include/core/SkRRect.h - skia - Git at Google

 /*
  * 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 SkRRect_DEFINED
 #define SkRRect_DEFINED

 #include "SkRect.h"
 #include "SkPoint.h"

 class SkPath;
 class SkMatrix;

 // Path forward:
 //   core work
 //      add contains(SkRect&)  - for clip stack
 //      add contains(SkRRect&) - for clip stack
 //      add heart rect computation (max rect inside RR)
 //      add 9patch rect computation
 //      add growToInclude(SkPath&)
 //   analysis
 //      use growToInclude to fit skp round rects & generate stats (RRs vs. real paths)
 //      check on # of rectorus's the RRs could handle
 //   rendering work
 //      update SkPath.addRRect() to only use quads
 //      add GM and bench
 //   further out
 //      detect and triangulate RRectorii rather than falling back to SW in Ganesh
 //

 /** \class SkRRect

     The SkRRect class represents a rounded rect with a potentially different
     radii for each corner. It does not have a constructor so must be
     initialized with one of the initialization functions (e.g., setEmpty,
     setRectRadii, etc.)

     This class is intended to roughly match CSS' border-*-*-radius capabilities.
     This means:
         If either of a corner's radii are 0 the corner will be square.
         Negative radii are not allowed (they are clamped to zero).
         If the corner curves overlap they will be proportionally reduced to fit.
 */
 class SK_API SkRRect {
 public:
     /** Default initialized to a rrect at the origin with zero width and height. */
     SkRRect() = default;

     SkRRect(const SkRRect& rrect) = default;
     SkRRect& operator=(const SkRRect& rrect) = default;

     /**
      * Enum to capture the various possible subtypes of RR. Accessed
      * by type(). The subtypes become progressively less restrictive.
      */
     enum Type {
         // !< The RR has zero width and/or zero height. All radii are zero.
         kEmpty_Type,

         //!< The RR is actually a (non-empty) rect (i.e., at least one radius
         //!< at each corner is zero)
         kRect_Type,

         //!< The RR is actually a (non-empty) oval (i.e., all x radii are equal
         //!< and >= width/2 and all the y radii are equal and >= height/2
         kOval_Type,

         //!< The RR is non-empty and all the x radii are equal & all y radii
         //!< are equal but it is not an oval (i.e., there are lines between
         //!< the curves) nor a rect (i.e., both radii are non-zero)
         kSimple_Type,

         //!< The RR is non-empty and the two left x radii are equal, the two top
         //!< y radii are equal, and the same for the right and bottom but it is
         //!< neither an rect, oval, nor a simple RR. It is called "nine patch"
         //!< because the centers of the corner ellipses form an axis aligned
         //!< rect with edges that divide the RR into an 9 rectangular patches:
         //!< an interior patch, four edge patches, and four corner patches.
         kNinePatch_Type,

         //!< A fully general (non-empty) RR. Some of the x and/or y radii are
         //!< different from the others and there must be one corner where
         //!< both radii are non-zero.
         kComplex_Type,

         kLastType = kComplex_Type,
     };

     /**
      * Returns the RR's sub type.
      */
     Type getType() const {
         SkASSERT(this->isValid());
         return static_cast<Type>(fType);
     }

     Type type() const { return this->getType(); }

     inline bool isEmpty() const { return kEmpty_Type == this->getType(); }
     inline bool isRect() const { return kRect_Type == this->getType(); }
     inline bool isOval() const { return kOval_Type == this->getType(); }
     inline bool isSimple() const { return kSimple_Type == this->getType(); }
     inline bool isNinePatch() const { return kNinePatch_Type == this->getType(); }
     inline bool isComplex() const { return kComplex_Type == this->getType(); }

     SkScalar width() const { return fRect.width(); }
     SkScalar height() const { return fRect.height(); }

     /**
      *  kSimple means that all corners have the same x,y radii. This returns the top/left
      *  corner's radii as representative of all corners. If the RRect is kComplex, then
      *  this still returns that corner's radii, but it is not indicative of the other corners.
      */
     SkVector getSimpleRadii() const {
         return fRadii[0];
     }

     /**
      * Same as default initialized - zero width and height at the origin.
      */
     void setEmpty() { *this = SkRRect(); }

     /**
      * Set this RR to match the supplied rect. All radii will be 0.
      */
     void setRect(const SkRect& rect) {
         if (!this->initializeRect(rect)) {
             return;
         }

         memset(fRadii, 0, sizeof(fRadii));
         fType = kRect_Type;

