/*
* Copyright 2005 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkRegion_DEFINED
#define SkRegion_DEFINED
#include "SkRect.h"
class SkPath;
class SkRgnBuilder;
namespace android {
class Region;
}
#define SkRegion_gEmptyRunHeadPtr ((SkRegion::RunHead*)-1)
#define SkRegion_gRectRunHeadPtr 0
/** \class SkRegion
The SkRegion class encapsulates the geometric region used to specify
clipping areas for drawing.
*/
class SK_API SkRegion {
public:
typedef int32_t RunType;
enum {
kRunTypeSentinel = 0x7FFFFFFF
};
SkRegion();
SkRegion(const SkRegion&);
explicit SkRegion(const SkIRect&);
~SkRegion();
SkRegion& operator=(const SkRegion&);
/**
* Return true if the two regions are equal. i.e. The enclose exactly
* the same area.
*/
bool operator==(const SkRegion& other) const;
/**
* Return true if the two regions are not equal.
*/
bool operator!=(const SkRegion& other) const {
return !(*this == other);
}
/**
* Replace this region with the specified region, and return true if the
* resulting region is non-empty.
*/
bool set(const SkRegion& src) {
SkASSERT(&src);
*this = src;
return !this->isEmpty();
}
/**
* Swap the contents of this and the specified region. This operation
* is gauarenteed to never fail.
*/
void swap(SkRegion&);
/** Return true if this region is empty */
bool isEmpty() const { return fRunHead == SkRegion_gEmptyRunHeadPtr; }
/** Return true if this region is a single, non-empty rectangle */
bool isRect() const { return fRunHead == SkRegion_gRectRunHeadPtr; }
/** Return true if this region consists of more than 1 rectangular area */
bool isComplex() const { return !this->isEmpty() && !this->isRect(); }
/**
* Return the bounds of this region. If the region is empty, returns an
* empty rectangle.
*/
const SkIRect& getBounds() const { return fBounds; }
/**
* Returns true if the region is non-empty, and if so, appends the
* boundary(s) of the region to the specified path.
* If the region is empty, returns false, and path is left unmodified.
*/
bool getBoundaryPath(SkPath* path) const;
/**
* Set the region to be empty, and return false, since the resulting
* region is empty
*/
bool setEmpty();
/**
* If rect is non-empty, set this region to that rectangle and return true,
* otherwise set this region to empty and return false.
*/
bool setRect(const SkIRect&);
/**
* If left < right and top < bottom, set this region to that rectangle and
* return true, otherwise set this region to empty and return false.
*/
bool setRect(int32_t left, int32_t top, int32_t right, int32_t bottom);
/**
* Set this region to the union of an array of rects. This is generally
* faster than calling region.op(rect, kUnion_Op) in a loop. If count is
* 0, then this region is set to the empty region.
* @return true if the resulting region is non-empty
*/
bool setRects(const SkIRect rects[], int count);
/**
* Set this region to the specified region, and return true if it is
* non-empty.
*/
bool setRegion(const SkRegion&);
/**
* Set this region to the area described by the path, clipped.
* Return true if the resulting region is non-empty.
* This produces a region that is identical to the pixels that would be
* drawn by the path (with no antialiasing) with the specified clip.
*/
bool setPath(const SkPath&, const SkRegion& clip);
/**
* Returns true if the specified rectangle has a non-empty intersection
* with this region.
*/
bool intersects(const SkIRect&) const;
/**
* Returns true if the specified region has a non-empty intersection
* with this region.
*/
bool intersects(const SkRegion&) const;
/**
* Return true if the specified x,y coordinate is inside the region.
*/
bool contains(int32_t x, int32_t y) const;
/**
* Return true if the specified rectangle is completely inside the region.
* This works for simple (rectangular) and complex regions, and always
* returns the correct result. Note: if either this region or the rectangle
* is empty, contains() returns false.
*/
bool contains(const SkIRect&) const;
/**
* Return true if the specified region is completely inside the region.
* This works for simple (rectangular) and complex regions, and always
* returns the correct result. Note: if either region is empty, contains()
* returns false.
*/
bool contains(const SkRegion&) const;
/**
* Return true if this region is a single rectangle (not complex) and the
* specified rectangle is contained by this region. Returning false is not
* a guarantee that the rectangle is not contained by this region, but
* return true is a guarantee that the rectangle is contained by this region.
*/
bool quickContains(const SkIRect& r) const {
return this->quickContains(r.fLeft, r.fTop, r.fRight, r.fBottom);
}
/**
* Return true if this region is a single rectangle (not complex) and the
* specified rectangle is contained by this region. Returning false is not
* a guarantee that the rectangle is not contained by this region, but
* return true is a guarantee that the rectangle is contained by this
* region.
*/
bool quickContains(int32_t left, int32_t top, int32_t right,
int32_t bottom) const {
SkASSERT(this->isEmpty() == fBounds.isEmpty()); // valid region
return left < right && top < bottom &&
fRunHead == SkRegion_gRectRunHeadPtr && // this->isRect()
/* fBounds.contains(left, top, right, bottom); */
fBounds.fLeft <= left && fBounds.fTop <= top &&
fBounds.fRight >= right && fBounds.fBottom >= bottom;
}
/**
* Return true if this region is empty, or if the specified rectangle does
* not intersect the region. Returning false is not a guarantee that they
* intersect, but returning true is a guarantee that they do not.
*/
bool quickReject(const SkIRect& rect) const {
return this->isEmpty() || rect.isEmpty() ||
!SkIRect::Intersects(fBounds, rect);
}
/**
* Return true if this region, or rgn, is empty, or if their bounds do not
* intersect. Returning false is not a guarantee that they intersect, but
* returning true is a guarantee that they do not.
