Source/WebCore/svg/SVGTransformDistance.cpp

/*
 * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 */

#include "config.h"
#include "SVGTransformDistance.h"

#include "FloatConversion.h"
#include "FloatPoint.h"
#include "FloatSize.h"
#include "SVGTransformValue.h"

#include <math.h>

namespace WebCore {
    
SVGTransformDistance::SVGTransformDistance()
    : m_type(SVGTransformValue::SVG_TRANSFORM_UNKNOWN)
    , m_angle(0)
    , m_cx(0)
    , m_cy(0)
{
}

SVGTransformDistance::SVGTransformDistance(SVGTransformValue::SVGTransformType type, float angle, float cx, float cy, const AffineTransform& transform)
    : m_type(type)
    , m_angle(angle)
    , m_cx(cx)
    , m_cy(cy)
    , m_transform(transform)
{
}

SVGTransformDistance::SVGTransformDistance(const SVGTransformValue& fromSVGTransform, const SVGTransformValue& toSVGTransform)
    : m_type(fromSVGTransform.type())
    , m_angle(0)
    , m_cx(0)
    , m_cy(0)
{
    ASSERT(m_type == toSVGTransform.type());
    
    switch (m_type) {
    case SVGTransformValue::SVG_TRANSFORM_MATRIX:
        ASSERT_NOT_REACHED();
#if !ASSERT_ENABLED
        FALLTHROUGH;
#endif
    case SVGTransformValue::SVG_TRANSFORM_UNKNOWN:
        break;
    case SVGTransformValue::SVG_TRANSFORM_ROTATE: {
        FloatSize centerDistance = toSVGTransform.rotationCenter() - fromSVGTransform.rotationCenter();
        m_angle = toSVGTransform.angle() - fromSVGTransform.angle();
        m_cx = centerDistance.width();
        m_cy = centerDistance.height();
        break;
    }
    case SVGTransformValue::SVG_TRANSFORM_TRANSLATE: {
        FloatSize translationDistance = toSVGTransform.translate() - fromSVGTransform.translate();
        m_transform.translate(translationDistance.width(), translationDistance.height());
        break;
    }
    case SVGTransformValue::SVG_TRANSFORM_SCALE: {
        float scaleX = toSVGTransform.scale().width() - fromSVGTransform.scale().width();        
        float scaleY = toSVGTransform.scale().height() - fromSVGTransform.scale().height();
        m_transform.scaleNonUniform(scaleX, scaleY);
        break;
    }
    case SVGTransformValue::SVG_TRANSFORM_SKEWX:
    case SVGTransformValue::SVG_TRANSFORM_SKEWY:
        m_angle = toSVGTransform.angle() - fromSVGTransform.angle();
        break;
    }
}

SVGTransformDistance SVGTransformDistance::scaledDistance(float scaleFactor) const
{
    switch (m_type) {
    case SVGTransformValue::SVG_TRANSFORM_MATRIX:
        ASSERT_NOT_REACHED();
#if !ASSERT_ENABLED
        FALLTHROUGH;
#endif
    case SVGTransformValue::SVG_TRANSFORM_UNKNOWN:
        return SVGTransformDistance();
    case SVGTransformValue::SVG_TRANSFORM_ROTATE:
        return SVGTransformDistance(m_type, m_angle * scaleFactor, m_cx * scaleFactor, m_cy * scaleFactor, AffineTransform());
    case SVGTransformValue::SVG_TRANSFORM_SCALE:
        return SVGTransformDistance(m_type, m_angle * scaleFactor, m_cx * scaleFactor, m_cy * scaleFactor, AffineTransform(m_transform).scale(scaleFactor));
    case SVGTransformValue::SVG_TRANSFORM_TRANSLATE: {
        AffineTransform newTransform(m_transform);
        newTransform.setE(m_transform.e() * scaleFactor);
        newTransform.setF(m_transform.f() * scaleFactor);
        return SVGTransformDistance(m_type, 0, 0, 0, newTransform);
    }
    case SVGTransformValue::SVG_TRANSFORM_SKEWX:
    case SVGTransformValue::SVG_TRANSFORM_SKEWY:
        return SVGTransformDistance(m_type, m_angle * scaleFactor, m_cx * scaleFactor, m_cy * scaleFactor, AffineTransform());
    }
    
    ASSERT_NOT_REACHED();
    return SVGTransformDistance();
}

SVGTransformValue SVGTransformDistance::addSVGTransforms(const SVGTransformValue& first, const SVGTransformValue& second, unsigned repeatCount)
{
    ASSERT(first.type() == second.type());
    
