OpenGL的屏幕闪烁问题 高分送上！！！

Question

SwapBuffer我用了，窗体的DoubleBuffer属性我也设置了。还是不行。

Answer 1

你应该在窗体的OnPaint事件里重画物体和背景，或者响应WM_PAINT消息。也就是说你应该在OnPaint里写OnTimer里几乎同样的代码，只不过不进行旋转参数递增。

Answer 2

使用InvalidateRect()，而不是Invalidate()
因为后者会重画整个画布，而前者只重画矩形区域，节省了时间，减少闪烁。

Answer 3

孤海闲鸥,请问你一个问题，在DELPHI中的FORM里面，如何调用OPENGL画图啊，要不要进行初始化，在DELPHI中，OPENGL的实用库和辅助库都用不了，应该怎么做呢？请你帮帮我，不胜感激！并有厚礼送上！多谢！

Answer 4

给你一OPENGL的初试化方法！unit MainOpenGL;interfaceuses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  OpenGL, StdCtrls, ExtCtrls;type
  TMainForm = class(TForm)
    procedure PreparePixelFormat(var Devc:HDC);
    procedure InitDC;
    procedure InitGL;
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure FormResize(Sender: TObject);
  private
    { Private declarations }
    DC:HDC;
    RC:HGLRC;
    procedure RenderScene;
    Protected
  public
    { Public declarations }
  end;var
  MainForm: TMainForm;         _no_mat: array[0..3] of GLfloat=(0.0,0.0,0.0,1.0);
        _ambient: array[0..3] of GLfloat=(0.7,0.7,0.7,1.0);
  _ambient_color: array[0..3] of GLfloat=(0.8,0.8,0.2,1.0);
        _diffuse: array[0..3] of GLfloat=(0.1,0.5,0.8,1.0);
       _specular: array[0..3] of GLfloat=(1.0,1.0,1.0,1.0);
       _emission: array[0..3] of GLfloat=(0.3,0.2,0.2,0.0);
   _no_shininess: array[0..0] of GLfloat=(0.0);
  _low_shininess: array[0..0] of GLfloat=(5.0);
 _high_shininess: array[0..0] of GLfloat=(100.0);
implementation{$R *.DFM}// 画图部分
procedure TMainForm.RenderScene;
var
            Obj:GLUquadricObj;         no_mat:PGLfloat;
        ambient:PGLfloat;
  ambient_color:PGLfloat;
        diffuse:PGLfloat;
       specular:PGLfloat;
       emission:PGLfloat;
   no_shininess:PGLfloat;
  low_shininess:PGLfloat;
 high_shininess:PGLfloat;begin
         no_mat:=@_no_mat[0];
        ambient:=@_ambient[0];
  ambient_color:=@_ambient_color[0];
        diffuse:=@_diffuse[0];
       specular:=@_specular[0];
       emission:=@_emission[0];
   no_shininess:=@_no_shininess;
  low_shininess:=@_low_shininess;
 high_shininess:=@_high_shininess;   glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
  //1,   obj:=gluNewQuadric;
   glPushMatrix;
      glTranslatef(-0.75,0.75,0.0);
      glMaterialfv(GL_FRONT,GL_AMBIENT,no_mat);
      glMaterialfv(GL_FRONT,GL_DIFFUSE,diffuse);
      glMaterialfv(GL_FRONT,GL_SPECULAR,no_mat);
      glMaterialfv(GL_FRONT,GL_SHININESS,no_shininess);
      glMaterialfv(GL_FRONT,GL_EMISSION,no_mat);
   gluSphere(Obj,0.1,10,10);
   glpopMatrix;
   gluDeleteQuadric(Obj);   SwapBuffers(DC);
end;
procedure TMainForm.PreparePixelFormat(var Devc:HDC);
var
   hHeap:THandle;
   nColors,i:Integer;
   PFD:TPixelFormatDescriptor;
   ChosenPixelFormat:Integer;
begin
   FillChar(PFD,SizeOf(TPixelFormatDescriptor),0);
   PFD.nSize:=SizeOf(TPixelFormatDescriptor);
   PFD.nVersion:=1;
   PFD.dwFlags:=PFD_DRAW_TO_WINDOW or PFD_SUPPORT_OPENGL
                or PFD_DOUBLEBUFFER;
   PFD.iPixelType:=PFD_TYPE_RGBA;
   PFD.cColorBits:=16;
   PFD.cDepthBits:=32;
   PFD.iLayerType:=PFD_MAIN_PLANE;
   ChosenPixelFormat:=ChoosePixelFormat(DevC,@PFD);
   if ChosenPixelFormat=0 then
      Raise ExcePtion.Create(' No failed!');
   SetPixelFormat(DevC,ChosenPixelFormat,@PFD);   end;procedure TMainForm.InitDC;
begin
    DC:=GetDC(Handle);
    PreparePixelFormat(DC);
end;procedure TMainForm.InitGL;
begin
    glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity;
    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glOrtho(-1,1,-1,1,-1,50);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity;
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_COLOR_MATERIAL);
    glShadeModel(GL_SMOOTH);
    gluLookAt(2,4,6,0,0,0,0,1,0);
    SwapBuffers(DC);
end;procedure TMainForm.FormCreate(Sender: TObject);
begin
    inherited;
    left:=0;
    top:=0;
    width:=Screen.Width;
    height:=Screen.Height;
    initDC;
    RC:=wglCreateContext(DC);
    wglMakeCurrent(DC,RC);
    initGL;
end;procedure TMainForm.FormDestroy(Sender: TObject);
begin
    wglMakeCurrent(0,0);
    wglDeleteContext(RC);
    ReleaseDC(Handle,DC);
end;procedure TMainForm.FormResize(Sender: TObject);
begin
    inherited;
    glViewPort(1,1,ClientWidth,ClientHeight);
     RenderScene;
end;