michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: #ifndef SkRRect_DEFINED
michael@0: #define SkRRect_DEFINED
michael@0: 
michael@0: #include "SkRect.h"
michael@0: #include "SkPoint.h"
michael@0: 
michael@0: class SkPath;
michael@0: class SkMatrix;
michael@0: 
michael@0: // Path forward:
michael@0: //   core work
michael@0: //      add validate method (all radii positive, all radii sums < rect size, etc.)
michael@0: //      add contains(SkRect&)  - for clip stack
michael@0: //      add contains(SkRRect&) - for clip stack
michael@0: //      add heart rect computation (max rect inside RR)
michael@0: //      add 9patch rect computation
michael@0: //      add growToInclude(SkPath&)
michael@0: //   analysis
michael@0: //      use growToInclude to fit skp round rects & generate stats (RRs vs. real paths)
michael@0: //      check on # of rectorus's the RRs could handle
michael@0: //   rendering work
michael@0: //      update SkPath.addRRect() to only use quads
michael@0: //      add GM and bench
michael@0: //   further out
michael@0: //      detect and triangulate RRectorii rather than falling back to SW in Ganesh
michael@0: //
michael@0: 
michael@0: /** \class SkRRect
michael@0: 
michael@0:     The SkRRect class represents a rounded rect with a potentially different
michael@0:     radii for each corner. It does not have a constructor so must be
michael@0:     initialized with one of the initialization functions (e.g., setEmpty,
michael@0:     setRectRadii, etc.)
michael@0: 
michael@0:     This class is intended to roughly match CSS' border-*-*-radius capabilities.
michael@0:     This means:
michael@0:         If either of a corner's radii are 0 the corner will be square.
michael@0:         Negative radii are not allowed (they are clamped to zero).
michael@0:         If the corner curves overlap they will be proportionally reduced to fit.
michael@0: */
michael@0: class SK_API SkRRect {
michael@0: public:
michael@0:     /**
michael@0:      * Enum to capture the various possible subtypes of RR. Accessed
michael@0:      * by type(). The subtypes become progressively less restrictive.
michael@0:      */
michael@0:     enum Type {
michael@0:         // !< Internal indicator that the sub type must be computed.
michael@0:         kUnknown_Type = -1,
michael@0: 
michael@0:         // !< The RR is empty
michael@0:         kEmpty_Type,
michael@0: 
michael@0:         //!< The RR is actually a (non-empty) rect (i.e., at least one radius
michael@0:         //!< at each corner is zero)
michael@0:         kRect_Type,
michael@0: 
michael@0:         //!< The RR is actually a (non-empty) oval (i.e., all x radii are equal
michael@0:         //!< and >= width/2 and all the y radii are equal and >= height/2
michael@0:         kOval_Type,
michael@0: 
michael@0:         //!< The RR is non-empty and all the x radii are equal & all y radii
michael@0:         //!< are equal but it is not an oval (i.e., there are lines between
michael@0:         //!< the curves) nor a rect (i.e., both radii are non-zero)
michael@0:         kSimple_Type,
michael@0: 
michael@0:         //!< A fully general (non-empty) RR. Some of the x and/or y radii are
michael@0:         //!< different from the others and there must be one corner where
michael@0:         //!< both radii are non-zero.
michael@0:         kComplex_Type,
michael@0:     };
michael@0: 
michael@0:     /**
michael@0:      * Returns the RR's sub type.
michael@0:      */
michael@0:     Type getType() const {
michael@0:         SkDEBUGCODE(this->validate();)
michael@0: 
michael@0:         if (kUnknown_Type == fType) {
michael@0:             this->computeType();
michael@0:         }
michael@0:         SkASSERT(kUnknown_Type != fType);
michael@0:         return fType;
michael@0:     }
michael@0: 
michael@0:     Type type() const { return this->getType(); }
michael@0: 
michael@0:     inline bool isEmpty() const { return kEmpty_Type == this->getType(); }
michael@0:     inline bool isRect() const { return kRect_Type == this->getType(); }
michael@0:     inline bool isOval() const { return kOval_Type == this->getType(); }
michael@0:     inline bool isSimple() const { return kSimple_Type == this->getType(); }
michael@0:     inline bool isSimpleCircular() const {
michael@0:         return this->isSimple() && fRadii[0].fX == fRadii[0].fY;
michael@0:     }
michael@0:     inline bool isComplex() const { return kComplex_Type == this->getType(); }
michael@0: 
michael@0:     bool allCornersCircular() const;
michael@0: 
michael@0:     /**
michael@0:      * Are both x-radii the same on the two left corners, and similar for the top, right, and
michael@0:      * bottom. When this is the case the four ellipse centers form a rectangle.
