gecko-dev/gfx/thebes/gfxRect.cpp

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Novell code.
 *
 * The Initial Developer of the Original Code is Novell Corporation.
 * Portions created by the Initial Developer are Copyright (C) 2006
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Robert O'Callahan (rocallahan@novell.com)
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * under the terms of either the GPL or the LGPL, and not to allow others to
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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
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#include "gfxRect.h"

#include "nsMathUtils.h"

gfxRect
gfxRect::Intersect(const gfxRect& aRect) const
{
  gfxRect result(0,0,0,0);

  gfxFloat x = PR_MAX(aRect.X(), X());
  gfxFloat xmost = PR_MIN(aRect.XMost(), XMost());
  if (x >= xmost)
    return result;

  gfxFloat y = PR_MAX(aRect.Y(), Y());
  gfxFloat ymost = PR_MIN(aRect.YMost(), YMost());
  if (y >= ymost)
    return result;

  result = gfxRect(x, y, xmost - x, ymost - y);
  return result;
}

gfxRect
gfxRect::Union(const gfxRect& aRect) const
{
  if (IsEmpty())
    return aRect;
  if (aRect.IsEmpty())
    return *this;

  gfxFloat x = PR_MIN(aRect.X(), X());
  gfxFloat xmost = PR_MAX(aRect.XMost(), XMost());
  gfxFloat y = PR_MIN(aRect.Y(), Y());
  gfxFloat ymost = PR_MAX(aRect.YMost(), YMost());
  return gfxRect(x, y, xmost - x, ymost - y);
}

PRBool
gfxRect::Contains(const gfxRect& aRect) const
{
  return aRect.X() >= X() && aRect.XMost() <= XMost() &&
         aRect.Y() >= Y() && aRect.YMost() <= YMost();
}

PRBool
gfxRect::Contains(const gfxPoint& aPoint) const
{
  return aPoint.x >= X() && aPoint.x <= XMost() &&
         aPoint.y >= Y() && aPoint.y <= YMost();
}

static PRBool
WithinEpsilonOfInteger(gfxFloat aX, gfxFloat aEpsilon)
{
    return fabs(NS_round(aX) - aX) <= fabs(aEpsilon);
}

PRBool
gfxRect::WithinEpsilonOfIntegerPixels(gfxFloat aEpsilon) const
{
    NS_ASSERTION(-0.5 < aEpsilon && aEpsilon < 0.5, "Nonsense epsilon value");
    return (WithinEpsilonOfInteger(pos.x, aEpsilon) &&
            WithinEpsilonOfInteger(pos.y, aEpsilon) &&
            WithinEpsilonOfInteger(size.width, aEpsilon) &&
            WithinEpsilonOfInteger(size.height, aEpsilon));
}

void
gfxRect::Round()
{
    // Note that don't use NS_round here. See the comment for this method in gfxRect.h
    gfxFloat x0 = NS_floor(X() + 0.5);
    gfxFloat y0 = NS_floor(Y() + 0.5);
    gfxFloat x1 = NS_floor(XMost() + 0.5);
    gfxFloat y1 = NS_floor(YMost() + 0.5);

    pos.x = x0;
    pos.y = y0;

    size.width = x1 - x0;
    size.height = y1 - y0;
}

void
gfxRect::RoundIn()
{
    gfxFloat x0 = NS_ceil(X());
    gfxFloat y0 = NS_ceil(Y());
    gfxFloat x1 = NS_floor(XMost());
    gfxFloat y1 = NS_floor(YMost());

    pos.x = x0;
    pos.y = y0;

    size.width = x1 - x0;
    size.height = y1 - y0;
}

void
gfxRect::RoundOut()
{
    gfxFloat x0 = NS_floor(X());
    gfxFloat y0 = NS_floor(Y());
    gfxFloat x1 = NS_ceil(XMost());
    gfxFloat y1 = NS_ceil(YMost());

    pos.x = x0;
    pos.y = y0;

    size.width = x1 - x0;
    size.height = y1 - y0;
}

/* Clamp r to CAIRO_COORD_MIN .. CAIRO_COORD_MAX
 * these are to be device coordinates.
 *
 * Cairo is currently using 24.8 fixed point,
 * so -2^24 .. 2^24-1 is our valid
 */

#define CAIRO_COORD_MAX (16777215.0)
#define CAIRO_COORD_MIN (-16777216.0)

void
gfxRect::Condition()
{
    // if either x or y is way out of bounds;
    // note that we don't handle negative w/h here
    if (pos.x > CAIRO_COORD_MAX) {
        pos.x = CAIRO_COORD_MAX;
        size.width = 0.0;
    } 

    if (pos.y > CAIRO_COORD_MAX) {
        pos.y = CAIRO_COORD_MAX;
        size.height = 0.0;
    }

    if (pos.x < CAIRO_COORD_MIN) {
        size.width += pos.x - CAIRO_COORD_MIN;
        if (size.width < 0.0)
            size.width = 0.0;
        pos.x = CAIRO_COORD_MIN;
    }

    if (pos.y < CAIRO_COORD_MIN) {
        size.height += pos.y - CAIRO_COORD_MIN;
        if (size.height < 0.0)
            size.height = 0.0;
        pos.y = CAIRO_COORD_MIN;
    }

    if (pos.x + size.width > CAIRO_COORD_MAX) {
        size.width = CAIRO_COORD_MAX - pos.x;
    }

    if (pos.y + size.height > CAIRO_COORD_MAX) {
        size.height = CAIRO_COORD_MAX - pos.y;
    }
}