Native bindings to the EXT_texture_shared_exponent extension.

Existing texture formats provide either fixed-point formats with limited range and precision but with compact encodings (allowing 32 or fewer bits per multi-component texel), or floating-point formats with tremendous range and precision but without compact encodings (typically 16 or 32 bits per component).

This extension adds a new packed format and new internal texture format for encoding 3-component vectors (typically RGB colors) with a single 5-bit exponent (biased up by 15) and three 9-bit mantissas for each respective component. There is no sign bit so all three components must be non-negative. The fractional mantissas are stored without an implied 1 to the left of the decimal point. Neither infinity nor not-a-number (NaN) are representable in this shared exponent format.

This 32 bits/texel shared exponent format is particularly well-suited to high dynamic range (HDR) applications where light intensity is typically stored as non-negative red, green, and blue components with considerable range.

Promoted to core in OpenGL 3.0.