There are many ways to do wobble. There is wobble only on X and wobble both on X and Y. The later is the yummie one
Sines would do it but used as look up tables (depending on the system your are working, in my opinion in modern GPUs with shaders, just go pure math,. but in software rendering even in modern PCs integer LUTs for sines would still be faster).
It's going to be a regular loop over X,Y bitmap pixels. Pseudocode
for (int y=0; y<height; ++y) {
int offsetY = sin(x * freq) * offsetHeight;
for (int x=0; x<width; ++x) {
int offsetX = sin(y * freq) * offsetWidth;
putpixel(x,y, bitmap[x + offsetX][y + offsetY]);
}
}
Of course don't use putpixel or sin directly,. that's just pseudo code. You can do more complex sines on the offsets, like offset = sin(x * freq1) + sin(x * freq2)
The other way, if you don't want to do per pixel offset is to split the screen into a grid of quad polygons, e.g. every 16*16 pixels, then offset the vertices (or the texture coordinates alternativelly). Interpolate texture between grid points. This way you could use float maths only for few point and not per pixel and still be fast enough, if you don't want to use LUTs. But I think the first per pixel method with some precalc of the sines in LUTs could be much easier, unless you are on a system with a texture rendering engine already.
