gluScaleImage(3)

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 )

       delim $$

PARAMETERS

       format   Specifies the  of the pixel data.  The following symbolic val-
                ues    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.

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  magni-
       fying  an image, the pixels from the source image are linearly interpo-
       lated 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 ALSO

       glDrawPixels(3G),       glReadPixels(3G),        gluBuild1DMipmaps(3G),
       gluBuild2DMipmaps(3G), gluBuild3DMipmaps(3G),  gluErrorString(3G)

                                                             GLUSCALEIMAGE(3G)