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// Copyright 2013 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.
#ifndef CC_ANIMATION_TRANSFORM_OPERATIONS_H_
#define CC_ANIMATION_TRANSFORM_OPERATIONS_H_
#include <vector>
#include "base/macros.h"
#include "base/memory/scoped_ptr.h"
#include "cc/animation/transform_operation.h"
#include "cc/base/cc_export.h"
#include "ui/gfx/transform.h"
namespace gfx {
class BoxF;
struct DecomposedTransform;
}
namespace cc {
// Transform operations are a decomposed transformation matrix. It can be
// applied to obtain a gfx::Transform at any time, and can be blended
// intelligently with other transform operations, so long as they represent the
// same decomposition. For example, if we have a transform that is made up of
// a rotation followed by skew, it can be blended intelligently with another
// transform made up of a rotation followed by a skew. Blending is possible if
// we have two dissimilar sets of transform operations, but the effect may not
// be what was intended. For more information, see the comments for the blend
// function below.
class CC_EXPORT TransformOperations {
public:
TransformOperations();
TransformOperations(const TransformOperations& other);
~TransformOperations();
// Returns a transformation matrix representing these transform operations.
gfx::Transform Apply() const;
// Given another set of transform operations and a progress in the range
// [0, 1], returns a transformation matrix representing the intermediate
// value. If this->MatchesTypes(from), then each of the operations are
// blended separately and then combined. Otherwise, the two sets of
// transforms are baked to matrices (using apply), and the matrices are
// then decomposed and interpolated. For more information, see
// http://www.w3.org/TR/2011/WD-css3-2d-transforms-20111215/#matrix-decomposition.
gfx::Transform Blend(const TransformOperations& from,
SkMScalar progress) const;
// Sets |bounds| be the bounding box for the region within which |box| will
// exist when it is transformed by the result of calling Blend on |from| and
// with progress in the range [min_progress, max_progress]. If this region
// cannot be computed, returns false.
bool BlendedBoundsForBox(const gfx::BoxF& box,
const TransformOperations& from,
SkMScalar min_progress,
SkMScalar max_progress,
gfx::BoxF* bounds) const;
// Returns true if these operations affect scale.
bool AffectsScale() const;
// Returns true if these operations are only translations.
bool IsTranslation() const;
// Returns false if the operations affect 2d axis alignment.
bool PreservesAxisAlignment() const;
// Returns true if this operation and its descendants have the same types
// as other and its descendants.
bool MatchesTypes(const TransformOperations& other) const;
// Returns true if these operations can be blended. It will only return
// false if we must resort to matrix interpolation, and matrix interpolation
// fails (this can happen if either matrix cannot be decomposed).
bool CanBlendWith(const TransformOperations& other) const;
// If these operations have no more than one scale operation, and if the only
// other operations are translations, sets |scale| to the scale component
// of these operations. Otherwise, returns false.
bool ScaleComponent(gfx::Vector3dF* scale) const;
void AppendTranslate(SkMScalar x, SkMScalar y, SkMScalar z);
void AppendRotate(SkMScalar x, SkMScalar y, SkMScalar z, SkMScalar degrees);
void AppendScale(SkMScalar x, SkMScalar y, SkMScalar z);
void AppendSkew(SkMScalar x, SkMScalar y);
void AppendPerspective(SkMScalar depth);
void AppendMatrix(const gfx::Transform& matrix);
void AppendIdentity();
bool IsIdentity() const;
private:
bool BlendInternal(const TransformOperations& from,
SkMScalar progress,
gfx::Transform* result) const;
std::vector<TransformOperation> operations_;
bool ComputeDecomposedTransform() const;
// For efficiency, we cache the decomposed transform.
mutable scoped_ptr<gfx::DecomposedTransform> decomposed_transform_;
mutable bool decomposed_transform_dirty_;
DISALLOW_ASSIGN(TransformOperations);
};
} // namespace cc
#endif // CC_ANIMATION_TRANSFORM_OPERATIONS_H_