new batch of docs
new batch of docs
Docs-Preview: https://skia.org/?cl=141244
Bug: skia:
Change-Id: I5a285778baaee2734495374adeb7359d524e47e3
Reviewed-on: https://skia-review.googlesource.com/141244
Reviewed-by: Cary Clark <caryclark@skia.org>
Commit-Queue: Cary Clark <caryclark@skia.org>
Auto-Submit: Cary Clark <caryclark@skia.org>
diff --git a/docs/SkRegion_Reference.bmh b/docs/SkRegion_Reference.bmh
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+++ b/docs/SkRegion_Reference.bmh
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+#Topic Region
+#Alias Region_Reference ##
+#Alias Regions ##
+
+Region is a compressed one bit mask. Region describes an aliased clipping area
+on integer boundaries. Region can also describe an array of integer rectangles.
+
+Canvas uses Region to reduce the current clip. Region may be drawn to Canvas;
+Paint determines if Region is filled or stroked, its Color, and so on.
+
+Region may be constructed from IRect array or Path. Diagonal lines and curves
+in Path become integer rectangle edges. Regions operators compute union,
+intersection, difference, and so on. Canvas allows only intersection and
+difference; successive clips can only reduce available Canvas area.
+
+#PhraseDef list_of_op_types
+kDifference_Op, kIntersect_Op, kUnion_Op, kXOR_Op, kReverseDifference_Op,
+kReplace_Op
+##
+
+#Class SkRegion
+
+SkRegion describes the set of pixels used to clip Canvas. SkRegion is compact,
+efficiently storing a single integer rectangle, or a run length encoded array
+of rectangles. SkRegion may reduce the current Canvas_Clip, or may be drawn as
+one or more integer rectangles. SkRegion iterator returns the scan lines or
+rectangles contained by it, optionally intersecting a bounding rectangle.
+
+#Subtopic Overview
+#Populate
+##
+
+#Subtopic Constant
+#Populate
+##
+
+#Subtopic Class
+#Populate
+##
+
+#Subtopic Constructor
+#Populate
+##
+
+#Subtopic Operator
+#Populate
+##
+
+#Subtopic Member_Function
+#Populate
+##
+
+# ------------------------------------------------------------------------------
+
+#Class Iterator
+#Line # iterator returning IRect ##
+
+#Code
+ class Iterator {
+ public:
+ Iterator();
+ Iterator(const SkRegion& region);
+ bool rewind();
+ void reset(const SkRegion& region);
+ bool done() const;
+ void next();
+ const SkIRect& rect();
+ const SkRegion* rgn();
+ };
+##
+
+Returns sequence of rectangles, sorted along y-axis, then x-axis, that make
+up Region.
+
+# ------------------------------------------------------------------------------
+
+#Method Iterator()
+#Line # constructs Region iterator ##
+Initializes Iterator with an empty Region. done() on Iterator returns true.
+Call reset() to initialized Iterator at a later time.
+
+#Return empty Region ierator ##
+
+#Example
+ SkRegion::Iterator iter;
+ SkRegion region;
+ region.setRect({1, 2, 3, 4});
+ iter.reset(region);
+ auto r = iter.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+#StdOut
+rect={1,2,3,4}
+##
+##
+
+#SeeAlso reset SkRegion
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method Iterator(const SkRegion& region)
+#Line # constructs Region iterator ##
+Sets Iterator to return elements of IRect array in region.
+#Param region Region to iterate ##
+
+#Return Region iterator ##
+
+#Example
+ SkRegion region;
+ region.setRect({1, 2, 3, 4});
+ SkRegion::Iterator iter(region);
+ auto r = iter.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+#StdOut
+rect={1,2,3,4}
+##
+##
+
+#SeeAlso reset SkRegion Cliperator Spanerator
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool rewind()
+#Line # points Iterator to start ##
+
+Points Iterator to start of Region.
+Returns true if Region was set; otherwise, returns false.
+
+#Return true if Region was set ##
+
+#Example
+#Bug 8186
+ auto debugster = [](const char* label, SkRegion::Iterator& iter, bool addRewind) -> void {
+ if (addRewind) {
+ bool success = iter.rewind();
+ SkDebugf("%14s rewind success=%s\n", label, success ? "true" : "false");
+ }
+ auto r = iter.rect();
+ SkDebugf("%14s rect={%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion::Iterator iter;
+ debugster("empty iter", iter, true);
+ SkRegion region;
+ iter.reset(region);
+ debugster("empty region", iter, true);
+ region.setRect({1, 2, 3, 4});
+ iter.reset(region);
+ debugster("after set rect", iter, false);
+ debugster("after rewind", iter, true);
+#StdOut
+#Volatile
+ empty iter rewind success=false
+ empty iter rect={0,0,0,0}
+ empty region rewind success=true
+ empty region rect={0,0,0,0}
+after set rect rect={1,2,3,4}
+ after rewind rewind success=true
+ after rewind rect={1,2,3,4}
+##
+##
+
+#SeeAlso reset
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method void reset(const SkRegion& region)
+#Line # sets Region to iterate ##
+
+Resets iterator, using the new Region.
+
+#Param region Region to iterate ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion::Iterator& iter) -> void {
+ SkDebugf("%14s: done=%s\n", label, iter.done() ? "true" : "false");
+ };
+ SkRegion region;
+ SkRegion::Iterator iter(region);
+ debugster("empty region", iter);
+ region.setRect({1, 2, 3, 4});
+ debugster("after set rect", iter);
+ iter.reset(region);
+ debugster("after reset", iter);
+#StdOut
+ empty region: done=true
+after set rect: done=true
+ after reset: done=false
+##
+##
+
+#SeeAlso rewind
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool done() const
+#Line # returns if data parsing is complete ##
+
+Returns true if Iterator is pointing to final IRect in Region.
+
+#Return true if data parsing is complete ##
+
+#Example
+ SkRegion region;
+ SkRegion::Iterator iter(region);
+ SkDebugf("done=%s\n", iter.done() ? "true" : "false");
+ region.setRect({1, 2, 3, 4});
+ iter.rewind();
+ SkDebugf("done=%s\n", iter.done() ? "true" : "false");
+#StdOut
+done=true
+done=false
+##
+##
+
+#SeeAlso next rect
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method void next()
+#Line # advances to next IRect ##
+
+Advances Iterator to next IRect in Region if it is not done.
