GLUSCALEIMAGE(3gl)GLUSCALEIMAGE(3gl)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 sym‐
bolic 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 des‐
tination image.
When shrinking an image, gluScaleImage uses a box filter to sample the
source image and create pixels for the destination image. When magnify‐
ing an image, the pixels from the source image are linearly interpo‐
lated 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
15 Mar 97 GLUSCALEIMAGE(3gl)
