// К заголовку RadialBlur(For OpenGL)
// Данный код работает правильно только, если в пректе 0 форм ,
// а сам код введен в DPR файл!
program RadialBlur;
uses
 Windows,
 Messages,
 OpenGL;
const
 WND_TITLE = 'Radial Blur';
 FPS_TIMER = 1; // Timer to calculate FPS
 FPS_INTERVAL = 1000; // Calculate FPS every 1000 ms
type
 TVector = array[0..2] of glFloat;
var
 h_Wnd: HWND; // Global window handle
 h_DC: HDC; // Global device context
 h_RC: HGLRC; // OpenGL rendering context
 keys: array[0..255] of Boolean; // Holds keystrokes
 FPSCount: Integer = 0; // Counter for FPS
 ElapsedTime: Integer; // Elapsed time between frames
 // Textures
 BlurTexture: glUint; // An Unsigned Int To Store The Texture Number
 // User vaiables
 Angle: glFloat;
 Vertexes: array[0..3] of TVector;
 normal: TVector;
 // Lights and Materials
 globalAmbient: array[0..3] of glFloat = (0.2, 0.2, 0.2, 1.0);
 // Set Ambient Lighting To Fairly Dark Light (No Color)
 Light0Pos: array[0..3] of glFloat = (0.0, 5.0, 10.0, 1.0);
 // Set The Light Position
 Light0Ambient: array[0..3] of glFloat = (0.2, 0.2, 0.2, 1.0);
 // More Ambient Light
 Light0Diffuse: array[0..3] of glFloat = (0.3, 0.3, 0.3, 1.0);
 // Set The Diffuse Light A Bit Brighter
 Light0Specular: array[0..3] of glFloat = (0.8, 0.8, 0.8, 1.0);
 // Fairly Bright Specular Lighting
 LmodelAmbient: array[0..3] of glFloat = (0.2, 0.2, 0.2, 1.0);
 // And More Ambient Light
{$R *.RES}
procedure glBindTexture(target: GLenum; texture: GLuint);
 stdcall; external opengl32;
procedure glGenTextures(n: GLsizei; var textures: GLuint);
 stdcall; external opengl32;
procedure glCopyTexSubImage2D(target: GLenum; level, xoffset,
 yoffset, x, y: GLint; width, height: GLsizei);
 stdcall; external opengl32;
procedure glCopyTexImage2D(target: GLenum; level: GLint;
 internalFormat: GLenum; x, y: GLint;
 width, height: GLsizei; border: GLint); stdcall; external opengl32;
{------------------------------------------------------------------}
{ Function to convert int to string. (No sysutils = smaller EXE) }
{------------------------------------------------------------------}
// using SysUtils increase file size by 100K
function IntToStr(Num: Integer): string;
begin
 Str(Num, result);
end;
function EmptyTexture: glUint;
var
 txtnumber: glUint;
 data: array of glUint;
 pData: Pointer;
begin
 // Create Storage Space For Texture Data (128x128x4)
 GetMem(pData, 128 * 128 * 4);
 glGenTextures(1, txtnumber); // Create 1 Texture
 glBindTexture(GL_TEXTURE_2D, txtnumber); // Bind The Texture
 glTexImage2D(GL_TEXTURE_2D, 0, 4, 128, 128, 0, GL_RGBA,
  GL_UNSIGNED_BYTE, pData);
 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 result := txtNumber;
end;
procedure ReduceToUnit(var vector: array of glFloat);
var
 length: glFLoat;
begin
 // Calculates The Length Of The Vector
 length := sqrt((vector[0] * vector[0]) + (vector[1] * vector[1]) +
  (vector[2] * vector[2]));
 if Length = 0 then
  Length := 1;
 vector[0] := vector[0] / length;
 vector[1] := vector[1] / length;
 vector[2] := vector[2] / length;
end;
procedure calcNormal(const v: array of TVector;
 var cross: array of glFloat);
var
 v1, v2: array[0..2] of glFloat;
begin
 // Finds The Vector Between 2 Points By Subtracting
 // The x,y,z Coordinates From One Point To Another.
