osx man page for glminmax

GLMINMAX(3G)															      GLMINMAX(3G)

NAME
       glMinmax - define minmax table

C SPECIFICATION
       void glMinmax( GLenum target,
		      GLenum internalformat,
		      GLboolean sink )

PARAMETERS
       target	       The minmax table whose parameters are to be set.  Must be GL_MINMAX.

       internalformat  The   of entries in the minmax table.  Must be one of GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE,
		       GL_LUMINANCE4,	  GL_LUMINANCE8,     GL_LUMINANCE12,	 GL_LUMINANCE16,     GL_LUMINANCE_ALPHA,     GL_LUMINANCE4_ALPHA4,
		       GL_LUMINANCE6_ALPHA2,	GL_LUMINANCE8_ALPHA8,	GL_LUMINANCE12_ALPHA4,	 GL_LUMINANCE12_ALPHA12,   GL_LUMINANCE16_ALPHA16,
		       GL_R3_G3_B2, GL_RGB, GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12,  GL_RGB16,  GL_RGBA,  GL_RGBA2,  GL_RGBA4,  GL_RGB5_A1,
		       GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.

       sink	       If  GL_TRUE, pixels will be consumed by the minmax process and no drawing or texture loading will take place.  If GL_FALSE,
		       pixels will proceed to the final conversion process after minmax.

DESCRIPTION
       When GL_MINMAX is enabled, the RGBA components of incoming pixels are compared to the minimum and maximum values for each component,  which
       are  stored  in	the  2-element minmax table.  (The first element stores the minima, and the second element stores the maxima.)	If a pixel
       component is greater than the corresponding component in the maximum element, then the maximum element is updated with the pixel  component
       value.	If a pixel component is less than the corresponding component in the minimum element, then the minimum element is updated with the
       pixel component value.  (In both cases, if the internal	of the minmax table includes luminance, then the R  color  component  of  incoming
       pixels  is  used  for  comparison.)   The contents of the minmax table may be retrieved at a later time by calling glGetMinmax.	The minmax
       operation is enabled or disabled by calling glEnable or glDisable, respectively, with an argument of GL_MINMAX.

       glMinmax redefines the current minmax table to have entries of the specified by internalformat.	The maximum element  is  initialized  with
       the  smallest  possible component values, and the minimum element is initialized with the largest possible component values.  The values in
       the previous minmax table, if any, are lost.  If sink is GL_TRUE, then pixels are discarded after minmax; no further processing of the pix-
       els takes place, and no drawing, texture loading, or pixel readback will result.

NOTES
       glMinmax 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 one of the allowable values.

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

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

ASSOCIATED GETS
       glGetMinmaxParameter

SEE ALSO
       glGetMinmax, glResetMinmax

																      GLMINMAX(3G)