no warnings;

# Draw a grid of hexagons
glMatrixMode(GL_MODELVIEW);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glColor3f(1,1,0);
glPointSize(10);
glLineWidth(1);
glDisable(GL_DEPTH_TEST);


glLoadIdentity();
glTranslatef(-5,-8,-30);
glPushMatrix();

glTranslatef(0,0,0);
for my $x (0..10)
{
	glTranslatef(cos(R30D),sin(R30D),0);
	glPushMatrix();
	for my $y(0..10)
	{
		glTranslatef(0,1,0);
		drawHex([$x%2,$y%2,0], [0,.5-$y/20,$y/10]);
	}
	glPopMatrix();
}
glPopMatrix();

glutSwapBuffers();


sub drawHex
{
	my $border=shift;
	my $fill = shift;
	my $r = shift || 0.5;
	my $bwidth = shift || 0.05;
	
	$r = $r-2*$bwidth;
	my $s = $r / cos(R30D);
	my $h = $s * sin(R30D);
	#print "$h, $r, $s";
	if (defined $fill)
	{
	glColor3f(@$fill);
	glBegin(GL_POLYGON);
		glVertex2f($bwidth+$h,-$r);
		glVertex2f($bwidth+$h+$s,-$r);
		glVertex2f($bwidth+2*$h+$s,0);
		glVertex2f($bwidth+$h+$s, $r);
		glVertex2f($bwidth+$h, $r);
		glVertex2f($bwidth,0);
	glEnd();
	}
	if (defined $border)
	{
	glColor3f(@$border);
	glBegin(GL_LINE_LOOP);
		glVertex2f($bwidth+$h,-$r);
		glVertex2f($bwidth+$h+$s,-$r);
		glVertex2f($bwidth+2*$h+$s,0);
		glVertex2f($bwidth+$h+$s, $r);
		glVertex2f($bwidth+$h, $r);
		glVertex2f($bwidth,0);
	glEnd();
	}
}