 // Calculate The Vector From Point 1 To Point 0
 v1[0] := v[0][0] - v[1][0]; // Vector 1.x=Vertex[0].x-Vertex[1].x
 v1[1] := v[0][1] - v[1][1]; // Vector 1.y=Vertex[0].y-Vertex[1].y
 v1[2] := v[0][2] - v[1][2]; // Vector 1.z=Vertex[0].y-Vertex[1].z
 // Calculate The Vector From Point 2 To Point 1
 v2[0] := v[1][0] - v[2][0]; // Vector 2.x=Vertex[0].x-Vertex[1].x
 v2[1] := v[1][1] - v[2][1]; // Vector 2.y=Vertex[0].y-Vertex[1].y
 v2[2] := v[1][2] - v[2][2]; // Vector 2.z=Vertex[0].z-Vertex[1].z
 // Compute The Cross Product To Give Us A Surface Normal
 cross[0] := v1[1] * v2[2] - v1[2] * v2[1]; // Cross Product For Y - Z
 cross[1] := v1[2] * v2[0] - v1[0] * v2[2]; // Cross Product For X - Z
 cross[2] := v1[0] * v2[1] - v1[1] * v2[0]; // Cross Product For X - Y
 ReduceToUnit(cross); // Normalize The Vectors
end;
// Draws A Helix
procedure ProcessHelix;
const
 Twists = 5;
 MaterialColor: array[1..4] of glFloat = (0.4, 0.2, 0.8, 1.0);
 Specular: array[1..4] of glFloat = (1, 1, 1, 1);
var
 x, y, z: glFLoat;
 phi, theta: Integer;
 r, u, v: glFLoat;
begin
 glLoadIdentity(); // Reset The Modelview Matrix
 // Eye Position (0,5,50) Center Of Scene (0,0,0), Up On Y Axis
 gluLookAt(0, 5, 50, 0, 0, 0, 0, 1, 0);
 glPushMatrix(); // Push The Modelview Matrix
 glTranslatef(0, 0, -50); // Translate 50 Units Into The Screen
 glRotatef(angle / 2.0, 1, 0, 0); // Rotate By angle/2 On The X-Axis
 glRotatef(angle / 3.0, 0, 1, 0); // Rotate By angle/3 On The Y-Axis
 glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, @MaterialColor);
 glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, @specular);
 r := 1.5; // Radius
 glBegin(GL_QUADS); // Begin Drawing Quads
 phi := 0;
 while phi < 360 do
 begin
  theta := 0;
  while theta < 360 * twists do
  begin
  v := phi / 180 * pi; // Calculate Angle Of First Point ( 0 )
  u := theta / 180.0 * pi; // Calculate Angle Of First Point ( 0 )
  x := cos(u) * (2 + cos(v)) * r; // Calculate x Position (1st Point)
  y := sin(u) * (2 + cos(v)) * r; // Calculate y Position (1st Point)
  z := (u - (2 * pi) + sin(v)) * r; // Calculate z Position (1st Point)
  vertexes[0][0] := x; // Set x Value Of First Vertex
  vertexes[0][1] := y; // Set y Value Of First Vertex
  vertexes[0][2] := z; // Set z Value Of First Vertex
  v := (phi / 180 * pi); // Calculate Angle Of Second Point ( 0 )
  u := ((theta + 20) / 180 * pi); // Calculate Angle Of Second Point ( 20 )
  x := cos(u) * (2 + cos(v)) * r; // Calculate x Position (2nd Point)
  y := sin(u) * (2 + cos(v)) * r; // Calculate y Positio
  z := (u - (2 * pi) + sin(v)) * r; // Calculate z Position (2nd Point)
  vertexes[1][0] := x; // Set x Value Of Second Vertex
  vertexes[1][1] := y; // Set y Value Of Second Vertex
  vertexes[1][2] := z; // Set z Value Of Second Vertex
  v := (phi + 20) / 180 * pi; // Calculate Angle Of Third Point ( 20 )
  u := (theta + 20) / 180 * pi; // Calculate Angle Of Third Point ( 20 )
  x := cos(u) * (2 + cos(v)) * r; // Calculate x Position (3rd Point)
  y := sin(u) * (2 + cos(v)) * r; // Calculate y Position (3rd Point)
  z := (u - (2 * pi) + sin(v)) * r; // Calculate z Position (3rd Point)
  vertexes[2][0] := x; // Set x Value Of Third Vertex
  vertexes[2][1] := y; // Set y Value Of Third Vertex
  vertexes[2][2] := z; // Set z Value Of Third Vertex
  v := (phi + 20) / 180 * pi; // Calculate Angle Of Fourth Point ( 20 )
