GLUSCALEIMAGE(3G)GLUSCALEIMAGE(3G)NAMEgluScaleImage - 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 )
delim $$
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, respectively, 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 pixels 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, 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.
DESCRIPTIONgluScaleImage 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 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 parameters.
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.
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 ALSOglDrawPixels(3G), glReadPixels(3G), gluBuild1DMipmaps(3G),
gluBuild2DMipmaps(3G), gluBuild3DMipmaps(3G), gluErrorString(3G)
March 1, 2011
