gluScaleImage(3G)	       OpenGL Reference		     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 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, GL_LUMINANCE_ALPHA, and GL_ABGR_EXT.

     wIn, hIn Specify the width	and height, respectively, in pixels 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, GL_FLOAT,
	      GL_UNSIGNED_BYTE_3_3_2_EXT, GL_UNSIGNED_SHORT_4_4_4_4_EXT,
	      GL_UNSIGNED_SHORT_5_5_5_1_EXT, GL_UNSIGNED_INT_8_8_8_8_EXT, or
	      GL_UNSIGNED_INT_10_10_10_2_EXT.

     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_EXT, GL_UNSIGNED_SHORT_4_4_4_4_EXT,
	      GL_UNSIGNED_SHORT_5_5_5_1_EXT, GL_UNSIGNED_INT_8_8_8_8_EXT, or
	      GL_UNSIGNED_INT_10_10_10_2_EXT.

     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.



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gluScaleImage(3G)	       OpenGL Reference		     gluScaleImage(3G)



     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 indicating what the problem was (see gluErrorString).

     Please refer to the glReadPixels reference	page for a description of the
     acceptable	values for the format, typeIn, and typeOut parameters.

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.

     GLU_INVALID_ENUM is returned if typeIn or typeOut is
     GL_UNSIGNED_BYTE_3_3_2_EXT	and format is not GL_RGB.

     GLU_INVALID_ENUM is returned if typeIn or typeOut is
     GL_UNSIGNED_SHORT_4_4_4_4_EXT and format is neither GL_RGBA nor
     GL_ABGR_EXT.

     GLU_INVALID_ENUM is returned if typeIn or typeOut is
     GL_UNSIGNED_SHORT_5_5_5_1_EXT and format is neither GL_RGBA nor
     GL_ABGR_EXT.

     GLU_INVALID_ENUM is returned if typeIn or typeOut is
     GL_UNSIGNED_INT_8_8_8_8_EXT and format is neither GL_RGBA nor
     GL_ABGR_EXT.

     GLU_INVALID_ENUM is returned if typeIn or typeOut is
     GL_UNSIGNED_INT_10_10_10_2_EXT and	format is neither GL_RGBA nor
     GL_ABGR_EXT.

SEE ALSO
     glDrawPixels, glReadPixels, gluBuild1DMipmaps, gluBuild2DMipmaps,
     gluErrorString

















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