         SkASSERT(this->isValid());
     }

     /** Makes an empty rrect at the origin with zero width and height. */
     static SkRRect MakeEmpty() { return SkRRect(); }

     static SkRRect MakeRect(const SkRect& r) {
         SkRRect rr;
         rr.setRect(r);
         return rr;
     }

     static SkRRect MakeOval(const SkRect& oval) {
         SkRRect rr;
         rr.setOval(oval);
         return rr;
     }

     static SkRRect MakeRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad) {
         SkRRect rr;
         rr.setRectXY(rect, xRad, yRad);
         return rr;
     }

     /**
      * Set this RR to match the supplied oval. All x radii will equal half the
      * width and all y radii will equal half the height.
      */
     void setOval(const SkRect& oval) {
         if (!this->initializeRect(oval)) {
             return;
         }

         SkScalar xRad = SkScalarHalf(fRect.width());
         SkScalar yRad = SkScalarHalf(fRect.height());

         for (int i = 0; i < 4; ++i) {
             fRadii[i].set(xRad, yRad);
         }
         fType = kOval_Type;

         SkASSERT(this->isValid());
     }

     /**
      * Initialize the RR with the same radii for all four corners.
      */
     void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad);

     /**
      * Initialize the rr with one radius per-side.
      */
     void setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
                       SkScalar rightRad, SkScalar bottomRad);

     /**
      * Initialize the RR with potentially different radii for all four corners.
      */
     void setRectRadii(const SkRect& rect, const SkVector radii[4]);

     // The radii are stored in UL, UR, LR, LL order.
     enum Corner {
         kUpperLeft_Corner,
         kUpperRight_Corner,
         kLowerRight_Corner,
         kLowerLeft_Corner,
     };

     const SkRect& rect() const { return fRect; }
     SkVector radii(Corner corner) const { return fRadii[corner]; }
     const SkRect& getBounds() const { return fRect; }

     friend bool operator==(const SkRRect& a, const SkRRect& b) {
         return a.fRect == b.fRect && SkScalarsEqual(&a.fRadii[0].fX, &b.fRadii[0].fX, 8);
     }

     friend bool operator!=(const SkRRect& a, const SkRRect& b) {
         return a.fRect != b.fRect || !SkScalarsEqual(&a.fRadii[0].fX, &b.fRadii[0].fX, 8);
     }

     /**
      *  Call inset on the bounds, and adjust the radii to reflect what happens
      *  in stroking: If the corner is sharp (no curvature), leave it alone,
      *  otherwise we grow/shrink the radii by the amount of the inset. If a
      *  given radius becomes negative, it is pinned to 0.
      *
      *  If the inset amount is larger than the width/height then the rrect collapses to
      *  a degenerate line or point.
      *
      *  If the inset is sufficiently negative to cause the bounds to become infinite then
      *  the result is a default initialized rrect.
      *
      *  It is valid for dst == this.
      */
     void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const;

     void inset(SkScalar dx, SkScalar dy) {
         this->inset(dx, dy, this);
     }

     /**
      *  Call outset on the bounds, and adjust the radii to reflect what happens
      *  in stroking: If the corner is sharp (no curvature), leave it alone,
      *  otherwise we grow/shrink the radii by the amount of the inset. If a
      *  given radius becomes negative, it is pinned to 0.
      *
      *  It is valid for dst == this.
      */
     void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
         this->inset(-dx, -dy, dst);
     }
     void outset(SkScalar dx, SkScalar dy) {
         this->inset(-dx, -dy, this);
     }

     /**
      * Translate the rrect by (dx, dy).
      */
     void offset(SkScalar dx, SkScalar dy) {
         fRect.offset(dx, dy);
     }

     SkRRect SK_WARN_UNUSED_RESULT makeOffset(SkScalar dx, SkScalar dy) const {
         return SkRRect(fRect.makeOffset(dx, dy), fRadii, fType);
     }

     /**
      *  Returns true if 'rect' is wholy inside the RR, and both
      *  are not empty.
      */
     bool contains(const SkRect& rect) const;

     bool isValid() const;

     static constexpr size_t kSizeInMemory = 12 * sizeof(SkScalar);

     /**
      *  Write the rrect into the specified buffer. This is guaranteed to always
      *  write kSizeInMemory bytes, and that value is guaranteed to always be
      *  a multiple of 4. Return kSizeInMemory.
      */
     size_t writeToMemory(void* buffer) const;

