Join Attributes (IM: XG)

Inside Macintosh: QuickDraw GX Graphics /

Chapter 3 - Geometric Styles / Geometric Styles Reference

Join Attributes
Each join structure contains a set of flags that allow you to specify level joins, sharp joins, and curve joins. These constants are defined in the gxJoinAttributes enumeration:
enum gxJoinAttributes {
   gxSharpJoin= 0x0000,
   gxCurveJoin= 0x0001,
   gxLevelJoin= 0x0002
};
typedef long gxJoinAttribute;
Constant descriptions

gxSharpJoin
Indicates that QuickDraw GX should continue the outside edges of the corners of the joined shape until they meet at a point. You can use the miter field of the join structure to limit the size of a sharp join for very sharp corners.
gxCurveJoin
Indicates that QuickDraw GX should connect the outside edges of the corners of the joined shape with a circular curve.
gxLevelJoin
Suppresses rotation of the shape specified by the join field of the join structure. When you set this flag, QuickDraw GX does not rotate the join shape to match the mid-angle of the joined corner. Instead, QuickDraw GX places the join shape onto the joined corner with the exact orientation specified by the geometry of the join shape.
QuickDraw GX draws a sharp join or a curve join for every corner of every geometric shape; you may additionally specify a join shape to be added to a shape's corner using the join field of the join structure.
The miter field of the join structure allows you to limit the size of sharp joins, which is particularly useful if the joined corner is very sharp. In the miter field, you specify the maximum distance between the actual corner (as specified by the joined shape's geometry) and the tip of the sharp corner as drawn.
See "Adding Standard Joins to a Shape" beginning on page 3-64 for an example of a standard join.