| /* |

| * Copyright 2013 Google Inc. |

| * |

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

| * found in the LICENSE file. |

| */ |

| |

| #ifndef SkMatrixUtils_DEFINED |

| #define SkMatrixUtils_DEFINED |

| |

| #include "SkMatrix.h" |

| |

| /** |

| * Number of subpixel bits used in skia's bilerp. |

| * See SkBitmapProcState_procs.h and SkBitmapProcState_filter.h |

| */ |

| #define kSkSubPixelBitsForBilerp 4 |

| |

| /** |

| * Given a matrix and width/height, return true if the computed dst-rect would |

| * align such that there is a 1-to-1 coorspondence between src and dst pixels. |

| * This can be called by drawing code to see if drawBitmap can be turned into |

| * drawSprite (which is faster). |

| * |

| * The src-rect is defined to be { 0, 0, width, height } |

| * |

| * The "closeness" test is based on the subpixelBits parameter. Pass 0 for |

| * round-to-nearest behavior (e.g. nearest neighbor sampling). Pass the number |

| * of subpixel-bits to simulate filtering. |

| */ |

| bool SkTreatAsSprite(const SkMatrix&, int width, int height, |

| unsigned subpixelBits); |

| |

| /** |

| * Calls SkTreatAsSprite() with default subpixelBits value to match Skia's |

| * filter-bitmap implementation (i.e. kSkSubPixelBitsForBilerp). |

| */ |

| static inline bool SkTreatAsSpriteFilter(const SkMatrix& matrix, |

| int width, int height) { |

| return SkTreatAsSprite(matrix, width, height, kSkSubPixelBitsForBilerp); |

| } |

| |

| /** Decomposes the upper-left 2x2 of the matrix into a rotation (represented by |

| the cosine and sine of the rotation angle), followed by a non-uniform scale, |

| followed by another rotation. If there is a reflection, one of the scale |

| factors will be negative. |

| Returns true if successful. Returns false if the matrix is degenerate. |

| */ |

| bool SkDecomposeUpper2x2(const SkMatrix& matrix, |

| SkPoint* rotation1, |

| SkPoint* scale, |

| SkPoint* rotation2); |

| |

| #endif |