* added documentation (in-code and pasdoc generated)

[glBitmap.git] / examples / Helper.pas

diff --git a/examples/Helper.pas b/examples/Helper.pas
new file mode 100644 (file)
index 0000000..5311e5c
--- /dev/null
+++ b/examples/Helper.pas
@@ -0,0 +1,91 @@
+unit Helper;
+
+{$mode objfpc}{$H+}
+
+interface
+
+uses
+  Classes, SysUtils, Windows, dglOpenGL;
+
+type
+  TOpenGLWindow = packed record
+    LWndClass: TWndClass;
+    hMainHandle: HWND;
+    DC: HDC;
+    RC: HGLRC;
+  end;
+
+function CreateOpenGLWindow(const aCaption: String; const aWidth, aHeight: Integer; const aWndProc: WNDPROC): TOpenGLWindow;
+function ProgressMesages: Boolean;
+procedure DestroyOpenGLWindow(const aWindow: TOpenGLWindow);
+
+implementation
+
+function CreateOpenGLWindow(const aCaption: String; const aWidth, aHeight: Integer; const aWndProc: WNDPROC): TOpenGLWindow;
+begin
+  //create the window
+  result.LWndClass.hInstance := hInstance;
+  with result.LWndClass do begin
+    lpszClassName := 'MyWinApiWnd';
+    Style         := CS_PARENTDC or CS_BYTEALIGNCLIENT;
+    hIcon         := LoadIcon(hInstance,'MAINICON');
+    lpfnWndProc   := aWndProc;
+    hbrBackground := COLOR_BTNFACE+1;
+    hCursor       := LoadCursor(0,IDC_ARROW);
+  end;
+  RegisterClass(result.LWndClass);
+  result.hMainHandle := CreateWindow(
+    result.LWndClass.lpszClassName,
+    PAnsiChar(aCaption),
+    WS_CAPTION or WS_MINIMIZEBOX or WS_SYSMENU or WS_VISIBLE,
+    (GetSystemMetrics(SM_CXSCREEN) - aWidth)  div 2,
+    (GetSystemMetrics(SM_CYSCREEN) - aHeight) div 2,
+    aWidth, aHeight, 0, 0, hInstance, nil);
+
+  // create and activate rendering context
+  result.DC := GetDC(result.hMainHandle);
+  if (result.DC = 0) then begin
+    WriteLn('unable to get DeviceContext');
+    halt;
+  end;
+  result.RC := CreateRenderingContext(result.DC, [opDoubleBuffered], 32, 24, 0, 0, 0, 0);
+  if (result.RC = 0) then begin
+    WriteLn('unable to create RenderingContext');
+    halt;
+  end;
+  ActivateRenderingContext(result.DC, result.RC);
+
+  // init OpenGL
+  glViewport(0, 0, aWidth, aHeight);
+  glClearColor(0, 0, 0, 0);
+  glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);
+
+  glDisable(GL_DEPTH_TEST);
+  glDisable(GL_CULL_FACE);
+
+  glMatrixMode(GL_PROJECTION);
+  glLoadIdentity;
+  glOrtho(0, aWidth, aHeight, 0, -10, 10);
+  glMatrixMode(GL_MODELVIEW);
+  glLoadIdentity;
+end;
+
+function ProgressMesages: Boolean;
+var
+  Msg: TMSG;
+begin
+  result := GetMessage(Msg, 0, 0, 0);
+  if result then begin
+    TranslateMessage(Msg);
+    DispatchMessage(Msg);
+  end;
+end;
+
+procedure DestroyOpenGLWindow(const aWindow: TOpenGLWindow);
+begin
+  DestroyRenderingContext(aWindow.RC);
+  ReleaseDC(aWindow.hMainHandle, aWindow.DC);
+end;
+
+end.
+