  u := theta / 180 * pi; // Calculate Angle Of Fourth Point ( 0 )
  x := cos(u) * (2 + cos(v)) * r; // Calculate x Position (4th Point)
  y := sin(u) * (2 + cos(v)) * r; // Calculate y Position (4th Point)
  z := (u - (2 * pi) + sin(v)) * r; // Calculate z Position (4th Point)
  vertexes[3][0] := x; // Set x Value Of Fourth Vertex
  vertexes[3][1] := y; // Set y Value Of Fourth Vertex
  vertexes[3][2] := z; // Set z Value Of Fourth Vertex
  calcNormal(vertexes, normal); // Calculate The Quad Normal
  glNormal3f(normal[0], normal[1], normal[2]); // Set The Normal
  // Render The Quad
  glVertex3f(vertexes[0][0], vertexes[0][1], vertexes[0][2]);
  glVertex3f(vertexes[1][0], vertexes[1][1], vertexes[1][2]);
  glVertex3f(vertexes[2][0], vertexes[2][1], vertexes[2][2]);
  glVertex3f(vertexes[3][0], vertexes[3][1], vertexes[3][2]);
  theta := theta + 20;
  end;
  phi := phi + 20;
 end;
 glEnd(); // Done Rendering Quads
 glPopMatrix(); // Pop The Matrix
end;
// Set Up An Ortho View
procedure ViewOrtho;
begin
 glMatrixMode(GL_PROJECTION); // Select Projection
 glPushMatrix(); // Push The Matrix
 glLoadIdentity(); // Reset The Matrix
 glOrtho(0, 640, 480, 0, -1, 1); // Select Ortho Mode (640x480)
 glMatrixMode(GL_MODELVIEW); // Select Modelview Matrix
 glPushMatrix(); // Push The Matrix
 glLoadIdentity(); // Reset The Matrix
end;
// Set Up A Perspective View
procedure ViewPerspective;
begin
 glMatrixMode(GL_PROJECTION); // Select Projection
 glPopMatrix(); // Pop The Matrix
 glMatrixMode(GL_MODELVIEW); // Select Modelview
 glPopMatrix(); // Pop The Matrix
end;
// Renders To A Texture
procedure RenderToTexture;
begin
 glViewport(0, 0, 128, 128); // Set Our Viewport (Match Texture Size)
 ProcessHelix(); // Render The Helix
 glBindTexture(GL_TEXTURE_2D, BlurTexture); // Bind To The Blur Texture
 // Copy Our ViewPort To The Blur Texture (From 0,0 To 128,128... No Border)
 glCopyTexImage2D(GL_TEXTURE_2D, 0, GL_LUMINANCE, 0, 0, 128, 128, 0);
 glClearColor(0.0, 0.0, 0.5, 0.5); // Set The Clear Color To Medium Blue
 // Clear The Screen And Depth Buffer
 glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
 glViewport(0, 0, 640, 480); // Set Viewport (0,0 to 640x480)
end;
// Draw The Blurred Image
procedure DrawBlur(const times: Integer; const inc: glFloat);
var
 spost, alpha, alphainc: glFloat;
 I: Integer;
begin
 alpha := 0.2;
 glEnable(GL_TEXTURE_2D); // Enable 2D Texture Mapping
 glDisable(GL_DEPTH_TEST); // Disable Depth Testing
 glBlendFunc(GL_SRC_ALPHA, GL_ONE); // Set Blending Mode
 glEnable(GL_BLEND); // Enable Blending
 glBindTexture(GL_TEXTURE_2D, BlurTexture); // Bind To The Blur Texture
 ViewOrtho(); // Switch To An Ortho View
 alphainc := alpha / times; // alphainc=0.2f / Times To Render Blur
 glBegin(GL_QUADS); // Begin Drawing Quads
 // Number Of Times To Render Blur
 for I := 0 to times - 1 do
 begin
  glColor4f(1.0, 1.0, 1.0, alpha); // Set The Alpha Value (Starts At 0.2)
  glTexCoord2f(0 + spost, 1 - spost); // Texture Coordinate ( 0, 1 )
  glVertex2f(0, 0); // First Vertex ( 0, 0 )
  glTexCoord2f(0 + spost, 0 + spost); // Texture Coordinate ( 0, 0 )
  glVertex2f(0, 480); // Second Vertex ( 0, 480 )
  glTexCoord2f(1 - spost, 0 + spost); // Texture Coordinate ( 1, 0 )
  glVertex2f(640, 480); // Third Vertex ( 640, 480 )