+
+#Example
+ SkRegion region;
+ SkIRect rects[] = {{1, 2, 3, 4}, {5, 6, 7, 8}};
+ region.setRects(rects, SK_ARRAY_COUNT(rects));
+ SkRegion::Iterator iter(region);
+ do {
+ auto r2 = iter.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r2.fLeft, r2.fTop, r2.fRight, r2.fBottom);
+ iter.next();
+ } while (!iter.done());
+#StdOut
+rect={1,2,3,4}
+rect={5,6,7,8}
+##
+##
+
+#SeeAlso done rect
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method const SkIRect& rect() const
+#Line # returns part of Region as IRect ##
+
+Returns IRect element in Region. Does not return predictable results if Region
+is empty.
+
+#Return part of Region as IRect ##
+
+#Example
+#Bug 8186
+ SkRegion region;
+ SkRegion::Iterator iter(region);
+ auto r1 = iter.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r1.fLeft, r1.fTop, r1.fRight, r1.fBottom);
+ region.setRect({1, 2, 3, 4});
+ iter.rewind();
+ auto r2 = iter.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r2.fLeft, r2.fTop, r2.fRight, r2.fBottom);
+#StdOut
+#Volatile
+rect={0,0,0,0}
+rect={1,2,3,4}
+##
+##
+
+#SeeAlso next done
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method const SkRegion* rgn() const
+#Line # returns original Region ##
+
+Returns Region if set; otherwise, returns nullptr.
+
+#Return iterated Region ##
+
+#Example
+ SkRegion region;
+ SkIRect rects[] = {{1, 2, 3, 4}, {3, 4, 5, 6}};
+ region.setRects(rects, SK_ARRAY_COUNT(rects));
+ SkRegion::Iterator iter(region);
+ auto r = iter.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+ auto b = iter.rgn()->getBounds();
+ SkDebugf("bounds={%d,%d,%d,%d}\n", b.fLeft, b.fTop, b.fRight, b.fBottom);
+##
+
+#SeeAlso Iterator reset
+
+#Method ##
+
+#Class Iterator ##
+
+# ------------------------------------------------------------------------------
+
+#Class Cliperator
+#Line # iterator returning IRect within clip ##
+
+#Code
+ class SK_API Cliperator {
+ public:
+ Cliperator(const SkRegion&, const SkIRect& clip);
+ bool done();
+ void next();
+ const SkIRect& rect() const;
+ };
+##
+
+Returns the sequence of rectangles, sorted along y-axis, then x-axis, that make
+up Region intersected with the specified clip rectangle.
+
+# ------------------------------------------------------------------------------
+
+#Method Cliperator(const SkRegion& region, const SkIRect& clip)
+#Line # constructs Region iterator with clip ##
+
+Sets Cliperator to return elements of IRect array in Region within clip.
+
+#Param region Region to iterate ##
+#Param clip bounds of iteration ##
+
+#Return Region iterator ##
+
+#Example
+ SkRegion region;
+ region.setRect({1, 2, 3, 4});
+ SkRegion::Cliperator clipper(region, {0, 0, 2, 3});
+ auto r = clipper.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+#StdOut
+rect={1,2,2,3}
+##
+##
+
+#SeeAlso SkRegion Iterator Spanerator
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool done()
+#Line # returns if data parsing is complete ##
+
+Returns true if Cliperator is pointing to final IRect in Region.
+
+#Return true if data parsing is complete ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ SkRegion::Cliperator clipper(region, {0, 0, 5, 5});
+ SkDebugf("%14s done=%s\n", label, clipper.done() ? "true" : "false");
+ };
+ SkRegion region;
+ debugster("empty region", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("after add rect", region);
+#StdOut
+ empty region done=true
+after add rect done=false
+##
+##
+
+#SeeAlso next rect
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method void next()
+#Line # advances to next IRect within clip ##
+
+Advances iterator to next IRect in Region contained by clip.
+
+#Example
+ SkRegion region;
+ SkIRect rects[] = {{1, 2, 3, 4}, {5, 6, 7, 8}};
+ region.setRects(rects, SK_ARRAY_COUNT(rects));
+ SkRegion::Cliperator clipper(region, {0, 3, 8, 7});
+ do {
+ auto r2 = clipper.rect();
+ SkDebugf("rect={%d,%d,%d,%d}\n", r2.fLeft, r2.fTop, r2.fRight, r2.fBottom);
+ clipper.next();
+ } while (!clipper.done());
+#StdOut
+rect={1,3,3,4}
+rect={5,6,7,7}
+##
+##
+
+#SeeAlso done
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method const SkIRect& rect() const
+#Line # returns part of Region as IRect intersected with clip ##
+
+Returns IRect element in Region, intersected with clip passed to Cliperator
+constructor. Does not return predictable results if Region
+is empty.
+
+#Return part of Region inside clip as IRect ##
+
+#Example
+#Bug 8186
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ SkRegion::Cliperator clipper(region, {0, 0, 5, 3});
+ auto r = clipper.rect();
+ SkDebugf("%14s rect={%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region;
+ debugster("empty region", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("after set rect", region);
+#StdOut
+#Volatile
+ empty region rect={1094713344,1065353216,0,-1}
+after set rect rect={1,2,3,3}
+##
+##
+
+#SeeAlso next done
+
+#Method ##
+
+#Class Cliperator ##
+
+# ------------------------------------------------------------------------------
+
+#Class Spanerator
+#Line # horizontal line segment iterator ##
+
+#Code
+ class Spanerator {
+ public:
+ Spanerator(const SkRegion& region, int y, int left, int right);
+ bool next(int* left, int* right);
+ };
+##
+
+Returns the line segment ends within Region that intersect a horizontal line.
+
+# ------------------------------------------------------------------------------
+
+#Method Spanerator(const SkRegion& region, int y, int left, int right)
+#Line # constructs Region iterator on scan line ##
+
+Sets Spanerator to return line segments in Region on scan line.
+
+
+#Param region Region to iterate ##
+#Param y horizontal line to intersect ##
+#Param left bounds of iteration ##
+#Param right bounds of iteration ##
+
+#Return Region iterator ##
+
+#Example
+ SkRegion region;
+ region.setRect({1, 2, 3, 4});
+ SkRegion::Spanerator spanner(region, 3, 2, 4);
+ int left, right;
+ bool result = spanner.next(&left, &right);
+ SkDebugf("result=%s left=%d right=%d\n", result ? "true" : "false", left, right);
+##
+
+#SeeAlso SkRegion Iterator Cliperator
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool next(int* left, int* right)
+#Line # advances to next span on horizontal line ##
+
+Advances iterator to next span intersecting Region within line segment provided
+in constructor. Returns true if interval was found.
