/lenasys/0.1

/********************************************************************************

   Mouse coordinate and canvas globals

   Handles both Touch and Mouse/Keyboard input at the same time

*********************************************************************************/

		// Mouse coordinate globals

		var gridx,gridy;

		var clickstate=0;

		var acanvas;

		var context;

/********************************************************************************

   Canvas Setup and Click Handling Code

   Handles both Touch and Mouse/Keyboard input at the same time and executes 

   handler callbacks.

   Also declares canvas globals

*********************************************************************************/

		function setupcanvas()

		{

				acanvas=document.getElementById('a');

				context=acanvas.getContext("2d");		

				setTimeout("foo();",50);

				setupClickHandling();		

		}

		function setupClickHandling()

		{

				// Mouse and Keyboard Events

				acanvas.addEventListener('mousemove', ev_mousemove, false);

				acanvas.addEventListener('mouseup', ev_mouseup, false);

				acanvas.addEventListener('mousedown', ev_mousedown, false);

				// Touch Events

				acanvas.addEventListener('touchstart', ev_touchstart, false);

				acanvas.addEventListener('touchend', ev_touchend, false);

				acanvas.addEventListener('touchmove', ev_touchmove, false);		

		}						

		// Keyboard/Mouse Mouse Up Handler

		function ev_mouseup(ev)

		{

				handler_mouseup(ev);

		}

		// Keyboard/Mouse Mouse Down Handler

		function ev_mousedown(ev)

		{

				handler_mousedown(ev);		

		}

		// Keyboard/Mouse Mouse Move Handler

		function ev_mousemove (ev) 

		{

			  var cx,cy=0;

			  if (ev.layerX||ev.layerX==0) { // Firefox

				    cx=ev.layerX-acanvas.offsetLeft;

				    cy=ev.layerY-acanvas.offsetTop;

			  } else if (ev.offsetX || ev.offsetX == 0) { // Opera

				    cx=ev.offsetX-acanvas.offsetLeft;

				    cy=ev.offsetY-acanvas.offsetTop;

			  }

			  coord=findPos(acanvas);

				cx=cx-coord.x;

				cy=cy-coord.y;

				handler_mousemove(cx,cy);

		}		

		// Touch start event

		function ev_touchstart(event){  

    		event.preventDefault();  

     		var numtouch = event.touches.length;  

				targetEvent =  event.touches.item(0);

				var cx = targetEvent.pageX;

				var cy = targetEvent.pageY;

				gridx=cx;

				gridy=cy;

 				handler_mousedown(event);

		}  

		// Touch end event

		function ev_touchend(event){  

    		event.preventDefault();  

     		var numtouch = event.touches.length;  

 				handler_mouseup();

		};  

		// Touch move event

		function ev_touchmove(event){  

    		event.preventDefault();  

     		var numtouch = event.touches.length;  

				targetEvent =  event.touches.item(0);

				var cx = targetEvent.pageX;

				var cy = targetEvent.pageY;

				handler_mousemove(cx,cy);				

		};  

		// Fix scrolling on touch devices

		var ScrollFix = function(elem) {

		    // Variables to track inputs

		    var startY, startTopScroll;

		    elem = elem || document.querySelector(elem);

		    // If there is no element, then do nothing  

		    if(!elem)

		        return;

		    // Handle the start of interactions

		    elem.addEventListener('touchstart', function(event){

		        startY = event.touches[0].pageY;

		        startTopScroll = elem.scrollTop;

		        if(startTopScroll <= 0)

		            elem.scrollTop = 1;

		        if(startTopScroll + elem.offsetHeight >= elem.scrollHeight)

		            elem.scrollTop = elem.scrollHeight - elem.offsetHeight - 1;

		    }, false);

		};

/********************************************************************************

   Canvas Diagram Drawing Code

*********************************************************************************/

		// Draws a perfect round circle

		function drawcircle(radius,color)

		{

				context.lineWidth   = 1.5;

				context.strokeStyle = color;

				context.arc(0, 0, radius, 0 , 2 * Math.PI, false);

		}

		// Draws 90 degree arc

		function drawellipse(x1,y1,x2,y2)

