Unix/Linux Go Back    


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

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


GLPIXELTRANSFER(3G)			  OpenGL Manual 		      GLPIXELTRANSFER(3G)

NAME
       glPixelTransfer - set pixel transfer modes

C SPECIFICATION
       void glPixelTransferf(GLenum pname, GLfloat param);

       void glPixelTransferi(GLenum pname, GLint param);

PARAMETERS
       pname
	   Specifies the symbolic name of the pixel transfer parameter to be set. Must be one of
	   the following: GL_MAP_COLOR, GL_MAP_STENCIL, GL_INDEX_SHIFT, GL_INDEX_OFFSET,
	   GL_RED_SCALE, GL_RED_BIAS, GL_GREEN_SCALE, GL_GREEN_BIAS, GL_BLUE_SCALE, GL_BLUE_BIAS,
	   GL_ALPHA_SCALE, GL_ALPHA_BIAS, GL_DEPTH_SCALE, or GL_DEPTH_BIAS.

	   Additionally, if the ARB_imaging extension is supported, the following symbolic names
	   are accepted: GL_POST_COLOR_MATRIX_RED_SCALE, GL_POST_COLOR_MATRIX_GREEN_SCALE,
	   GL_POST_COLOR_MATRIX_BLUE_SCALE, GL_POST_COLOR_MATRIX_ALPHA_SCALE,
	   GL_POST_COLOR_MATRIX_RED_BIAS, GL_POST_COLOR_MATRIX_GREEN_BIAS,
	   GL_POST_COLOR_MATRIX_BLUE_BIAS, GL_POST_COLOR_MATRIX_ALPHA_BIAS,
	   GL_POST_CONVOLUTION_RED_SCALE, GL_POST_CONVOLUTION_GREEN_SCALE,
	   GL_POST_CONVOLUTION_BLUE_SCALE, GL_POST_CONVOLUTION_ALPHA_SCALE,
	   GL_POST_CONVOLUTION_RED_BIAS, GL_POST_CONVOLUTION_GREEN_BIAS,
	   GL_POST_CONVOLUTION_BLUE_BIAS, and GL_POST_CONVOLUTION_ALPHA_BIAS.

       param
	   Specifies the value that pname is set to.

DESCRIPTION
       glPixelTransfer sets pixel transfer modes that affect the operation of subsequent
       glCopyPixels(), glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage1D(),
       glCopyTexSubImage2D(), glCopyTexSubImage3D(), glDrawPixels(), glReadPixels(),
       glTexImage1D(), glTexImage2D(), glTexImage3D(), glTexSubImage1D(), glTexSubImage2D(), and
       glTexSubImage3D() commands. Additionally, if the ARB_imaging subset is supported, the
       routines glColorTable(), glColorSubTable(), glConvolutionFilter1D(),
       glConvolutionFilter2D(), glHistogram(), glMinmax(), and glSeparableFilter2D() are also
       affected. The algorithms that are specified by pixel transfer modes operate on pixels
       after they are read from the frame buffer (glCopyPixels()glCopyTexImage1D(),
       glCopyTexImage2D(), glCopyTexSubImage1D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(),
       and glReadPixels()), or unpacked from client memory (glDrawPixels(), glTexImage1D(),
       glTexImage2D(), glTexImage3D(), glTexSubImage1D(), glTexSubImage2D(), and
       glTexSubImage3D()). Pixel transfer operations happen in the same order, and in the same
       manner, regardless of the command that resulted in the pixel operation. Pixel storage
       modes (see glPixelStore()) control the unpacking of pixels being read from client memory
       and the packing of pixels being written back into client memory.

       Pixel transfer operations handle four fundamental pixel types: color, color index, depth,
       and stencil.  Color pixels consist of four floating-point values with unspecified mantissa
       and exponent sizes, scaled such that 0 represents zero intensity and 1 represents full
       intensity.  Color indices comprise a single fixed-point value, with unspecified precision
       to the right of the binary point.  Depth pixels comprise a single floating-point value,
       with unspecified mantissa and exponent sizes, scaled such that 0.0 represents the minimum
       depth buffer value, and 1.0 represents the maximum depth buffer value. Finally, stencil
       pixels comprise a single fixed-point value, with unspecified precision to the right of the
       binary point.

