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 /* * 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 skgpu_RectanizerPow2_DEFINED #define skgpu_RectanizerPow2_DEFINED #include "include/private/SkMalloc.h" #include "src/core/SkIPoint16.h" #include "src/core/SkMathPriv.h" #include "src/gpu/Rectanizer.h" namespace skgpu { // 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 RectanizerPow2 final : public Rectanizer { public: RectanizerPow2(int w, int h) : Rectanizer(w, h) { this->reset(); } ~RectanizerPow2() 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; } 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; } }; } // End of namespace skgpu #endif