GLUSCALEIMAGE(3G) UNIX Programmer's Manual GLUSCALEIMAGE(3G)
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 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_BGR, GL_BGRA, GL_LUMINANCE, and
GL_LUMINANCE_ALPHA.
wIn, hIn Specify in pixels the width and height, respec-
tively, of the source image.
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, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and
GL_UNSIGNED_INT_2_10_10_10_REV.
dataIn Specifies a pointer to the source image.
wOut, hOut
Specify the width and height, respectively, in pix-
els 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,
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GLUSCALEIMAGE(3G) UNIX Programmer's Manual GLUSCALEIMAGE(3G)
GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2,
GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5,
GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4,
GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1,
GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8,
GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, or
GL_UNSIGNED_INT_2_10_10_10_REV.
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 destina-
tion image. When magnifying an image, the pixels from the
source image are linearly interpolated to create the desti-
nation image.
A return value of zero indicates success, otherwise a GLU
error code is returned (see gluErrorString).
See the glReadPixels reference page for a description of the
acceptable values for the format, typeIn, and typeOut param-
eters.
NOTES
Formats GL_BGR, and GL_BGRA, and types
GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV,
GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV,
GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV,
GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV,
GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV,
GL_UNSIGNED_INT_10_10_10_2, and
GL_UNSIGNED_INT_2_10_10_10_REV are only available if the GL
version is 1.2 or greater.
ERRORS
GLU_INVALID_VALUE is returned if wIn, hIn, wOut, or hOut is
negative.
GLU_INVALID_ENUM is returned if format, typeIn, or typeOut
is not legal.
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GLUSCALEIMAGE(3G) UNIX Programmer's Manual GLUSCALEIMAGE(3G)
GLU_INVALID_OPERATION is returned if typeIn or typeOut is
GL_UNSIGNED_BYTE_3_3_2 or GL_UNSIGNED_BYTE_2_3_3_REV and
format is not GL_RGB.
GLU_INVALID_OPERATION is returned if typeIn or typeOut is
GL_UNSIGNED_SHORT_5_6_5 or GL_UNSIGNED_SHORT_5_6_5_REV and
format is not GL_RGB.
GLU_INVALID_OPERATION is returned if typeIn or typeOut is
GL_UNSIGNED_SHORT_4_4_4_4 or GL_UNSIGNED_SHORT_4_4_4_4_REV
and format is neither GL_RGBA nor GL_BGRA.
GLU_INVALID_OPERATION is returned if typeIn or typeOut is
GL_UNSIGNED_SHORT_5_5_5_1 or GL_UNSIGNED_SHORT_1_5_5_5_REV
and format is neither GL_RGBA nor GL_BGRA.
GLU_INVALID_OPERATION is returned if typeIn or typeOut is
GL_UNSIGNED_INT_8_8_8_8 or GL_UNSIGNED_INT_8_8_8_8_REV and
format is neither GL_RGBA nor GL_BGRA.
GLU_INVALID_OPERATION is returned if typeIn or typeOut is
GL_UNSIGNED_INT_10_10_10_2 or GL_UNSIGNED_INT_2_10_10_10_REV
and format is neither GL_RGBA nor GL_BGRA.
SEE ALSO
glDrawPixels(3G), glReadPixels(3G), gluBuild1DMipmaps(3G),
gluBuild2DMipmaps(3G), gluBuild3DMipmaps(3G),
gluErrorString(3G)
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