Add cone for SDF 1.12

Signed-off-by: Benjamin Perseghetti <bperseghetti@rudislabs.com>

sdf/1.12/CMakeLists.txt

@@ -11,6 +11,7 @@ set (sdfs
   camera.sdf
   capsule_shape.sdf
   collision.sdf
+  cone_shape.sdf
   contact.sdf
   cylinder_shape.sdf
   ellipsoid_shape.sdf

sdf/1.12/cone_shape.sdf

@@ -0,0 +1,9 @@
+<element name="cone" required="0">
+  <description>Cone shape</description>
+  <element name="radius" type="double" default="1" required="1">
+    <description>Radius of the cone</description>
+  </element>
+  <element name="length" type="double" default="1" required="1">
+    <description>Length of the cone along the z axis</description>
+  </element>
+</element>

sdf/1.12/geometry.sdf

@@ -8,6 +8,7 @@
 
   <include filename="box_shape.sdf" required="0"/>
   <include filename="capsule_shape.sdf" required="0"/>
+  <include filename="cone_shape.sdf" required="0"/>
   <include filename="cylinder_shape.sdf" required="0"/>
   <include filename="ellipsoid_shape.sdf" required="0"/>
   <include filename="heightmap_shape.sdf" required="0"/>

sdf/1.12/particle_emitter.sdf

@@ -7,7 +7,7 @@
   </attribute>
 
   <attribute name="type" type="string" default="point" required="1">
-    <description>The type of a particle emitter. One of "box", "cylinder", "ellipsoid", or "point".</description>
+    <description><description>The type of a particle emitter. One of "box", "cylinder", "cone", "ellipsoid", or "point".</description>
   </attribute>
 
   <element name="emitting" type="bool" default="true" required="0">
@@ -26,6 +26,8 @@
     depending on the emmiter type:
       - point: The area is ignored.
       - box: The area is interpreted as width X height X depth.
+      - cone: The area is interpreted as the bounding box of the
+                  cone. The cone is oriented along the Z-axis.
       - cylinder: The area is interpreted as the bounding box of the
                   cylinder. The cylinder is oriented along the Z-axis.
       - ellipsoid: The area is interpreted as the bounding box of an