[ Tips ]

OpenGL ES 2.0. Renderer: VideoCore IV HW (Raspberry Pi):
    * for(;;) loop maximum number of iterations = 16;
    * int i = 0 must be inside of the for(;;); example: for( int i = 0;...

Floating point numbers must be written with a dot (even zeros, when comparing or in function parameters).
Convert from int to float: f = float( i )

[ Known bugs ]

OpenGL version: 3.0 Mesa 9.2.2. Renderer: Mesa DRI Intel(R) Ivybridge Mobile. GLSL: 1.30. - Invalid read from i965_dri.so (valgrind test). Some bug in the driver?
Two solutions: 1) remove the "const" from fshader; OR 2) don't remove the shaders after the program link (in Pixilang code).
FIXED IN MESA 13.0.6 (tested 9 feb 2018).
