support for r=f(theta) type functions

main.js

@@ -49,7 +49,8 @@ function compile(n){
     var yfuncs=[];
 
     //Functions of theta
-
+    var tfuncs=[];
+
     //Functions of r
     var rfuncs=[];
 
@@ -78,7 +79,9 @@ function compile(n){
                 yfuncs.push(eq[1]);
             }else if(dirty(eq[0])=="theta"){
                 rfuncs.push(eq[1]);
-            }else if(eq[0]!=""){
+            }else if(dirty(eq[0])=="r"){
+				tfuncs.push(eq[1]);
+			}else if(eq[0]!=""){
                 //a *variable* is defined by this graph. Add it to vars.
                 var varname=dirty(eq[0]);
                 vars[varname]=eq[1].eval();
@@ -361,7 +364,7 @@ function compile(n){
             }
 
             //begin the path. Colour (fill and stroke) is already done for us in ui.js
-            builder+="ctx.beginPath();var r=0;ctx.move(r,"+jsc+");";
+            builder+="ctx.beginPath();var r=0;ctx.move(0,0);";
             if(0 && singularities.length){
                 //Better plot logic.
                 //For example, this would allow us to plot y=sqrt(1-x^2) from [-1,1] exactly with no abrupt endings.
@@ -389,6 +392,62 @@ function compile(n){
         }
 
     }
+
+	if(tfuncs.length){
+        for(var i=0;i<tfuncs.length;i++){
+
+            var fn=tfuncs[i].simplify();
+
+            //Get javascript expression.
+            var jsc=fn.getString(0,true);
+
+			//A little messy:
+            jsc=jsc.replace(/app\.variables\[\"(x|y|z|r|theta)\"\]/g,"$1");
+
+            if(first){
+                //The first value of a multi-valued function shall be its
+                //primary value.
+
+                ret.f=new Function("theta","return "+jsc);
+                first=false;
+            }
+
+
+            var singularities=[];
+            try{
+                var singularities=fn.singularities();
+
+                //We don't care about singularites way out there:
+                singularities.remove(Infinity);
+                singularities.remove(-Infinity);
+            }catch(ex){
+                if(__debug(1,0)){
+                    //when debugging we want to see the error
+                    throw(ex);
+                }
+            }
+
+            //begin the path. Colour (fill and stroke) is already done for us in ui.js
+            builder+="ctx.beginPath();var theta=0;ctx.move("+jsc+"*cos(theta),"+jsc+"*sin(theta));";
+            if(0 && singularities.length){
+                //Better plot logic.
+                //For example, this would allow us to plot y=sqrt(1-x^2) from [-1,1] exactly with no abrupt endings.
+
+            }else{
+                //The loop is within the function because calling a function is too slow in javascript (last time I checked)
+                //Plot each point: (jsc is the expression generated by CAS)
+                /*
+					tinc: reciprcal of pixels along max *circle* (ellipse to complicated) around screen area?
+					
+                */
+                builder+="var tinc=1/max(width,height);for(var theta=0;theta<(2*pi);theta+=tinc){var rtmp=("+jsc+");ctx.line(rtmp*cos(theta),rtmp*sin(theta));}ctx.line("+jsc+",0);ctx.stroke();";
+            }
+			console.log(builder);
+
+        }
+
+    }
+
     //Add our vars and funcdefs to the global CAS variables (app.variables)
     //TODO: should not be app, but cas.variables. (javascript-cas will support variables natively someday)
     if(window && window.app && window.app.variables){