SkRect.h

/*
 * Copyright 2006 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 SkRect_DEFINED
#define SkRect_DEFINED

#include "SkPoint.h"
#include "SkSize.h"

struct SkRect;

struct SK_API SkIRect {
    int32_t fLeft, fTop, fRight, fBottom;

    static SkIRect SK_WARN_UNUSED_RESULT MakeEmpty() {
        SkIRect r;
        r.setEmpty();
        return r;
    }

    static SkIRect SK_WARN_UNUSED_RESULT MakeLargest() {
        SkIRect r;
        r.setLargest();
        return r;
    }

    static SkIRect SK_WARN_UNUSED_RESULT MakeWH(int32_t w, int32_t h) {
        SkIRect r;
        r.set(0, 0, w, h);
        return r;
    }

    static SkIRect SK_WARN_UNUSED_RESULT MakeSize(const SkISize& size) {
        SkIRect r;
        r.set(0, 0, size.width(), size.height());
        return r;
    }

    static SkIRect SK_WARN_UNUSED_RESULT MakeLTRB(int32_t l, int32_t t, int32_t r, int32_t b) {
        SkIRect rect;
        rect.set(l, t, r, b);
        return rect;
    }

    static SkIRect SK_WARN_UNUSED_RESULT MakeXYWH(int32_t x, int32_t y, int32_t w, int32_t h) {
        SkIRect r;
        r.set(x, y, x + w, y + h);
        return r;
    }

    int left() const { return fLeft; }
    int top() const { return fTop; }
    int right() const { return fRight; }
    int bottom() const { return fBottom; }

    int x() const { return fLeft; }
    int y() const { return fTop; }
    int width() const { return fRight - fLeft; }

    int height() const { return fBottom - fTop; }

    SkISize size() const { return SkISize::Make(this->width(), this->height()); }

    int centerX() const { return (fRight + fLeft) >> 1; }

    int centerY() const { return (fBottom + fTop) >> 1; }

    bool isEmpty() const { return fLeft >= fRight || fTop >= fBottom; }

    bool isLargest() const { return SK_MinS32 == fLeft &&
                                    SK_MinS32 == fTop &&
                                    SK_MaxS32 == fRight &&
                                    SK_MaxS32 == fBottom; }

    friend bool operator==(const SkIRect& a, const SkIRect& b) {
        return !memcmp(&a, &b, sizeof(a));
    }

    friend bool operator!=(const SkIRect& a, const SkIRect& b) {
        return !(a == b);
    }

    bool is16Bit() const {
        return  SkIsS16(fLeft) && SkIsS16(fTop) &&
                SkIsS16(fRight) && SkIsS16(fBottom);
    }

    void setEmpty() { memset(this, 0, sizeof(*this)); }

    void set(int32_t left, int32_t top, int32_t right, int32_t bottom) {
        fLeft   = left;
        fTop    = top;
        fRight  = right;
        fBottom = bottom;
    }
    // alias for set(l, t, r, b)
    void setLTRB(int32_t left, int32_t top, int32_t right, int32_t bottom) {
        this->set(left, top, right, bottom);
    }

    void setXYWH(int32_t x, int32_t y, int32_t width, int32_t height) {
        fLeft = x;
        fTop = y;
        fRight = x + width;
        fBottom = y + height;
    }

    void setLargest() {
        fLeft = fTop = SK_MinS32;
        fRight = fBottom = SK_MaxS32;
    }

    void setLargestInverted() {
        fLeft = fTop = SK_MaxS32;
        fRight = fBottom = SK_MinS32;
    }

    SkIRect makeOffset(int32_t dx, int32_t dy) const {
        return MakeLTRB(fLeft + dx, fTop + dy, fRight + dx, fBottom + dy);
    }

    SkIRect makeInset(int32_t dx, int32_t dy) const {
        return MakeLTRB(fLeft + dx, fTop + dy, fRight - dx, fBottom - dy);
    }