+
+#Param left pointer to span start; may be nullptr ##
+#Param right pointer to span end; may be nullptr ##
+
+#Return true if interval was found ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ SkRegion::Spanerator spanner(region, 3, 2, 4);
+ int left, right;
+ bool result = spanner.next(&left, &right);
+ SkDebugf("%14s: result=%s", label, result ? "true" : "false");
+ if (result) SkDebugf(" left=%d right=%d", left, right);
+ SkDebugf("\n");
+ };
+ SkRegion region;
+ debugster("empty region", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("after set rect", region);
+#StdOut
+ empty region: result=false
+after set rect: result=true left=2 right=3
+##
+##
+
+#SeeAlso done
+
+#Method ##
+
+#Class Spanerator ##
+
+# ------------------------------------------------------------------------------
+
+#Method SkRegion()
+#In Constructor
+#Line # constructs with default values ##
+
+Constructs an empty Region. Region is set to empty bounds
+at (0, 0) with zero width and height.
+
+#Return empty Region ##
+
+#Example
+SkRegion region;
+SkIRect r = region.getBounds();
+SkDebugf("region bounds: {%d, %d, %d, %d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+#StdOut
+region bounds: {0, 0, 0, 0}
+##
+##
+
+#SeeAlso setEmpty
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method SkRegion(const SkRegion& region)
+#In Constructor
+#Line # makes a shallow copy ##
+Constructs a copy of an existing region.
+Copy constructor makes two regions identical by value. Internally, region and
+the returned result share pointer values. The underlying Rect array is
+copied when modified.
+
+Creating a Region copy is very efficient and never allocates memory.
+Regions are always copied by value from the interface; the underlying shared
+pointers are not exposed.
+
+#Param region Region to copy by value ##
+
+#Return copy of Region ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: {%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region({1, 2, 3, 4});
+ SkRegion region2(region);
+ debugster("region bounds", region);
+ debugster("region2 bounds", region2);
+ region.setEmpty();
+ SkDebugf(" after region set empty:\n");
+ debugster("region bounds", region);
+ debugster("region2 bounds", region2);
+#StdOut
+ region bounds: {1,2,3,4}
+region2 bounds: {1,2,3,4}
+ after region set empty:
+ region bounds: {0,0,0,0}
+region2 bounds: {1,2,3,4}
+##
+##
+
+#SeeAlso setRegion operator=(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method explicit SkRegion(const SkIRect& rect)
+#In Constructor
+#Line # constructs Region matching IRect ##
+Constructs a rectangular Region matching the bounds of rect.
+
+#Param rect bounds of constructed Region ##
+
+#Return rectangular Region ##
+
+#Example
+ SkRegion region({1, 2, 3, 4});
+ SkRegion region2;
+ region2.setRect({1, 2, 3, 4});
+ SkDebugf("region %c= region2\n", region == region2 ? '=' : '!');
+##
+
+#SeeAlso setRect setRegion
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method ~SkRegion()
+#In Constructor
+#Line # decreases Reference_Count of owned objects ##
+Releases ownership of any shared data and deletes data if Region is sole owner.
+
+#Example
+#Description
+delete calls Region Destructor, but copy of original in region2 is unaffected.
+##
+ SkRegion* region = new SkRegion({1, 2, 3, 4});
+ SkRegion region2(*region);
+ delete region;
+ auto r = region2.getBounds();
+ SkDebugf("region2 bounds: {%d,%d,%d,%d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+#StdOut
+region2 bounds: {1,2,3,4}
+##
+##
+
+#SeeAlso SkRegion() SkRegion(const SkRegion& region) SkRegion(const SkIRect& rect) operator=(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method SkRegion& operator=(const SkRegion& region)
+#In Operator
+#Line # makes a shallow copy ##
+Constructs a copy of an existing region.
+Makes two regions identical by value. Internally, region and
+the returned result share pointer values. The underlying Rect array is
+copied when modified.
+
+Creating a Region copy is very efficient and never allocates memory.
+Regions are always copied by value from the interface; the underlying shared
+pointers are not exposed.
+
+#Param region Region to copy by value ##
+
+#Return Region to copy by value ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: {%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region1({1, 2, 3, 4});
+ SkRegion region2 = region1;
+ debugster("region1 bounds", region1);
+ debugster("region2 bounds", region2);
+#StdOut
+region1 bounds: {1,2,3,4}
+region2 bounds: {1,2,3,4}
+##
+##
+
+#SeeAlso set swap SkRegion(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool operator==(const SkRegion& other)_const
+#In Operator
+#Line # compares Regions for equality ##
+
+Compares Region and other; returns true if they enclose exactly
+the same area.
+
+#Param other Region to compare ##
+
+#Return true if Region pair are equivalent ##
+
+#Example
+ auto debugster = [](const char* prefix, const SkRegion& a, const SkRegion& b) -> void {
+ SkDebugf("%s one %c= two\n", prefix, a == b ? '=' : '!');
+ };
+ SkRegion one;
+ SkRegion two;
+ debugster("empty", one, two);
+ one.setRect({1, 2, 3, 4});
+ debugster("set rect", one, two);
+ one.setEmpty();
+ debugster("set empty", one, two);
+#StdOut
+empty one == two
+set rect one != two
+set empty one == two
+##
+##
+
+#SeeAlso operator!=(const SkRegion& other)_const operator=(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool operator!=(const SkRegion& other)_const
+#In Operator
+#Line # compares Regions for inequality ##
+
+Compares Region and other; returns true if they do not enclose the same area.
+
+#Param other Region to compare ##
+
+#Return true if Region pair are not equivalent ##
+
+#Example
+ auto debugster = [](const char* prefix, const SkRegion& a, const SkRegion& b) -> void {
+ SkDebugf("%s one %c= two\n", prefix, a != b ? '!' : '=');
+ };
+ SkRegion one;
+ SkRegion two;
+ debugster("empty", one, two);
+ one.setRect({1, 2, 3, 4});
+ two.setRect({1, 2, 3, 3});
+ debugster("set rect", one, two);
+ two.op({1, 3, 3, 4}, SkRegion::kUnion_Op);
+ debugster("union rect", one, two);
+#StdOut
+empty one == two
+set rect one != two
+union rect one == two
+##
+##
+
+#SeeAlso operator==(const SkRegion& other)_const operator=(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool set(const SkRegion& src)
+#In Constructor
+#Line # makes a shallow copy ##
+
+Sets Region to src, and returns true if src bounds is not empty.