    SVGTransformValue transform;
    
    switch (first.type()) {
    case SVGTransformValue::SVG_TRANSFORM_MATRIX:
        ASSERT_NOT_REACHED();
#if !ASSERT_ENABLED
        FALLTHROUGH;
#endif
    case SVGTransformValue::SVG_TRANSFORM_UNKNOWN:
        return { };
    case SVGTransformValue::SVG_TRANSFORM_ROTATE: {
        transform.setRotate(first.angle() + second.angle() * repeatCount, first.rotationCenter().x() + second.rotationCenter().x() * repeatCount, first.rotationCenter().y() + second.rotationCenter().y() * repeatCount);
        return transform;
    }
    case SVGTransformValue::SVG_TRANSFORM_TRANSLATE: {
        float dx = first.translate().x() + second.translate().x() * repeatCount;
        float dy = first.translate().y() + second.translate().y() * repeatCount;
        transform.setTranslate(dx, dy);
        return transform;
    }
    case SVGTransformValue::SVG_TRANSFORM_SCALE: {
        FloatSize scale = second.scale();
        scale.scale(repeatCount);
        scale += first.scale();
        transform.setScale(scale.width(), scale.height());
        return transform;
    }
    case SVGTransformValue::SVG_TRANSFORM_SKEWX:
        transform.setSkewX(first.angle() + second.angle() * repeatCount);
        return transform;
    case SVGTransformValue::SVG_TRANSFORM_SKEWY:
        transform.setSkewY(first.angle() + second.angle() * repeatCount);
        return transform;
    }
    ASSERT_NOT_REACHED();
    return { };
}

SVGTransformValue SVGTransformDistance::addToSVGTransform(const SVGTransformValue& transform) const
{
    ASSERT(m_type == transform.type() || !transform.isValid());
    
    SVGTransformValue newTransform(transform);
    
    switch (m_type) {
    case SVGTransformValue::SVG_TRANSFORM_MATRIX:
        ASSERT_NOT_REACHED();
#if !ASSERT_ENABLED
        FALLTHROUGH;
#endif
    case SVGTransformValue::SVG_TRANSFORM_UNKNOWN:
        return { };
    case SVGTransformValue::SVG_TRANSFORM_TRANSLATE: {
        FloatPoint translation = transform.translate();
        translation += FloatSize::narrowPrecision(m_transform.e(), m_transform.f());
        newTransform.setTranslate(translation.x(), translation.y());
        return newTransform;
    }
    case SVGTransformValue::SVG_TRANSFORM_SCALE: {
        FloatSize scale = transform.scale();
        scale += FloatSize::narrowPrecision(m_transform.a(), m_transform.d());
        newTransform.setScale(scale.width(), scale.height());
        return newTransform;
    }
    case SVGTransformValue::SVG_TRANSFORM_ROTATE: {
        FloatPoint center = transform.rotationCenter();
        newTransform.setRotate(transform.angle() + m_angle, center.x() + m_cx, center.y() + m_cy);
        return newTransform;
    }
    case SVGTransformValue::SVG_TRANSFORM_SKEWX:
        newTransform.setSkewX(transform.angle() + m_angle);
        return newTransform;
    case SVGTransformValue::SVG_TRANSFORM_SKEWY:
        newTransform.setSkewY(transform.angle() + m_angle);
        return newTransform;
    }
    
    ASSERT_NOT_REACHED();
    return { };
}

bool SVGTransformDistance::isZero() const
{
    return m_transform.isIdentity() && !m_angle;
}

float SVGTransformDistance::distance() const
{
    switch (m_type) {
    case SVGTransformValue::SVG_TRANSFORM_MATRIX:
        ASSERT_NOT_REACHED();
#if !ASSERT_ENABLED
        FALLTHROUGH;
#endif
    case SVGTransformValue::SVG_TRANSFORM_UNKNOWN:
        return 0;
    case SVGTransformValue::SVG_TRANSFORM_ROTATE:
        return std::hypot(m_angle, m_cx, m_cy);
    case SVGTransformValue::SVG_TRANSFORM_SCALE:
        return static_cast<float>(std::hypot(m_transform.a(), m_transform.d()));
    case SVGTransformValue::SVG_TRANSFORM_TRANSLATE:
        return static_cast<float>(std::hypot(m_transform.e(), m_transform.f()));
    case SVGTransformValue::SVG_TRANSFORM_SKEWX:
    case SVGTransformValue::SVG_TRANSFORM_SKEWY:
        return m_angle;
    }
    ASSERT_NOT_REACHED();
    return 0;
}

}