michael@0:      */
michael@0:     bool isNinePatch() const {
michael@0:         return fRadii[kUpperLeft_Corner].fX == fRadii[kLowerLeft_Corner].fX &&
michael@0:                fRadii[kUpperRight_Corner].fX == fRadii[kLowerRight_Corner].fX &&
michael@0:                fRadii[kUpperLeft_Corner].fY == fRadii[kUpperRight_Corner].fY &&
michael@0:                fRadii[kLowerLeft_Corner].fY == fRadii[kLowerRight_Corner].fY;
michael@0:     }
michael@0: 
michael@0:     SkScalar width() const { return fRect.width(); }
michael@0:     SkScalar height() const { return fRect.height(); }
michael@0: 
michael@0:     /**
michael@0:      * Set this RR to the empty rectangle (0,0,0,0) with 0 x & y radii.
michael@0:      */
michael@0:     void setEmpty() {
michael@0:         fRect.setEmpty();
michael@0:         memset(fRadii, 0, sizeof(fRadii));
michael@0:         fType = kEmpty_Type;
michael@0: 
michael@0:         SkDEBUGCODE(this->validate();)
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Set this RR to match the supplied rect. All radii will be 0.
michael@0:      */
michael@0:     void setRect(const SkRect& rect) {
michael@0:         if (rect.isEmpty()) {
michael@0:             this->setEmpty();
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         fRect = rect;
michael@0:         memset(fRadii, 0, sizeof(fRadii));
michael@0:         fType = kRect_Type;
michael@0: 
michael@0:         SkDEBUGCODE(this->validate();)
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Set this RR to match the supplied oval. All x radii will equal half the
michael@0:      * width and all y radii will equal half the height.
michael@0:      */
michael@0:     void setOval(const SkRect& oval) {
michael@0:         if (oval.isEmpty()) {
michael@0:             this->setEmpty();
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         SkScalar xRad = SkScalarHalf(oval.width());
michael@0:         SkScalar yRad = SkScalarHalf(oval.height());
michael@0: 
michael@0:         fRect = oval;
michael@0:         for (int i = 0; i < 4; ++i) {
michael@0:             fRadii[i].set(xRad, yRad);
michael@0:         }
michael@0:         fType = kOval_Type;
michael@0: 
michael@0:         SkDEBUGCODE(this->validate();)
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Initialize the RR with the same radii for all four corners.
michael@0:      */
michael@0:     void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad);
michael@0: 
michael@0:     /**
michael@0:      * Initialize the RR with potentially different radii for all four corners.
michael@0:      */
michael@0:     void setRectRadii(const SkRect& rect, const SkVector radii[4]);
michael@0: 
michael@0:     // The radii are stored in UL, UR, LR, LL order.
michael@0:     enum Corner {
michael@0:         kUpperLeft_Corner,
michael@0:         kUpperRight_Corner,
michael@0:         kLowerRight_Corner,
michael@0:         kLowerLeft_Corner
michael@0:     };
michael@0: 
michael@0:     const SkRect& rect() const { return fRect; }
michael@0:     const SkVector& radii(Corner corner) const { return fRadii[corner]; }
michael@0:     const SkRect& getBounds() const { return fRect; }
michael@0: 
michael@0:     /**
michael@0:      *  When a rrect is simple, all of its radii are equal. This returns one
michael@0:      *  of those radii. This call requires the rrect to be non-complex.
