glpixelzoom
- Man Page
glPixelZoom(3G) OpenGL Reference glPixelZoom(3G)
NAME
glPixelZoom - specify the pixel zoom factors
C SPECIFICATION
void glPixelZoom( GLfloat xfactor,
GLfloat yfactor )
PARAMETERS
xfactor, yfactor Specify the x and y zoom factors for pixel write
operations.
DESCRIPTION
glPixelZoom specifies values for the x and y zoom factors. Let, (xr, yr)
be the current raster position, and let interlace be either 1 or 2
corresponding to whether GL_INTERLACE_SGIX is enabled or not,
respectively. Then, during the execution of glDrawPixels or
glCopyPixels, for a pixel that is in the mth row and nth column of the
source image, the destination pixels that are candidate for replacement
are those whose centers are on the bottom or left edge of, or inside the
rectangle with corners at
(xr + n x xfactor, yr + m x interlace x yfactor) and
(xr + (n + 1) x xfactor,yr + (m x interlace + 1) x yfactor)
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 executed between the
execution of glBegin and the corresponding execution of glEnd.
ASSOCIATED GETS
glGet with argument GL_ZOOM_X
glGet with argument GL_ZOOM_Y
glGet with argument GL_INTERLACE_SGIX
MACHINE DEPENDENCIES
The SGIX_interlace extension is supported only on InfiniteReality systems
and on RealityEngine, RealityEngine2, and VTX systems.
SEE ALSO
glCopyPixels, glEnable, glDrawPixels.
Page 1