draft 1 of triangle/sas algorithm

gwdean/journal.org

@@ -282,6 +282,12 @@ var ctx = canvas.getContext('2d');
 
 An Explanation will follow later.
 ** Testing?
+
+* 11/09/28 -> Completed second part of the algorithm.
+Made a simple change to the algorithm, extending it
+to cover triangles which have angle values of greater
+than 90 degrees. I am saving this as a new file called
+my-triangle-sas.js.
 * Reference
 ---------
 ** Whalesong README

gwdean/my-triangle-sas.js

@@ -0,0 +1,56 @@
+// These two functions represent the first draft of a workable
+// triangle/sas function for Whalesong. They need to be cleaned
+// up and tested, but the basic logic seems to work. 
+
+function drawLessThan90(){
+        var canvas = document.getElementById('1');
+        if (canvas.getContext){
+
+          var ctx = canvas.getContext('2d');
+          var x = 50;
+          var y = 50;
+          var a = 100;
+          var b = 10;
+          var c = 50;
+          var radians = b * 0.0174532952;
+          var height = a * Math.sin(radians);
+          var width = Math.sqrt((a * a) - (height * height));
+
+          // works for <90
+
+          ctx.beginPath();
+          ctx.moveTo(x,y);
+          ctx.lineTo(c+x,y);
+          ctx.lineTo((c-width)+x,height+y);
+          ctx.lineTo(x,y);
+          ctx.fill();
+        }
+
+      }
+
+
+ function drawGreaterThan90(){
+        var canvas = document.getElementById('2');
+        if (canvas.getContext){
+
+          var ctx = canvas.getContext('2d');
+          var x = 50;
+          var y = 50;
+          var a = 100;
+          var b = 150;
+          var c = 50;
+          var radians = b * 0.0174532952;
+          var height = a * Math.sin(radians);
+          var width = Math.sqrt((a * a) - (height * height));
+
+          // works for >90
+
+          ctx.beginPath();
+          ctx.moveTo(x,y);
+          ctx.lineTo(c+x,y);
+          ctx.lineTo((c+width)+x,height+y);
+          ctx.lineTo(x,y);
+          ctx.fill();
+        }
+
+      }