glpixelzoom(3)
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 oper
- ations.
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 element is in the mth row and nth column
of the pixel rectangle, then pixels whose centers are in the rectangle
with corners at
- (xr+nxfactor, yr+myfactor)
- (xr+(n+1)xfactor, yr+(m+1)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
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