  glTexCoord2f(1 - spost, 1 - spost); // Texture Coordinate ( 1, 1 )
  glVertex2f(640, 0); // Fourth Vertex ( 640, 0 )
  // Gradually Increase spost (Zooming Closer To Texture Center)
  spost := spost + inc;
  // Gradually Decrease alpha (Gradually Fading Image Out)
  alpha := alpha - alphainc;
 end;
 glEnd(); // Done Drawing Quads
 ViewPerspective(); // Switch To A Perspective View
 glEnable(GL_DEPTH_TEST); // Enable Depth Testing
 glDisable(GL_TEXTURE_2D); // Disable 2D Texture Mapping
 glDisable(GL_BLEND); // Disable Blending
 glBindTexture(GL_TEXTURE_2D, 0); // Unbind The Blur Texture
end;
{------------------------------------------------------------------}
{ Function to draw the actual scene }
{------------------------------------------------------------------}
procedure glDraw();
begin
 // Clear The Screen And The Depth Buffer
 glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
 glLoadIdentity(); // Reset The View
 RenderToTexture; // Render To A Texture
 ProcessHelix; // Draw Our Helix
 DrawBlur(25, 0.02); // Draw The Blur Effect
 angle := ElapsedTime / 5; // Update angle Based On The Clock
end;
{------------------------------------------------------------------}
{ Initialise OpenGL }
{------------------------------------------------------------------}
procedure glInit();
begin
 glClearColor(0.0, 0.0, 0.0, 0.5); // Black Background
 glShadeModel(GL_SMOOTH); // Enables Smooth Color Shading
 glClearDepth(1.0); // Depth Buffer Setup
 glDepthFunc(GL_LESS); // The Type Of Depth Test To Do
 glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
 file:
 //Realy Nice perspective calculations
 glEnable(GL_DEPTH_TEST); // Enable Depth Buffer
 glEnable(GL_TEXTURE_2D); // Enable Texture Mapping
 // Set The Ambient Light Model
 glLightModelfv(GL_LIGHT_MODEL_AMBIENT, @LmodelAmbient);
 // Set The Global Ambient Light Model
 glLightModelfv(GL_LIGHT_MODEL_AMBIENT, @GlobalAmbient);
 glLightfv(GL_LIGHT0, GL_POSITION, @light0Pos); // Set The Lights Position
 glLightfv(GL_LIGHT0, GL_AMBIENT, @light0Ambient); // Set The Ambient Light
 glLightfv(GL_LIGHT0, GL_DIFFUSE, @light0Diffuse); // Set The Diffuse Light
 // Set Up Specular Lighting
 glLightfv(GL_LIGHT0, GL_SPECULAR, @light0Specular);
 glEnable(GL_LIGHTING); // Enable Lighting
 glEnable(GL_LIGHT0); // Enable Light0
 BlurTexture := EmptyTexture(); // Create Our Empty Texture
 glShadeModel(GL_SMOOTH); // Select Smooth Shading
 glMateriali(GL_FRONT, GL_SHININESS, 128);
end;
{------------------------------------------------------------------}
{ Handle window resize }
{------------------------------------------------------------------}
procedure glResizeWnd(Width, Height: Integer);
begin
 if (Height = 0) then // prevent divide by zero exception
  Height := 1;
 glViewport(0, 0, Width, Height); // Set the viewport for the OpenGL window
 glMatrixMode(GL_PROJECTION); // Change Matrix Mode to Projection
 glLoadIdentity(); // Reset View
 gluPerspective(45.0, Width / Height, 2.0, 200.0);
 // Do the perspective calculations. Last value = max clipping depth
 glMatrixMode(GL_MODELVIEW); // Return to the modelview matrix
 glLoadIdentity(); // Reset View
end;
{------------------------------------------------------------------}
{ Processes all the keystrokes }
{------------------------------------------------------------------}
procedure ProcessKeys;
begin
end;