     /**
      * Reads the rrect from the specified buffer
      *
      * If the specified buffer is large enough, this will read kSizeInMemory bytes,
      * and that value is guaranteed to always be a multiple of 4.
      *
      * @param buffer Memory to read from
      * @param length Amount of memory available in the buffer
      * @return number of bytes read (must be a multiple of 4) or
      *         0 if there was not enough memory available
      */
     size_t readFromMemory(const void* buffer, size_t length);

     /**
      *  Transform by the specified matrix, and put the result in dst.
      *
      *  @param matrix SkMatrix specifying the transform. Must only contain
      *      scale and/or translate, or this call will fail.
      *  @param dst SkRRect to store the result. It is an error to use this,
      *      which would make this function no longer const.
      *  @return true on success, false on failure.
      */
     bool transform(const SkMatrix& matrix, SkRRect* dst) const;

     void dump(bool asHex) const;
     void dump() const { this->dump(false); }
     void dumpHex() const { this->dump(true); }

 private:
     static bool AreRectAndRadiiValid(const SkRect&, const SkVector[4]);

     SkRRect(const SkRect& rect, const SkVector radii[4], int32_t type)
         : fRect(rect)
         , fRadii{radii[0], radii[1], radii[2], radii[3]}
         , fType(type) {}

     /**
      * Initializes fRect. If the passed in rect is not finite or empty the rrect will be fully
      * initialized and false is returned. Otherwise, just fRect is initialized and true is returned.
      */
     bool initializeRect(const SkRect&);

     void computeType();
     bool checkCornerContainment(SkScalar x, SkScalar y) const;
     void scaleRadii(const SkRect& rect);

     SkRect fRect = SkRect::MakeEmpty();
     // Radii order is UL, UR, LR, LL. Use Corner enum to index into fRadii[]
     SkVector fRadii[4] = {{0, 0}, {0, 0}, {0,0}, {0,0}};
     // use an explicitly sized type so we're sure the class is dense (no uninitialized bytes)
     int32_t fType = kEmpty_Type;
     // TODO: add padding so we can use memcpy for flattening and not copy uninitialized data

     // to access fRadii directly
     friend class SkPath;
     friend class SkRRectPriv;
 };

 #endif
	/*
	* 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 SkRRect_DEFINED
	#define SkRRect_DEFINED

	#include "SkRect.h"
	#include "SkPoint.h"

	class SkPath;
	class SkMatrix;

	// Path forward:
	// core work
	// add contains(SkRect&) - for clip stack
	// add contains(SkRRect&) - for clip stack
	// add heart rect computation (max rect inside RR)
	// add 9patch rect computation
	// add growToInclude(SkPath&)
	// analysis
	// use growToInclude to fit skp round rects & generate stats (RRs vs. real paths)
	// check on # of rectorus's the RRs could handle
	// rendering work
	// update SkPath.addRRect() to only use quads
	// add GM and bench
	// further out
	// detect and triangulate RRectorii rather than falling back to SW in Ganesh
	//

	/** \class SkRRect

	The SkRRect class represents a rounded rect with a potentially different
	radii for each corner. It does not have a constructor so must be
	initialized with one of the initialization functions (e.g., setEmpty,
	setRectRadii, etc.)

	This class is intended to roughly match CSS' border---radius capabilities.
	This means:
	If either of a corner's radii are 0 the corner will be square.
	Negative radii are not allowed (they are clamped to zero).
	If the corner curves overlap they will be proportionally reduced to fit.
	*/
	class SK_API SkRRect {
	public:
	/** Default initialized to a rrect at the origin with zero width and height. */
	SkRRect() = default;

	SkRRect(const SkRRect& rrect) = default;
	SkRRect& operator=(const SkRRect& rrect) = default;

	/**
	* Enum to capture the various possible subtypes of RR. Accessed
	* by type(). The subtypes become progressively less restrictive.
	*/
	enum Type {
	// !< The RR has zero width and/or zero height. All radii are zero.
	kEmpty_Type,

	//!< The RR is actually a (non-empty) rect (i.e., at least one radius
	//!< at each corner is zero)
	kRect_Type,

	//!< The RR is actually a (non-empty) oval (i.e., all x radii are equal
	//!< and >= width/2 and all the y radii are equal and >= height/2
	kOval_Type,

