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GLGETMINMAX(3G)                                                                              GLGETMINMAX(3G)



NAME
       glGetMinmax - get minimum and maximum pixel values


C SPECIFICATION
       void glGetMinmax( GLenum target,
                         GLboolean reset,
                         GLenum format,
                         GLenum type,
                         GLvoid *values )


PARAMETERS
       target  Must be GL_MINMAX.

       reset   If  GL_TRUE,  all  entries  in the minmax table that are actually returned are reset to their
               initial values.  (Other entries are unaltered.)  If GL_FALSE, the minmax table is  unaltered.

       format  The   of  the  data  to  be  returned  in  values.  Must be one of GL_RED, GL_GREEN, GL_BLUE,
               GL_ALPHA, GL_RGB, GL_BGR, GL_RGBA, GL_BGRA, GL_LUMINANCE, or GL_LUMINANCE_ALPHA.

       type    The type of the data to be returned in values.  Symbolic constants 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
               are accepted.

       values  A pointer to storage for the returned values.

DESCRIPTION
       glGetMinmax returns the accumulated minimum and maximum pixel values  (computed  on  a  per-component
       basis) in a one-dimensional image of width 2.  The first set of return values are the minima, and the
       second set of return values are the maxima.  The  of the return values is determined by  format,  and
       their type is determined by type.

       No  pixel  transfer  operations  are performed on the return values, but pixel storage modes that are
       applicable to 1-dimensional images are performed.  Color components that are requested in the  speci-fied specified
       fied  format,  but  that are not included in the internal  of the minmax table, are returned as zero.
       The assignment of internal color components to the components requested by format are as follows:


        Internal Component     Resulting Component
        Red                    Red
        Green                  Green
        Blue                   Blue
        Alpha                  Alpha
        Luminance              Red


       If reset is GL_TRUE, the minmax table entries corresponding to the return values are reset  to  their
       initial  values.  Minimum and maximum values that are not returned are not modified, even if reset is
       GL_TRUE.

NOTES
       glGetMinmax is present only if GL_ARB_imaging is returned when glGetString is called with an argument
       of GL_EXTENSIONS.

ERRORS
       GL_INVALID_ENUM is generated if target is not GL_MINMAX.

       GL_INVALID_ENUM is generated if format is not one of the allowable values.

       GL_INVALID_ENUM is generated if type is not one of the allowable values.

       GL_INVALID_OPERATION is generated if glGetMinmax is executed between the execution of glBegin and the
       corresponding execution of glEnd.

       GL_INVALID_OPERATION    is    generated    if    type    is    one     of     GL_UNSIGNED_BYTE_3_3_2,
       GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not
       GL_RGB.

       GL_INVALID_OPERATION   is    generated    if    type    is    one    of    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 and format is neither GL_RGBA nor GL_BGRA.

SEE ALSO
       glMinmax(3G), glResetMinmax(3G), glGetMinmaxParameter(3G)




                                                                                             GLGETMINMAX(3G)