Add base types for path ops
Paths contain lines, quads, and cubics, which are
collectively curves.
To work with path intersections, intermediary curves
are constructed. For now, those intermediates use
doubles to guarantee sufficient precision.
The DVector, DPoint, DLine, DQuad, and DCubic
structs encapsulate these intermediate curves.
The DRect and DTriangle structs are created to
describe intersectable areas of interest.
The Bounds struct inherits from SkRect to create
a SkScalar-based rectangle that intersects shared
edges.
This also includes common math equalities and
debugging that the remainder of path ops builds on,
as well as a temporary top-level interface in
include/pathops/SkPathOps.h.
Review URL: https://codereview.chromium.org/12827020
git-svn-id: http://skia.googlecode.com/svn/trunk@8551 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/pathops/SkOpEdgeBuilder.h b/src/pathops/SkOpEdgeBuilder.h
new file mode 100644
index 0000000..68afc93
--- /dev/null
+++ b/src/pathops/SkOpEdgeBuilder.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright 2012 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkOpEdgeBuilder_DEFINED
+#define SkOpEdgeBuilder_DEFINED
+
+#include "SkOpContour.h"
+#include "SkPathWriter.h"
+#include "SkTArray.h"
+#include "SkTDArray.h"
+
+class SkOpEdgeBuilder {
+public:
+ SkOpEdgeBuilder(const SkPathWriter& path, SkTArray<SkOpContour>& contours)
+ : fPath(path.nativePath())
+ , fContours(contours) {
+ init();
+ }
+
+ SkOpEdgeBuilder(const SkPath& path, SkTArray<SkOpContour>& contours)
+ : fPath(&path)
+ , fContours(contours) {
+ init();
+ }
+
+ void complete() {
+ if (fCurrentContour && fCurrentContour->segments().count()) {
+ fCurrentContour->complete();
+ fCurrentContour = NULL;
+ }
+ }
+
+ SkPathOpsMask xorMask() const {
+ return fXorMask[fOperand];
+ }
+
+ void addOperand(const SkPath& path);
+ void finish();
+ void init();
+
+private:
+ int preFetch();
+ void walk();
+
+ const SkPath* fPath;
+ SkTDArray<SkPoint> fPathPts; // FIXME: point directly to path pts instead
+ SkTDArray<uint8_t> fPathVerbs; // FIXME: remove
+ SkOpContour* fCurrentContour;
+ SkTArray<SkOpContour>& fContours;
+ SkTDArray<SkPoint> fReducePts; // segments created on the fly
+ SkTDArray<int> fExtra; // -1 marks new contour, > 0 offsets into contour
+ SkPathOpsMask fXorMask[2];
+ int fSecondHalf;
+ bool fOperand;
+};
+
+#endif