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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/gfx_export.h"
#include "ui/gfx/transform.h"
namespace gfx {
class Point;
class Rect;
// Returns a scale transform at |anchor| point.
GFX_EXPORT Transform GetScaleTransform(const Point& anchor, float scale);
// Contains the components of a factored transform. These components may be
// blended and recomposed.
struct GFX_EXPORT DecomposedTransform {
// The default constructor initializes the components in such a way that
// if used with Compose below, will produce the identity transform.
SkMScalar translate[3];
SkMScalar scale[3];
SkMScalar skew[3];
SkMScalar perspective[4];
SkMScalar quaternion[4];
std::string ToString() const;
// Copy and assign are allowed.
// Interpolates the decomposed components |to| with |from| using the
// routines described in
// |progress| is in the range [0, 1] (0 leaves |out| unchanged, and 1
// assigns |from| to |out|).
GFX_EXPORT bool BlendDecomposedTransforms(DecomposedTransform* out,
const DecomposedTransform& to,
const DecomposedTransform& from,
double progress);
// Decomposes this transform into its translation, scale, skew, perspective,
// and rotation components following the routines detailed in this spec:
GFX_EXPORT bool DecomposeTransform(DecomposedTransform* out,
const Transform& transform);
// Composes a transform from the given translation, scale, skew, prespective,
// and rotation components following the routines detailed in this spec:
GFX_EXPORT Transform ComposeTransform(const DecomposedTransform& decomp);
GFX_EXPORT bool SnapTransform(Transform* out,
const Transform& transform,
const Rect& viewport);
// Calculates a transform with a transformed origin. The resulting tranform is
// created by composing P * T * P^-1 where P is a constant transform to the new
// origin.
GFX_EXPORT Transform TransformAboutPivot(const gfx::Point& pivot,
const gfx::Transform& transform);
} // namespace gfx