    SkIRect makeOutset(int32_t dx, int32_t dy) const {
        return MakeLTRB(fLeft - dx, fTop - dy, fRight + dx, fBottom + dy);
    }

    void offset(int32_t dx, int32_t dy) {
        fLeft   += dx;
        fTop    += dy;
        fRight  += dx;
        fBottom += dy;
    }

    void offset(const SkIPoint& delta) {
        this->offset(delta.fX, delta.fY);
    }

    void offsetTo(int32_t newX, int32_t newY) {
        fRight += newX - fLeft;
        fBottom += newY - fTop;
        fLeft = newX;
        fTop = newY;
    }

    void inset(int32_t dx, int32_t dy) {
        fLeft   += dx;
        fTop    += dy;
        fRight  -= dx;
        fBottom -= dy;
    }

    void outset(int32_t dx, int32_t dy)  { this->inset(-dx, -dy); }

    bool quickReject(int l, int t, int r, int b) const {
        return l >= fRight || fLeft >= r || t >= fBottom || fTop >= b;
    }

    bool contains(int32_t x, int32_t y) const {
        return  (unsigned)(x - fLeft) < (unsigned)(fRight - fLeft) &&
                (unsigned)(y - fTop) < (unsigned)(fBottom - fTop);
    }

    bool contains(int32_t left, int32_t top, int32_t right, int32_t bottom) const {
        return  left < right && top < bottom && !this->isEmpty() && // check for empties
                fLeft <= left && fTop <= top &&
                fRight >= right && fBottom >= bottom;
    }

    bool contains(const SkIRect& r) const {
        return  !r.isEmpty() && !this->isEmpty() &&     // check for empties
                fLeft <= r.fLeft && fTop <= r.fTop &&
                fRight >= r.fRight && fBottom >= r.fBottom;
    }

    bool contains(const SkRect& r) const;

    bool containsNoEmptyCheck(int32_t left, int32_t top,
                              int32_t right, int32_t bottom) const {
        SkASSERT(fLeft < fRight && fTop < fBottom);
        SkASSERT(left < right && top < bottom);

        return fLeft <= left && fTop <= top &&
               fRight >= right && fBottom >= bottom;
    }

    bool containsNoEmptyCheck(const SkIRect& r) const {
        return containsNoEmptyCheck(r.fLeft, r.fTop, r.fRight, r.fBottom);
    }

    bool SK_WARN_UNUSED_RESULT intersect(const SkIRect& r) {
        return this->intersect(r.fLeft, r.fTop, r.fRight, r.fBottom);
    }

    bool SK_WARN_UNUSED_RESULT intersect(const SkIRect& a, const SkIRect& b) {

        if (!a.isEmpty() && !b.isEmpty() &&
                a.fLeft < b.fRight && b.fLeft < a.fRight &&
                a.fTop < b.fBottom && b.fTop < a.fBottom) {
            fLeft   = SkMax32(a.fLeft,   b.fLeft);
            fTop    = SkMax32(a.fTop,    b.fTop);
            fRight  = SkMin32(a.fRight,  b.fRight);
            fBottom = SkMin32(a.fBottom, b.fBottom);
            return true;
        }
        return false;
    }

    bool SK_WARN_UNUSED_RESULT intersectNoEmptyCheck(const SkIRect& a, const SkIRect& b) {
        SkASSERT(!a.isEmpty() && !b.isEmpty());

        if (a.fLeft < b.fRight && b.fLeft < a.fRight &&
                a.fTop < b.fBottom && b.fTop < a.fBottom) {
            fLeft   = SkMax32(a.fLeft,   b.fLeft);
            fTop    = SkMax32(a.fTop,    b.fTop);
            fRight  = SkMin32(a.fRight,  b.fRight);
            fBottom = SkMin32(a.fBottom, b.fBottom);
            return true;
        }
        return false;
    }

    bool SK_WARN_UNUSED_RESULT intersect(int32_t left, int32_t top, 
                                         int32_t right, int32_t bottom) {
        if (left < right && top < bottom && !this->isEmpty() &&
                fLeft < right && left < fRight && fTop < bottom && top < fBottom) {
            if (fLeft < left) fLeft = left;
            if (fTop < top) fTop = top;
            if (fRight > right) fRight = right;
            if (fBottom > bottom) fBottom = bottom;
            return true;
        }
        return false;
    }

    static bool Intersects(const SkIRect& a, const SkIRect& b) {
        return  !a.isEmpty() && !b.isEmpty() &&              // check for empties
                a.fLeft < b.fRight && b.fLeft < a.fRight &&
                a.fTop < b.fBottom && b.fTop < a.fBottom;
    }

    static bool IntersectsNoEmptyCheck(const SkIRect& a, const SkIRect& b) {
        SkASSERT(!a.isEmpty());
        SkASSERT(!b.isEmpty());
        return  a.fLeft < b.fRight && b.fLeft < a.fRight &&
                a.fTop < b.fBottom && b.fTop < a.fBottom;
    }

    void join(int32_t left, int32_t top, int32_t right, int32_t bottom);

