DragonFly On-Line Manual Pages

Search: Section:  

GLPIXELZOOM()                                                    GLPIXELZOOM()


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.  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 + n . xfactor, yr + m . yfactor)

                                          (
       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


SEE ALSO

       glCopyPixels, glDrawPixels

                                                                 GLPIXELZOOM()

Search: Section: