Source/core/html/canvas/CanvasPathMethods.cpp

/*
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
 * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
 * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
 * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
 * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
 * Copyright (C) 2012 Intel Corporation. All rights reserved.
 * Copyright (C) 2012, 2013 Adobe Systems Incorporated. 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 THE COPYRIGHT HOLDER "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 THE COPYRIGHT HOLDER 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 "core/html/canvas/CanvasPathMethods.h"

#include "core/dom/ExceptionCode.h"
#include "core/platform/graphics/FloatRect.h"
#include "wtf/MathExtras.h"

namespace WebCore {

void CanvasPathMethods::closePath()
{
    if (m_path.isEmpty())
        return;

    FloatRect boundRect = m_path.boundingRect();
    if (boundRect.width() || boundRect.height())
        m_path.closeSubpath();
}

void CanvasPathMethods::moveTo(float x, float y)
{
    if (!std::isfinite(x) || !std::isfinite(y))
        return;
    if (!isTransformInvertible())
        return;
    m_path.moveTo(FloatPoint(x, y));
}

void CanvasPathMethods::lineTo(float x, float y)
{
    if (!std::isfinite(x) || !std::isfinite(y))
        return;
    if (!isTransformInvertible())
        return;

    FloatPoint p1 = FloatPoint(x, y);
    if (!m_path.hasCurrentPoint())
        m_path.moveTo(p1);
    else if (p1 != m_path.currentPoint())
        m_path.addLineTo(p1);
}

void CanvasPathMethods::quadraticCurveTo(float cpx, float cpy, float x, float y)
{
    if (!std::isfinite(cpx) || !std::isfinite(cpy) || !std::isfinite(x) || !std::isfinite(y))
        return;
    if (!isTransformInvertible())
        return;
    if (!m_path.hasCurrentPoint())
        m_path.moveTo(FloatPoint(cpx, cpy));

    FloatPoint p1 = FloatPoint(x, y);
    FloatPoint cp = FloatPoint(cpx, cpy);
    if (p1 != m_path.currentPoint() || p1 != cp)
        m_path.addQuadCurveTo(cp, p1);
}

void CanvasPathMethods::bezierCurveTo(float cp1x, float cp1y, float cp2x, float cp2y, float x, float y)
{
    if (!std::isfinite(cp1x) || !std::isfinite(cp1y) || !std::isfinite(cp2x) || !std::isfinite(cp2y) || !std::isfinite(x) || !std::isfinite(y))
        return;
    if (!isTransformInvertible())
        return;
    if (!m_path.hasCurrentPoint())
        m_path.moveTo(FloatPoint(cp1x, cp1y));

    FloatPoint p1 = FloatPoint(x, y);
    FloatPoint cp1 = FloatPoint(cp1x, cp1y);
    FloatPoint cp2 = FloatPoint(cp2x, cp2y);
    if (p1 != m_path.currentPoint() || p1 != cp1 ||  p1 != cp2)
        m_path.addBezierCurveTo(cp1, cp2, p1);
}

void CanvasPathMethods::arcTo(float x1, float y1, float x2, float y2, float r, ExceptionCode& ec)
{
    ec = 0;
    if (!std::isfinite(x1) || !std::isfinite(y1) || !std::isfinite(x2) || !std::isfinite(y2) || !std::isfinite(r))
        return;

    if (r < 0) {
        ec = IndexSizeError;
        return;
    }

    if (!isTransformInvertible())
        return;

    FloatPoint p1 = FloatPoint(x1, y1);
    FloatPoint p2 = FloatPoint(x2, y2);

    if (!m_path.hasCurrentPoint())
        m_path.moveTo(p1);
    else if (p1 == m_path.currentPoint() || p1 == p2 || !r)
        lineTo(x1, y1);
    else
        m_path.addArcTo(p1, p2, r);
}

void CanvasPathMethods::arc(float x, float y, float r, float sa, float ea, bool anticlockwise, ExceptionCode& ec)
{
    ec = 0;
    if (!std::isfinite(x) || !std::isfinite(y) || !std::isfinite(r) || !std::isfinite(sa) || !std::isfinite(ea))
        return;

    if (r < 0) {
        ec = IndexSizeError;
        return;
    }

    if (!r || sa == ea) {
        // The arc is empty but we still need to draw the connecting line.
        lineTo(x + r * cosf(sa), y + r * sinf(sa));
        return;
    }

    if (!isTransformInvertible())
        return;

    // If 'sa' and 'ea' differ by more than 2Pi, just add a circle starting/ending at 'sa'.
    if (anticlockwise && sa - ea >= 2 * piFloat) {
        m_path.addArc(FloatPoint(x, y), r, sa, sa - 2 * piFloat, anticlockwise);
        return;
    }
    if (!anticlockwise && ea - sa >= 2 * piFloat) {
        m_path.addArc(FloatPoint(x, y), r, sa, sa + 2 * piFloat, anticlockwise);
        return;
    }

    m_path.addArc(FloatPoint(x, y), r, sa, ea, anticlockwise);
}

void CanvasPathMethods::rect(float x, float y, float width, float height)
{
    if (!isTransformInvertible())
        return;

    if (!std::isfinite(x) || !std::isfinite(y) || !std::isfinite(width) || !std::isfinite(height))
        return;

    if (!width && !height) {
        m_path.moveTo(FloatPoint(x, y));
        return;
    }

    m_path.addRect(FloatRect(x, y, width, height));
}
}