Question

我和 OpenGL 有一些麻烦, 首先, 我有一个我正在建造的定制控制器, 封装 OpenGL 。我有一个问题, 它会迅速闪烁, 就像它正在闪烁。控制器太大,太复杂了, 无法在这里张贴, 所以我做了一个新的小型演示应用程序, 来演示和重新创建相同的场景。

现在的问题是:我没有得到任何图像。事情会在我的海关控制中表现良好,但是由于我复制了代码,并在一个小的演示应用程序中把它拆下来,它不会显示图像。所以我手头有两个问题:闪烁(或闪烁),现在图像甚至没有显示。闪烁过去没有发生,但经过一些主要的代码修改后,它开始闪烁。它改变的代码太多,无法解释什么是完全改变的,只是关于一切的。

背景显示, 所以我知道它画的东西( 彩色的) 。它应该只绘制一个立方体用于演示目的, 但我什么也看不到。我不得不把它从大约1000行的代码中删除到不到300行。

这不是通常所谓的闪烁器,实际上它更像是闪烁,或闪烁,想象汽车闪烁器开着和关着。它肯定与计时器有关,因为我加定时器的间隔越长,它闪烁的速度越慢。

为什么我什么都看不见?一旦修好了,为什么它会这么闪闪发光呢?

无需 DFM :

unit uMain;

interface

uses
  Winapi.Windows, Winapi.Messages, Winapi.OpenGL,
  System.SysUtils, System.Variants, System.Classes,
  Vcl.Graphics, Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.ExtCtrls;

type
  TForm1 = class(TForm)
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
    procedure Timer1Timer(Sender: TObject);
    procedure FormResize(Sender: TObject);
  private
    FDrawing: Bool;
    FDC: HDC;
    FRC: HGLRC;
    FDL: glUint;
    FTimer: TTimer;
    procedure Draw;
    procedure SetDC(const Value: HDC);
    procedure SetRC(const Value: HGLRC);
    procedure SetDL(const Value: glUint);
  public
    property DC: HDC read FDC write SetDC;
    property RC: HGLRC read FRC write SetRC;
    property DL: glUint read FDL write SetDL;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  PixelFormat: glUint;
  pfd: TPIXELFORMATDESCRIPTOR;
begin
  FDrawing := False;
  FDC := GetDC(Handle);
  with pfd do begin
    nSize := SizeOf(TPIXELFORMATDESCRIPTOR);
    nVersion := 1; // The version of this data structure
    dwFlags := PFD_DRAW_TO_WINDOW // Buffer supports drawing to window
      or PFD_SUPPORT_OPENGL // Buffer supports OpenGL drawing
      or PFD_DOUBLEBUFFER; // Supports double buffering
    iPixelType := PFD_TYPE_RGBA; // RGBA color format
    cColorBits := 32; // OpenGL color depth
    cRedBits := 0; // Number of red bitplanes
    cRedShift := 0; // Shift count for red bitplanes
    cGreenBits := 0; // Number of green bitplanes
    cGreenShift := 0; // Shift count for green bitplanes
    cBlueBits := 0; // Number of blue bitplanes
    cBlueShift := 0; // Shift count for blue bitplanes
    cAlphaBits := 0; // Not supported
    cAlphaShift := 0; // Not supported
    cAccumBits := 0; // No accumulation buffer
    cAccumRedBits := 0; // Number of red bits in a-buffer
    cAccumGreenBits := 0; // Number of green bits in a-buffer
    cAccumBlueBits := 0; // Number of blue bits in a-buffer
    cAccumAlphaBits := 0; // Number of alpha bits in a-buffer
    cDepthBits := 16; // Specifies the depth of the depth buffer
    cStencilBits := 0; // Turn off stencil buffer
    cAuxBuffers := 0; // Not supported
    iLayerType := PFD_MAIN_PLANE; // Ignored
    bReserved := 0; // Number of overlay and underlay planes
    dwLayerMask := 0; // Ignored
    dwVisibleMask := 0; // Transparent color of underlay plane
    dwDamageMask := 0; // Ignored
  end;
  PixelFormat := ChoosePixelFormat(FDC, @pfd);
  SetPixelFormat(FDC, PixelFormat, @pfd);
  FRC := wglCreateContext(FDC);
  wglMakeCurrent(FDC, FRC);
  FormResize(nil);
  wglMakeCurrent(FDC, FRC);
  glClearColor(0.8, 0.8, 0.9, 0.0);
  glShadeModel(GL_FLAT);
  glClearDepth(1.0);
  glEnable(GL_DEPTH_TEST);
  glDepthFunc(GL_LESS);
  glEnable(GL_ALPHA_TEST);
  glAlphaFunc(GL_GREATER, 0.4);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glEnable(GL_BLEND);
  glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
  glEnable(GL_TEXTURE_2D);
  glNewList(FDL, GL_COMPILE);
    glBegin(GL_QUADS);
      // Front Face
      glTexCoord2f(0.0, 0.0);
      glVertex3f(-2.0, -1.0, 1.0);
      glTexCoord2f(2.0, 0.0);
      glVertex3f(2.0, -1.0, 1.0);
      glTexCoord2f(2.0, 1.0);
      glVertex3f(2.0, 1.0, 1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(-2.0, 1.0, 1.0);
      // Back Face
      glTexCoord2f(2.0, 0.0);
      glVertex3f(-2.0, -1.0, -1.0);
      glTexCoord2f(2.0, 1.0);
      glVertex3f(-2.0, 1.0, -1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(2.0, 1.0, -1.0);
      glTexCoord2f(0.0, 0.0);
      glVertex3f(2.0, -1.0, -1.0);
      // Top Face
      glTexCoord2f(0.0, 1.0);
      glVertex3f(-2.0, 1.0, -1.0);
      glTexCoord2f(0.0, 0.0);
      glVertex3f(-2.0, 1.0, 1.0);
      glTexCoord2f(2.0, 0.0);
      glVertex3f(2.0, 1.0, 1.0);
      glTexCoord2f(2.0, 1.0);
      glVertex3f(2.0, 1.0, -1.0);
      // Bottom Face
      glTexCoord2f(2.0, 1.0);
      glVertex3f(-2.0, -1.0, -1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(2.0, -1.0, -1.0);
      glTexCoord2f(0.0, 0.0);
      glVertex3f(2.0, -1.0, 1.0);
      glTexCoord2f(2.0, 0.0);
      glVertex3f(-2.0, -1.0, 1.0);
      // Left Face
      glTexCoord2f(0.0, 0.0);
      glVertex3f(2.0, -1.0, -1.0);
      glTexCoord2f(1.0, 0.0);
      glVertex3f(2.0, -1.0, 1.0);
      glTexCoord2f(1.0, 1.0);
      glVertex3f(2.0, 1.0, 1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(2.0, 1.0, -1.0);
    glEnd();
  glEndList();
  FTimer:= TTimer.Create(nil);
  FTimer.OnTimer:= Timer1Timer;
  FTimer.Interval:= 100;
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  FTimer.Free;
  if (not wglMakeCurrent(FDC, 0)) then
    MessageBox(0,  Release of DC and RC failed! ,  Error , MB_OK or MB_ICONERROR);
  if (not wglDeleteContext(FRC)) then begin
    MessageBox(0,  Release of rendering context failed! ,  Error , MB_OK or MB_ICONERROR);
    FRC := 0;
  end;
  if ((FDC > 0) and (ReleaseDC(Handle, FDC) = 0)) then begin
    MessageBox(0,  Release of device context failed! ,  Error , MB_OK or MB_ICONERROR);
    FDC := 0;
  end;
end;

