HP b2600 Reference Guide

C
glCopyPixels
Chapter 3
70
glCopyPixels
glCopyPixels: copy pixels in the frame buffer.
C Specification
void glCopyPixels(
GLint x,
GLint y,
GLsizei width,
GLsizei height,
GLenum type)
Parameters
x, y Specify the window coordinates of the lower left corner of the
rectangular region of pixels to be copied.
width, height Specify the dimensions of the rectangular region of pixels to be copied.
Both must be nonnegative.
type Specifies whether color values, depth values, or stencil values are to be
copied. Symbolic constants GL_COLOR, GL_DEPTH, and
GL_STENCIL are accepted.
Description
glCopyPixels copies a screen-aligned rectangle of pixels from the specified frame buffer
location to a region relative to the current raster position. Its operation is well defined
only if the entire pixel source region is within the exposed portion of the window. Results
of copies from outside the window, or from regions of the window that are not exposed,
are hardware dependent and undefined.
x and y specify the window coordinates of the lower left corner of the rectangular region
to be copied. width and height specify the dimensions of the rectangular region to be
copied. Both width and height must not be negative.
Several parameters control the processing of the pixel data while it is being copied.
These parameters are set with three commands: glPixelTransfer, glPixelMap, and
glPixelZoom. This reference page describes the effects on glCopyPixels of most, but not
all, of the parameters specified by these three commands.
glCopyPixels copies values from each pixel with the lower left-hand corner at (x + i,y+j)
for 0 ≥ i<width and 0 ≥ j<height. This pixel is said to be the ith pixel in the jth row. Pixels
are copied in row order from the lowest to the highest row, left to right in each row.
type specifies whether color, depth, or stencil data is to be copied. The details of the
transfer for each data type are as follows:
GL_COLOR
Indices or RGBA colors are read from the buffer currently specified as the read source
buffer (see glReadBuffer). If the GL is in color index mode, each index that is read from
this buffer is converted to a fixed-point format with an unspecified number of bits to the

HP b2600 Specifications

General

Brand	HP
Model	b2600
Category	Desktop
Language	English