		{

					var rx=(x2-x1)/2.0;

					var ry=(y2-y1)/2.0;

					var x3=x1+rx;

					var y3=y1+ry;

					context.beginPath();					

					context.moveTo(x1,y1+ry);

					context.quadraticCurveTo(x1,y1,x1+rx,y1);

					context.quadraticCurveTo(x2,y1,x2,y1+ry);

					context.quadraticCurveTo(x2,y2,x2-rx,y2);

					context.quadraticCurveTo(x1,y2,x1,y1+ry);

					context.stroke();

		}	

		// Draw a point		

		function point(x,y,col)

		{

				context.strokeStyle="#000";

				context.lineWidth = 1;

				context.fillStyle=col;

				context.fillRect(x-4,y-4,8,8);		

				context.strokeRect(x-4,y-4,8,8);						

		}

		// Draw a box around a point to indicate highlight

		function highlight(px,py)

		{

				context.strokeStyle="#aaa";

				context.lineWidth = 1;

				context.strokeRect(px-8,py-8,16,16);						

		}

		// Draw a line using current context

		function drawline(x1,y1,x2,y2,strokestyle,linewidth)

		{

						context.strokeStyle = strokestyle;

						context.lineWidth   = linewidth;

						context.beginPath();

						context.moveTo(x1,y1);

						context.lineTo(x2,y2);

						context.stroke();							

		}

		function fourpoints(x1,y1,x2,y2,x3,y3,x4,y4,col)

		{

				point(x1,y1,col);

				point(x2,y2,col);

				point(x3,y3,col);

				point(x4,y4,col);				

		}

		function drawdiamond(x1,y1,rx,ry,expand)

		{

				context.beginPath();					

				context.moveTo(x1-expand,y1+ry);

				context.lineTo(x1+rx,y2+expand);

				context.lineTo(x2+expand,y1+ry);

				context.lineTo(x1+rx,y1-expand);

				context.lineTo(x1-expand,y1+ry);			

				context.stroke();											

		}

		// Dashed Line in Segments of given size

		function dashedline(sx,sy,ex,ey,dashlen,linewidth,col)

		{

			var dx=ex-sx;

			var dy=ey-sy;

			len=Math.sqrt((dx*dx)+(dy*dy));

			notimes=Math.round(len/dashlen);

			dx=dx/notimes;

			dy=dy/notimes;

			context.lineWidth = linewidth;

			context.strokeStyle=col;

			context.beginPath();

			var xk,yk;

			xk=sx;

			yk=sy;

			xh=dx/2.0;

			yh=dy/2.0;

			for(var i=0;i<notimes;i++){

					context.moveTo(xk,yk);				

					context.lineTo(xk+xh,yk+yh);

					xk+=dx;

					yk+=dy;

			}

			context.stroke();

		}

		// Arcto only works if both x1 and y2 are on circle border

		function arcto(x0,y0,x1,y1,x2,y2)

		{

				var r = Math.sqrt((x1-x0)*(x1-x0) + (y1-y0)*(y1-y0));

				var x = x0-r;

				var y = y0-r;

				var startAngle = (180/Math.PI*Math.atan2(y1-y0, x1-x0));

				var endAngle = (180/Math.PI*Math.atan2(y2-y0, x2-x0));

				context.arc(x0, y0, r, 0, Math.PI*2.0, 1.0);

		}

		// Draws 90 degree arc

		function arcdeg(x1,y1,x2,y2,x3,y3)

		{

					// First quadrant positive positive			

					dashedline(x1,y1,x2,y2,8,1.0,"#999");

					dashedline(x3,y3,x2,y2,8,1.0,"#999");					

					point(x1,y1,"#ff5");

					point(x2,y2,"#f55");

					point(x3,y3,"#f55");

					k=(y3-y1)/(x3-x1);					

					yk=y1+((x2-x1)*k);

					rx=x3-x1;

					ry=y3-y1;

					point(x2,yk,"#f5f");

					context.strokeStyle = '#49f';

					context.lineWidth   = 1.0;					

					context.beginPath();					

					context.moveTo(x1,y1);

					for(i=0;i<48;i++){

							if(y3>=y1){

									if(yk>=y2){

											context.lineTo(x1+(Math.sin(((Math.PI/96.0)*-i)+(Math.PI*1.0))*rx),y3+(Math.cos(((Math.PI/96.0)*-i)+(Math.PI*1.0))*ry));