	//!< The RR is non-empty and all the x radii are equal & all y radii
	//!< are equal but it is not an oval (i.e., there are lines between
	//!< the curves) nor a rect (i.e., both radii are non-zero)
	kSimple_Type,

	//!< The RR is non-empty and the two left x radii are equal, the two top
	//!< y radii are equal, and the same for the right and bottom but it is
	//!< neither an rect, oval, nor a simple RR. It is called "nine patch"
	//!< because the centers of the corner ellipses form an axis aligned
	//!< rect with edges that divide the RR into an 9 rectangular patches:
	//!< an interior patch, four edge patches, and four corner patches.
	kNinePatch_Type,

	//!< A fully general (non-empty) RR. Some of the x and/or y radii are
	//!< different from the others and there must be one corner where
	//!< both radii are non-zero.
	kComplex_Type,

	kLastType = kComplex_Type,
	};

	/**
	* Returns the RR's sub type.
	*/
	Type getType() const {
	SkASSERT(this->isValid());
	return static_cast<Type>(fType);
	}

	Type type() const { return this->getType(); }

	inline bool isEmpty() const { return kEmpty_Type == this->getType(); }
	inline bool isRect() const { return kRect_Type == this->getType(); }
	inline bool isOval() const { return kOval_Type == this->getType(); }
	inline bool isSimple() const { return kSimple_Type == this->getType(); }
	inline bool isNinePatch() const { return kNinePatch_Type == this->getType(); }
	inline bool isComplex() const { return kComplex_Type == this->getType(); }

	SkScalar width() const { return fRect.width(); }
	SkScalar height() const { return fRect.height(); }

	/**
	* kSimple means that all corners have the same x,y radii. This returns the top/left
	* corner's radii as representative of all corners. If the RRect is kComplex, then
	* this still returns that corner's radii, but it is not indicative of the other corners.
	*/
	SkVector getSimpleRadii() const {
	return fRadii[0];
	}

	/**
	* Same as default initialized - zero width and height at the origin.
	*/
	void setEmpty() { *this = SkRRect(); }

	/**
	* Set this RR to match the supplied rect. All radii will be 0.
	*/
	void setRect(const SkRect& rect) {
	if (!this->initializeRect(rect)) {
	return;
	}

	memset(fRadii, 0, sizeof(fRadii));
	fType = kRect_Type;

	SkASSERT(this->isValid());
	}

	/** Makes an empty rrect at the origin with zero width and height. */
	static SkRRect MakeEmpty() { return SkRRect(); }

	static SkRRect MakeRect(const SkRect& r) {
	SkRRect rr;
	rr.setRect(r);
	return rr;
	}

	static SkRRect MakeOval(const SkRect& oval) {
	SkRRect rr;
	rr.setOval(oval);
	return rr;
	}

	static SkRRect MakeRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad) {
	SkRRect rr;
	rr.setRectXY(rect, xRad, yRad);
	return rr;
	}

	/**
	* Set this RR to match the supplied oval. All x radii will equal half the
	* width and all y radii will equal half the height.
	*/
	void setOval(const SkRect& oval) {
	if (!this->initializeRect(oval)) {
	return;
	}

	SkScalar xRad = SkScalarHalf(fRect.width());
	SkScalar yRad = SkScalarHalf(fRect.height());

	for (int i = 0; i < 4; ++i) {
	fRadii[i].set(xRad, yRad);
	}
	fType = kOval_Type;

	SkASSERT(this->isValid());
	}

	/**
	* Initialize the RR with the same radii for all four corners.
	*/
	void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad);

	/**
	* Initialize the rr with one radius per-side.
	*/
	void setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
	SkScalar rightRad, SkScalar bottomRad);

	/**
	* Initialize the RR with potentially different radii for all four corners.
	*/
	void setRectRadii(const SkRect& rect, const SkVector radii[4]);

	// The radii are stored in UL, UR, LR, LL order.
	enum Corner {
	kUpperLeft_Corner,
	kUpperRight_Corner,
	kLowerRight_Corner,
	kLowerLeft_Corner,
	};

	const SkRect& rect() const { return fRect; }
	SkVector radii(Corner corner) const { return fRadii[corner]; }
	const SkRect& getBounds() const { return fRect; }

	friend bool operator==(const SkRRect& a, const SkRRect& b) {
	return a.fRect == b.fRect && SkScalarsEqual(&a.fRadii[0].fX, &b.fRadii[0].fX, 8);
	}

	friend bool operator!=(const SkRRect& a, const SkRRect& b) {
	return a.fRect != b.fRect \|\| !SkScalarsEqual(&a.fRadii[0].fX, &b.fRadii[0].fX, 8);
	}