       The pixel transfer operations performed on the four basic pixel types are as follows:

       Color
	   Each of the four color components is multiplied by a scale factor, then added to a
	   bias factor. That is, the red component is multiplied by GL_RED_SCALE, then added to
	   GL_RED_BIAS; the green component is multiplied by GL_GREEN_SCALE, then added to
	   GL_GREEN_BIAS; the blue component is multiplied by GL_BLUE_SCALE, then added to
	   GL_BLUE_BIAS; and the alpha component is multiplied by GL_ALPHA_SCALE, then added to
	   GL_ALPHA_BIAS. After all four color components are scaled and biased, each is clamped
	   to the range 0 1. All color, scale, and bias values are specified with
	   glPixelTransfer.

	   If GL_MAP_COLOR is true, each color component is scaled by the size of the
	   corresponding color-to-color map, then replaced by the contents of that map indexed by
	   the scaled component. That is, the red component is scaled by
	   GL_PIXEL_MAP_R_TO_R_SIZE, then replaced by the contents of GL_PIXEL_MAP_R_TO_R indexed
	   by itself. The green component is scaled by GL_PIXEL_MAP_G_TO_G_SIZE, then replaced by
	   the contents of GL_PIXEL_MAP_G_TO_G indexed by itself. The blue component is scaled by
	   GL_PIXEL_MAP_B_TO_B_SIZE, then replaced by the contents of GL_PIXEL_MAP_B_TO_B indexed
	   by itself. And the alpha component is scaled by GL_PIXEL_MAP_A_TO_A_SIZE, then
	   replaced by the contents of GL_PIXEL_MAP_A_TO_A indexed by itself. All components
	   taken from the maps are then clamped to the range 0 1.  GL_MAP_COLOR is specified with
	   glPixelTransfer. The contents of the various maps are specified with glPixelMap().

	   If the ARB_imaging extension is supported, each of the four color components may be
	   scaled and biased after transformation by the color matrix. That is, the red component
	   is multiplied by GL_POST_COLOR_MATRIX_RED_SCALE, then added to
	   GL_POST_COLOR_MATRIX_RED_BIAS; the green component is multiplied by
	   GL_POST_COLOR_MATRIX_GREEN_SCALE, then added to GL_POST_COLOR_MATRIX_GREEN_BIAS; the
	   blue component is multiplied by GL_POST_COLOR_MATRIX_BLUE_SCALE, then added to
	   GL_POST_COLOR_MATRIX_BLUE_BIAS; and the alpha component is multiplied by
	   GL_POST_COLOR_MATRIX_ALPHA_SCALE, then added to GL_POST_COLOR_MATRIX_ALPHA_BIAS. After
	   all four color components are scaled and biased, each is clamped to the range 0 1.

	   Similarly, if the ARB_imaging extension is supported, each of the four color
	   components may be scaled and biased after processing by the enabled convolution
	   filter. That is, the red component is multiplied by GL_POST_CONVOLUTION_RED_SCALE,
	   then added to GL_POST_CONVOLUTION_RED_BIAS; the green component is multiplied by
	   GL_POST_CONVOLUTION_GREEN_SCALE, then added to GL_POST_CONVOLUTION_GREEN_BIAS; the
	   blue component is multiplied by GL_POST_CONVOLUTION_BLUE_SCALE, then added to
	   GL_POST_CONVOLUTION_BLUE_BIAS; and the alpha component is multiplied by
	   GL_POST_CONVOLUTION_ALPHA_SCALE, then added to GL_POST_CONVOLUTION_ALPHA_BIAS. After
	   all four color components are scaled and biased, each is clamped to the range 0 1.

