A WTL class for developping OpenGL programs using WTL

• Download demo project - 30 Kb
• Download source - 11 Kb

Overview

Recently, I studied up on how to write OpenGL programs. I have tried GLUT, a window system independent toolkit for writing OpenGL programs. But I don't like it since it is C-style and need an additional glut32.dll. I have played with WTL for a while, I really like this great framework for developing Win32 program, so I decided to write OpenGL programs using WTL.

Actually, WTL DOES provide OpenGL support in atlgdi.h. If you didn't define _ATL_NO_OPENGL, you should be able to use ChoosePixelFormat, wglCreateContext, etc. However, you have to do a lot of work every time to write an OpenGL program. For simplification, I developed a class COpenGL which can be easily plugged into your WTL programs.

Using COpenGL

COpenGL is a template class which implements most necessary work for OpenGL. It is defined in atlopengl.h. For using it in your program, you have to do the following steps: (assume your main program is Cube.cpp, your OpenGL window is CMainFrame.)

• copy atlopengl.h to WTL\include.
• add #include <atlopengl.h> in Cube.cpp file.
• derive your OpenGL window CMainFrame from COpenGL<CMainFrame>.
• chain message map to COpenGL by adding CHAIN_MSG_MAP(COpenGL<CMainFrame>) in CMainFrame's message map.
• if you have implemented OnCreate function in CMainFrame, set bHandled = FALSE; before return 0;
• implement three functions in CMainFrame: OnInit(), OnRender(), OnResize()
• (optional) if you want to do animation, derive CMainFrame from CIdleHandler and implement OnIdle. In additional, change CMessageLoop to CGLMessageLoop in Cube.cpp. (you have to do this, otherwise, you cannot get animation).

Similarly you can use it in your view windows. Read atlopengl.h and the demo project for more details.

Conclusion

atlopengl.h is still very simple, but it is a good start for writing OpenGL programs using WTL.

Comment

Partial codes in demo project generated by "OpenGL AppWizard" developed by Ulf Öhlén. See here for details.