Well, I finally took the time to make this really work. Starting and finishing angles are measured in radians, measured counter clockwise from the +x axis. I needed to add 360 to the finishing angle.
When:
vector = Geom::Vector3d.new 0,0,1 @vector2 = Geom::Vector3d.new 1,0,0 @vector3 = vector.normalize!
The correct arc is drawn by:
my_arc = @entities.add_arc [@entity[0]+@block_x, @entity[1]+@block_y, @entity[2]+@block_z], @vector2, @vector3, @entity[3], (@entity[4]*Math::PI)/180, ((360+@entity[5])*Math::PI)/180
@block_? is the location of the block/group from the origin. When an entity, its value is 0.0, nothing.
Only problem now, is that the data from my Cad's DxfOut, and Acad's seems to be different. I have to check the spec. by their version numbers, but I can't believe they have changed that much.>_< But "Oh well", that's why I am writting this s*^&&y app.:-)
Addenda: I found this variable tags 210, 220, and 230 (extrusion direction) wherein my Cad's DxfOut is [0,0,-1], and the default Acad's is [0,0,1]. What's an extrusion direction?
Addenda: z=-1 in [x,y,z] seems to mean that the arc is mirrored around the world view origin. It appears that when z=1 in [x,y,z], the arc is mirrored on the y axis, and set by (see the green (-)) below:
my_arc = @entities.add_arc [%(#008000)[-]@entity[0]+@block_x, @entity[1]+@block_y, @entity[2]+@block_z], @vector2, @vector3, @entity[3], (@entity[4]*Math::PI)/180, ((360+@entity[5])*Math::PI)/180