{------------------------------------------------------------------}
{ Determines the application's response to the messages received }
{------------------------------------------------------------------}
function WndProc(hWnd: HWND; Msg: UINT; wParam: WPARAM; lParam: LPARAM):
 LRESULT; stdcall;
begin
 case (Msg) of
  WM_CREATE:
  begin
  // Insert stuff you want executed when the program starts
  end;
  WM_CLOSE:
  begin
  PostQuitMessage(0);
  Result := 0
  end;
  // Set the pressed key (wparam) to equal true so we can check if its pressed
  WM_KEYDOWN:
  begin
  keys[wParam] := True;
  Result := 0;
  end;
  // Set the released key (wparam) to equal false so we can check if its pressed
  WM_KEYUP:
  begin
  keys[wParam] := False;
  Result := 0;
  end;
  WM_SIZE: // Resize the window with the new width and height
  begin
  glResizeWnd(LOWORD(lParam), HIWORD(lParam));
  Result := 0;
  end;
  WM_TIMER: // Add code here for all timers to be used.
  begin
  if wParam = FPS_TIMER then
  begin
  FPSCount := Round(FPSCount * 1000 / FPS_INTERVAL);
  // calculate to get per Second incase intercal is
  // less or greater than 1 second
  SetWindowText(h_Wnd, PChar(WND_TITLE + ' [' + intToStr(FPSCount)
  + ' FPS]'));
  FPSCount := 0;
  Result := 0;
  end;
  end;
 else
  // Default result if nothing happens
  Result := DefWindowProc(hWnd, Msg, wParam, lParam);
 end;
end;
{---------------------------------------------------------------------}
{ Properly destroys the window created at startup (no memory leaks) }
{---------------------------------------------------------------------}
procedure glKillWnd(Fullscreen: Boolean);
begin
 if Fullscreen then // Change back to non fullscreen
 begin
  ChangeDisplaySettings(devmode(nil^), 0);
  ShowCursor(True);
 end;
 // Makes current rendering context not current, and releases the device
 // context that is used by the rendering context.
 if (not wglMakeCurrent(h_DC, 0)) then
  MessageBox(0, 'Release of DC and RC failed!', 'Error',
  MB_OK or MB_ICONERROR);
 // Attempts to delete the rendering context
 if (not wglDeleteContext(h_RC)) then
 begin
  MessageBox(0, 'Release of rendering context failed!', 'Error',
  MB_OK or MB_ICONERROR);
  h_RC := 0;
 end;
 // Attemps to release the device context
 if ((h_DC = 1) and (ReleaseDC(h_Wnd, h_DC) < > 0)) then
 begin
  MessageBox(0, 'Release of device context failed!', 'Error',
  MB_OK or MB_ICONERROR);
  h_DC := 0;
 end;
 // Attempts to destroy the window
 if ((h_Wnd < > 0) and (not DestroyWindow(h_Wnd))) then
 begin
  MessageBox(0, 'Unable to destroy window!', 'Error', MB_OK or
  h_Wnd := 0;
 end;
 // Attempts to unregister the window class
 if (not UnRegisterClass('OpenGL', hInstance)) then
 begin
  MessageBox(0, 'Unable to unregister window class!', 'Error',
  MB_OK or MB_ICONERROR);
  hInstance := 0;
 end;
end;
{--------------------------------------------------------------------}
{ Creates the window and attaches a OpenGL rendering context to it }
{--------------------------------------------------------------------}
function glCreateWnd(Width, Height: Integer; Fullscreen: Boolean;
 PixelDepth: Integer): Boolean;
var
 wndClass: TWndClass; // Window class
 dwStyle: DWORD; // Window styles
 dwExStyle: DWORD; // Extended window styles
 dmScreenSettings: DEVMODE; // Screen settings (fullscreen, etc...)
