WebCore/platform/graphics/AffineTransform.cpp

/*
 * Copyright (C) 2005, 2006 Apple Computer, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
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 *    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
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#include "config.h"
#include "AffineTransform.h"

#include "FloatRect.h"
#include "IntRect.h"

#include <math.h>

namespace WebCore {

const double deg2rad = 0.017453292519943295769; // pi/180

bool AffineTransform::isInvertible() const
{
    return det() != 0.0;
}

AffineTransform& AffineTransform::multiply(const AffineTransform& other)
{
    return (*this) *= other;
}

AffineTransform& AffineTransform::scale(double s)
{
    return scale(s, s);
}

AffineTransform& AffineTransform::scaleNonUniform(double sx, double sy)
{
    return scale(sx, sy);
}

AffineTransform& AffineTransform::rotateFromVector(double x, double y)
{
    return rotate(atan2(y, x) / deg2rad);
}

AffineTransform& AffineTransform::flipX()
{
    return scale(-1.0f, 1.0f);
}

AffineTransform& AffineTransform::flipY()
{
    return scale(1.0f, -1.0f);
}

AffineTransform& AffineTransform::skewX(double angle)
{
    return shear(tan(angle * deg2rad), 0.0f);
}

AffineTransform& AffineTransform::skewY(double angle)
{
    return shear(0.0f, tan(angle * deg2rad));
}

}