{===================================================================

	graphics1.p

	Started by Jeff Ondich on 1/25/95
	Last modified 10/11/96


	1. Compile it, run it, and read all the procedures to
	   see what they do.

	2. Try changing the parameters passed to SayHello.  What
	   do rmoveto and rlineto do?  Which is a more generally
	   useful procedure--SayHello, or SayHelloAgain?  Why?

 ===================================================================}

#include	<gpc-graphics.h>

program drawSomeStuff(Input, Output);

import graphics;

const	windowWidth = 600;
		windowHeight = 600;
		windowBottom = 100;
		windowLeft = 100;

{===================================================================
	StartGraphics initializes the graphics package
	and opens a black window for drawing.
 ===================================================================}
procedure StartGraphics;
begin
 	initializegraphics;

	createwindow( windowLeft, windowBottom,
			windowLeft + windowWidth, windowBottom + windowHeight );
	setrgbcolor( 0.0, 0.0, 0.0 );
	flood; 
	flushgraphics
end;

procedure SayHello( startX, startY : integer );
begin
	setrgbcolor( 1.0, 1.0, 1.0 );
	moveto( startX, startY );
	rlineto( 30, 80 );
	rlineto( -10, 20 );
	rlineto( 0, -100 );
	rlineto( 10, 30 );
	rlineto( 10, 0 );
	rlineto( 10, -30 );
	rlineto( 15, 0 );
	rlineto( 10, 30 );
	rlineto( 5, -20 );
	rmoveto( -10, 40 );
	rlineto( 0, 2 );
	flushgraphics
end;

procedure SayHelloAgain;
var		greeting : string(20);
begin
	setrgbcolor( 1, 0, 0 );
	setfont( 1, 36 );
	greeting := 'Howdy.';
	displaytextxy( 350, 400, greeting );
	setrgbcolor( 0, 1, 0 );
	moveto( 380, 350 );
	displaytext( greeting );
	flushgraphics
end;

procedure DrawSomeCircles;
begin
	setrgbcolor( 0, 0, 1 );
	circle( 150, 250, 50 );
	circlefilled( 350, 250, 50 );
	flushgraphics
end;

{===================================================================
	main program
 ===================================================================}
begin
	StartGraphics;
	SayHello( 100, 490 );
	SayHelloAgain;
	DrawSomeCircles;
	readln
end.