procedure TForm1.Draw;
var
  I: Integer;
begin
  if not FDrawing then begin
    FDrawing := TRUE;
    try
      glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
      glEnable(GL_NORMALIZE);
      glShadeModel(GL_FLAT);
      glCullFace(GL_BACK);
      glLoadIdentity;
      glPushMatrix();
      glCallList(DL);
      glPopMatrix();
      SwapBuffers(wglGetCurrentDC);
    finally
      FDrawing := False;
    end;
  end;
end;

procedure TForm1.FormResize(Sender: TObject);
begin
  glViewport(0, 0, Width, Height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(45.0, Width / Height, 0.1, 500.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
end;

procedure TForm1.SetDC(const Value: HDC);
begin
  FDC := Value;
end;

procedure TForm1.SetDL(const Value: glUint);
begin
  FDL := Value;
end;

procedure TForm1.SetRC(const Value: HGLRC);
begin
  FRC := Value;
end;

procedure TForm1.Timer1Timer(Sender: TObject);
begin
  Draw;
end;

end.

上述代码与我的原代码的运作方式有很大不同。原始的 < code> draw 程序通过一个天体列表进行迭代, 每个天体都包含自己的 < code> Draw 程序。因此, 控件 s 绘制程序会准备整个场景, 然后逐项绘制, 像这样 :

procedure TGLImage.Draw;
var
  X: Integer;
begin
  if not FDrawing then begin
    FDrawing := TRUE;
    try
      glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
      glEnable(GL_NORMALIZE);
      glShadeModel(GL_FLAT);
      glCullFace(GL_BACK);
      glLoadIdentity();

      glRotatef(FElapsedTime / 70, 0, 0, 1);
      glRotatef(90, 0, 1, 0);
      glTranslatef(-FElapsedTime / 400, 0, 0);

      if FInitialized then begin
        for X := 0 to FItems.Count - 1 do begin
          FItems[X].Draw;
        end;
      end;

