glClearColor(0.0, 0.0, 0.0, 0.0);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glClearColor 0.0 0.0 0.0 0.0
glClear [expr $GL::GL_COLOR_BUFFER_BIT | $GL::GL_DEPTH_BUFFER_BIT]

GLbyte lst[] = {5, 7, 9};
GLint vp[4]; 
glCallLists(3, GL_BYTE, lst);
glGetIntegerv(GL_VIEWPORT, vp);
printf("viewport : %d %d %d %d\n", vp[0], vp[1], vp[2], vp[4]);

set lst {5 7 9}
glCallLists 3 $GL::GL_BYTE $lst
glGetIntegerv $GL::GL_VIEWPORT vp
puts "viewport : $vp"

glCallLists 3 $GL::GL_BYTE {5 7 9}

# tex is 64 * 64 * 3 bytes binary string read from file
glTexImage2D -binary -variable $GL::GL_TEXTURE_2D 0 3 64 64 0\
            $GL::GL_RGB $GL::GL_UNSIGNED_BYTE tex

% tom .gl
.gl	
% .gl params
-ascii -value
% .gl params -binary
% .gl params
-binary -value
% .gl p -a -var
% .gl p
-ascii -variable