NAME
glPixelZoom
- specify the pixel zoom factors
C SPECIFICATION
void ggllPPiixxeellZZoooomm(
GLfloat _x_f_a_c_t_o_r,
GLfloat _y_f_a_c_t_o_r )
delim $$
PARAMETERS
-
_x_f_a_c_t_o_r, _y_f_a_c_t_o_r
-
Specify the $x$ and $y$ zoom factors for pixel write operations.
DESCRIPTION
ggllPPiixxeellZZoooomm specifies values for the $x$ and $y$ zoom factors.
During the execution of ggllDDrraawwPPiixxeellss or ggllCCooppyyPPiixxeellss,
if ($xr $, $yr $) is the current raster position,
and a given element is in the $m$th row and $n$th column of the pixel rectangle,
then pixels whose centers are in the rectangle with corners at
($xr ~+~ n cdot "xfactor"$, $yr ~+~ m cdot "yfactor"$)
($xr ~+~ (n+1) cdot "xfactor"$, $yr ~+~ (m+1) cdot "yfactor"$)
are candidates for replacement.
Any pixel whose center lies on the bottom or left edge of this rectangular
region is also modified.
Pixel zoom factors are not limited to positive values.
Negative zoom factors reflect the resulting image about the current
raster position.
ERRORS
GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllPPiixxeellZZoooomm
is executed between the execution of ggllBBeeggiinn
and the corresponding execution of ggllEEnndd.
ASSOCIATED GETS
ggllGGeett with argument GGLL__ZZOOOOMM__XX
ggllGGeett with argument GGLL__ZZOOOOMM__YY
SEE ALSO
ggllCCooppyyPPiixxeellss((33GG)),
ggllDDrraawwPPiixxeellss((33GG))