Unix/Linux Go Back    


CentOS 7.0 - man page for gltexenviv (centos section 3G)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)


GLTEXENV(3G)				  OpenGL Manual 			     GLTEXENV(3G)

NAME
       glTexEnv - set texture environment parameters

C SPECIFICATION
       void glTexEnvf(GLenum target, GLenum pname, GLfloat param);

       void glTexEnvi(GLenum target, GLenum pname, GLint param);

PARAMETERS
       target
	   Specifies a texture environment. May be GL_TEXTURE_ENV, GL_TEXTURE_FILTER_CONTROL or
	   GL_POINT_SPRITE.

       pname
	   Specifies the symbolic name of a single-valued texture environment parameter. May be
	   either GL_TEXTURE_ENV_MODE, GL_TEXTURE_LOD_BIAS, GL_COMBINE_RGB, GL_COMBINE_ALPHA,
	   GL_SRC0_RGB, GL_SRC1_RGB, GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, GL_SRC2_ALPHA,
	   GL_OPERAND0_RGB, GL_OPERAND1_RGB, GL_OPERAND2_RGB, GL_OPERAND0_ALPHA,
	   GL_OPERAND1_ALPHA, GL_OPERAND2_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, or
	   GL_COORD_REPLACE.

       param
	   Specifies a single symbolic constant, one of GL_ADD, GL_ADD_SIGNED, GL_INTERPOLATE,
	   GL_MODULATE, GL_DECAL, GL_BLEND, GL_REPLACE, GL_SUBTRACT, GL_COMBINE, GL_TEXTURE,
	   GL_CONSTANT, GL_PRIMARY_COLOR, GL_PREVIOUS, GL_SRC_COLOR, GL_ONE_MINUS_SRC_COLOR,
	   GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, a single boolean value for the point sprite
	   texture coordinate replacement, a single floating-point value for the texture
	   level-of-detail bias, or 1.0, 2.0, or 4.0 when specifying the GL_RGB_SCALE or
	   GL_ALPHA_SCALE.

C SPECIFICATION
       void glTexEnvfv(GLenum target, GLenum pname, const GLfloat * params);

       void glTexEnviv(GLenum target, GLenum pname, const GLint * params);

PARAMETERS
       target
	   Specifies a texture environment. May be either GL_TEXTURE_ENV, or
	   GL_TEXTURE_FILTER_CONTROL.

       pname
	   Specifies the symbolic name of a texture environment parameter. Accepted values are
	   GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR, or GL_TEXTURE_LOD_BIAS.

       params
	   Specifies a pointer to a parameter array that contains either a single symbolic
	   constant, single floating-point number, or an RGBA color.

DESCRIPTION
       A texture environment specifies how texture values are interpreted when a fragment is
       textured. When target is GL_TEXTURE_FILTER_CONTROL, pname must be GL_TEXTURE_LOD_BIAS.
       When target is GL_TEXTURE_ENV, pname can be GL_TEXTURE_ENV_MODE, GL_TEXTURE_ENV_COLOR,
       GL_COMBINE_RGB, GL_COMBINE_ALPHA, GL_RGB_SCALE, GL_ALPHA_SCALE, GL_SRC0_RGB, GL_SRC1_RGB,
       GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, or GL_SRC2_ALPHA.

       If pname is GL_TEXTURE_ENV_MODE, then params is (or points to) the symbolic name of a
       texture function. Six texture functions may be specified: GL_ADD, GL_MODULATE, GL_DECAL,
       GL_BLEND, GL_REPLACE, or GL_COMBINE.

       The following table shows the correspondence of filtered texture values R t, G t, B t, A
       t, L t, I t to texture source components.  C s and A s are used by the texture functions
       described below.

