spec - OpenGL

2.14. VERTEX SHADERS 126
uniform block, a matrix stride of zero is returned.
If pname is UNIFORM_IS_ROW_MAJOR, then an array identifying whether each
of the uniforms specified by the corresponding array of uniformIndices is a rowmajor
matrix or not is returned. A value of one indicates a row-major matrix, and
a value of zero indicates a column-major matrix, a matrix in the default uniform
block, or a non-matrix.
If pname is UNIFORM_ATOMIC_COUNTER_BUFFER_INDEX, then an array
identifying the active atomic counter buffer index of each of the uniforms specified
by the corresponding array of uniformIndices is returned. For uniforms other
than atomic counters, the returned buffer index is -1. The returned indices can be
passed to GetActiveAtomicCounterBufferiv to query properties of the associated
buffer, and not necessarily the binding point specified in the uniform declaration.
Loading Uniform Variables In The Default Uniform Block
To load values into the uniform variables except for subroutine uniforms and
atomic counters, of the default uniform block of the active program object, use
the commands
void Uniform{1234}{ifd}( int location, T value );
void Uniform{1234}{ifd}v( int location, sizei count,
const T value );
void Uniform{1234}ui( int location, T value );
void Uniform{1234}uiv( int location, sizei count, const
T value );
void UniformMatrix{234}{fd}v( int location, sizei count,
boolean transpose, const float *value );
void UniformMatrix{2x3,3x2,2x4,4x2,3x4,4x3}{fd}v(
int location, sizei count, boolean transpose, const
float *value );
If a non-zero program object is bound by UseProgram, it is the active program
object whose uniforms are updated by these commands. If no program object
is bound using UseProgram, the active program object of the current program
pipeline object set by ActiveShaderProgram is the active program object. If the
current program pipeline object has no active program or there is no current program
pipeline object, then there is no active program.
The given values are loaded into the default uniform block uniform variable
location identified by location.
OpenGL 4.2 (Compatibility Profile) - August 22, 2011