in a mesh
GLint j )
eqn not supported
glEvalCoord1( i$^cdot^DELTA u ~+~ u sub 1$ );where
$DELTA u ~=~ ( u sub 2 - u sub 1 ) ^/^ n$
and $n$, $u sub 1$, and $u sub 2$ are the arguments to the most recent glMapGrid1 command. The one absolute numeric requirement is that if $i~=~n$, then the value computed from $i ^cdot^ DELTA u ~+~ u sub 1$ is exactly $u sub 2$.
In the two-dimensional
case, glEvalPoint2, let
$DELTA u ~=~ mark ( u sub 2 - u sub 1 ) ^/^ n$ $DELTA v ~=~ mark ( v sub 2 - v sub 1 ) ^/^ m,$
where $n$, $u sub 1$, $u sub 2$, $m$, $v sub 1$, and $v sub 2$ are the
arguments to the most recent glMapGrid2 command. Then the glEvalPoint2 command
is equivalent to calling
glEvalCoord2( i$^cdot^DELTA u ~+~ u sub 1$, j$^cdot^DELTA v ~+~ v sub 1$ );The only absolute numeric requirements are that if $i~=~n$, then the value computed from $i ^cdot^DELTA u ~+~ u sub 1$ is exactly $u sub 2$, and if $j~=~m$, then the value computed from $i ^cdot^DELTA v ~+~ v sub 1$ is exactly $v sub 2$.