1 files changed, 79 insertions, 0 deletions
diff --git a/chromium/third_party/skia/src/gpu/GrRectanizer_pow2.h b/chromium/third_party/skia/src/gpu/GrRectanizer_pow2.h
new file mode 100644
index 00000000000..7bf2b868c05
--- /dev/null
+++ b/chromium/third_party/skia/src/gpu/GrRectanizer_pow2.h
@@ -0,0 +1,79 @@
+/*
+* 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 GrRectanizer_pow2_DEFINED
+#define GrRectanizer_pow2_DEFINED
+
+#include "GrRectanizer.h"
+#include "SkPoint.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.
+class GrRectanizerPow2 : public GrRectanizer {
+public:
+    GrRectanizerPow2(int w, int h) : INHERITED(w, h) {
+        this->reset();
+    }
+
+    virtual ~GrRectanizerPow2() { }
+
+    virtual void reset() SK_OVERRIDE {
+        fNextStripY = 0;
+        fAreaSoFar = 0;
+        sk_bzero(fRows, sizeof(fRows));
+    }
+
+    virtual bool addRect(int w, int h, SkIPoint16* loc) SK_OVERRIDE;
+
+    virtual float percentFull() const SK_OVERRIDE {
+        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;
+    }
+
+    typedef GrRectanizer INHERITED;
+};
+
+#endif