       Color index
	   Each color index is shifted left by GL_INDEX_SHIFT bits; any bits beyond the number of
	   fraction bits carried by the fixed-point index are filled with zeros. If
	   GL_INDEX_SHIFT is negative, the shift is to the right, again zero filled. Then
	   GL_INDEX_OFFSET is added to the index.  GL_INDEX_SHIFT and GL_INDEX_OFFSET are
	   specified with glPixelTransfer.

	   From this point, operation diverges depending on the required format of the resulting
	   pixels. If the resulting pixels are to be written to a color index buffer, or if they
	   are being read back to client memory in GL_COLOR_INDEX format, the pixels continue to
	   be treated as indices. If GL_MAP_COLOR is true, each index is masked by 2 n - 1, where
	   n is GL_PIXEL_MAP_I_TO_I_SIZE, then replaced by the contents of GL_PIXEL_MAP_I_TO_I
	   indexed by the masked value.  GL_MAP_COLOR is specified with glPixelTransfer. The
	   contents of the index map is specified with glPixelMap().

	   If the resulting pixels are to be written to an RGBA color buffer, or if they are read
	   back to client memory in a format other than GL_COLOR_INDEX, the pixels are converted
	   from indices to colors by referencing the four maps GL_PIXEL_MAP_I_TO_R,
	   GL_PIXEL_MAP_I_TO_G, GL_PIXEL_MAP_I_TO_B, and GL_PIXEL_MAP_I_TO_A. Before being
	   dereferenced, the index is masked by 2 n - 1, where n is GL_PIXEL_MAP_I_TO_R_SIZE for
	   the red map, GL_PIXEL_MAP_I_TO_G_SIZE for the green map, GL_PIXEL_MAP_I_TO_B_SIZE for
	   the blue map, and GL_PIXEL_MAP_I_TO_A_SIZE for the alpha map. All components taken
	   from the maps are then clamped to the range 0 1. The contents of the four maps is
	   specified with glPixelMap().

       Depth
	   Each depth value is multiplied by GL_DEPTH_SCALE, added to GL_DEPTH_BIAS, then clamped
	   to the range 0 1.

       Stencil
	   Each index is shifted GL_INDEX_SHIFT bits just as a color index is, then added to
	   GL_INDEX_OFFSET. If GL_MAP_STENCIL is true, each index is masked by 2 n - 1, where n
	   is GL_PIXEL_MAP_S_TO_S_SIZE, then replaced by the contents of GL_PIXEL_MAP_S_TO_S
	   indexed by the masked value.

       The following table gives the type, initial value, and range of valid values for each of
       the pixel transfer parameters that are set with glPixelTransfer.

       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |				 |				|				  |				  |
       |			pname	 |			   Type |			  Initial |			    Valid |
       |				 |				| Value 			  | Range			  |
       |				 |				|				  |				  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_MAP_COLOR			 |	     boolean		|	       false		  |	     true/false 	  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_MAP_STENCIL			 |	     boolean		|	       false		  |	     true/false 	  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_INDEX_SHIFT			 |	     integer		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_INDEX_OFFSET 		 |	     integer		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_RED_SCALE			 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_GREEN_SCALE			 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_BLUE_SCALE			 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_ALPHA_SCALE			 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_DEPTH_SCALE			 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_RED_BIAS			 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_GREEN_BIAS			 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_BLUE_BIAS			 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_ALPHA_BIAS			 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_DEPTH_BIAS			 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_RED_SCALE	 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_GREEN_SCALE |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_BLUE_SCALE  |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_ALPHA_SCALE |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_RED_BIAS	 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_GREEN_BIAS  |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_BLUE_BIAS	 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_COLOR_MATRIX_ALPHA_BIAS  |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_RED_SCALE	 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_GREEN_SCALE  |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_BLUE_SCALE	 |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_ALPHA_SCALE  |	      float		|		 1		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_RED_BIAS	 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_GREEN_BIAS	 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_BLUE_BIAS	 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+
       |GL_POST_CONVOLUTION_ALPHA_BIAS	 |	      float		|		 0		  |		  -		  |
       +---------------------------------+------------------------------+---------------------------------+-------------------------------+

       glPixelTransferf can be used to set any pixel transfer parameter. If the parameter type is
       boolean, 0 implies false and any other value implies true. If pname is an integer
       parameter, param is rounded to the nearest integer.