+This makes Region and src identical by value. Internally,
+Region and src share pointer values. The underlying Rect array is
+copied when modified.
+
+Creating a Region copy is very efficient and never allocates memory.
+Regions are always copied by value from the interface; the underlying shared
+pointers are not exposed.
+
+#Param src Region to copy ##
+
+#Return copy of src ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: {%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region1({1, 2, 3, 4});
+ SkRegion region2;
+ region2.set(region1);
+ debugster("region1 bounds", region1);
+ debugster("region2 bounds", region2);
+#StdOut
+region1 bounds: {1,2,3,4}
+region2 bounds: {1,2,3,4}
+##
+##
+
+#SeeAlso operator=(const SkRegion& region) swap SkRegion(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method void swap(SkRegion& other)
+#In Operator
+#Line # exchanges Region pair ##
+
+Exchanges IRect array of Region and other. swap() internally exchanges pointers,
+so it is lightweight and does not allocate memory.
+
+swap() usage has largely been replaced by operator=(const SkRegion& region).
+Paths do not copy their content on assignment until they are written to,
+making assignment as efficient as swap().
+
+#Param other operator=(const SkRegion& region) set ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: {%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region1({1, 2, 3, 4});
+ SkRegion region2;
+ region1.swap(region2);
+ debugster("region1 bounds", region1);
+ debugster("region2 bounds", region2);
+#StdOut
+region1 bounds: {0,0,0,0}
+region2 bounds: {1,2,3,4}
+##
+##
+
+#SeeAlso operator=(const SkRegion& region) set SkRegion(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isEmpty() const
+#In Property
+#Line # returns if bounds has no width or height ##
+
+Returns true if Region is empty.
+Empty Region has bounds width or height less than or equal to zero.
+SkRegion() constructs empty Region; setEmpty
+and setRect with dimensionless data make Region empty.
+
+#Return true if bounds has no width or height ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ SkDebugf("%14s: region is %s" "empty\n", label, region.isEmpty() ? "" : "not ");
+ };
+ SkRegion region;
+ debugster("initial", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("set rect", region);
+ region.setEmpty();
+ debugster("set empty", region);
+#StdOut
+ initial: region is empty
+ set rect: region is not empty
+ set empty: region is empty
+##
+##
+
+#SeeAlso isRect isComplex operator==(const SkRegion& other)_const
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isRect() const
+#In Property
+#Line # returns if Region contains one IRect ##
+
+Returns true if Region is one IRect with positive dimensions.
+
+#Return true if Region contains one IRect ##
+
+#Example
+ auto debugster = [](const char* label, const SkRegion& region) -> void {
+ SkDebugf("%s: region is %s" "rect\n", label, region.isRect() ? "" : "not ");
+ };
+ SkRegion region;
+ debugster("initial", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("set rect", region);
+ region.setEmpty();
+ debugster("set empty", region);
+#StdOut
+initial: region is not rect
+set rect: region is rect
+set empty: region is not rect
+##
+##
+
+#SeeAlso isEmpty isComplex
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool isComplex() const
+#In Property
+#Line # returns true if Region contains more than one IRect ##
+
+Returns true if Region is described by more than one rectangle.
+
+#Return true if Region contains more than one IRect ##
+
+#Example
+ auto debugster = [](const char* label, const SkRegion& region) -> void {
+ SkDebugf("%s: region is %s" "complex\n", label, region.isComplex() ? "" : "not ");
+ };
+ SkRegion region;
+ debugster("initial", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("set rect", region);
+ region.op({2, 3, 4, 5}, SkRegion::kUnion_Op);
+ debugster("op rect", region);
+#StdOut
+initial: region is not complex
+set rect: region is not complex
+op rect: region is complex
+##
+##
+
+#SeeAlso isEmpty isRect
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method const SkIRect& getBounds() const
+#In Property
+#Line # returns maximum and minimum of IRect array ##
+
+Returns minimum and maximum axes values of IRect array.
+Returns (0, 0, 0, 0) if Region is empty.
+
+#Return combined bounds of all IRect elements ##
+
+#Example
+ SkRegion region({1, 2, 3, 4});
+ region.op({2, 3, 4, 5}, SkRegion::kUnion_Op);
+ auto r = region.getBounds();
+ SkDebugf("bounds: {%d,%d,%d,%d}\n", r.fLeft, r.fTop, r.fRight, r.fBottom);
+#StdOut
+bounds: {1,2,4,5}
+##
+##
+
+#SeeAlso isEmpty isRect
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method int computeRegionComplexity() const
+#In Property
+#Line # returns relative complexity ##
+
+Returns a value that increases with the number of
+elements in Region. Returns zero if Region is empty.
+Returns one if Region equals IRect; otherwise, returns
+value greater than one indicating that Region is complex.
+
+Call to compare Regions for relative complexity.
+
+#Return relative complexity ##
+
+#Example
+ auto debugster = [](const char* label, const SkRegion& region) -> void {
+ SkDebugf("%s: region complexity %d\n", label, region.computeRegionComplexity());
+ };
+ SkRegion region;
+ debugster("initial", region);
+ region.setRect({1, 2, 3, 4});
+ debugster("set rect", region);
+ region.op({2, 3, 4, 5}, SkRegion::kUnion_Op);
+ debugster("op rect", region);
+#StdOut
+initial: region complexity 0
+set rect: region complexity 1
+op rect: region complexity 3
+##
+##
+
+#SeeAlso isRect isComplex
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool getBoundaryPath(SkPath* path) const
+#In Property
+#Line # appends Region outline to Path ##
+
+Appends outline of Region to path.
+Returns true if Region is not empty; otherwise, returns false, and leaves path
+unmodified.
+
+#Param path Path to append to ##
+
+#Return true if path changed ##
+
+#Example
+#Height 100
+ SkRegion region;
+ region.setRect({10, 20, 90, 60});
+ region.op({30, 40, 60, 80}, SkRegion::kXOR_Op);
+ canvas->drawRegion(region, SkPaint());
+ SkPath path;
+ region.getBoundaryPath(&path);
+ path.offset(100, 0);
+ canvas->drawPath(path, SkPaint());
+##
+
+#SeeAlso isEmpty isComplex
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool setEmpty()
+#In Constructor
+#Line # constructs with default values ##
+
+Constructs an empty Region. Region is set to empty bounds
+at (0, 0) with zero width and height. Always returns false.
+
+#Return false ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: {%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region({1, 2, 3, 4});
+ debugster("region bounds", region);
+ region.setEmpty();
+ SkDebugf(" after region set empty:\n");
+ debugster("region bounds", region);
+#StdOut
+ region bounds: {1,2,3,4}
+ after region set empty:
+ region bounds: {0,0,0,0}
+##
+##
+
+#SeeAlso SkRegion()
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool setRect(const SkIRect& rect)
+#In Constructor
+#Line # constructs Region matching IRect ##
+
+Constructs a rectangular Region matching the bounds of rect.
+If rect is empty, constructs empty and returns false.
+
+#Param rect bounds of constructed Region ##
+
+#Return true if rect is not empty ##
+
+#Example
+ SkRegion region({1, 2, 3, 4});
+ SkDebugf("region is %s" "empty\n", region.isEmpty() ? "" : "not ");
+ bool setEmpty = region.setRect({1, 2, 1, 4});
+ SkDebugf("region is %s" "empty\n", region.isEmpty() ? "" : "not ");
+ SkDebugf("setEmpty: %s\n", setEmpty ? "true" : "false");
+#StdOut
+region is not empty
+region is empty
+setEmpty: false
+##
+##
+
+#SeeAlso SkRegion(const SkIRect& rect)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool setRect(int32_t left, int32_t top, int32_t right, int32_t bottom)
+#In Constructor
+#Line # constructs Region matching bounds ##
+
+Constructs Region with bounds (left, top, right, bottom).
+Returns true if left is less than right and top is less than bottom; otherwise,
+constructs empty Region and returns false.
+
+#Param left edge of bounds on x-axis ##
+#Param top edge of bounds on y-axis ##
+#Param right edge of bounds on x-axis ##
+#Param bottom edge of bounds on y-axis ##
+
+#Return rectangular Region ##
+
+#Example
+ auto debugster = [](const char* label, bool success, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: success:%s {%d,%d,%d,%d}\n", label, success ? "true" : "false",
+ r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region;
+ bool success = region.setRect(1, 2, 3, 4);
+ debugster("set to: 1,2,3,4", success, region);
+ success = region.setRect(3, 2, 1, 4);
+ debugster("set to: 3,2,1,4", success, region);
+#StdOut
+set to: 1,2,3,4: success:true {1,2,3,4}
+set to: 3,2,1,4: success:false {0,0,0,0}
+##
+##
+
+#SeeAlso SkRegion(const SkIRect& rect)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool setRects(const SkIRect rects[], int count)
+#In Constructor
+#Line # sets IRect array ##
+
+Constructs Region as the union of IRect in rects array. If count is
+zero, constructs empty Region. Returns false if constructed Region is empty.
+
+May be faster than repeated calls to op().
+
+#Param rects array of IRects ##
+#Param count array size ##
+
+#Return true if constructed Region is not empty ##
+
+#Example
+#Height 70
+ SkIRect rects[] = { {10, 10, 40, 40}, {20, 20, 50, 50}, {30, 30, 60, 60} };
+ SkRegion region;
+ region.setRects(rects, SK_ARRAY_COUNT(rects));
+ canvas->drawRegion(region, SkPaint());
+ region.setEmpty();
+ for (auto add : rects) {
+ region.op(add, SkRegion::kUnion_Op);
+ }
+ region.translate(100, 0);
+ canvas->drawRegion(region, SkPaint());
+##
+
+#SeeAlso setRect op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool setRegion(const SkRegion& region)
+#In Constructor
+#Line # copies Region ##
+
+Constructs a copy of an existing region.
+Makes two regions identical by value. Internally, region and
+the returned result share pointer values. The underlying Rect array is
+copied when modified.
+
+Creating a Region copy is very efficient and never allocates memory.
+Regions are always copied by value from the interface; the underlying shared
+pointers are not exposed.
+
+#Param region Region to copy by value ##
+
+#Return Region to copy by value ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ auto r = region.getBounds();
+ SkDebugf("%14s: {%d,%d,%d,%d}\n", label, r.fLeft, r.fTop, r.fRight, r.fBottom);
+ };
+ SkRegion region({1, 2, 3, 4});
+ SkRegion region2;
+ region2.setRegion(region);
+ debugster("region bounds", region);
+ debugster("region2 bounds", region2);
+ region2.setEmpty();
+ SkDebugf(" after region set empty:\n");
+ debugster("region bounds", region);
+ debugster("region2 bounds", region2);
+#StdOut
+ region bounds: {1,2,3,4}
+region2 bounds: {1,2,3,4}
+ after region set empty:
+ region bounds: {1,2,3,4}
+region2 bounds: {0,0,0,0}
+##
+##
+
+#SeeAlso SkRegion(const SkRegion& region)
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool setPath(const SkPath& path, const SkRegion& clip)
+#In Constructor
+#Line # constructs Region from clipped Path ##
+
+Constructs Region to match outline of path within clip.
+Returns false if constructed Region is empty.
+
+Constructed Region draws the same pixels as path through clip when
+Anti_Aliasing is disabled.
+
+#Param path Path providing outline ##
+#Param clip Region containing path ##
+
+#Return true if constructed Region is not empty ##
+
+#Example
+#Height 120
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath textPath;
+ paint.getTextPath("Q", 1, 0, 110, &textPath);
+ SkIRect clipRect = {20, 20, 100, 120};
+ SkRegion clipRegion(clipRect);
+ SkRegion region;
+ region.setPath(textPath, clipRegion);
+ canvas->drawRegion(region, SkPaint());
+ clipRect.offset(100, 0);
+ textPath.offset(100, 0);
+ canvas->clipRect(SkRect::Make(clipRect), false);
+ canvas->drawPath(textPath, SkPaint());
+##
+
+#SeeAlso setRects op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool intersects(const SkIRect& rect) const
+#In Intersection
+#Line # returns true if areas overlap ##
+
+Returns true if Region intersects rect.
+Returns false if either rect or Region is empty, or do not intersect.