	/**
	* Call inset on the bounds, and adjust the radii to reflect what happens
	* in stroking: If the corner is sharp (no curvature), leave it alone,
	* otherwise we grow/shrink the radii by the amount of the inset. If a
	* given radius becomes negative, it is pinned to 0.
	*
	* If the inset amount is larger than the width/height then the rrect collapses to
	* a degenerate line or point.
	*
	* If the inset is sufficiently negative to cause the bounds to become infinite then
	* the result is a default initialized rrect.
	*
	* It is valid for dst == this.
	*/
	void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const;

	void inset(SkScalar dx, SkScalar dy) {
	this->inset(dx, dy, this);
	}

	/**
	* Call outset on the bounds, and adjust the radii to reflect what happens
	* in stroking: If the corner is sharp (no curvature), leave it alone,
	* otherwise we grow/shrink the radii by the amount of the inset. If a
	* given radius becomes negative, it is pinned to 0.
	*
	* It is valid for dst == this.
	*/
	void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
	this->inset(-dx, -dy, dst);
	}
	void outset(SkScalar dx, SkScalar dy) {
	this->inset(-dx, -dy, this);
	}

	/**
	* Translate the rrect by (dx, dy).
	*/
	void offset(SkScalar dx, SkScalar dy) {
	fRect.offset(dx, dy);
	}

	SkRRect SK_WARN_UNUSED_RESULT makeOffset(SkScalar dx, SkScalar dy) const {
	return SkRRect(fRect.makeOffset(dx, dy), fRadii, fType);
	}

	/**
	* Returns true if 'rect' is wholy inside the RR, and both
	* are not empty.
	*/
	bool contains(const SkRect& rect) const;

	bool isValid() const;

	static constexpr size_t kSizeInMemory = 12 * sizeof(SkScalar);

	/**
	* Write the rrect into the specified buffer. This is guaranteed to always
	* write kSizeInMemory bytes, and that value is guaranteed to always be
	* a multiple of 4. Return kSizeInMemory.
	*/
	size_t writeToMemory(void* buffer) const;

	/**
	* Reads the rrect from the specified buffer
	*
	* If the specified buffer is large enough, this will read kSizeInMemory bytes,
	* and that value is guaranteed to always be a multiple of 4.
	*
	* @param buffer Memory to read from
	* @param length Amount of memory available in the buffer
	* @return number of bytes read (must be a multiple of 4) or
	* 0 if there was not enough memory available
	*/
	size_t readFromMemory(const void* buffer, size_t length);

	/**
	* Transform by the specified matrix, and put the result in dst.
	*
	* @param matrix SkMatrix specifying the transform. Must only contain
	* scale and/or translate, or this call will fail.
	* @param dst SkRRect to store the result. It is an error to use this,
	* which would make this function no longer const.
	* @return true on success, false on failure.
	*/
	bool transform(const SkMatrix& matrix, SkRRect* dst) const;

	void dump(bool asHex) const;
	void dump() const { this->dump(false); }
	void dumpHex() const { this->dump(true); }

	private:
	static bool AreRectAndRadiiValid(const SkRect&, const SkVector[4]);

	SkRRect(const SkRect& rect, const SkVector radii[4], int32_t type)
	: fRect(rect)
	, fRadii{radii[0], radii[1], radii[2], radii[3]}
	, fType(type) {}

	/**
	* Initializes fRect. If the passed in rect is not finite or empty the rrect will be fully
	* initialized and false is returned. Otherwise, just fRect is initialized and true is returned.
	*/
	bool initializeRect(const SkRect&);

	void computeType();
	bool checkCornerContainment(SkScalar x, SkScalar y) const;
	void scaleRadii(const SkRect& rect);

	SkRect fRect = SkRect::MakeEmpty();
	// Radii order is UL, UR, LR, LL. Use Corner enum to index into fRadii[]
	SkVector fRadii[4] = {{0, 0}, {0, 0}, {0,0}, {0,0}};
	// use an explicitly sized type so we're sure the class is dense (no uninitialized bytes)
	int32_t fType = kEmpty_Type;
	// TODO: add padding so we can use memcpy for flattening and not copy uninitialized data

	// to access fRadii directly
	friend class SkPath;
	friend class SkRRectPriv;
	};

	#endif