1 // Copyright (c) 2012 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef UI_GFX_TRANSFORM_UTIL_H_ 6 #define UI_GFX_TRANSFORM_UTIL_H_ 7 8 #include "ui/gfx/gfx_export.h" 9 #include "ui/gfx/transform.h" 10 11 namespace gfx { 12 13 class Point; 14 class Rect; 15 16 // Returns a scale transform at |anchor| point. 17 GFX_EXPORT Transform GetScaleTransform(const Point& anchor, float scale); 18 19 // Contains the components of a factored transform. These components may be 20 // blended and recomposed. 21 struct GFX_EXPORT DecomposedTransform { 22 // The default constructor initializes the components in such a way that 23 // if used with Compose below, will produce the identity transform. 24 DecomposedTransform(); 25 26 SkMScalar translate[3]; 27 SkMScalar scale[3]; 28 SkMScalar skew[3]; 29 SkMScalar perspective[4]; 30 SkMScalar quaternion[4]; 31 32 std::string ToString() const; 33 34 // Copy and assign are allowed. 35 }; 36 37 // Interpolates the decomposed components |to| with |from| using the 38 // routines described in http://www.w3.org/TR/css3-3d-transform/. 39 // |progress| is in the range [0, 1] (0 leaves |out| unchanged, and 1 40 // assigns |from| to |out|). 41 GFX_EXPORT bool BlendDecomposedTransforms(DecomposedTransform* out, 42 const DecomposedTransform& to, 43 const DecomposedTransform& from, 44 double progress); 45 46 // Decomposes this transform into its translation, scale, skew, perspective, 47 // and rotation components following the routines detailed in this spec: 48 // http://www.w3.org/TR/css3-3d-transforms/. 49 GFX_EXPORT bool DecomposeTransform(DecomposedTransform* out, 50 const Transform& transform); 51 52 // Composes a transform from the given translation, scale, skew, prespective, 53 // and rotation components following the routines detailed in this spec: 54 // http://www.w3.org/TR/css3-3d-transforms/. 55 GFX_EXPORT Transform ComposeTransform(const DecomposedTransform& decomp); 56 57 GFX_EXPORT bool SnapTransform(Transform* out, 58 const Transform& transform, 59 const Rect& viewport); 60 61 } // namespace gfx 62 63 #endif // UI_GFX_TRANSFORM_UTIL_H_ 64