+
+#Param rect IRect to intersect ##
+
+#Return true if rect and Region have area in common ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath textPath;
+ paint.getTextPath("W", 1, 20, 110, &textPath);
+ SkRegion region;
+ region.setPath(textPath, SkRegion({0, 0, 256, 256}));
+ canvas->drawRegion(region, SkPaint());
+ SkIRect iRect = SkIRect::MakeXYWH(frame * 160, 55, 10, 10);
+ paint.setColor(region.intersects(iRect) ? SK_ColorBLUE : SK_ColorRED);
+ canvas->drawRect(SkRect::Make(iRect), paint);
+##
+
+#SeeAlso contains SkRect::intersects
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool intersects(const SkRegion& other) const
+
+Returns true if Region intersects other.
+Returns false if either other or Region is empty, or do not intersect.
+
+#Param other Region to intersect ##
+
+#Return true if other and Region have area in common ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath hPath, dotPath;
+ paint.getTextPath("H", 1, 40, 110, &hPath);
+ paint.getTextPath(",", 1, frame * 180, 95, &dotPath);
+ SkRegion hRegion, dotRegion;
+ hRegion.setPath(hPath, SkRegion({0, 0, 256, 256}));
+ dotRegion.setPath(dotPath, SkRegion({0, 0, 256, 256}));
+ canvas->drawRegion(hRegion, paint);
+ paint.setColor(hRegion.intersects(dotRegion) ? SK_ColorBLUE : SK_ColorRED);
+ canvas->drawRegion(dotRegion, paint);
+##
+
+#SeeAlso contains SkRect::intersects
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool contains(int32_t x, int32_t y) const
+#In Intersection
+#Line # returns true if points are equal or inside ##
+
+Returns true if IPoint (x, y) is inside Region.
+Returns false if Region is empty.
+
+#Param x test IPoint x-coordinate ##
+#Param y test IPoint y-coordinate ##
+
+#Return true if (x, y) is inside Region ##
+
+#Example
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ SkRegion xRegion;
+ xRegion.setPath(xPath, SkRegion({0, 0, 256, 256}));
+ canvas->drawRegion(xRegion, paint);
+ for (int y = 0; y < 128; y += 8) {
+ for (int x = 0; x < 128; x += 8) {
+ paint.setColor(xRegion.contains(x, y) ? SK_ColorWHITE : SK_ColorRED);
+ canvas->drawPoint(x, y, paint);
+ }
+ }
+##
+
+#SeeAlso intersects SkRect::contains
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool contains(const SkIRect& other) const
+
+Returns true if other is completely inside Region.
+Returns false if Region or other is empty.
+
+#Param other IRect to contain ##
+
+#Return true if other is inside Region ##
+
+#Example
+#Height 128
+#Duration 4
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ SkRegion xRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ xRegion.op(drawBounds, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+ SkIRect test = SkIRect::MakeXYWH(frame* 128, 64, 5, 5);
+ if (xRegion.contains(test)) {
+ paint.setColor(SK_ColorYELLOW);
+ canvas->drawRect(SkRect::Make(test), paint);
+ }
+##
+
+#SeeAlso intersects SkRect::contains
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool contains(const SkRegion& other) const
+
+Returns true if other is completely inside Region.
+Returns false if Region or other is empty.
+
+#Param other Region to contain ##
+
+#Return true if other is inside Region ##
+
+#Example
+#Height 128
+#Duration 4
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath, testPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ paint.getTextPath("`", 1, frame * 150 - 40, 150, &testPath);
+ SkRegion xRegion, testRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ testRegion.setPath(testPath, SkRegion(drawBounds));
+ xRegion.op(drawBounds, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+ if (xRegion.contains(testRegion)) {
+ paint.setColor(SK_ColorYELLOW);
+ canvas->drawRegion(testRegion, paint);
+ }
+##
+
+#SeeAlso intersects SkRect::contains
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool quickContains(const SkIRect& r) const
+#In Intersection
+#Line # returns true quickly if points are equal or inside ##
+
+Returns true if Region is a single rectangle and contains r.
+May return false even though Region contains r.
+
+#Param r IRect to contain ##
+
+#Return true quickly if r points are equal or inside ##
+
+#Example
+ SkRegion region({1, 2, 3, 4});
+ SkIRect test = {2, 2, 3, 3};
+ SkDebugf("quickContains 1: %s\n", region.quickContains(test) ? "true" : "false");
+ region.op({1, 4, 3, 6}, SkRegion::kUnion_Op);
+ SkDebugf("quickContains 2: %s\n", region.quickContains(test) ? "true" : "false");
+ region.op({1, 7, 3, 8}, SkRegion::kUnion_Op);
+ SkDebugf("quickContains 3: %s\n", region.quickContains(test) ? "true" : "false");
+#StdOut
+quickContains 1: true
+quickContains 2: true
+quickContains 3: false
+##
+##
+
+#SeeAlso contains quickReject intersects
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool quickContains(int32_t left, int32_t top, int32_t right,
+ int32_t bottom) const
+
+Returns true if Region is a single rectangle and contains IRect
+(left, top, right, bottom).
+Returns false if Region is empty or IRect (left, top, right, bottom) is empty.
+May return false even though Region contains (left, top, right, bottom).
+
+#Param left edge of bounds on x-axis ##
+#Param top edge of bounds on y-axis ##
+#Param right edge of bounds on x-axis ##
+#Param bottom edge of bounds on y-axis ##
+
+#Return true quickly if IRect are equal or inside ##
+
+#Example
+ auto debugster = [](const char* label, SkRegion& region) -> void {
+ SkDebugf("%s: %s\n", label, region.quickContains(2, 2, 3, 3) ? "true" : "false");
+ };
+ SkRegion region({1, 2, 3, 4});
+ debugster("quickContains 1", region);
+ region.op({1, 4, 3, 6}, SkRegion::kUnion_Op);
+ debugster("quickContains 2", region);
+ region.op({1, 7, 3, 8}, SkRegion::kUnion_Op);
+ debugster("quickContains 3", region);
+#StdOut
+quickContains 1: true
+quickContains 2: true
+quickContains 3: false
+##
+##
+
+#SeeAlso contains quickReject intersects
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool quickReject(const SkIRect& rect) const
+#In Intersection
+#Line # returns true quickly if points are outside ##
+
+Returns true if Region does not intersect rect.
+Returns true if rect is empty or Region is empty.
+May return false even though Region does not intersect rect.
