Distorted Android

Beginnings of the WAVE effect.

Correct an important bug in the vertex shader.

b = 1/a if a!=0, 1 otherwise was incorrectly computed as b = 1.0 / (a+1.0-sign(a)). This, when 0<a<2^-24, suffers from 'round-off error': then a+1.0 = 1.0 (sic!) thus b = 1/0 !.

Correct way: b = 1.0 / ( a - (sign(a)-1.0) )

Fix for Bug #17: Regions of Fragment Effects migrate.

Fix is: don't send vertex position and the Fragment Effect region to the fragment shader already multiplied by the ModelView matrix (that introduces the imprecise interpolation because of the projection effect) but simply send both of them in local coords.

Remove the MACROBLOCK Effect altogether.

Fix for Bug #16: When rotated at an angle, surfaces get increasingly transparent.

This also fixes the saturation, chroma, alpha + contrast effects, while completely breaking macroblocks :)

Fix for Bug #18: DISTORT effect: disappearing triangles

Fix for Bug 19: SWIRL effect: mess if Center out of Region.

revert latest changes to the fragment shader.
small things in DistortedObjects.

some improvements for the way we test DistortedObjects.

fix fragment effects :)