									}else{

											context.lineTo(x3+(Math.sin(((Math.PI/96.0)*i)+(Math.PI*1.5))*rx),y1+(Math.cos(((Math.PI/96.0)*i)+(Math.PI*1.5))*ry));

									}

							}else{

									if(yk<=y2){

											context.lineTo(x1+(Math.sin(((Math.PI/96.0)*-i)+(Math.PI*1.0))*rx),y3+(Math.cos(((Math.PI/96.0)*-i)+(Math.PI*1.0))*ry));

									}else{

											context.lineTo(x3+(Math.sin(((Math.PI/96.0)*i)+(Math.PI*1.5))*rx),y1+(Math.cos(((Math.PI/96.0)*i)+(Math.PI*1.5))*ry));

									}							

							}

					}

					context.stroke();

		}		

		// function that draws one part of the sun	

		function sundial(radius,angle,scale)

		{

					cosv=Math.cos(angle);

					sinv=Math.sin(angle);

					yaddx=scale*cosv;

					yaddy=scale*sinv;

					xaddx=-scale*sinv;

					xaddy=scale*cosv;

					xk=cosv*radius;

					yk=sinv*radius;

					context.bezierCurveTo((-1.5*xaddx)+(yaddx*1.5)+xk,(-1.5*xaddy)+(yaddy*1.5)+yk,xaddx+(yaddx*2.0)+xk,xaddy+(yaddy*2.0)+yk,xaddx+(yaddx*3.0)+xk,xaddy+(yaddy*3.0)+yk);

					context.bezierCurveTo(xaddx+yaddx+xk,xaddy+yaddy+yk,(1.5*xaddx)+yaddx+xk,(1.5*xaddy)+yaddy+yk,(3.0*xaddx)+xk,(3.0*xaddy)+yk);

		}

		// function that daws the sun

		function drawsun()

		{

				context.fillStyle = "#fe9";

				context.strokeStyle = "#d82";

				context.lineWidth   = 1.5;

				context.beginPath();

				context.moveTo(30,0);

				for(i=0.0;i<360.0;i+=22.5){

						angle=(i/360.0)*2*Math.PI;

						sundial(30,angle,3);

				}

				context.stroke();

				context.fill();															

		}

		// Draws the ball (used in various examples)

		function drawball(cx,cy,radie,innerradie,ballradie,col1,inangle,inangleadd)

		{

					angleadd=(inangleadd/360.0)*2*Math.PI;

					context.fillStyle = col1;					

					for(i=0;i<360;i+=inangle){

							angle=(i/360.0)*2*Math.PI;

							angle2=angle+angleadd;

							angle3=angle+(angleadd*2.0);

							angle4=angle-angleadd;

							cosv=Math.cos(angle);

							sinv=Math.sin(angle);

							cosv2=Math.cos(angle2);

							sinv2=Math.sin(angle2);

							cosv4=Math.cos(angle4);

							sinv4=Math.sin(angle4);

							context.beginPath();

							context.moveTo(cx,cy);

							context.quadraticCurveTo(cx+(cosv*innerradie),cy+(sinv*innerradie),cx+(cosv2*radie),cy+(sinv2*radie));							

							context.arc(cx,cy,radie,angle2,angle,1.0);

							context.quadraticCurveTo(cx+(cosv4*innerradie),cy+(sinv4*innerradie),cx,cy);							

							context.fill();															

					}	

					context.beginPath();

					context.arc(cx,cy,radie,0,Math.PI*2.0,1.0);												

					context.stroke();															

		}

/********************************************************************************

   Canvas and Diagram Measuring Functions

	These functions allow us to measure pixels in diagram and other apps

*********************************************************************************/

		// Recursive Pos of div in document - should work in most browsers

		function findPos(obj) {

			var curleft = curtop = 0;

			if (obj.offsetParent) {

				curleft = obj.offsetLeft

				curtop = obj.offsetTop

				while (obj = obj.offsetParent) {

					curleft += obj.offsetLeft

					curtop += obj.offsetTop

				}

			}

			return {

						x:curleft,

						y:curtop

				}

		}

		// Make side coordinates for drawing Model

		function makeside(side,x1,y1,x2,y2,perc){

				var xk=0;

				var yk=0;

				if(side==1){

						xk=x1;

						yk=y1+((y2-y1)*perc);

				}else if(side==2){

						xk=x1+((x2-x1)*perc);

						yk=y2;

