroup
　　Left = 8
　　Top = 198
　　Width = 190
　　Height = 83
　　Caption = 'RadioGroup1'
　　TabOrder = 1
　　OnClick = RadioGroup1Click
　end
end