       +----------------------+----------------------------+---------------------------+
       |Texture Base Internal | C			   | A			       |
       |Format		      | 			s  |			     s |
       +----------------------+----------------------------+---------------------------+
       |GL_ALPHA	      | (0, 0, 0)		   | A			       |
       |		      | 			   |			     t |
       +----------------------+----------------------------+---------------------------+
       |GL_LUMINANCE	      | (			   | 1			       |
       |		      | 			L  |			       |
       |		      | 			t, |			       |
       |		      | 			L  |			       |
       |		      | 			t, |			       |
       |		      | 			L  |			       |
       |		      | 			t  |			       |
       |		      | 			)  |			       |
       +----------------------+----------------------------+---------------------------+
       |GL_LUMINANCE_ALPHA    | (			   | A			       |
       |		      | 			L  |			     t |
       |		      | 			t, |			       |
       |		      | 			L  |			       |
       |		      | 			t, |			       |
       |		      | 			L  |			       |
       |		      | 			t  |			       |
       |		      | 			)  |			       |
       +----------------------+----------------------------+---------------------------+
       |GL_INTENSITY	      | (			   | I			       |
       |		      | 			I  |			     t |
       |		      | 			t, |			       |
       |		      | 			I  |			       |
       |		      | 			t, |			       |
       |		      | 			I  |			       |
       |		      | 			t  |			       |
       |		      | 			)  |			       |
       +----------------------+----------------------------+---------------------------+
       |GL_RGB		      | (			   | 1			       |
       |		      | 			R  |			       |
       |		      | 			t, |			       |
       |		      | 			G  |			       |
       |		      | 			t, |			       |
       |		      | 			B  |			       |
       |		      | 			t  |			       |
       |		      | 			)  |			       |
       +----------------------+----------------------------+---------------------------+
       |GL_RGBA 	      | (			   | A			       |
       |		      | 			R  |			     t |
       |		      | 			t, |			       |
       |		      | 			G  |			       |
       |		      | 			t, |			       |
       |		      | 			B  |			       |
       |		      | 			t  |			       |
       |		      | 			)  |			       |
       +----------------------+----------------------------+---------------------------+

       A texture function acts on the fragment to be textured using the texture image value that
       applies to the fragment (see glTexParameter()) and produces an RGBA color for that
       fragment. The following table shows how the RGBA color is produced for each of the first
       five texture functions that can be chosen.  C is a triple of color values (RGB) and A is
       the associated alpha value. RGBA values extracted from a texture image are in the range
       [0,1]. The subscript p refers to the color computed from the previous texture stage (or
       the incoming fragment if processing texture stage 0), the subscript s to the texture
       source color, the subscript c to the texture environment color, and the subscript v
       indicates a value produced by the texture function.

