NAME
gluScaleImage - scale an image to an arbitrary size
C SPECIFICATION
GLint gluScaleImage( GLenum format,
GLsizei wIn,
GLsizei hIn,
GLenum typeIn,
const void *dataIn,
GLsizei wOut,
GLsizei hOut,
GLenum typeOut,
GLvoid* dataOut )
PARAMETERS
format Specifies the format of the pixel data. The
following symbolic values are valid:
GL_COLOR_INDEX, GL_STENCIL_INDEX,
GL_DEPTH_COMPONENT, GL_RED, GL_GREEN, GL_BLUE,
GL_ALPHA, GL_RGB, GL_RGBA, GL_LUMINANCE, and
GL_LUMINANCE_ALPHA.
wIn, hIn Specify the width and height, respectively, of the
source image that is scaled.
typeIn Specifies the data type for dataIn. Must be one of
GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP,
GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT,
GL_INT, or GL_FLOAT.
dataIn Specifies a pointer to the source image.
wOut, hOut
Specify the width and height, respectively, of the
destination image.
typeOut Specifies the data type for dataOut. Must be one of
GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP,
GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT,
GL_INT, or GL_FLOAT.
dataOut Specifies a pointer to the destination image.
DESCRIPTION
gluScaleImage scales a pixel image using the appropriate
pixel store modes to unpack data from the source image and
pack data into the destination image.
When shrinking an image, gluScaleImage uses a box filter to
sample the source image and create pixels for the
destination image. When magnifying an image, the pixels from
the source image are linearly interpolated to create the
destination image.
A return value of 0 indicates success, otherwise a GLU error
code is returned (see gluErrorString).
See the glReadPixels reference page for a description of the
acceptable values for format, typeIn, and typeOut.
ERRORS
GLU_INVALID_VALUE is returned if wIn, hIn, wOut, or hOut are
< 0.
GLU_INVALID_ENUM is returned if format, typeIn, or typeOut
are not legal.
SEE ALSO
glDrawPixels, glReadPixels, gluBuild1DMipmaps,
gluBuild2DMipmaps, gluErrorString