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); //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; // Top 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 // Top level window
WS_EX_WINDOWEDGE; // Border with a raised edge
ShowCursor(False); // Turn of the cursor (gets in the way)
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
nSize := SizeOf(TPIXELFORMATDESCRIPTOR); // Size Of This Pixel Format Descriptor
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;
