Delphi 与 DirectX 之 DelphiX(83): TDIB.FilterLine()、FilterRect();

本例效果图:

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代码文件:

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unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DIB, StdCtrls;

type
  TForm1 = class(TForm)
    DXPaintBox1: TDXPaintBox;
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses TypInfo;

var
  dib: TDIB;
  f: Integer;

procedure TForm1.Button1Click(Sender: TObject);
const
  clr = clRed;
var
  w,h,a,b: Integer;
begin
  DXPaintBox1.DIB.Assign(dib);

  w := DXPaintBox1.ClientWidth;
  h := DXPaintBox1.ClientHeight;
  a := w div 7;
  b := h div 7;

  DXPaintBox1.DIB.FilterLine(0, b, w, b, clr, TFilterMode(f));
  DXPaintBox1.DIB.FilterLine(0, h-b, w, h-b, clr, TFilterMode(f));
  DXPaintBox1.DIB.FilterLine(a, 0, a, h, clr, TFilterMode(f));
  DXPaintBox1.DIB.FilterLine(w-a, 0, w-a, h, clr, TFilterMode(f));
  DXPaintBox1.DIB.FilterRect(w div 5, h div 5, w div 5*3, h div 5*3, clr, TFilterMode(f));
  DXPaintBox1.Repaint;

  Text := GetEnumName(TypeInfo(TFilterMode), f);
  Inc(f); f := f and 3;
end;

procedure TForm1.FormCreate(Sender: TObject);
const
  ImgPath1 = 'C:\Temp\DX.jpg';
begin
  dib := TDIB.Create;
  dib.LoadFromFile(ImgPath1);
  DXPaintBox1.DIB.Assign(dib);
  DXPaintBox1.Width := dib.Width;
  DXPaintBox1.Height := dib.Height;
  DXPaintBox1.Repaint;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  dib.Free;
end;

end.

窗体文件:

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object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 142
  ClientWidth = 226
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  OnCreate = FormCreate
  OnDestroy = FormDestroy
  PixelsPerInch = 96
  TextHeight = 13
  object DXPaintBox1: TDXPaintBox
    Left = 8
    Top = 8
    Width = 81
    Height = 73
    AutoStretch = False
    Center = False
    KeepAspect = False
    Stretch = False
    ViewWidth = 0
    ViewHeight = 0
  end
  object Button1: TButton
    Left = 143
    Top = 101
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 0
    OnClick = Button1Click
  end
end