From 422f3da9c428a66dd1b6692864adecab81f736fa Mon Sep 17 00:00:00 2001
From: walterhiggins <walter.higgins@gmail.com>
Date: Mon, 14 Jan 2013 22:54:24 +0000
Subject: [PATCH] Added 1st draft of sphere() and sphere0() methods

---
 js-plugins/drone/drone.js  | 10 ++---
 js-plugins/drone/sphere.js | 82 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 6 deletions(-)
 create mode 100644 js-plugins/drone/sphere.js

diff --git a/js-plugins/drone/drone.js b/js-plugins/drone/drone.js
index 978701e..e91a89c 100644
--- a/js-plugins/drone/drone.js
+++ b/js-plugins/drone/drone.js
@@ -572,12 +572,10 @@ var Drone = Drone || {
             var xo = (a-x0);
             var yo = (b-y0);
             if (fill){
-                if (xo < 0 && yo < 0){
-                    // bottom left quadrant
-                    drone.fwd(yo).right(xo)
-                        .box(block,Math.abs(xo*2)+1,height,Math.abs(yo*2)+1)
-                        .back(yo).left(xo);
-                }
+					 // wph 20130114 more efficient esp. for large cylinders/spheres
+					 if (yo < 0){
+						  drone.fwd(yo).right(xo).box(block,1,height,Math.abs(yo*2)+1).back(yo).left(xo);
+					 }
             }
             gotoxy(xo,yo).box(block,1,height,1).move('center');
         };
diff --git a/js-plugins/drone/sphere.js b/js-plugins/drone/sphere.js
new file mode 100644
index 0000000..766ec64
--- /dev/null
+++ b/js-plugins/drone/sphere.js
@@ -0,0 +1,82 @@
+load(__folder + "drone.js");
+
+Drone.extend('sphere', function(block,radius)
+{
+	 var lastRadius = radius;
+	 var slices = [[radius,0]];
+	 var diameter = radius*2;
+	 for (var i = 0; i <= radius;i++){
+		  var newRadius = Math.round(Math.sqrt(radius*radius - i*i));
+		  if (newRadius == lastRadius)
+				slices[slices.length-1][1]++;
+		  else
+				slices.push([newRadius,1]);
+		  lastRadius = newRadius;
+	 }
+	 this.chkpt('sphere');
+	 //
+	 // mid section
+	 //
+	 this.up(radius - slices[0][1])
+		  .cylinder(block,radius,(slices[0][1]*2)-1)
+		  .down(radius-slices[0][1]);
+	 
+	 var yOffset = -1;
+	 for (var i = 1; i < slices.length;i++){
+		  yOffset += slices[i-1][1];
+		  var sr = slices[i][0];
+		  var sh = slices[i][1];
+		  // northern hemisphere
+		  this.up(radius + yOffset).fwd(radius-sr).right(radius-sr)
+				.cylinder(block,sr,sh)
+				.left(radius - sr).back( radius - sr). down(radius + yOffset);
+		  // southern hemisphere
+		  this.up(radius - (yOffset+sh+1)).fwd(radius-sr).right(radius-sr)
+				.cylinder(block,sr,sh)
+				.left(radius - sr).back( radius - sr). down(radius - (yOffset+sh+1));
+	 }
+	 return this.move('sphere');
+});
+//
+// sphere0 creates an empty sphere but the code needs work
+// - there are gaps in the sphere due to rasterization.
+//
+Drone.extend('sphere0', function(block,radius)
+{
+	 var lastRadius = radius;
+	 var slices = [[radius,0]];
+	 var diameter = radius*2;
+	 for (var i = 0; i <= radius;i++){
+		  var newRadius = Math.round(Math.sqrt(radius*radius - i*i));
+		  if (newRadius == lastRadius)
+				slices[slices.length-1][1]++;
+		  else
+				slices.push([newRadius,1]);
+		  lastRadius = newRadius;
+	 }
+	 this.chkpt('sphere0');
+	 //
+	 // mid section
+	 //
+	 this.up(radius - slices[0][1])
+		  .cylinder0(block,radius,(slices[0][1]*2)-1)
+		  .down(radius-slices[0][1]);
+	 
+	 var yOffset = -1;
+	 for (var i = 1; i < slices.length;i++){
+		  yOffset += slices[i-1][1];
+		  var sr = slices[i][0];
+		  var sh = slices[i][1];
+
+		  // northern hemisphere
+		  this.up(radius + yOffset).fwd(radius-sr).right(radius-sr)
+				.cylinder0(block,sr,sh)
+				.left(radius - sr).back( radius - sr). down(radius + yOffset);
+
+		  // southern hemisphere
+		  this.up(radius - (yOffset+sh+1)).fwd(radius-sr).right(radius-sr)
+				.cylinder0(block,sr,sh)
+				.left(radius - sr).back( radius - sr). down(radius - (yOffset+sh+1));
+	 }
+	 return this.move('sphere0');
+});