GLSL uniforms foo

glsl.c

// i = uniform location of vec4 array

// this is fine
glUniform4fv (i, 4, GL_FALSE, ptr); // load 4 elements of an array

// this is NOT fine!
glUniform4fv (i+0, 1, GL_FALSE, ptr); // this will set one element of an array
glUniform4fv (i+1, 1, GL_FALSE, ptr+4); // this and following may or might not work!
glUniform4fv (i+2, 1, GL_FALSE, ptr+8);
glUniform4fv (i+3, 1, GL_FALSE, ptr+12);

// i.e. you can't do arithmetic on uniform locations. To get uniform location of any individual
// array element you have to explicitly query it's location!