FloatRect.cpp   [plain text]

/*
 * Copyright (C) 2003, 2006, 2007 Apple Inc.  All rights reserved.
 * Copyright (C) 2005 Nokia.  All rights reserved.
 *
 * 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.
 */

#include "config.h"
#include "FloatRect.h"

#include "FloatConversion.h"
#include "IntRect.h"
#include <algorithm>
#include <limits>
#include <math.h>

using std::max;
using std::min;

namespace WebCore {

FloatRect::FloatRect(const IntRect& r) : m_location(r.location()), m_size(r.size())
{
}

FloatRect FloatRect::narrowPrecision(double x, double y, double width, double height)
{
    return FloatRect(narrowPrecisionToFloat(x), narrowPrecisionToFloat(y), narrowPrecisionToFloat(width), narrowPrecisionToFloat(height));
}

bool FloatRect::intersects(const FloatRect& other) const
{
    // Checking emptiness handles negative widths as well as zero.
    return !isEmpty() && !other.isEmpty()
        && x() < other.right() && other.x() < right()
        && y() < other.bottom() && other.y() < bottom();
}

bool FloatRect::contains(const FloatRect& other) const
{
    return x() <= other.x() && right() >= other.right()
        && y() <= other.y() && bottom() >= other.bottom();
}

void FloatRect::intersect(const FloatRect& other)
{
    float l = max(x(), other.x());
    float t = max(y(), other.y());
    float r = min(right(), other.right());
    float b = min(bottom(), other.bottom());

    // Return a clean empty rectangle for non-intersecting cases.
    if (l >= r || t >= b) {
        l = 0;
        t = 0;
        r = 0;
        b = 0;
    }

    m_location.setX(l);
    m_location.setY(t);
    m_size.setWidth(r - l);
    m_size.setHeight(b - t);
}

void FloatRect::unite(const FloatRect& other)
{
    // Handle empty special cases first.
    if (other.isEmpty())
        return;
    if (isEmpty()) {
        *this = other;
        return;
    }

    float l = min(x(), other.x());
    float t = min(y(), other.y());
    float r = max(right(), other.right());
    float b = max(bottom(), other.bottom());

    m_location.setX(l);
    m_location.setY(t);
    m_size.setWidth(r - l);
    m_size.setHeight(b - t);
}

void FloatRect::scale(float sx, float sy)
{
    m_location.setX(x() * sx);
    m_location.setY(y() * sy);
    m_size.setWidth(width() * sx);
    m_size.setHeight(height() * sy);
}

static inline int safeFloatToInt(float x)
{
    static const int s_intMax = std::numeric_limits<int>::max();
    static const int s_intMin = std::numeric_limits<int>::min();

    if (x >= static_cast<float>(s_intMax))
        return s_intMax;
    if (x < static_cast<float>(s_intMin))
        return s_intMin;
    return static_cast<int>(x);
}

IntRect enclosingIntRect(const FloatRect& rect)
{
    float left = floorf(rect.x());
    float top = floorf(rect.y());
    float width = ceilf(rect.right()) - left;
    float height = ceilf(rect.bottom()) - top;
    return IntRect(safeFloatToInt(left), safeFloatToInt(top), 
                   safeFloatToInt(width), safeFloatToInt(height));
}

FloatRect mapRect(const FloatRect& r, const FloatRect& srcRect, const FloatRect& destRect)
{
    if (srcRect.width() == 0 || srcRect.height() == 0)
        return FloatRect();

    float widthScale = destRect.width() / srcRect.width();
    float heightScale = destRect.height() / srcRect.height();
    return FloatRect(destRect.x() + (r.x() - srcRect.x()) * widthScale,
                     destRect.y() + (r.y() - srcRect.y()) * heightScale,
                     r.width() * widthScale, r.height() * heightScale);
}

}