ac10a2d039
git-svn-id: http://skia.googlecode.com/svn/trunk@649 2bbb7eff-a529-9590-31e7-b0007b416f81
111 lines
3.9 KiB
C++
111 lines
3.9 KiB
C++
/*
|
|
Copyright 2010 Google Inc.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
|
|
#ifndef GrPathIter_DEFINED
|
|
#define GrPathIter_DEFINED
|
|
|
|
#include "GrTypes.h"
|
|
|
|
struct GrPoint;
|
|
|
|
/**
|
|
2D Path iterator. Porting layer creates a subclass of this. It allows Ganesh to
|
|
parse the top-level API's 2D paths. Supports lines, quadratics, and cubic
|
|
pieces and moves (multi-part paths).
|
|
*/
|
|
class GrPathIter {
|
|
public:
|
|
/**
|
|
Returned by next(). Indicates the next piece of the path.
|
|
*/
|
|
enum Command {
|
|
kMove_Command, //!< next() returns 1 pt
|
|
// Starts a new subpath at
|
|
// at the returned point
|
|
kLine_Command, //!< next() returns 2 pts
|
|
// Adds a line segment
|
|
kQuadratic_Command, //!< next() returns 3 pts
|
|
// Adds a quadratic segment
|
|
kCubic_Command, //!< next() returns 4 pts
|
|
// Adds a cubic segment
|
|
kClose_Command, //!< next() returns 0 pts
|
|
kEnd_Command //!< next() returns 0 pts
|
|
// Implictly closes the last
|
|
// point
|
|
};
|
|
|
|
enum ConvexHint {
|
|
kNone_ConvexHint, //<! No hint about convexity
|
|
// of the path
|
|
kConvex_ConvexHint, //<! Path is one convex piece
|
|
kNonOverlappingConvexPieces_ConvexHint, //<! Multiple convex pieces,
|
|
// pieces are known to be
|
|
// disjoint
|
|
kSameWindingConvexPieces_ConvexHint, //<! Multiple convex pieces,
|
|
// may or may not intersect,
|
|
// either all wind cw or all
|
|
// wind ccw.
|
|
kConcave_ConvexHint //<! Path is known to be
|
|
// concave
|
|
};
|
|
|
|
static int NumCommandPoints(Command cmd) {
|
|
static const int numPoints[] = {
|
|
1, 2, 3, 4, 0, 0
|
|
};
|
|
return numPoints[cmd];
|
|
}
|
|
|
|
virtual ~GrPathIter() {};
|
|
|
|
/**
|
|
Iterates through the path. Should not be called after
|
|
kEnd_Command has been returned once. This version retrieves the
|
|
points for the command.
|
|
@param points The points relevant to returned commend. See Command
|
|
enum for number of points valid for each command.
|
|
@return The next command of the path.
|
|
*/
|
|
virtual Command next(GrPoint points[4]) = 0;
|
|
|
|
/**
|
|
* If the host API has knowledge of the convexity of the path
|
|
* it can be communicated by this hint. Ganesh can make these
|
|
* determinations itself. So it is not necessary to compute
|
|
* convexity status if it isn't already determined.
|
|
*
|
|
* @return a hint about the convexity of the path.
|
|
*/
|
|
virtual ConvexHint hint() const { return kNone_ConvexHint; }
|
|
|
|
/**
|
|
Iterates through the path. Should not be called after
|
|
kEnd_Command has been returned once. This version does not retrieve the
|
|
points for the command.
|
|
@return The next command of the path.
|
|
*/
|
|
virtual Command next() = 0;
|
|
|
|
/**
|
|
Restarts iteration from the beginning.
|
|
*/
|
|
virtual void rewind() = 0;
|
|
|
|
};
|
|
|
|
#endif
|