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Font rendering and the joys of C++

At the moment, all the menu text in the game is stored in separated images – one for every menu item. For example, this is the “New Game” button:

menu-newgame

Of course, storing each menu item as a separate picture is not very efficient, so I decided to add text rendering capability to the game.

My first choice was the OGLFT library. It’s a really easy to use and complete OpenGL text rendering library based on FreeType. I quickly added it to the project, and it worked perfectly, until I closed the application and got a nice “Access violation” exception 🙁

After hours of tinkering, I finally found out that the error was related to the FreeType library. For some mysterious reason, just trying to open a font file with FreeType caused the erroneous behavior.

So, since I couldn’t use FreeType, I decided to create a text rendering class myself, based on the font texture approach.

In order to create suitable font maps, I modified Irrlicht Font Maker to create non-irrlicht-specific font maps. I also added a couple of options and the ability to export the control points as custom text  or in a handy binary format:

New Options in Irrlicht Font Maker Text export

But that’s only the first part of the story: once ready, I took my new text rendering class for a test drive and, with much surprise, I discovered that the program triggered the same exception it did before! OH MY!

After an hour or so of debugging, I finally found out the root cause of the problem: a single call to fopen to read the font control points was enough to send the program to C++ hell.

I have since replaced all the standard C file IO functions (fopen, fread, …) with the modern C++ equivalent (fstream) and now the program ends with no errors.

In the end, I’m happy with the new font rendering method, as it gave me a chance to clean up and improve Irrlicht Font Maker, however once again I feel like I misplaced my foot in the minefield that is programming in C++ 🙂

This entry was posted on Wednesday, October 21st, 2009 at 5:30 pm and is filed under game. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

One Response to “Font rendering and the joys of C++”

  1. user's GrAvatar Me October 21st, 2013 at 6:46 am

    That’s the worst thing I’ve ever heard someone do. If you can’t figure out what you’re doing wrong with standard C functions, you shouldn’t be using C++. My two cents.