+
+#Param rect IRect to intersect ##
+
+#Return true if rect does not intersect ##
+
+#Example
+ SkRegion region({1, 2, 3, 4});
+ SkIRect test = {4, 2, 5, 3};
+ SkDebugf("quickReject 1: %s\n", region.quickReject(test) ? "true" : "false");
+ region.op({1, 4, 3, 6}, SkRegion::kUnion_Op);
+ SkDebugf("quickReject 2: %s\n", region.quickReject(test) ? "true" : "false");
+ region.op({4, 7, 5, 8}, SkRegion::kUnion_Op);
+ SkDebugf("quickReject 3: %s\n", region.quickReject(test) ? "true" : "false");
+#StdOut
+quickReject 1: true
+quickReject 2: true
+quickReject 3: false
+##
+##
+
+#SeeAlso quickContains contains intersects
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool quickReject(const SkRegion& rgn) const
+
+Returns true if Region does not intersect rgn.
+Returns true if rgn is empty or Region is empty.
+May return false even though Region does not intersect rgn.
+
+#Param rgn Region to intersect ##
+
+#Return true if rgn does not intersect ##
+
+#Example
+ SkRegion region({1, 2, 3, 4});
+ SkRegion test;
+ SkIRect rects[] = {{4, 2, 5, 3}, {7, 2, 8, 3}};
+ test.setRects(rects, SK_ARRAY_COUNT(rects));
+ SkDebugf("quickReject 1: %s\n", region.quickReject(test) ? "true" : "false");
+ region.op({1, 4, 3, 6}, SkRegion::kUnion_Op);
+ SkDebugf("quickReject 2: %s\n", region.quickReject(test) ? "true" : "false");
+ region.op({4, 7, 5, 8}, SkRegion::kUnion_Op);
+ SkDebugf("quickReject 3: %s\n", region.quickReject(test) ? "true" : "false");
+#StdOut
+quickReject 1: true
+quickReject 2: true
+quickReject 3: false
+##
+##
+
+#SeeAlso quickContains contains intersects
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method void translate(int dx, int dy)
+#In Transform
+#Line # translates IPoints in Region ##
+
+Offsets Region by IVector (dx, dy). Has no effect if Region is empty.
+
+#Param dx x-axis offset ##
+#Param dy y-axis offset ##
+
+#Example
+#Height 90
+ SkRegion test;
+ SkIRect rects[] = {{40, 20, 50, 30}, {70, 40, 80, 50}, { 60, 10, 70, 20}};
+ test.setRects(rects, SK_ARRAY_COUNT(rects));
+ SkPaint paint;
+ for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorMAGENTA } ) {
+ paint.setColor(color);
+ canvas->drawRegion(test, paint);
+ test.translate(10, 10);
+ }
+##
+
+#SeeAlso SkCanvas::translate SkIRect::offset SkPath::offset
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method void translate(int dx, int dy, SkRegion* dst) const
+
+Offsets Region by IVector (dx, dy), writing result to dst. Region may be passed
+as dst parameter, translating Region in place. Has no effect if dst is nullptr.
+If Region is empty, sets dst to empty.
+
+#Param dx x-axis offset ##
+#Param dy y-axis offset ##
+#Param dst translated result ##
+
+#Example
+ SkRegion test;
+ SkIRect rects[] = {{40, 20, 50, 30}, {70, 40, 80, 50}, { 60, 10, 70, 20}};
+ test.setRects(rects, SK_ARRAY_COUNT(rects));
+ SkPaint paint;
+ for (auto color : { SK_ColorRED, SK_ColorBLUE, SK_ColorGREEN, SK_ColorMAGENTA } ) {
+ paint.setColor(color);
+ canvas->drawRegion(test, paint);
+ SkRegion second;
+ test.translate(10, test.getBounds().fBottom, &second);
+ test.op(second, SkRegion::kXOR_Op);
+ test.translate(30, 0);
+ }
+##
+
+#SeeAlso SkCanvas::translate SkIRect::offset SkPath::offset
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Enum Op
+#Line # binary operator combining Regions ##
+
+#Code
+ enum Op {
+ kDifference_Op,
+ kIntersect_Op,
+ kUnion_Op,
+ kXOR_Op,
+ kReverseDifference_Op,
+ kReplace_Op,
+ kLastOp = kReplace_Op,
+ };
+##
+
+The logical operations that can be performed when combining two Regions.
+
+#Const kDifference_Op 0
+#Line # target minus operand ##
+Subtracts operand Region from target Region.
+##
+#Const kIntersect_Op 1
+#Line # target intersected with operand ##
+Intersects operand Region and target Region.
+##
+#Const kUnion_Op 2
+#Line # target unioned with operand ##
+Unions operand Region and target Region.
+##
+#Const kXOR_Op 3
+#Line # target exclusive or with operand ##
+Replaces target Region with area exclusive to both Regions.
+##
+#Const kReverseDifference_Op 4
+#Line # operand minus target ##
+Subtracts target Region from operand Region.
+##
+#Const kReplace_Op 5
+#Line # replace target with operand ##
+Replaces target Region with operand Region.
+##
+#Const kLastOp 5
+#Line # last operator ##
+##
+
+#Example
+ SkRegion operand({35, 35, 85, 85});
+ const char* labels[] = {"difference", "intersect", "union", "xor", "reverse diff", "replace"};
+ int index = 0;
+ SkPaint paint;
+ paint.setTextAlign(SkPaint::kCenter_Align);
+ for (auto op : { SkRegion::kDifference_Op, SkRegion::kIntersect_Op, SkRegion::kUnion_Op,
+ SkRegion::kXOR_Op, SkRegion::kReverseDifference_Op, SkRegion::kReplace_Op } ) {
+ SkRegion target({10, 10, 60, 60});
+ target.op(operand, op);
+ canvas->drawRegion(target, paint);
+ canvas->drawString(labels[index++], 40, 100, paint);
+ canvas->translate(80, 0);
+ if (SkRegion::kUnion_Op == op) {
+ canvas->translate(-240, 120);
+ }
+ }
+##
+
+#SeeAlso SkPathOp
+
+#Enum ##
+
+# ------------------------------------------------------------------------------
+
+#Const kOpCnt 6
+#Line # number of operators defined ##
+May be used to verify that Op is a legal value.
+#Const ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool op(const SkIRect& rect, Op op)
+#In Transform
+#Line # applies binary operator ##
+
+Replaces Region with the result of Region op rect.
+Returns true if replaced Region is not empty.