       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |  Texture Base	 |	       Value		  |	     GL_REPLACE 	   |		GL_MODULATE		|		  GL_DECAL		     |		       GL_BLEND 		  |		GL_ADD		       |
       |  Internal	 |				  |	     Function		   |		Function		|		  Function		     |		       Function 		  |		Function	       |
       |  Format	 |				  |				   |					|					     |						  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |    GL_ALPHA	 C				  C				   | C					|		  undefined		     |	   C					  | C				       |
       |		 |				 v|				  p|				     p	|					     |					   p	  |				    p  |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |		 A				  A				   A					|					     |	 A					  A				       |
       |		 |				 v|				  s|				       p|					     |					 v	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |					 =	  |				       |
       |		 |				  |				   |				       A|					     |						  |				      A|
       |		 |				  |				   |				       s|					     |					     A	  |				      s|
       |		 |				  |				   |					|					     |					     p	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					     A	  |				       |
       |		 |				  |				   |					|					     |					     s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |  GL_LUMINANCE	 C				  C				   C					|		  undefined		     C						  C				       |
       |		 |				 v|				  s|				       p|					     |					 p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				      +|
       |		 |				  |				   |				       C|					     |						  |				      C|
       |		 |				  |				   |				       s|					     |						  |				      s|
       |		 |				  |				   |					|					     |						 1|				       |
       |		 |				  |				   |					|					     |						 -|				       |
       |		 |				  |				   |					|					     |						 C|				       |
       |		 |				  |				   |					|					     |						 s|				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 +	  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 c	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |     (or 1)	 A				  A				   | A					|					     |	   A					  | A				       |
       |		 |				 v|				  p|				     p	|					     |					   p	  |				    p  |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       GL_LUMINANCE_ALPHAC				  C				   C					|		  undefined		     C						  C				       |
       |		 |				 v|				  s|				       p|					     |					 p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				      +|
       |		 |				  |				   |				       C|					     |						  |				      C|
       |		 |				  |				   |				       s|					     |						  |				      s|
       |		 |				  |				   |					|					     |						 1|				       |
       |		 |				  |				   |					|					     |						 -|				       |
       |		 |				  |				   |					|					     |						 C|				       |
       |		 |				  |				   |					|					     |						 s|				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 +	  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 c	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |     (or 2)	 A				  A				   A					|					     |	 A					  A				       |
       |		 |				 v|				  s|				       p|					     |					     p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				       |
       |		 |				  |				   |				       A|					     |					     A	  |				      A|
       |		 |				  |				   |				       s|					     |					     s	  |				      s|
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |  GL_INTENSITY	 C				  C				   C					|		  undefined		     C						  C				       |
       |		 |				 v|				  s|				       p|					     |					 p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				      +|
       |		 |				  |				   |				       C|					     |						  |				      C|
       |		 |				  |				   |				       s|					     |						  |				      s|
       |		 |				  |				   |					|					     |						 1|				       |
       |		 |				  |				   |					|					     |						 -|				       |
       |		 |				  |				   |					|					     |						 C|				       |
       |		 |				  |				   |					|					     |						 s|				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 +	  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 c	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |		 A				  A				   A					|					     A						  A				       |
       |		 |				 v|				  s|				       p|					     |					 p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				      +|
       |		 |				  |				   |				       A|					     |						  |				      A|
       |		 |				  |				   |				       s|					     |						  |				      s|
       |		 |				  |				   |					|					     |						 1|				       |
       |		 |				  |				   |					|					     |						 -|				       |
       |		 |				  |				   |					|					     |						 A|				       |
       |		 |				  |				   |					|					     |						 s|				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 +	  |				       |
       |		 |				  |				   |					|					     |					 A	  |				       |
       |		 |				  |				   |					|					     |					 c	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 A	  |				       |
       |		 |				  |				   |					|					     |					 s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |     GL_RGB	 C				  C				   C					|     C 				     C						  C				       |
       |		 |				 v|				  s|				       p|				      s      |					 p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				      +|
       |		 |				  |				   |				       C|					     |						  |				      C|
       |		 |				  |				   |				       s|					     |						  |				      s|
       |		 |				  |				   |					|					     |						 1|				       |
       |		 |				  |				   |					|					     |						 -|				       |
       |		 |				  |				   |					|					     |						 C|				       |
       |		 |				  |				   |					|					     |						 s|				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 +	  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 c	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |					 C	  |				       |
       |		 |				  |				   |					|					     |					 s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |     (or 3)	 A				  A				   | A					|     A 				     |	   A					  | A				       |
       |		 |				 v|				  p|				     p	|				      p      |					   p	  |				    p  |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |    GL_RGBA	 C				  C				   C					C					     C						  C				       |
       |		 |				 v|				  s|				       p|				    p	     |					 p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				      +|
       |		 |				  |				   |				       C|					     |						  |				      C|
       |		 |				  |				   |				       s|					     |						  |				      s|
       |		 |				  |				   |					|					    1|						 1|				       |
       |		 |				  |				   |					|					    -|						 -|				       |
       |		 |				  |				   |					|					    A|						 C|				       |
       |		 |				  |				   |					|					    s|						 s|				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|				    +	     |					 +	  |				       |
       |		 |				  |				   |					|				    C	     |					 C	  |				       |
       |		 |				  |				   |					|				    s	     |					 c	  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				  |				   |					|				    A	     |					 C	  |				       |
       |		 |				  |				   |					|				    s	     |					 s	  |				       |
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+
       |     (or 4)	 A				  A				   A					|     A 				     |	 A					  A				       |
       |		 |				 v|				  s|				       p|				      p      |					     p	  |				      p|
       |		 |				  |				   |					|					     |						  |				       |
       |		 |				 =|				   |					|					     |						  |				       |
       |		 |				  |				   |				       A|					     |					     A	  |				      A|
       |		 |				  |				   |				       s|					     |					     s	  |				      s|
       +-----------------+--------------------------------+--------------------------------+------------------------------------+--------------------------------------------+--------------------------------------------+------------------------------------+

       If pname is GL_TEXTURE_ENV_MODE, and params is GL_COMBINE, the form of the texture
       function depends on the values of GL_COMBINE_RGB and GL_COMBINE_ALPHA.

       The following describes how the texture sources, as specified by GL_SRC0_RGB, GL_SRC1_RGB,
       GL_SRC2_RGB, GL_SRC0_ALPHA, GL_SRC1_ALPHA, and GL_SRC2_ALPHA, are combined to produce a
       final texture color. In the following tables, GL_SRC0_c is represented by Arg0, GL_SRC1_c
       is represented by Arg1, and GL_SRC2_c is represented by Arg2.

