third_party/WebKit/Source/platform/transforms/AffineTransform.h

   1 /*
   2  * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
   3  *               2010 Dirk Schulze <krit@webkit.org>
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  15  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  17  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  18  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  19  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  20  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  21  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  22  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  24  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #ifndef AffineTransform_h
  28 #define AffineTransform_h
  29
  30 #include "platform/transforms/TransformationMatrix.h"
  31
  32 #include <string.h> // for memcpy
  33 #include "wtf/FastAllocBase.h"
  34
  35 namespace blink {
  36
  37 class FloatPoint;
  38 class FloatQuad;
  39 class FloatRect;
  40 class IntPoint;
  41 class IntRect;
  42 class TransformationMatrix;
  43
  44 class PLATFORM_EXPORT AffineTransform {
  45     WTF_MAKE_FAST_ALLOCATED(AffineTransform);
  46 public:
  47     typedef double Transform[6];
  48
  49     AffineTransform();
  50     AffineTransform(double a, double b, double c, double d, double e, double f);
  51
  52     void setMatrix(double a, double b, double c, double d, double e, double f);
  53
  54     void setTransform(const AffineTransform& other) { setMatrix(other.m_transform); }
  55
  56     void map(double x, double y, double& x2, double& y2) const;
  57
  58     // Rounds the mapped point to the nearest integer value.
  59     IntPoint mapPoint(const IntPoint&) const;
  60
  61     FloatPoint mapPoint(const FloatPoint&) const;
  62
  63     IntSize mapSize(const IntSize&) const;
  64
  65     FloatSize mapSize(const FloatSize&) const;
  66
  67     // Rounds the resulting mapped rectangle out. This is helpful for bounding
  68     // box computations but may not be what is wanted in other contexts.
  69     IntRect mapRect(const IntRect&) const;
  70
  71     FloatRect mapRect(const FloatRect&) const;
  72     FloatQuad mapQuad(const FloatQuad&) const;
  73
  74     bool isIdentity() const;
  75
  76     double a() const { return m_transform[0]; }
  77     void setA(double a) { m_transform[0] = a; }
  78     double b() const { return m_transform[1]; }
  79     void setB(double b) { m_transform[1] = b; }
  80     double c() const { return m_transform[2]; }
  81     void setC(double c) { m_transform[2] = c; }
  82     double d() const { return m_transform[3]; }
  83     void setD(double d) { m_transform[3] = d; }
  84     double e() const { return m_transform[4]; }
  85     void setE(double e) { m_transform[4] = e; }
  86     double f() const { return m_transform[5]; }
  87     void setF(double f) { m_transform[5] = f; }
  88
  89     void makeIdentity();
  90
  91     // this' = this * other
  92     AffineTransform& multiply(const AffineTransform& other);
  93     // this' = other * this
  94     AffineTransform& preMultiply(const AffineTransform& other);
  95
  96     AffineTransform& scale(double);
  97     AffineTransform& scale(double sx, double sy);
  98     AffineTransform& scaleNonUniform(double sx, double sy);
  99     AffineTransform& rotate(double a);
 100     AffineTransform& rotateRadians(double a);
 101     AffineTransform& rotateFromVector(double x, double y);
 102     AffineTransform& translate(double tx, double ty);
 103     AffineTransform& shear(double sx, double sy);
 104     AffineTransform& flipX();
 105     AffineTransform& flipY();
 106     AffineTransform& skew(double angleX, double angleY);
 107     AffineTransform& skewX(double angle);
 108     AffineTransform& skewY(double angle);
 109
 110     double xScale() const;
 111     double yScale() const;
 112
 113     double det() const;
 114     bool isInvertible() const;
 115     AffineTransform inverse() const;
 116
 117     TransformationMatrix toTransformationMatrix() const;
 118
 119     bool isIdentityOrTranslation() const
 120     {
 121         return m_transform[0] == 1 && m_transform[1] == 0 && m_transform[2] == 0 && m_transform[3] == 1;
 122     }
 123
 124     bool isIdentityOrTranslationOrFlipped() const
 125     {
 126         return m_transform[0] == 1 && m_transform[1] == 0 && m_transform[2] == 0 && (m_transform[3] == 1 || m_transform[3] == -1);
 127     }
 128
 129     bool preservesAxisAlignment() const
 130     {
 131         return (m_transform[1] == 0 && m_transform[2] == 0) || (m_transform[0] == 0 && m_transform[3] == 0);
 132     }
 133
 134     bool operator== (const AffineTransform& m2) const
 135     {
 136         return (m_transform[0] == m2.m_transform[0]
 137              && m_transform[1] == m2.m_transform[1]
 138              && m_transform[2] == m2.m_transform[2]
 139              && m_transform[3] == m2.m_transform[3]
 140              && m_transform[4] == m2.m_transform[4]
 141              && m_transform[5] == m2.m_transform[5]);
 142     }
 143
 144     bool operator!=(const AffineTransform& other) const { return !(*this == other); }
 145
 146     // *this = *this * t (i.e., a multRight)
 147     AffineTransform& operator*=(const AffineTransform& t)
 148     {
 149         return multiply(t);
 150     }
 151
 152     // result = *this * t (i.e., a multRight)
 153     AffineTransform operator*(const AffineTransform& t) const
 154     {
 155         AffineTransform result = *this;
 156         result *= t;
 157         return result;
 158     }
 159
 160     static AffineTransform translation(double x, double y)
 161     {
 162         return AffineTransform(1, 0, 0, 1, x, y);
 163     }
 164
 165     // decompose the matrix into its component parts
 166     typedef struct {
 167         double scaleX, scaleY;
 168         double angle;
 169         double remainderA, remainderB, remainderC, remainderD;
 170         double translateX, translateY;
 171     } DecomposedType;
 172
 173     bool decompose(DecomposedType&) const;
 174     void recompose(const DecomposedType&);
 175
 176 private:
 177     void setMatrix(const Transform m)
 178     {
 179         if (m && m != m_transform)
 180             memcpy(m_transform, m, sizeof(Transform));
 181     }
 182
 183     Transform m_transform;
 184 };
 185
 186 }
 187
 188 #endif