NAME

glDepthRange - specify mapping of depth values from normalized device coordinates to window coordinates

C SPECIFICATION

void ggllDDeepptthhRRaannggee( GLclampd _n_e_a_r___v_a_l,
                   GLclampd _f_a_r___v_a_l )

delim $$

PARAMETERS

_n_e_a_r___v_a_l
Specifies the mapping of the near clipping plane to window coordinates. The initial value is 0.
_f_a_r___v_a_l
Specifies the mapping of the far clipping plane to window coordinates. The initial value is 1.

DESCRIPTION

After clipping and division by _w, depth coordinates range from -1 to 1, corresponding to the near and far clipping planes. ggllDDeepptthhRRaannggee specifies a linear mapping of the normalized depth coordinates in this range to window depth coordinates. Regardless of the actual depth buffer implementation, window coordinate depth values are treated as though they range from 0 through 1 (like color components). Thus, the values accepted by ggllDDeepptthhRRaannggee are both clamped to this range before they are accepted.

The setting of (0,1) maps the near plane to 0 and the far plane to 1. With this mapping, the depth buffer range is fully utilized.

NOTES

It is not necessary that _n_e_a_r___v_a_l be less than _f_a_r___v_a_l. Reverse mappings such as $"near_val" ~=~ 1$, and $"far_val" ~=~ 0$ are acceptable.

ERRORS

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllDDeepptthhRRaannggee is executed between the execution of ggllBBeeggiinn and the corresponding execution of ggllEEnndd.

ASSOCIATED GETS

ggllGGeett with argument GGLL__DDEEPPTTHH__RRAANNGGEE

SEE ALSO

ggllDDeepptthhFFuunncc((33GG)), ggllPPoollyyggoonnOOffffsseett((33GG)), ggllVViieewwppoorrtt((33GG))