Parabola
My goal was to create the curves above. I knew if I could draw it then I could move a box or game object along that path. It took me about two weeks of casual time and many math questions posted to yahoo answers.
The problem is, implementing a math formula in C++. It’s just not as pretty as the equation and any algebra tricks are hard to express in code. Not to mention remembering algebra period. ?
Eventually, I ended up with this. I specified the starting point, the ending point and how tall I want the curve. A series of horrible equations builds the rest into a vector of x,y point structs. There’s an LOD thing too that says how pretty the curve should be.
Of course, it’s pixilated and kinda ugly. I tried anti-aliasing it but it doesn’t look much better. Also, I might have some math issues because in some places there seems to be small humps. I might be running into precision problems again. ?
Overall, I’m pretty exhausted. I don’t know what my next project will be, I don’t know if I want to make more of a game that’s interactive instead of these little graphics tests.
Also, C++ is pretty ugly imo. It’s used everywhere, I understand but I might pick up an actionscript book and see how much of this graphics stuff could be wrapped up in flash. I bet you can do some cool low-level drawing in flash; and then it’d be more ‘portable’ than an OSX app.
Anyway … it’s a thing of goddamn beauty for now. Except the code, which is ugly, untidy and probably doesn’t compile by itself. I’ll update it so it’s stand-alone.
I can’t view the code, that link doesn’t work. You can make portable C++ if use portable libraries such as SDL and OpenGL.
I don’t know if you have already or if you are still maintaining either of these, but if you are, a reasonably simple mod would be combining Parabola with Animated Box for double the awesomeness.
http://squarism.com/2007/04/01/animated-box/
Another cool thing which would tick one of your goals, is adding lua support.
http://squarism.com/questions/
I haven’t done much lua, but you could maybe have a function in your lua file (Pseudo code):
void GetYValue(in x, out& y)
{
y = x;
}
and you can easily add a million variations:
void GetYValue(in x, out& y)
{
y = sin(x);
}
etc.
It’s is kind of limited like that, ie. you can’t get a vertical line. You could extend it to actually read a string so that you can specify either y = … or x = … and your program would magically work it all out.
I’m not sure if lua does it or not, but you could even have a check in your update function that compares the last modified time of the currently loaded script with the modified time of the script on the hard drive and reloads it if it is newer, so you edit the script in XCode or whatever and save it and the graph magically shows up.