 PixelFormat: GLuint; // Settings for the OpenGL rendering
 h_Instance: HINST; // Current instance
 pfd: TPIXELFORMATDESCRIPTOR; // Settings for the OpenGL window
begin
 h_Instance := GetModuleHandle(nil);
 file: //Grab An Instance For Our Window
 ZeroMemory(@wndClass, SizeOf(wndClass)); // Clear the window class structure
 with wndClass do // Set up the window class
 begin
  style := CS_HREDRAW or // Redraws entire window if length changes
  CS_VREDRAW or // Redraws entire window if height changes
  CS_OWNDC; // Unique device context for the window
  lpfnWndProc := @WndProc; // Set the window procedure to our func WndProc
  hInstance := h_Instance;
  hCursor := LoadCursor(0, IDC_ARROW);
  lpszClassName := 'OpenGL';
 end;
 if (RegisterClass(wndClass) = 0) then // Attemp to register the window class
 begin
  MessageBox(0, 'Failed to register the window class!', 'Error',
  MB_OK or MB_ICONERROR);
  Result := False;
  Exit
 end;
 // Change to fullscreen if so desired
 if Fullscreen then
 begin
  ZeroMemory(@dmScreenSettings, SizeOf(dmScreenSettings));
  with dmScreenSettings do
  begin // Set parameters for the screen setting
  dmSize := SizeOf(dmScreenSettings);
  dmPelsWidth := Width; // Window width
  dmPelsHeight := Height; // Window height
  dmBitsPerPel := PixelDepth; // Window color depth
  dmFields := DM_PELSWIDTH or DM_PELSHEIGHT or DM_BITSPERPEL;
  end;
  // Try to change screen mode to fullscreen
  if (ChangeDisplaySettings(dmScreenSettings, CDS_FULLSCREEN) =
  DISP_CHANGE_FAILED) then
  begin
  MessageBox(0, 'Unable to switch to fullscreen!', 'Error',
  MB_OK or MB_ICONERROR);
  Fullscreen := False;
  end;
 end;
 // If we are still in fullscreen then
 if (Fullscreen) then
 begin
  dwStyle := WS_POPUP or // Creates a popup window
  WS_CLIPCHILDREN // Doesn't draw within child windows
  or WS_CLIPSIBLINGS; // Doesn't draw within sibling windows
  dwExStyle := WS_EX_APPWINDOW; //  level window
  ShowCursor(False); // Turn of the cursor (gets in the way)
 end
 else
 begin
  dwStyle := WS_OVERLAPPEDWINDOW or // Creates an overlapping window
  WS_CLIPCHILDREN or // Doesn't draw within child windows
  WS_CLIPSIBLINGS; // Doesn't draw within sibling windows
  dwExStyle := WS_EX_APPWINDOW or //  level window
  WS_EX_WINDOWEDGE; // Border with a raised edge
 end;
 // Attempt to create the actual window
 h_Wnd := CreateWindowEx(dwExStyle, // Extended window styles
  'OpenGL', // Class name
  WND_TITLE, // Window title (caption)
  dwStyle, // Window styles
  0, 0, // Window position
  Width, Height, // Size of window
  0, // No parent window
  0, // No menu
  h_Instance, // Instance
  nil); // Pass nothing to WM_CREATE
 if h_Wnd = 0 then
 begin
  glKillWnd(Fullscreen); // Undo all the settings we've changed
  MessageBox(0, 'Unable to create window!', 'Error', MB_OK or MB_ICONERROR);
  Result := False;
  Exit;
 end;
 // Try to get a device context
 h_DC := GetDC(h_Wnd);
 if (h_DC = 0) then
 begin
  glKillWnd(Fullscreen);
  MessageBox(0, 'Unable to get a device context!', 'Error',
  MB_OK or MB_ICONERROR);
  Result := False;
  Exit;
 end;
 // Settings for the OpenGL window
 with pfd do
 begin
  // Size Of This Pixel Format Descriptor
  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 := PixelDepth; // 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;
 // Attempts to find the pixel format supported by a device context that
 // is the best match to a given pixel format specification.
