| /* |
| * 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/base/SkAssert.h" |
| #include "include/private/base/SkMalloc.h" |
| #include "src/base/SkMathPriv.h" |
| #include "src/core/SkIPoint16.h" |
| #include "src/gpu/Rectanizer.h" |
| |
| #include <cstdint> |
| |
| 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 |