glBlendColorEXT(3G)	       OpenGL Reference		   glBlendColorEXT(3G)



NAME
     glBlendColorEXT - set the blend color


C SPECIFICATION
     void glBlendColorEXT( GLclampf red,
			   GLclampf green,
			   GLclampf blue,
			   GLclampf alpha )


PARAMETERS
     red, green, blue, alpha specify the components of GL_BLEND_COLOR_EXT


DESCRIPTION
     The GL_BLEND_COLOR_EXT may	be used	to calculate the source	and
     destination blending factors. See glBlendFunc for a complete description
     of	the blending operations.  Initially the	GL_BLEND_COLOR_EXT is set to
     (0,0,0,0).

NOTES
     glBlendColorEXT is	part of	the EXT_blend_color extension, not part	of the
     core GL command set.  If GL_EXT_blend_color is included in	the string
     returned by glGetString, when called with argument	GL_EXTENSIONS,
     extension EXT_blend_color is supported by the connection.

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

ASSOCIATED GETS
     glGet with	an argument of GL_BLEND_COLOR_EXT.


MACHINE	DEPENDENCIES
     RealityEngine, RealityEngine2, and	VTX systems do not support the use of
     source blend factor GL_SRC_ALPHA_SATURATE and a destination factor	based
     on	the constant blend color (GL_.._CONSTANT_.._EXT); such combinations
     produce incorrect results.


SEE ALSO
     glBlendFunc, glGetString.











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