SkRRect.h

/*
 * 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 validate method (all radii positive, all radii sums < rect size, etc.)
//      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 SK_API SkRRect {
public:
    SkRRect() { /* unititialized */ }
    SkRRect(const SkRRect&) = default;
    SkRRect& operator=(const SkRRect&) = default;

    enum Type {
        // !< The RR is empty
        kEmpty_Type,

        kRect_Type,

        kOval_Type,

        kSimple_Type,

        kNinePatch_Type,

        kComplex_Type,
    };

    Type getType() const {
        SkDEBUGCODE(this->validate();)
        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(); }
    // TODO: should isSimpleCircular & isCircle take a tolerance? This could help
    // instances where the mapping to device space is noisy.
    inline bool isSimpleCircular() const {
        return this->isSimple() && SkScalarNearlyEqual(fRadii[0].fX, fRadii[0].fY);
    }
    inline bool isCircle() const {
        return this->isOval() && SkScalarNearlyEqual(fRadii[0].fX, fRadii[0].fY);
    }
    inline bool isNinePatch() const { return kNinePatch_Type == this->getType(); }
    inline bool isComplex() const { return kComplex_Type == this->getType(); }

    bool allCornersCircular() const;

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

    void setEmpty() {
        fRect.setEmpty();
        memset(fRadii, 0, sizeof(fRadii));
        fType = kEmpty_Type;

        SkDEBUGCODE(this->validate();)
    }

    void setRect(const SkRect& rect) {
        fRect = rect;
        fRect.sort();

        if (fRect.isEmpty()) {
            this->setEmpty();
            return;
        }

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

        SkDEBUGCODE(this->validate();)
    }

    static SkRRect MakeEmpty() {
        SkRRect rr;
        rr.setEmpty();
        return rr;
    }

    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;
    }

    void setOval(const SkRect& oval) {
        fRect = oval;
        fRect.sort();

        if (fRect.isEmpty()) {
            this->setEmpty();
            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;

        SkDEBUGCODE(this->validate();)
    }

    void setRectXY(const SkRect& rect, SkScalar xRad, SkScalar yRad);

    void setNinePatch(const SkRect& rect, SkScalar leftRad, SkScalar topRad,
                      SkScalar rightRad, SkScalar bottomRad);

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

    const SkVector& getSimpleRadii() const {
        SkASSERT(!this->isComplex());
        return fRadii[0];
    }

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

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

    void inset(SkScalar dx, SkScalar dy, SkRRect* dst) const;

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

    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);
    }

    bool contains(const SkRect& rect) const;

    SkDEBUGCODE(void validate() const;)

    enum {
        kSizeInMemory = 12 * sizeof(SkScalar)
    };

    size_t writeToMemory(void* buffer) const;

    size_t readFromMemory(const void* buffer, size_t length);

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

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

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

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

#endif