      SwapBuffers(wglGetCurrentDC);
    finally
      FDrawing := False;
    end;
  end;
end;

这是它画的物品之一...

constructor TGLBeam.Create(AOwner: TGLItems);
begin
  inherited;
  glNewList(DL, GL_COMPILE);
    glBegin(GL_QUADS);
      // Front Face
      glTexCoord2f(0.0, 0.0);
      glVertex3f(-2.0, -1.0, 1.0);
      glTexCoord2f(2.0, 0.0);
      glVertex3f(2.0, -1.0, 1.0);
      glTexCoord2f(2.0, 1.0);
      glVertex3f(2.0, 1.0, 1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(-2.0, 1.0, 1.0);
      // Back Face
      glTexCoord2f(2.0, 0.0);
      glVertex3f(-2.0, -1.0, -1.0);
      glTexCoord2f(2.0, 1.0);
      glVertex3f(-2.0, 1.0, -1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(2.0, 1.0, -1.0);
      glTexCoord2f(0.0, 0.0);
      glVertex3f(2.0, -1.0, -1.0);
      // Top Face
      glTexCoord2f(0.0, 1.0);
      glVertex3f(-2.0, 1.0, -1.0);
      glTexCoord2f(0.0, 0.0);
      glVertex3f(-2.0, 1.0, 1.0);
      glTexCoord2f(2.0, 0.0);
      glVertex3f(2.0, 1.0, 1.0);
      glTexCoord2f(2.0, 1.0);
      glVertex3f(2.0, 1.0, -1.0);
      // Bottom Face
      glTexCoord2f(2.0, 1.0);
      glVertex3f(-2.0, -1.0, -1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(2.0, -1.0, -1.0);
      glTexCoord2f(0.0, 0.0);
      glVertex3f(2.0, -1.0, 1.0);
      glTexCoord2f(2.0, 0.0);
      glVertex3f(-2.0, -1.0, 1.0);
      // Left Face
      glTexCoord2f(0.0, 0.0);
      glVertex3f(2.0, -1.0, -1.0);
      glTexCoord2f(1.0, 0.0);
      glVertex3f(2.0, -1.0, 1.0);
      glTexCoord2f(1.0, 1.0);
      glVertex3f(2.0, 1.0, 1.0);
      glTexCoord2f(0.0, 1.0);
      glVertex3f(2.0, 1.0, -1.0);
    glEnd();
  glEndList();
end;

procedure TGLBeam.Draw;
var
  I: Integer;
begin
  glRotatef(Directions.X, 1.0, 0.0, 0.0);
  glRotatef(Directions.Y, 0.0, 1.0, 0.0);
  glRotatef(Directions.Z, 0.0, 0.0, 1.0);
  for I := 1 to 10 do begin
    //Main Center
    glPushMatrix();
    glTranslatef(I * 4 + Owner.Owner.ClockTime * 4, 0, 0);
    glCallList(DL);
    glPopMatrix();
    //Above
    glPushMatrix();
    glTranslatef(I * 4 + Owner.Owner.ClockTime * 4, 6, 0);
    glCallList(DL);
    glPopMatrix();
  end;
end;

Answer 1

闪烁的问题被发现了, 这是一个非常巨大的错误, 我并不期望您在没有整个工程的情况下发现。问题在于我创建了这些控管的“ 坚固的TWO'/坚固的”, 它们相互干扰/ 相互争斗。事实上, 因为 OpenGL 是在一个细线基础上( 或者在一个背景下)工作的, 有两个不同的控管, 试图自己画画, 将会干扰- 在同一时间造成两个控控管发生同样的事情。因此闪烁是因为每个控管都试图轮流绘制。我问的新问题涉及将这张画放进Tread 里面, 完全可以解决这个问题。这是一个愚蠢的错误, 我为浪费任何人的时间感到抱歉。

Answer 2

glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
glEnable(GL_NORMALIZE);
glShadeModel(GL_FLAT);
glCullFace(GL_BACK);
glLoadIdentity;
glPushMatrix();
glCallList(DL);
glPopMatrix();
SwapBuffers(wglGetCurrentDC);

< strike> 首先在您的调用 < code> gl Loadadidentity 的调用中添加 () 。

您装入身份矩阵, 然后按住它, 然后生成和弹出它, 而实际上没有做任何转换。

要么删除 3 行

glLoadIdentity;
glPushMatrix();

glPopMatrix();

或移动 glPushMatrix () 到 gl Loadidentity () 前的线

我还想建议关闭阴影和围网,以确保它们不会受到干扰。四方被宣布为略为错误的顺序,背面被割断,即使你不希望它们从前面被割开,它们也会被割开。

友情链接