*/
bool quickReject(const SkRegion& rgn) const {
return this->isEmpty() || rgn.isEmpty() ||
!SkIRect::Intersects(fBounds, rgn.fBounds);
}
/** Translate the region by the specified (dx, dy) amount. */
void translate(int dx, int dy) { this->translate(dx, dy, this); }
/**
* Translate the region by the specified (dx, dy) amount, writing the
* resulting region into dst. Note: it is legal to pass this region as the
* dst parameter, effectively translating the region in place. If dst is
* null, nothing happens.
*/
void translate(int dx, int dy, SkRegion* dst) const;
/**
* The logical operations that can be performed when combining two regions.
*/
enum Op {
kDifference_Op, //!< subtract the op region from the first region
kIntersect_Op, //!< intersect the two regions
kUnion_Op, //!< union (inclusive-or) the two regions
kXOR_Op, //!< exclusive-or the two regions
/** subtract the first region from the op region */
kReverseDifference_Op,
kReplace_Op //!< replace the dst region with the op region
};
/**
* Set this region to the result of applying the Op to this region and the
* specified rectangle: this = (this op rect).
* Return true if the resulting region is non-empty.
*/
bool op(const SkIRect& rect, Op op) { return this->op(*this, rect, op); }
/**
* Set this region to the result of applying the Op to this region and the
* specified rectangle: this = (this op rect).
* Return true if the resulting region is non-empty.
*/
bool op(int left, int top, int right, int bottom, Op op) {
SkIRect rect;
rect.set(left, top, right, bottom);
return this->op(*this, rect, op);
}
/**
* Set this region to the result of applying the Op to this region and the
* specified region: this = (this op rgn).
* Return true if the resulting region is non-empty.
*/
bool op(const SkRegion& rgn, Op op) { return this->op(*this, rgn, op); }
/**
* Set this region to the result of applying the Op to the specified
* rectangle and region: this = (rect op rgn).
* Return true if the resulting region is non-empty.
*/
bool op(const SkIRect& rect, const SkRegion& rgn, Op);
/**
* Set this region to the result of applying the Op to the specified
* region and rectangle: this = (rgn op rect).
* Return true if the resulting region is non-empty.
*/
bool op(const SkRegion& rgn, const SkIRect& rect, Op);
/**
* Set this region to the result of applying the Op to the specified
* regions: this = (rgna op rgnb).
* Return true if the resulting region is non-empty.
*/
bool op(const SkRegion& rgna, const SkRegion& rgnb, Op op);
#ifdef SK_BUILD_FOR_ANDROID
/** Returns a new char* containing the list of rectangles in this region
*/
char* toString();
#endif
/**
* Returns the sequence of rectangles, sorted in Y and X, that make up
* this region.
*/
class SK_API Iterator {
public:
Iterator() : fRgn(NULL), fDone(true) {}
Iterator(const SkRegion&);
// if we have a region, reset to it and return true, else return false
bool rewind();
// reset the iterator, using the new region
void reset(const SkRegion&);
bool done() const { return fDone; }
void next();
const SkIRect& rect() const { return fRect; }
// may return null
const SkRegion* rgn() const { return fRgn; }
private:
const SkRegion* fRgn;
const RunType* fRuns;
SkIRect fRect;
bool fDone;
};
/**
* Returns the sequence of rectangles, sorted in Y and X, that make up
* this region intersected with the specified clip rectangle.
*/
class SK_API Cliperator {
public:
Cliperator(const SkRegion&, const SkIRect& clip);
bool done() { return fDone; }
void next();
const SkIRect& rect() const { return fRect; }
private:
Iterator fIter;
SkIRect fClip;
SkIRect fRect;
bool fDone;
};
/**
* Returns the sequence of runs that make up this region for the specified
* Y scanline, clipped to the specified left and right X values.
*/
class Spanerator {
public:
Spanerator(const SkRegion&, int y, int left, int right);
bool next(int* left, int* right);
private:
const SkRegion::RunType* fRuns;
int fLeft, fRight;
bool fDone;
};
/**
* Write the region to the buffer, and return the number of bytes written.
* If buffer is NULL, it still returns the number of bytes.
*/
uint32_t flatten(void* buffer) const;
/**
* Initialized the region from the buffer, returning the number
* of bytes actually read.
*/
uint32_t unflatten(const void* buffer);
/**
* Returns a reference to a global empty region. Just a convenience for
* callers that need a const empty region.
*/
static const SkRegion& GetEmptyRegion();
SkDEBUGCODE(void dump() const;)
SkDEBUGCODE(void validate() const;)
SkDEBUGCODE(static void UnitTest();)
// expose this to allow for regression test on complex regions
SkDEBUGCODE(bool debugSetRuns(const RunType runs[], int count);)
private:
enum {
kOpCount = kReplace_Op + 1
};
enum {
kRectRegionRuns = 6 // need to store a region of a rect [T B L R S S]
};
friend class android::Region; // needed for marshalling efficiently
void allocateRuns(int count); // allocate space for count runs
struct RunHead;
SkIRect fBounds;
RunHead* fRunHead;
void freeRuns();
const RunType* getRuns(RunType tmpStorage[], int* count) const;
bool setRuns(RunType runs[], int count);
int count_runtype_values(int* itop, int* ibot) const;
static void BuildRectRuns(const SkIRect& bounds,
RunType runs[kRectRegionRuns]);
// returns true if runs are just a rect
static bool ComputeRunBounds(const RunType runs[], int count,
SkIRect* bounds);
friend struct RunHead;
friend class Iterator;
friend class Spanerator;
friend class SkRgnBuilder;
friend class SkFlatRegion;
};
#endif