+
+#Param rect IRect operand ##
+#Param op operator, one of: #list_of_op_types#
+##
+
+#Return false if result is empty ##
+
+#Example
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ SkRegion xRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ xRegion.op(drawBounds, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+##
+
+#SeeAlso setRects Op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool op(int left, int top, int right, int bottom, Op op)
+
+Replaces Region with the result of Region op IRect (left, top, right, bottom).
+Returns true if replaced Region is not empty.
+
+#Param left edge of bounds on x-axis ##
+#Param top edge of bounds on y-axis ##
+#Param right edge of bounds on x-axis ##
+#Param bottom edge of bounds on y-axis ##
+#Param op operator, one of: #list_of_op_types#
+##
+
+#Return false if result is empty ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ SkRegion xRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ xRegion.op(drawBounds.fLeft + frame * drawBounds.width(), drawBounds.fTop,
+ drawBounds.fRight, drawBounds.fBottom, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+##
+
+#SeeAlso setRects Op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool op(const SkRegion& rgn, Op op)
+
+Replaces Region with the result of Region op rgn.
+Returns true if replaced Region is not empty.
+
+#Param rgn Region operand ##
+#Param op operator, one of: #list_of_op_types#
+##
+
+#Return false if result is empty ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath, opPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ opPath.addCircle(64, 64, frame * 64);
+ SkRegion xRegion, opRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ opRegion.setPath(opPath, SkRegion(drawBounds));
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ xRegion.op(opRegion, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+##
+
+#SeeAlso setRects Op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool op(const SkIRect& rect, const SkRegion& rgn, Op op)
+
+Replaces Region with the result of rect op rgn.
+Returns true if replaced Region is not empty.
+
+#Param rect IRect operand ##
+#Param rgn Region operand ##
+#Param op operator, one of: #list_of_op_types#
+##
+
+#Return false if result is empty ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath, opPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ opPath.addCircle(64, 64, frame * 64);
+ SkRegion xRegion, opRegion, rectRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ opRegion.setPath(opPath, SkRegion(drawBounds));
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ drawBounds.inset(frame * drawBounds.width() / 2, 0);
+ rectRegion.op(drawBounds, opRegion, SkRegion::kIntersect_Op);
+ xRegion.op(rectRegion, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+##
+
+#SeeAlso setRects Op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool op(const SkRegion& rgn, const SkIRect& rect, Op op)
+
+Replaces Region with the result of rgn op rect.
+Returns true if replaced Region is not empty.
+
+#Param rgn Region operand ##
+#Param rect IRect operand ##
+#Param op operator, one of: #list_of_op_types#
+##
+
+#Return false if result is empty ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath, opPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ opPath.addCircle(64, 64, frame * 64);
+ SkRegion xRegion, opRegion, rectRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ opRegion.setPath(opPath, SkRegion(drawBounds));
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ drawBounds.inset(frame * drawBounds.width() / 2, 0);
+ rectRegion.op(opRegion, drawBounds, SkRegion::kUnion_Op);
+ xRegion.op(rectRegion, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+##
+
+#SeeAlso setRects Op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method bool op(const SkRegion& rgna, const SkRegion& rgnb, Op op)
+
+Replaces Region with the result of rgna op rgnb.
+Returns true if replaced Region is not empty.
+
+#Param rgna Region operand ##
+#Param rgnb Region operand ##
+#Param op operator, one of: #list_of_op_types#
+##
+
+#Return false if result is empty ##
+
+#Example
+#Duration 4
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath, opPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ xPath.setFillType(SkPath::kInverseWinding_FillType);
+ opPath.addCircle(64, 64, frame * 64);
+ opPath.setFillType(SkPath::kInverseWinding_FillType);
+ SkRegion xRegion, opRegion, rectRegion;
+ SkIRect drawBounds = {0, 0, 128, 128};
+ opRegion.setPath(opPath, SkRegion(drawBounds));
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ drawBounds.inset(frame * drawBounds.width() / 2, 0);
+ rectRegion.setRect(drawBounds);
+ rectRegion.op(xRegion, SkRegion::kIntersect_Op);
+ xRegion.op(rectRegion, opRegion, SkRegion::kReverseDifference_Op);
+ canvas->drawRegion(xRegion, paint);
+##
+
+#SeeAlso setRects Op
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method char* toString()
+#In Utility
+#Line # exists for Android framework only ##
+#Private
+Android framework only.
+##
+#Return string representation of Region ##
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method size_t writeToMemory(void* buffer) const
+#In Utility
+#Line # writes to buffer ##
+
+Writes Region to buffer, and returns number of bytes written.
+If buffer is nullptr, returns number number of bytes that would be written.
+
+#Param buffer storage for binary data ##
+
+#Return size of Region ##
+
+#Example
+#Height 128
+ SkPaint paint;
+ paint.setTextSize(128);
+ SkPath xPath;
+ paint.getTextPath("X", 1, 20, 110, &xPath);
+ SkIRect drawBounds = {0, 0, 128, 128};
+ SkRegion xRegion;
+ xRegion.setPath(xPath, SkRegion(drawBounds));
+ size_t size = xRegion.writeToMemory(nullptr);
+ sk_sp<SkData> data = SkData::MakeUninitialized(size);
+ xRegion.writeToMemory(data->writable_data());
+ SkRegion copy;
+ copy.readFromMemory(data->data(), data->size());
+ canvas->drawRegion(copy, paint);
+##
+
+#SeeAlso readFromMemory
+
+#Method ##
+
+# ------------------------------------------------------------------------------
+
+#Method size_t readFromMemory(const void* buffer, size_t length)
+#In Utility
+#Line # reads from buffer ##
+
+Constructs Region from buffer of size length. Returns bytes read.
+Returned value will be multiple of four or zero if length was too small.
+
+#Param buffer storage for binary data ##
+#Param length size of buffer ##
+
+#Return bytes read ##
+
+#Example
+#Height 100
+ SkRegion region({20, 20, 80, 80});
+ size_t size = region.writeToMemory(nullptr);
+ sk_sp<SkData> data = SkData::MakeUninitialized(size);
+ region.writeToMemory(data->writable_data());
+ SkRegion copy;
+ copy.readFromMemory(data->data(), data->size());
+ canvas->drawRegion(copy, SkPaint());
+##
+
+#SeeAlso writeToMemory
+
+#Method ##
+
+#Class SkRegion ##
+
+#Topic Region ##