    void join(const SkIRect& r) {
        this->join(r.fLeft, r.fTop, r.fRight, r.fBottom);
    }

    void sort();

    static const SkIRect& SK_WARN_UNUSED_RESULT EmptyIRect() {
        static const SkIRect gEmpty = { 0, 0, 0, 0 };
        return gEmpty;
    }
};

struct SK_API SkRect {
    SkScalar    fLeft, fTop, fRight, fBottom;

    static constexpr SkRect SK_WARN_UNUSED_RESULT MakeEmpty() {
        return SkRect{0, 0, 0, 0};
    }

    static SkRect SK_WARN_UNUSED_RESULT MakeLargest() {
        SkRect r;
        r.setLargest();
        return r;
    }

    static SkRect SK_WARN_UNUSED_RESULT MakeWH(SkScalar w, SkScalar h) {
        SkRect r;
        r.set(0, 0, w, h);
        return r;
    }

    static SkRect SK_WARN_UNUSED_RESULT MakeIWH(int w, int h) {
        SkRect r;
        r.set(0, 0, SkIntToScalar(w), SkIntToScalar(h));
        return r;
    }

    static SkRect SK_WARN_UNUSED_RESULT MakeSize(const SkSize& size) {
        SkRect r;
        r.set(0, 0, size.width(), size.height());
        return r;
    }

    static constexpr SkRect SK_WARN_UNUSED_RESULT MakeLTRB(SkScalar l, SkScalar t, SkScalar r,
                                                           SkScalar b) {
        return SkRect {l, t, r, b};
    }

    static SkRect SK_WARN_UNUSED_RESULT MakeXYWH(SkScalar x, SkScalar y, SkScalar w, SkScalar h) {
        SkRect r;
        r.set(x, y, x + w, y + h);
        return r;
    }

    SK_ATTR_DEPRECATED("use Make()")
    static SkRect SK_WARN_UNUSED_RESULT MakeFromIRect(const SkIRect& irect) {
        SkRect r;
        r.set(SkIntToScalar(irect.fLeft),
              SkIntToScalar(irect.fTop),
              SkIntToScalar(irect.fRight),
              SkIntToScalar(irect.fBottom));
        return r;
    }

    static SkRect SK_WARN_UNUSED_RESULT Make(const SkIRect& irect) {
        SkRect r;
        r.set(SkIntToScalar(irect.fLeft),
              SkIntToScalar(irect.fTop),
              SkIntToScalar(irect.fRight),
              SkIntToScalar(irect.fBottom));
        return r;
    }

    bool isEmpty() const { return fLeft >= fRight || fTop >= fBottom; }

    bool isLargest() const { return SK_ScalarMin == fLeft &&
                                    SK_ScalarMin == fTop &&
                                    SK_ScalarMax == fRight &&
                                    SK_ScalarMax == fBottom; }

    bool isFinite() const {
        float accum = 0;
        accum *= fLeft;
        accum *= fTop;
        accum *= fRight;
        accum *= fBottom;

        // accum is either NaN or it is finite (zero).
        SkASSERT(0 == accum || SkScalarIsNaN(accum));

        // value==value will be true iff value is not NaN
        // TODO: is it faster to say !accum or accum==accum?
        return !SkScalarIsNaN(accum);
    }

    SkScalar    x() const { return fLeft; }
    SkScalar    y() const { return fTop; }
    SkScalar    left() const { return fLeft; }
    SkScalar    top() const { return fTop; }
    SkScalar    right() const { return fRight; }
    SkScalar    bottom() const { return fBottom; }
    SkScalar    width() const { return fRight - fLeft; }
    SkScalar    height() const { return fBottom - fTop; }
    SkScalar    centerX() const { return SkScalarHalf(fLeft + fRight); }
    SkScalar    centerY() const { return SkScalarHalf(fTop + fBottom); }

    friend bool operator==(const SkRect& a, const SkRect& b) {
        return SkScalarsEqual((SkScalar*)&a, (SkScalar*)&b, 4);
    }

    friend bool operator!=(const SkRect& a, const SkRect& b) {
        return !SkScalarsEqual((SkScalar*)&a, (SkScalar*)&b, 4);
    }

    void toQuad(SkPoint quad[4]) const;

    void setEmpty() { *this = MakeEmpty(); }

    void set(const SkIRect& src) {
        fLeft   = SkIntToScalar(src.fLeft);
        fTop    = SkIntToScalar(src.fTop);
        fRight  = SkIntToScalar(src.fRight);
        fBottom = SkIntToScalar(src.fBottom);
    }