       Likewise, glPixelTransferi can be used to set any of the pixel transfer parameters.
       Boolean parameters are set to false if param is 0 and to true otherwise.  param is
       converted to floating point before being assigned to real-valued parameters.

NOTES
       If a glColorTable(), glColorSubTable(), glConvolutionFilter1D(), glConvolutionFilter2D(),
       glCopyPixels(), glCopyTexImage1D(), glCopyTexImage2D(), glCopyTexSubImage1D(),
       glCopyTexSubImage2D(), glCopyTexSubImage3D(), glDrawPixels(), glReadPixels(),
       glSeparableFilter2D(), glTexImage1D(), glTexImage2D(), glTexImage3D(), glTexSubImage1D(),
       glTexSubImage2D(), or glTexSubImage3D() command is placed in a display list (see
       glNewList() and glCallList()), the pixel transfer mode settings in effect when the display
       list is executed are the ones that are used. They may be different from the settings when
       the command was compiled into the display list.

ERRORS
       GL_INVALID_ENUM is generated if pname is not an accepted value.

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

ASSOCIATED GETS
       glGet() with argument GL_MAP_COLOR

       glGet() with argument GL_MAP_STENCIL

       glGet() with argument GL_INDEX_SHIFT

       glGet() with argument GL_INDEX_OFFSET

       glGet() with argument GL_RED_SCALE

       glGet() with argument GL_RED_BIAS

       glGet() with argument GL_GREEN_SCALE

       glGet() with argument GL_GREEN_BIAS

       glGet() with argument GL_BLUE_SCALE

       glGet() with argument GL_BLUE_BIAS

       glGet() with argument GL_ALPHA_SCALE

       glGet() with argument GL_ALPHA_BIAS

       glGet() with argument GL_DEPTH_SCALE

       glGet() with argument GL_DEPTH_BIAS

       glGet() with argument GL_POST_COLOR_MATRIX_RED_SCALE

       glGet() with argument GL_POST_COLOR_MATRIX_RED_BIAS

       glGet() with argument GL_POST_COLOR_MATRIX_GREEN_SCALE

       glGet() with argument GL_POST_COLOR_MATRIX_GREEN_BIAS

       glGet() with argument GL_POST_COLOR_MATRIX_BLUE_SCALE

       glGet() with argument GL_POST_COLOR_MATRIX_BLUE_BIAS

       glGet() with argument GL_POST_COLOR_MATRIX_ALPHA_SCALE

       glGet() with argument GL_POST_COLOR_MATRIX_ALPHA_BIAS

       glGet() with argument GL_POST_CONVOLUTION_RED_SCALE

       glGet() with argument GL_POST_CONVOLUTION_RED_BIAS

       glGet() with argument GL_POST_CONVOLUTION_GREEN_SCALE

       glGet() with argument GL_POST_CONVOLUTION_GREEN_BIAS

       glGet() with argument GL_POST_CONVOLUTION_BLUE_SCALE

       glGet() with argument GL_POST_CONVOLUTION_BLUE_BIAS

       glGet() with argument GL_POST_CONVOLUTION_ALPHA_SCALE

       glGet() with argument GL_POST_CONVOLUTION_ALPHA_BIAS

SEE ALSO
       glCallList(), glColorTable(), glColorSubTable(), glConvolutionFilter1D(),
       glConvolutionFilter2D(), glCopyPixels(), glCopyTexImage1D(), glCopyTexImage2D(),
       glCopyTexSubImage1D(), glCopyTexSubImage2D(), glCopyTexSubImage3D(), glDrawPixels(),
       glNewList(), glPixelMap(), glPixelStore(), glPixelZoom(), glReadPixels(), glTexImage1D(),
       glTexImage2D(), glTexImage3D(), 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			      GLPIXELTRANSFER(3G)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums


All times are GMT -4. The time now is 01:09 AM.