				}else if(side==3){

						xk=x2;

						yk=y1+((y2-y1)*perc);						

				}else if(side==4){

						xk=x1+((x2-x1)*perc)

						yk=y1;

				}

				return {

							x:xk,

							y:yk

					}

		}		

		// Computes side identifier for a mouse coordinate and object coordinates

		function computeside(x,y,x1,y1,x2,y2,sidetol){

				var obj_sidentifier="None";

				var obj_sideperc=0;

				var obj_centerdist=0;

				// Left Side

				if(x>x1-sidetol&&x<x1+sidetol&&y>y1-sidetol&&y<y2+sidetol){

						obj_sidentifier=1;

						obj_sideperc=makesideperc(y,y1,y2);

						obj_centerdist=centerdist(y,y1,y2);

				}

				// Bottom Not Including Left Side or Right Side

				if(x>x1+sidetol&&x<x2-sidetol&&y>y2-sidetol&&y<y2+sidetol){

						obj_sidentifier=2;

						obj_sideperc=makesideperc(x,x1,x2);

						obj_centerdist=centerdist(x,x1,x2);

				}

				// Right Side

				if(x>x2-sidetol&&x<x2+sidetol&&y>y1-sidetol&&y<y2+sidetol){

						obj_sidentifier=3;

						obj_sideperc=makesideperc(y,y1,y2);

						obj_centerdist=centerdist(y,y1,y2);

				}

				// Top Not Including Left Side or Right Side

				if(x>x1+sidetol&&x<x2-sidetol&&y>y1-sidetol&&y<y1+sidetol){

						obj_sidentifier=4;

						obj_sideperc=makesideperc(x,x1,x2);

						obj_centerdist=centerdist(x,x1,x2);

				}

				return {

							side:obj_sidentifier,

							perc:obj_sideperc,

							dist:obj_centerdist

					}

		}		

		// Make side perc for ER model

		function makesideperc(x,x1,x2){

				r=x2-x1;

				perc=(x-x1)/r;

				if(perc>1.0) perc=1.0;

				if(perc<0.0) perc=0.0;

				return perc;

		}

		function centerdist(x,x1,x2){

				r=x1+((x2-x1)*0.5);

				return (x-r);

		}

		// Euclidian distance - Yo!

		function distance(x1,y1,x2,y2){

				var dist=Math.sqrt(((y2-y1)*(y2-y1))+((x2-x1)*(x2-x1)));

				return dist;

		}

		// Are we over a line or not.

		function overline(x,y,x1,y1,x2,y2,tolerance)

		{

				var distance=10000;

				dx=x2-x1;

				dy=y2-y1;

				straighttolerance=2.0;

				// Straight X, Straight Y or Positive or Negative Incline

				if(Math.abs(dx)<straighttolerance){

						if(y1<y2){

								if(y>y1-tolerance&&y<y2+tolerance){

										distance=Math.abs(x1-x);

								}

						}else{

								if(y>y2-tolerance&&y<y1+tolerance){

										distance=Math.abs(x1-x);

								}						

						}

						drawline(x1,y1,x2,y2,"#ff0",2.0);

				}else if(Math.abs(dy)<straighttolerance){

						if(x1<x2){

								if(x>x1-tolerance&&x<x2+tolerance){

										distance=Math.abs(y1-y);

								}

						}else{

								if(x>x2-tolerance&&x<x1+tolerance){

										distance=Math.abs(y1-y);

								}

						}

						drawline(x1,y1,x2,y2,"#ff0",2.0);

				}else if(Math.abs(dx)>=Math.abs(dy)){

						k=dy/dx;

						yk=y1+((x-x1)*k);

						distance=Math.abs(yk-y);

						point(x,yk,"#f5f");

						point(x1,y1,"#fff");						

						point(x2,y2,"#fff");						

						drawline(x1,y1,x2,y2,"#f00",2.0);

				}else if(Math.abs(dx)>=Math.abs(dy)){

						k=dy/dx;

						yk=y1+((x-x1)*k);

						distance=Math.abs(yk-y);

						point(x,yk,"#f5f");

						point(x1,y1,"#fff");						

						point(x2,y2,"#fff");

						drawline(x1,y1,x2,y2,"#0f0",2.0);						

				}

				return distance;		

		}