    void set(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) {
        fLeft   = left;
        fTop    = top;
        fRight  = right;
        fBottom = bottom;
    }
    // alias for set(l, t, r, b)
    void setLTRB(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) {
        this->set(left, top, right, bottom);
    }

    void iset(int left, int top, int right, int bottom) {
        fLeft   = SkIntToScalar(left);
        fTop    = SkIntToScalar(top);
        fRight  = SkIntToScalar(right);
        fBottom = SkIntToScalar(bottom);
    }

    void isetWH(int width, int height) {
        fLeft = fTop = 0;
        fRight = SkIntToScalar(width);
        fBottom = SkIntToScalar(height);
    }

    void set(const SkPoint pts[], int count) {
        // set() had been checking for non-finite values, so keep that behavior
        // for now. Now that we have setBoundsCheck(), we may decide to make
        // set() be simpler/faster, and not check for those.
        (void)this->setBoundsCheck(pts, count);
    }

    // alias for set(pts, count)
    void setBounds(const SkPoint pts[], int count) {
        (void)this->setBoundsCheck(pts, count);
    }

    bool setBoundsCheck(const SkPoint pts[], int count);

    void set(const SkPoint& p0, const SkPoint& p1) {
        fLeft =   SkMinScalar(p0.fX, p1.fX);
        fRight =  SkMaxScalar(p0.fX, p1.fX);
        fTop =    SkMinScalar(p0.fY, p1.fY);
        fBottom = SkMaxScalar(p0.fY, p1.fY);
    }

    void setXYWH(SkScalar x, SkScalar y, SkScalar width, SkScalar height) {
        fLeft = x;
        fTop = y;
        fRight = x + width;
        fBottom = y + height;
    }

    void setWH(SkScalar width, SkScalar height) {
        fLeft = 0;
        fTop = 0;
        fRight = width;
        fBottom = height;
    }

    void setLargest() {
        fLeft = fTop = SK_ScalarMin;
        fRight = fBottom = SK_ScalarMax;
    }

    void setLargestInverted() {
        fLeft = fTop = SK_ScalarMax;
        fRight = fBottom = SK_ScalarMin;
    }

    SkRect makeOffset(SkScalar dx, SkScalar dy) const {
        return MakeLTRB(fLeft + dx, fTop + dy, fRight + dx, fBottom + dy);
    }
    
    SkRect makeInset(SkScalar dx, SkScalar dy) const {
        return MakeLTRB(fLeft + dx, fTop + dy, fRight - dx, fBottom - dy);
    }

    SkRect makeOutset(SkScalar dx, SkScalar dy) const {
        return MakeLTRB(fLeft - dx, fTop - dy, fRight + dx, fBottom + dy);
    }

    void offset(SkScalar dx, SkScalar dy) {
        fLeft   += dx;
        fTop    += dy;
        fRight  += dx;
        fBottom += dy;
    }

    void offset(const SkPoint& delta) {
        this->offset(delta.fX, delta.fY);
    }

    void offsetTo(SkScalar newX, SkScalar newY) {
        fRight += newX - fLeft;
        fBottom += newY - fTop;
        fLeft = newX;
        fTop = newY;
    }

    void inset(SkScalar dx, SkScalar dy)  {
        fLeft   += dx;
        fTop    += dy;
        fRight  -= dx;
        fBottom -= dy;
    }

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

    bool SK_WARN_UNUSED_RESULT intersect(const SkRect& r);

    bool SK_WARN_UNUSED_RESULT intersect(SkScalar left, SkScalar top, 
                                         SkScalar right, SkScalar bottom);

    bool SK_WARN_UNUSED_RESULT intersect(const SkRect& a, const SkRect& b);


private:
    static bool Intersects(SkScalar al, SkScalar at, SkScalar ar, SkScalar ab,
                           SkScalar bl, SkScalar bt, SkScalar br, SkScalar bb) {
        SkScalar L = SkMaxScalar(al, bl);
        SkScalar R = SkMinScalar(ar, br);
        SkScalar T = SkMaxScalar(at, bt);
        SkScalar B = SkMinScalar(ab, bb);
        return L < R && T < B;
    }

public:
    bool intersects(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom) const {
        return Intersects(fLeft, fTop, fRight, fBottom, left, top, right, bottom);
    }

    bool intersects(const SkRect& r) const {
        return Intersects(fLeft, fTop, fRight, fBottom,
                          r.fLeft, r.fTop, r.fRight, r.fBottom);
    }