 PixelFormat := ChoosePixelFormat(h_DC, @pfd);
 if (PixelFormat = 0) then
 begin
  glKillWnd(Fullscreen);
  MessageBox(0, 'Unable to find a suitable pixel format', 'Error',
  MB_OK or MB_ICONERROR);
  Result := False;
  Exit;
 end;
 // Sets the specified device context's pixel format to the format
 // specified by the PixelFormat.
 if (not SetPixelFormat(h_DC, PixelFormat, @pfd)) then
 begin
  glKillWnd(Fullscreen);
  MessageBox(0, 'Unable to set the pixel format', 'Error',
  MB_OK or MB_ICONERROR);
  Result := False;
  Exit;
 end;
 // Create a OpenGL rendering context
 h_RC := wglCreateContext(h_DC);
 if (h_RC = 0) then
 begin
  glKillWnd(Fullscreen);
  MessageBox(0, 'Unable to create an OpenGL rendering context',
  'Error', MB_OK or MB_ICONERROR);
  Result := False;
  Exit;
 end;
 // Makes the specified OpenGL rendering context the calling
 // thread's current rendering context
 if (not wglMakeCurrent(h_DC, h_RC)) then
 begin
  glKillWnd(Fullscreen);
  MessageBox(0, 'Unable to activate OpenGL rendering context', 'Error',
  MB_OK or MB_ICONERROR);
  Result := False;
  Exit;
 end;
 // Initializes the timer used to calculate the FPS
 SetTimer(h_Wnd, FPS_TIMER, FPS_INTERVAL, nil);
 // Settings to ensure that the window is the topmost window
 ShowWindow(h_Wnd, SW_SHOW);
 SetForegroundWindow(h_Wnd);
 SetFocus(h_Wnd);
 // Ensure the OpenGL window is resized properly
 glResizeWnd(Width, Height);
 glInit();
 Result := True;
end;
{--------------------------------------------------------------------}
{ Main message loop for the application }
{--------------------------------------------------------------------}
function WinMain(hInstance: HINST; hPrevInstance: HINST;
 lpCmdLine: PChar; nCmdShow: Integer): Integer; stdcall;
var
 msg: TMsg;
 finished: Boolean;
 DemoStart, LastTime: DWord;
begin
 finished := False;
 // Perform application initialization:
 if not glCreateWnd(640, 480, FALSE, 32) then
 begin
  Result := 0;
  Exit;
 end;
 DemoStart := GetTickCount(); // Get Time when demo started
 // Main message loop:
 while not finished do
 begin
  // Check if there is a message for this window
  if (PeekMessage(msg, 0, 0, 0, PM_REMOVE)) then
  begin
  // If WM_QUIT message received then we are done
  if (msg.message = WM_QUIT) then
  finished := True
  else
  begin // Else translate and dispatch the message to this window
  TranslateMessage(msg);
  DispatchMessage(msg);
  end;
  end
  else
  begin
  Inc(FPSCount); // Increment FPS Counter
  LastTime := ElapsedTime;
  ElapsedTime := GetTickCount() - DemoStart; // Calculate Elapsed Time
  // Average it out for smoother movement
  ElapsedTime := (LastTime + ElapsedTime) div 2;
  glDraw(); // Draw the scene
  SwapBuffers(h_DC); // Display the scene
  if (keys[VK_ESCAPE]) then // If user pressed ESC then set finised TRUE
  finished := True
  else
  ProcessKeys; // Check for any other key Pressed
  end;
 end;
 glKillWnd(FALSE);
 Result := msg.wParam;
end;
begin
 WinMain(hInstance, hPrevInst, CmdLine, CmdShow);
end.