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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.
- We'll need some animated textures
- not too difficult. Just draw some. Keep them small, otherwise they'll slow
the program down.
- We'll tile the animation onto
one surface; make it a vertical surface to avoid the problems with wide surfaces.
- We dont need to have a pre-drawn
surface for the text - we can create a blank surface and draw the text on
ourselves.
- 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.
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