glevalmesh2 man page on Solaris

Man page or keyword search:  
man Server   20652 pages
apropos Keyword Search (all sections)
Output format
Solaris logo
[printable version]

GLEVALMESH(3gl)						       GLEVALMESH(3gl)

NAME
       glEvalMesh1,  glEvalMesh2  -  compute a one- or two-dimensional grid of
       points or lines

C SPECIFICATION
       void glEvalMesh1( GLenum mode,
			 GLint i1,
			 GLint i2 )

PARAMETERS
       mode  In glEvalMesh1, specifies whether to  compute  a  one-dimensional
	     mesh of points or lines.  Symbolic constants GL_POINT and GL_LINE
	     are accepted.

       i1, i2
	     Specify the first and last integer values for grid	 domain	 vari‐
	     able i.

C SPECIFICATION
       void glEvalMesh2( GLenum mode,
			 GLint i1,
			 GLint i2,
			 GLint j1,
			 GLint j2 )

PARAMETERS
       mode   In  glEvalMesh2,	specifies whether to compute a two-dimensional
	      mesh  of	points,	 lines,	 or  polygons.	  Symbolic   constants
	      GL_POINT, GL_LINE, and GL_FILL are accepted.

       i1, i2 Specify  the first and last integer values for grid domain vari‐
	      able i.

       j1, j2 Specify the first and last integer values for grid domain	 vari‐
	      able j.

DESCRIPTION
       glMapGrid and glEvalMesh are used in tandem to efficiently generate and
       evaluate a series of evenly-spaced map domain values.  glEvalMesh steps
       through	the  integer  domain  of a one- or two-dimensional grid, whose
       range is the domain of the evaluation  maps  specified  by  glMap1  and
       glMap2.	 mode  determines whether the resulting vertices are connected
       as points, lines, or filled polygons.

       In the one-dimensional case, glEvalMesh1, the mesh is generated	as  if
       the following code fragment were executed:
       glBegin ();
       for (i = i1; i <= i2; i += 1)
	    glEvalCoord1(i⋅Δu+u1)
       glEnd();
	      where

	      Δu=(u2−u1)/n

       and  n, u1, and u2 are the arguments to the most recent glMapGrid1 com‐
       mand.
	is GL_POINTS if mode is GL_POINT, or GL_LINES if mode is GL_LINE.  The
       one  absolute  numeric  requirement is that if i=n, then the value com‐
       puted from i⋅Δu+u1 is exactly u2.

       In the two-dimensional case, glEvalMesh2, let

				    Δu=(u2−u1)/n

				    Δv=(v2−v1)/m,

       where n, u1, u2, m, v1, and v2 are the arguments	 to  the  most	recent
       glMapGrid2  command.  Then, if mode is GL_FILL, the glEvalMesh2 command
       is equivalent to:
       for (j = j1;  j < j2; j += 1) {
	   glBegin (GL_QUAD_STRIP);
	   for (i = i1; i <= i2; i += 1) {
	       glEvalCoord2(i⋅Δu+u1,j⋅Δv+v1);
	       glEvalCoord2(i⋅Δu+u1, (j+1)⋅Δv+v1);
	   }
	   glEnd();
       }

       If mode is GL_LINE, then a call to glEvalMesh2 is equivalent to:
       for (j = j1;  j <= j2; j += 1) {
	   glBegin(GL_LINE_STRIP);
	   for (i = i1; i <= i2; i += 1)
	       glEvalCoord2(i⋅Δu+u1,j⋅Δv+v1);
	   glEnd();
       }
       for (i = i1;  i <= i2; i += 1) {
	   glBegin(GL_LINE_STRIP);
	   for (j = j1; j <= j1; j += 1)
	       glEvalCoord2)(i⋅Δu+u1,j⋅Δv+v1);
	   glEnd();
       }

       And finally, if mode is GL_POINT, then a call to glEvalMesh2 is equiva‐
       lent to:
       glBegin (GL_POINTS);
       for (j = j1;  j <= j2; j += 1) {
	   for (i = i1; i <= i2; i += 1) {
	       glEvalCoord2(i⋅Δu+u1,j⋅Δv+v1);
	   }
       }
       glEnd();

       In  all three cases, the only absolute numeric requirements are that if
       i=n, then the value computed from i⋅Δu+u1 is exactly u2,	 and  if  j=m,
       then the value computed from j⋅Δv+v1 is exactly v2.

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

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

ASSOCIATED GETS
       glGet with argument GL_MAP1_GRID_DOMAIN
       glGet with argument GL_MAP2_GRID_DOMAIN
       glGet with argument GL_MAP1_GRID_SEGMENTS
       glGet with argument GL_MAP2_GRID_SEGMENTS

SEE ALSO
       glBegin, glEvalCoord, glEvalPoint, glMap1, glMap2, glMapGrid

				   15 Mar 97		       GLEVALMESH(3gl)
[top]

List of man pages available for Solaris

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Tweet
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
....................................................................
Vote for polarhome
Free Shell Accounts :: the biggest list on the net