- specify the pixel zoom factors
C SPECIFICATION
PARAMETERS
_param1, _param2 Specify the x and y zoom factors for
pixel write operations.
DESCRIPTION
glPixelZoom specifies values for the x and y zoom factors.
During the execution of glDrawPixels or glCopyPixels, if
(xr, yr) is the current raster position, and a given ele-
ment is in the mth row and nth column of the pixel rectan-
gle, then pixels whose centers are in the rectangle with
corners at
(xr+n._eqnparam1, yr+m._eqnparam2)
(xr+(n+1)._eqnparam1, yr+(m+1)._eqnparam2)
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
GL_INVALID_OPERATION is generated if glPixelZoom is exe-
cuted between the execution of glBegin and the correspond-
ing execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_ZOOM_X
glGet with argument GL_ZOOM_Y
SEE ALSO
glCopyPixels, glDrawPixels
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