       GL_COMBINE_RGB accepts any of GL_REPLACE, GL_MODULATE, GL_ADD, GL_ADD_SIGNED,
       GL_INTERPOLATE, GL_SUBTRACT, GL_DOT3_RGB, or GL_DOT3_RGBA.

       +---------------------------------------+------------------------------------------------------------------+
       |				       |								  |
       |			GL_COMBINE_RGB |			 Texture				  |
       |				       | Function							  |
       |				       |								  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_REPLACE			       | Arg0								  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_MODULATE			       | Arg0								  |
       |				       |				 x				  |
       |				       |				 Arg1				  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_ADD				       | Arg0								  |
       |				       |				 +				  |
       |				       |				 Arg1				  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_ADD_SIGNED			       | Arg0								  |
       |				       |				 +				  |
       |				       |				 Arg1				  |
       |				       |				 -				  |
       |				       |				 0.5				  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_INTERPOLATE			       | Arg0								  |
       |				       |				     x				  |
       |				       |				     Arg2			  |
       |				       |								  |
       |				       |				 +				  |
       |				       |								  |
       |				       |				     Arg1			  |
       |				       |				     x				  |
       |				       |								  |
       |				       |								  |
       |				       |					     1			  |
       |				       |					     -			  |
       |				       |					     Arg2		  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_SUBTRACT			       | Arg0								  |
       |				       |				 -				  |
       |				       |				 Arg1				  |
       +---------------------------------------+------------------------------------------------------------------+
       |GL_DOT3_RGB			       | 4								  |
       |			or	       |				 x				  |
       |			GL_DOT3_RGBA   |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |							     Arg0 |
       |				       |							     r	  |
       |				       |								  |
       |				       |								  |
       |				       |							 -	  |
       |				       |							 0.5	  |
       |				       |								  |
       |				       |								  |
       |				       |						 x		  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |							     Arg1 |
       |				       |							     r	  |
       |				       |								  |
       |				       |								  |
       |				       |							 -	  |
       |				       |							 0.5	  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |					 +			  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |							     Arg0 |
       |				       |							     g	  |
       |				       |								  |
       |				       |								  |
       |				       |							 -	  |
       |				       |							 0.5	  |
       |				       |								  |
       |				       |								  |
       |				       |						 x		  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |							     Arg1 |
       |				       |							     g	  |
       |				       |								  |
       |				       |								  |
       |				       |							 -	  |
       |				       |							 0.5	  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |					 +			  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |							     Arg0 |
       |				       |							     b	  |
       |				       |								  |
       |				       |								  |
       |				       |							 -	  |
       |				       |							 0.5	  |
       |				       |								  |
       |				       |								  |
       |				       |						 x		  |
       |				       |								  |
       |				       |								  |
       |				       |								  |
       |				       |							     Arg1 |
       |				       |							     b	  |
       |				       |								  |
       |				       |								  |
       |				       |							 -	  |
       |				       |							 0.5	  |
       +---------------------------------------+------------------------------------------------------------------+

       The scalar results for GL_DOT3_RGB and GL_DOT3_RGBA are placed into each of the 3 (RGB) or
       4 (RGBA) components on output.

       Likewise, GL_COMBINE_ALPHA accepts any of GL_REPLACE, GL_MODULATE, GL_ADD, GL_ADD_SIGNED,
       GL_INTERPOLATE, or GL_SUBTRACT. The following table describes how alpha values are
       combined:

       +-----------------------------------------+--------------------------------------------------+
       |					 |						    |
       |			GL_COMBINE_ALPHA |			   Texture		    |
       |					 | Function					    |
       |					 |						    |
       +-----------------------------------------+--------------------------------------------------+
       |GL_REPLACE				 | Arg0 					    |
       +-----------------------------------------+--------------------------------------------------+
       |GL_MODULATE				 | Arg0 					    |
       |					 |				   x		    |
       |					 |				   Arg1 	    |
       +-----------------------------------------+--------------------------------------------------+
       |GL_ADD					 | Arg0 					    |
       |					 |				   +		    |
       |					 |				   Arg1 	    |
       +-----------------------------------------+--------------------------------------------------+
       |GL_ADD_SIGNED				 | Arg0 					    |
       |					 |				   +		    |
       |					 |				   Arg1 	    |
       |					 |				   -		    |
       |					 |				   0.5		    |
       +-----------------------------------------+--------------------------------------------------+
       |GL_INTERPOLATE				 | Arg0 					    |
       |					 |				       x	    |
       |					 |				       Arg2	    |
       |					 |						    |
       |					 |				   +		    |
       |					 |						    |
       |					 |				       Arg1	    |
       |					 |				       x	    |
       |					 |						    |
       |					 |						    |
       |					 |					       1    |
       |					 |					       -    |
       |					 |					       Arg2 |
       +-----------------------------------------+--------------------------------------------------+
       |GL_SUBTRACT				 | Arg0 					    |
       |					 |				   -		    |
       |					 |				   Arg1 	    |
       +-----------------------------------------+--------------------------------------------------+

