/*

* Copyright 2014 Google Inc.

*

* Use of this source code is governed by a BSD-style license that can be

* found in the LICENSE file.

*/

#ifndef GrRectanizerPow2_DEFINED

#define GrRectanizerPow2_DEFINED

#include "include/private/SkMalloc.h"

#include "src/core/SkIPoint16.h"

#include "src/core/SkMathPriv.h"

#include "src/gpu/GrRectanizer.h"

// This Rectanizer quantizes the incoming rects to powers of 2. Each power

// of two can have, at most, one active row/shelf. Once a row/shelf for

// a particular power of two gets full its fRows entry is recycled to point

// to a new row.

// The skyline algorithm almost always provides a better packing.

//

// Mark this class final in an effort to avoid the vtable when this subclass is used explicitly.

class GrRectanizerPow2 final : public GrRectanizer {

public:

    GrRectanizerPow2(int w, int h) : INHERITED(w, h) {

        this->reset();

    }

    ~GrRectanizerPow2() final {}

    void reset() final {

        fNextStripY = 0;

        fAreaSoFar = 0;

        sk_bzero(fRows, sizeof(fRows));

    }

    bool addRect(int w, int h, SkIPoint16* loc) final;

    float percentFull() const final {

        return fAreaSoFar / ((float)this->width() * this->height());

    }

private:

    static const int kMIN_HEIGHT_POW2 = 2;

    static const int kMaxExponent = 16;

    struct Row {

        SkIPoint16  fLoc;

        // fRowHeight is actually known by this struct's position in fRows

        // but it is used to signal if there exists an open row of this height

        int         fRowHeight;

        bool canAddWidth(int width, int containerWidth) const {

            return fLoc.fX + width <= containerWidth;

        }

    };

    Row fRows[kMaxExponent];    // 0-th entry will be unused

    int fNextStripY;

    int32_t fAreaSoFar;

    static int HeightToRowIndex(int height) {

        SkASSERT(height >= kMIN_HEIGHT_POW2);

        int index = 32 - SkCLZ(height - 1);

        SkASSERT(index < kMaxExponent);

        return index;

    }

Unexecuted instantiation: GrRectanizerPow2::HeightToRowIndex(int)

Unexecuted instantiation: GrRectanizerPow2::HeightToRowIndex(int)

    bool canAddStrip(int height) const {

        return fNextStripY + height <= this->height();

    }

    void initRow(Row* row, int rowHeight) {

        row->fLoc.set(0, fNextStripY);

        row->fRowHeight = rowHeight;

        fNextStripY += rowHeight;

    }

    using INHERITED = GrRectanizer;

};

#endif