Defined in Graphics.Def Inherits from Object
The Magic Cap graphics system defines objects of class Path to represent arbitrary areas on the screen. Paths are constructed by specifying lines and boxes while accumulating the area that's inside the lines and boxes. The resulting accumulated area is a path.
Remember that if the documentation and the software (especially the definition files) disagree, always trust the software.
Class Path is a direct descendant of class Object. Path objects include a couple of private fields, including one containing the smallest box that surrounds the entire path.
Path objects are usually only in use for a short time. You'll often create a path to use with a drawing call, then destroy the path after the call is made. You'll create paths using the path creation methods described below. You won't find any paths in the Magic Hat or elsewhere in the software.
Instantiate: sometimes Subclass: rarely Call its methods: sometimes
Usually, you'll create a path object in order to define a clipping path for a Draw call. Whenever you create a new class of viewable object, you override Draw to define how to draw the objects. The system passes in a clipping path when it calls your Draw method. You can compute a more refined clipping path in your overridden Draw method, then calculate the intersection of that smaller path and the passed-in path to make drawing faster.You might also create a path object if you want to fill a complex area on the screen.
Class Path defines methods for constructing paths from lines and boxes, for performing operations on paths, such as intersection and difference, and for testing whether the path includes a given box or dot.
The Path class has the following methods you might call:
| Method | Description |
|---|---|
| SetBoxPath | Sets a path to the given box |
| SectPath | Compute the intersection of two paths |
| AddLine | Add the given line to the path |
| AddBox | Add the given box to the path |
| OpenPath | Prepare to constructing a new path |
| ClosePath | Finished constructing new path |
The Path class defines the following fields:
| Field | Type | Description |
|---|---|---|
| count | Unsigned | Used internally |
operation SetBoxPath(box1: Box) call: sometimes Override: rarely
Call NewBoxPath to set the path object to the area described by the given box.
operation SectPath(srcA: Path; srcB: Path) call: sometimes Override: rarely
Call SectPath to compute the intersection of two given paths. SectPath calculates the intersecting area of the two paths in srcA and srcB, then put the resulting path into the object.
operation AddLine(dot1: Dot; dot2: Dot) call: sometimes Override: rarely
If you want to construct a path that's not simply a box, you can call AddLine to add a line to the path's edge. AddLine adds the line described by the given dots to the path's edge. You can mix calls to AddLine, AddBox, and AddRoundBox to construct the path.
Before calling AddLine, you should have created the path object (by calling New, for example) and prepared it by calling OpenPath.
operation AddBox(box1: Box) call: sometimes Override: rarely
If you want to construct a path that's not simply a box, but includes a box in its description, you can call AddBox to add a box to the path. AddBox adds the given box to the path. You can mix calls to AddLine, AddBox, and AddRoundBox to construct the path.
Before calling AddBox, you should have created the path object (by calling New, for example) and prepared it by calling OpenPath.
operation OpenPath() call: sometimes Override: rarely
If you want to construct a path that's not simply a box, call OpenPath after you've created the path object (by calling New, for example). After calling OpenPath, you can call path construction methods (AddLine, AddBox, and AddRoundBox) to construct the path. Call ClosePath to finish constructing the path.
operation ClosePath()
If you've called OpenPath to construct a path, call ClosePath when you're done describing the path with path construction methods (AddLine, AddBox, and AddRoundBox).