HP b2600 Reference Manual page 72

C
glCopyPixels
The rasterization described thus far assumes pixel zoom factors of 1.0. If glPixelZoom is
used to change the x and y pixel zoom factors, pixels are converted to fragments as
follows. If (x
the jth row of the source pixel rectangle, then fragments are generated for pixels whose
centers are in the rectangle with corners at
(x
and
(x
where zoom
Examples
To copy the color pixel in the lower left corner of the window to the current raster
position, use
glCopyPixels(0, 0, 1, 1, GL_COLOR);
Notes
Modes specified by glPixelStore have no effect on the operation of glCopyPixels.
Errors
•
•
•
•
•
Associated Gets
glGet with argument GL_CURRENT_RASTER_POSITION
glGet with argument GL_CURRENT_RASTER_POSITION_VALID
See Also
glDepthFunc,
glDrawBuffer,
glDrawPixels,
glPixelMap,
glPixelTransfer,
glPixelZoom,
glRasterPos,
72
, y ) is the current raster position, and a given pixel is in the ith location in
r r
+ zoom i, y + zoom
r x r y
+ zoom (i+1), y + zoom
r x r
is the value of GL_ZOOM_X and zoom
x
GL_INVALID_ENUM is generated if type is not an accepted value.
GL_INVALID_VALUE is generated if either width or height is negative.
GL_INVALID_OPERATION is generated if type is GL_DEPTH and there is no depth
buffer.
GL_INVALID_OPERATION is generated if type is GL_STENCIL and there is no
stencil buffer.
GL_INVALID_OPERATION is generated if glCopyPixels is executed between the
execution of glBegin and the corresponding execution of glEnd.
j)
(j+1))
y
is the value of GL_ZOOM_Y.
y
Chapter 3