michael@0:      */
michael@0:     const SkVector& getSimpleRadii() const {
michael@0:         SkASSERT(!this->isComplex());
michael@0:         return fRadii[0];
michael@0:     }
michael@0: 
michael@0:     friend bool operator==(const SkRRect& a, const SkRRect& b) {
michael@0:         return a.fRect == b.fRect &&
michael@0:                SkScalarsEqual(a.fRadii[0].asScalars(),
michael@0:                               b.fRadii[0].asScalars(), 8);
michael@0:     }
michael@0: 
michael@0:     friend bool operator!=(const SkRRect& a, const SkRRect& b) {
michael@0:         return a.fRect != b.fRect ||
michael@0:                !SkScalarsEqual(a.fRadii[0].asScalars(),
michael@0:                                b.fRadii[0].asScalars(), 8);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Call inset on the bounds, and adjust the radii to reflect what happens
michael@0:      *  in stroking: If the corner is sharp (no curvature), leave it alone,
michael@0:      *  otherwise we grow/shrink the radii by the amount of the inset. If a
michael@0:      *  given radius becomes negative, it is pinned to 0.
michael@0:      *
michael@0:      *  It is valid for dst == this.
michael@0:      */
michael@0:     void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const;
michael@0: 
michael@0:     void inset(SkScalar dx, SkScalar dy) {
michael@0:         this->inset(dx, dy, this);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Call outset on the bounds, and adjust the radii to reflect what happens
michael@0:      *  in stroking: If the corner is sharp (no curvature), leave it alone,
michael@0:      *  otherwise we grow/shrink the radii by the amount of the inset. If a
michael@0:      *  given radius becomes negative, it is pinned to 0.
michael@0:      *
michael@0:      *  It is valid for dst == this.
michael@0:      */
michael@0:     void outset(SkScalar dx, SkScalar dy, SkRRect* dst) const {
michael@0:         this->inset(-dx, -dy, dst);
michael@0:     }
michael@0:     void outset(SkScalar dx, SkScalar dy) {
michael@0:         this->inset(-dx, -dy, this);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Translate the rrect by (dx, dy).
michael@0:      */
michael@0:     void offset(SkScalar dx, SkScalar dy) {
michael@0:         fRect.offset(dx, dy);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      *  Returns true if 'rect' is wholy inside the RR, and both
michael@0:      *  are not empty.
michael@0:      */
michael@0:     bool contains(const SkRect& rect) const;
michael@0: 
michael@0:     SkDEBUGCODE(void validate() const;)
michael@0: 
michael@0:     enum {
michael@0:         kSizeInMemory = 12 * sizeof(SkScalar)
michael@0:     };
michael@0: 
michael@0:     /**
michael@0:      *  Write the rrect into the specified buffer. This is guaranteed to always
michael@0:      *  write kSizeInMemory bytes, and that value is guaranteed to always be
michael@0:      *  a multiple of 4. Return kSizeInMemory.
michael@0:      */
michael@0:     size_t writeToMemory(void* buffer) const;
michael@0: 
michael@0:     /**
michael@0:      * Reads the rrect from the specified buffer
michael@0:      *
michael@0:      * If the specified buffer is large enough, this will read kSizeInMemory bytes,
michael@0:      * and that value is guaranteed to always be a multiple of 4.
michael@0:      *
michael@0:      * @param buffer Memory to read from
michael@0:      * @param length Amount of memory available in the buffer
michael@0:      * @return number of bytes read (must be a multiple of 4) or
michael@0:      *         0 if there was not enough memory available
michael@0:      */
michael@0:     size_t readFromMemory(const void* buffer, size_t length);
michael@0: 
michael@0:     /**
michael@0:      *  Transform by the specified matrix, and put the result in dst.
michael@0:      *
michael@0:      *  @param matrix SkMatrix specifying the transform. Must only contain
michael@0:      *      scale and/or translate, or this call will fail.
michael@0:      *  @param dst SkRRect to store the result. It is an error to use this,
michael@0:      *      which would make this function no longer const.
michael@0:      *  @return true on success, false on failure. If false, dst is unmodified.
michael@0:      */
michael@0:     bool transform(const SkMatrix& matrix, SkRRect* dst) const;
michael@0: 
michael@0: private:
michael@0:     SkRect fRect;
michael@0:     // Radii order is UL, UR, LR, LL. Use Corner enum to index into fRadii[]
michael@0:     SkVector fRadii[4];
michael@0:     mutable Type fType;
michael@0:     // TODO: add padding so we can use memcpy for flattening and not copy
michael@0:     // uninitialized data
michael@0: 
michael@0:     void computeType() const;
michael@0:     bool checkCornerContainment(SkScalar x, SkScalar y) const;
michael@0: 
michael@0:     // to access fRadii directly
michael@0:     friend class SkPath;
michael@0: };
michael@0: 
michael@0: #endif