       In the following tables, the value C s represents the color sampled from the currently
       bound texture, C c represents the constant texture-environment color, C f represents the
       primary color of the incoming fragment, and C p represents the color computed from the
       previous texture stage or C f if processing texture stage 0. Likewise, A s, A c, A f, and
       A p represent the respective alpha values.

       The following table describes the values assigned to Arg0, Arg1, and Arg2 based upon the
       RGB sources and operands:

       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    |					      | 				      |
       |			GL_SRCn_RGB |			      GL_OPERANDn_RGB | 			  Argument    |
       |				    |					      |   Value 			      |
       |				    |					      | 				      |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |GL_TEXTURE			    | GL_SRC_COLOR			      |   C				      |
       |				    |					      | 				  s   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_COLOR		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    C |
       |				    |					      | 				    s |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_SRC_ALPHA			      |   A				      |
       |				    |					      | 				  s   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_ALPHA		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    A |
       |				    |					      | 				    s |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |GL_TEXTUREn			    | GL_SRC_COLOR			      |   C				      |
       |				    |					      | 				  s   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_COLOR		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    C |
       |				    |					      | 				    s |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_SRC_ALPHA			      |   A				      |
       |				    |					      | 				  s   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_ALPHA		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    A |
       |				    |					      | 				    s |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |GL_CONSTANT			    | GL_SRC_COLOR			      |   C				      |
       |				    |					      | 				  c   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_COLOR		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    C |
       |				    |					      | 				    c |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_SRC_ALPHA			      |   A				      |
       |				    |					      | 				  c   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_ALPHA		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    A |
       |				    |					      | 				    c |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |GL_PRIMARY_COLOR		    | GL_SRC_COLOR			      |   C				      |
       |				    |					      | 				  f   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_COLOR		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    C |
       |				    |					      | 				    f |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_SRC_ALPHA			      |   A				      |
       |				    |					      | 				  f   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_ALPHA		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    A |
       |				    |					      | 				    f |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |GL_PREVIOUS			    | GL_SRC_COLOR			      |   C				      |
       |				    |					      | 				  p   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_COLOR		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    C |
       |				    |					      | 				    p |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_SRC_ALPHA			      |   A				      |
       |				    |					      | 				  p   |
       +------------------------------------+-----------------------------------------+---------------------------------------+
       |				    | GL_ONE_MINUS_SRC_ALPHA		      | 1				      |
       |				    |					      | 				-     |
       |				    |					      | 				      |
       |				    |					      | 				    A |
       |				    |					      | 				    p |
       +------------------------------------+-----------------------------------------+---------------------------------------+

       For GL_TEXTUREn sources, C s and A s represent the color and alpha, respectively, produced
       from texture stage n.

       The follow table describes the values assigned to Arg0, Arg1, and Arg2 based upon the
       alpha sources and operands:

       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |				      | 					  |					  |
       |			GL_SRCn_ALPHA | 			GL_OPERANDn_ALPHA |			      Argument	  |
       |				      | 					  |   Value				  |
       |				      | 					  |					  |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |GL_TEXTURE			      | GL_SRC_ALPHA				  |   A 				  |
       |				      | 					  |				      s   |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |				      | GL_ONE_MINUS_SRC_ALPHA			  | 1					  |
       |				      | 					  |				    -	  |
       |				      | 					  |					  |
       |				      | 					  |					A |
       |				      | 					  |					s |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |GL_TEXTUREn			      | GL_SRC_ALPHA				  |   A 				  |
       |				      | 					  |				      s   |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |				      | GL_ONE_MINUS_SRC_ALPHA			  | 1					  |
       |				      | 					  |				    -	  |
       |				      | 					  |					  |
       |				      | 					  |					A |
       |				      | 					  |					s |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |GL_CONSTANT			      | GL_SRC_ALPHA				  |   A 				  |
       |				      | 					  |				      c   |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |				      | GL_ONE_MINUS_SRC_ALPHA			  | 1					  |
       |				      | 					  |				    -	  |
       |				      | 					  |					  |
       |				      | 					  |					A |
       |				      | 					  |					c |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |GL_PRIMARY_COLOR		      | GL_SRC_ALPHA				  |   A 				  |
       |				      | 					  |				      f   |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |				      | GL_ONE_MINUS_SRC_ALPHA			  | 1					  |
       |				      | 					  |				    -	  |
       |				      | 					  |					  |
       |				      | 					  |					A |
       |				      | 					  |					f |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |GL_PREVIOUS			      | GL_SRC_ALPHA				  |   A 				  |
       |				      | 					  |				      p   |
       +--------------------------------------+-------------------------------------------+---------------------------------------+
       |				      | GL_ONE_MINUS_SRC_ALPHA			  | 1					  |
       |				      | 					  |				    -	  |
       |				      | 					  |					  |
       |				      | 					  |					A |
       |				      | 					  |					p |
       +--------------------------------------+-------------------------------------------+---------------------------------------+

       The RGB and alpha results of the texture function are multipled by the values of
       GL_RGB_SCALE and GL_ALPHA_SCALE, respectively, and clamped to the range 0 1.

       If pname is GL_TEXTURE_ENV_COLOR, params is a pointer to an array that holds an RGBA color
       consisting of four values. Integer color components are interpreted linearly such that the
       most positive integer maps to 1.0, and the most negative integer maps to -1.0. The values
       are clamped to the range [0,1] when they are specified.	C c takes these four values.

       If pname is GL_TEXTURE_LOD_BIAS, the value specified is added to the texture
       level-of-detail parameter, that selects which mipmap, or mipmaps depending upon the
       selected GL_TEXTURE_MIN_FILTER, will be sampled.

       GL_TEXTURE_ENV_MODE defaults to GL_MODULATE and GL_TEXTURE_ENV_COLOR defaults to (0, 0, 0,
       0).

       If target is GL_POINT_SPRITE and pname is GL_COORD_REPLACE, the boolean value specified is
       used to either enable or disable point sprite texture coordinate replacement. The default
       value is GL_FALSE.

NOTES
       GL_REPLACE may only be used if the GL version is 1.1 or greater.

       GL_TEXTURE_FILTER_CONTROL and GL_TEXTURE_LOD_BIAS may only be used if the GL version is
       1.4 or greater.

       GL_COMBINE mode and its associated constants may only be used if the GL version is 1.3 or
       greater.

       GL_TEXTUREn may only be used if the GL version is 1.4 or greater.

       Internal formats other than 1, 2, 3, or 4 may only be used if the GL version is 1.1 or
       greater.

       For OpenGL versions 1.3 and greater, or when the ARB_multitexture extension is supported,
       glTexEnv controls the texture environment for the current active texture unit, selected by
       glActiveTexture().

       GL_POINT_SPRITE and GL_COORD_REPLACE are available only if the GL version is 2.0 or
       greater.

ERRORS
       GL_INVALID_ENUM is generated when target or pname is not one of the accepted defined
       values, or when params should have a defined constant value (based on the value of pname)
       and does not.

       GL_INVALID_VALUE is generated if the params value for GL_RGB_SCALE or GL_ALPHA_SCALE are
       not one of 1.0, 2.0, or 4.0.

       GL_INVALID_OPERATION is generated if glTexEnv is executed between the execution of
       glBegin() and the corresponding execution of glEnd().

ASSOCIATED GETS
       glGetTexEnv()

SEE ALSO
       glActiveTexture(), glCopyPixels(), glCopyTexImage1D(), glCopyTexImage2D(),
       glCopyTexSubImage1D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(), glTexImage1D(),
       glTexImage2D(), glTexImage3D(), glTexParameter(), glTexSubImage1D(), glTexSubImage2D(),
       glTexSubImage3D()

COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI
       Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

AUTHORS
       opengl.org

opengl.org				    06/10/2014				     GLTEXENV(3G)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 03:48 AM.