    static bool Intersects(const SkRect& a, const SkRect& b) {
        return Intersects(a.fLeft, a.fTop, a.fRight, a.fBottom,
                          b.fLeft, b.fTop, b.fRight, b.fBottom);
    }

    void join(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom);

    void join(const SkRect& r) {
        this->join(r.fLeft, r.fTop, r.fRight, r.fBottom);
    }

    void joinNonEmptyArg(const SkRect& r) {
        SkASSERT(!r.isEmpty());
        // if we are empty, just assign
        if (fLeft >= fRight || fTop >= fBottom) {
            *this = r;
        } else {
            this->joinPossiblyEmptyRect(r);
        }
    }

    void joinPossiblyEmptyRect(const SkRect& r) {
        fLeft   = SkMinScalar(fLeft, r.left());
        fTop    = SkMinScalar(fTop, r.top());
        fRight  = SkMaxScalar(fRight, r.right());
        fBottom = SkMaxScalar(fBottom, r.bottom());
    }

    void growToInclude(SkScalar x, SkScalar y) {
        fLeft  = SkMinScalar(x, fLeft);
        fRight = SkMaxScalar(x, fRight);
        fTop    = SkMinScalar(y, fTop);
        fBottom = SkMaxScalar(y, fBottom);
    }

    void growToInclude(const SkPoint pts[], int count) {
        this->growToInclude(pts, sizeof(SkPoint), count);
    }

    void growToInclude(const SkPoint pts[], size_t stride, int count) {
        SkASSERT(count >= 0);
        SkASSERT(stride >= sizeof(SkPoint));
        const SkPoint* end = (const SkPoint*)((intptr_t)pts + count * stride);
        for (; pts < end; pts = (const SkPoint*)((intptr_t)pts + stride)) {
            this->growToInclude(pts->fX, pts->fY);
        }
    }

    bool contains(const SkRect& r) const {
        // todo: can we eliminate the this->isEmpty check?
        return  !r.isEmpty() && !this->isEmpty() &&
                fLeft <= r.fLeft && fTop <= r.fTop &&
                fRight >= r.fRight && fBottom >= r.fBottom;
    }

    bool contains(const SkIRect& r) const {
        // todo: can we eliminate the this->isEmpty check?
        return  !r.isEmpty() && !this->isEmpty() &&
                fLeft <= SkIntToScalar(r.fLeft) && fTop <= SkIntToScalar(r.fTop) &&
                fRight >= SkIntToScalar(r.fRight) && fBottom >= SkIntToScalar(r.fBottom);
    }

    void round(SkIRect* dst) const {
        SkASSERT(dst);
        dst->set(SkScalarRoundToInt(fLeft), SkScalarRoundToInt(fTop),
                 SkScalarRoundToInt(fRight), SkScalarRoundToInt(fBottom));
    }

    void roundOut(SkIRect* dst) const {
        SkASSERT(dst);
        dst->set(SkScalarFloorToInt(fLeft), SkScalarFloorToInt(fTop),
                 SkScalarCeilToInt(fRight), SkScalarCeilToInt(fBottom));
    }

    void roundOut(SkRect* dst) const {
        dst->set(SkScalarFloorToScalar(fLeft),
                 SkScalarFloorToScalar(fTop),
                 SkScalarCeilToScalar(fRight),
                 SkScalarCeilToScalar(fBottom));
    }

    void roundIn(SkIRect* dst) const {
        SkASSERT(dst);
        dst->set(SkScalarCeilToInt(fLeft), SkScalarCeilToInt(fTop),
                 SkScalarFloorToInt(fRight), SkScalarFloorToInt(fBottom));
    }

    SkIRect round() const {
        SkIRect ir;
        this->round(&ir);
        return ir;
    }
    
    SkIRect roundOut() const {
        SkIRect ir;
        this->roundOut(&ir);
        return ir;
    }
    
    void sort() {
        if (fLeft > fRight) {
            SkTSwap<SkScalar>(fLeft, fRight);
        }

        if (fTop > fBottom) {
            SkTSwap<SkScalar>(fTop, fBottom);
        }
    }

    const SkScalar* asScalars() const { return &fLeft; }

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

inline bool SkIRect::contains(const SkRect& r) const {
    return  !r.isEmpty() && !this->isEmpty() &&     // check for empties
            (SkScalar)fLeft <= r.fLeft && (SkScalar)fTop <= r.fTop &&
            (SkScalar)fRight >= r.fRight && (SkScalar)fBottom >= r.fBottom;
}

#endif