/*
 * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
 *               2010 Dirk Schulze <krit@webkit.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef AffineTransform_h
#define AffineTransform_h

#include "platform/transforms/TransformationMatrix.h"

#include "wtf/Allocator.h"
#include <string.h>  // for memcpy

namespace blink {

class FloatPoint;
class FloatQuad;
class FloatRect;
class IntPoint;
class IntRect;
class TransformationMatrix;

#define IDENTITY_TRANSFORM \
  { 1, 0, 0, 1, 0, 0 }

class PLATFORM_EXPORT AffineTransform {
  DISALLOW_NEW();

 public:
  typedef double Transform[6];

  AffineTransform();
  AffineTransform(double a, double b, double c, double d, double e, double f);
  AffineTransform(const Transform transform) { setMatrix(transform); }

  void setMatrix(double a, double b, double c, double d, double e, double f);

  void setTransform(const AffineTransform& other) {
    setMatrix(other.m_transform);
  }

  void map(double x, double y, double& x2, double& y2) const;

  // Rounds the mapped point to the nearest integer value.
  IntPoint mapPoint(const IntPoint&) const;

  FloatPoint mapPoint(const FloatPoint&) const;

  IntSize mapSize(const IntSize&) const;

  FloatSize mapSize(const FloatSize&) const;

  // Rounds the resulting mapped rectangle out. This is helpful for bounding
  // box computations but may not be what is wanted in other contexts.
  IntRect mapRect(const IntRect&) const;

  FloatRect mapRect(const FloatRect&) const;
  FloatQuad mapQuad(const FloatQuad&) const;

  bool isIdentity() const;

  double a() const { return m_transform[0]; }
  void setA(double a) { m_transform[0] = a; }
  double b() const { return m_transform[1]; }
  void setB(double b) { m_transform[1] = b; }
  double c() const { return m_transform[2]; }
  void setC(double c) { m_transform[2] = c; }
  double d() const { return m_transform[3]; }
  void setD(double d) { m_transform[3] = d; }
  double e() const { return m_transform[4]; }
  void setE(double e) { m_transform[4] = e; }
  double f() const { return m_transform[5]; }
  void setF(double f) { m_transform[5] = f; }

  void makeIdentity();

  // this' = this * other
  AffineTransform& multiply(const AffineTransform& other);
  // this' = other * this
  AffineTransform& preMultiply(const AffineTransform& other);

  AffineTransform& scale(double);
  AffineTransform& scale(double sx, double sy);
  AffineTransform& scaleNonUniform(double sx, double sy);
  AffineTransform& rotate(double a);
  AffineTransform& rotateRadians(double a);
  AffineTransform& rotateFromVector(double x, double y);
  AffineTransform& translate(double tx, double ty);
  AffineTransform& shear(double sx, double sy);
  AffineTransform& flipX();
  AffineTransform& flipY();
  AffineTransform& skew(double angleX, double angleY);
  AffineTransform& skewX(double angle);
  AffineTransform& skewY(double angle);

  double xScaleSquared() const;
  double xScale() const;
  double yScaleSquared() const;
  double yScale() const;

  double det() const;
  bool isInvertible() const;
  AffineTransform inverse() const;

  TransformationMatrix toTransformationMatrix() const;

  bool isIdentityOrTranslation() const {
    return m_transform[0] == 1 && m_transform[1] == 0 && m_transform[2] == 0 &&
           m_transform[3] == 1;
  }

  bool isIdentityOrTranslationOrFlipped() const {
    return m_transform[0] == 1 && m_transform[1] == 0 && m_transform[2] == 0 &&
           (m_transform[3] == 1 || m_transform[3] == -1);
  }

  bool preservesAxisAlignment() const {
    return (m_transform[1] == 0 && m_transform[2] == 0) ||
           (m_transform[0] == 0 && m_transform[3] == 0);
  }

  bool operator==(const AffineTransform& m2) const {
    return (m_transform[0] == m2.m_transform[0] &&
            m_transform[1] == m2.m_transform[1] &&
            m_transform[2] == m2.m_transform[2] &&
            m_transform[3] == m2.m_transform[3] &&
            m_transform[4] == m2.m_transform[4] &&
            m_transform[5] == m2.m_transform[5]);
  }

  bool operator!=(const AffineTransform& other) const {
    return !(*this == other);
  }

  // *this = *this * t (i.e., a multRight)
  AffineTransform& operator*=(const AffineTransform& t) { return multiply(t); }

  // result = *this * t (i.e., a multRight)
  AffineTransform operator*(const AffineTransform& t) const {
    AffineTransform result = *this;
    result *= t;
    return result;
  }

  static AffineTransform translation(double x, double y) {
    return AffineTransform(1, 0, 0, 1, x, y);
  }

  // decompose the matrix into its component parts
  typedef struct {
    double scaleX, scaleY;
    double angle;
    double remainderA, remainderB, remainderC, remainderD;
    double translateX, translateY;
  } DecomposedType;

  bool decompose(DecomposedType&) const;
  void recompose(const DecomposedType&);

  void copyTransformTo(Transform m) {
    memcpy(m, m_transform, sizeof(Transform));
  }

  // If |asMatrix| is true, the transform is returned as a matrix in row-major
  // order. Otherwise, the transform's decomposition is returned which shows
  // the translation, scale, etc.
  String toString(bool asMatrix = false) const;

 private:
  void setMatrix(const Transform m) {
    if (m && m != m_transform)
      memcpy(m_transform, m, sizeof(Transform));
  }

  Transform m_transform;
};

// Redeclared here to avoid ODR issues.
// See platform/testing/TransformPrinters.h.
void PrintTo(const AffineTransform&, std::ostream*);

}  // namespace blink

#endif
