DirectDraw: Combining Features
By: Jack Hoxley
Written: June 2000
Download: DD_TitleProgram.zip (96kb)

This isn't so much of a tutorial; more an example of how to do the above. I had this thought about doing a credits screen for a game; but using textured text - and the texture would be animated.

It is best understood by seeing the program in action - I was quite impressed with it; it may not be 3D, but it's simple, almost every computer will support it and its FAST.

Normally all the text you draw is one colour; unless you create your own text drawing procedure or use a weird font. This particular program uses this *problem* to create a new effect - If the text is all one colour, you can make it the transparent colour. That means that you can see everything underneath it. If you can see everything underneath it - lets put something cool and good looking underneath it. How about animate the picture underneath it? Even better.

So, some simple thinking makes for a rather clever use of resources available to us. Next; putting this idea into something we can program.

1. We'll need some animated textures - not too difficult. Just draw some. Keep them small, otherwise they'll slow the program down.
2. We'll tile the animation onto one surface; make it a vertical surface to avoid the problems with wide surfaces.
3. We dont need to have a pre-drawn surface for the text - we can create a blank surface and draw the text on ourselves.
4. We'll use a source colour key rather than a detination colour key - as there's much better support for the source colour key.

Here's the texture we'll be using. It's going to be made up of 20 frames - 10 up, 10 down, to get everything moving smoothly. The text to be drawn will be size 20; so we need the texture to be 30 pixels high - 20 of these means that it'll be 600 pixels high in total. Not too bad. The width needs to be 300 pixels to suit our text. Overall dimensions = 600x300.

It may look small, but when the screen is at 640x480 it won't be too bad.

Download the example program - it's the only way you'll see proper animation. You can get it from the top of this page, or from the downloads page.