RenderSVGRect.cpp   [plain text]

/*
 * Copyright (C) 2011 University of Szeged
 * Copyright (C) 2011 Renata Hodovan <reni@webkit.org>
 * 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 UNIVERSITY OF SZEGED ``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 UNIVERSITY OF SZEGED 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 "RenderSVGRect.h"

#include <wtf/IsoMallocInlines.h>

namespace WebCore {

WTF_MAKE_ISO_ALLOCATED_IMPL(RenderSVGRect);

RenderSVGRect::RenderSVGRect(SVGRectElement& element, RenderStyle&& style)
    : RenderSVGShape(element, WTFMove(style))
    , m_usePathFallback(false)
{
}

RenderSVGRect::~RenderSVGRect() = default;

SVGRectElement& RenderSVGRect::rectElement() const
{
    return downcast<SVGRectElement>(RenderSVGShape::graphicsElement());
}

void RenderSVGRect::updateShapeFromElement()
{
    // Before creating a new object we need to clear the cached bounding box
    // to avoid using garbage.
    m_fillBoundingBox = FloatRect();
    m_innerStrokeRect = FloatRect();
    m_outerStrokeRect = FloatRect();
    clearPath();

    SVGLengthContext lengthContext(&rectElement());
    FloatSize boundingBoxSize(lengthContext.valueForLength(style().width(), LengthModeWidth), lengthContext.valueForLength(style().height(), LengthModeHeight));

    // Element is invalid if either dimension is negative.
    if (boundingBoxSize.width() < 0 || boundingBoxSize.height() < 0)
        return;

    // Rendering enabled? Spec: "A value of zero disables rendering of the element."
    if (!boundingBoxSize.isEmpty()) {
        if (rectElement().rx().value(lengthContext) > 0 || rectElement().ry().value(lengthContext) > 0 || hasNonScalingStroke()) {
            // Fall back to RenderSVGShape
            RenderSVGShape::updateShapeFromElement();
            m_usePathFallback = true;
            return;
        }
        m_usePathFallback = false;
    }

    m_fillBoundingBox = FloatRect(FloatPoint(lengthContext.valueForLength(style().svgStyle().x(), LengthModeWidth),
        lengthContext.valueForLength(style().svgStyle().y(), LengthModeHeight)),
        boundingBoxSize);

    // To decide if the stroke contains a point we create two rects which represent the inner and
    // the outer stroke borders. A stroke contains the point, if the point is between them.
    m_innerStrokeRect = m_fillBoundingBox;
    m_outerStrokeRect = m_fillBoundingBox;

    if (style().svgStyle().hasStroke()) {
        float strokeWidth = this->strokeWidth();
        m_innerStrokeRect.inflate(-strokeWidth / 2);
        m_outerStrokeRect.inflate(strokeWidth / 2);
    }

    m_strokeBoundingBox = m_outerStrokeRect;

#if USE(CG)
    // CoreGraphics can inflate the stroke by 1px when drawing a rectangle with antialiasing disabled at non-integer coordinates, we need to compensate.
    if (style().svgStyle().shapeRendering() == ShapeRendering::CrispEdges)
        m_strokeBoundingBox.inflate(1);
#endif
}

void RenderSVGRect::fillShape(GraphicsContext& context) const
{
    if (m_usePathFallback) {
        RenderSVGShape::fillShape(context);
        return;
    }

#if USE(CG)
    // FIXME: CG implementation of GraphicsContextCG::fillRect has an own
    // shadow drawing method, which draws an extra shadow.
    // This is a workaround for switching off the extra shadow.
    // https://bugs.webkit.org/show_bug.cgi?id=68899
    if (context.hasShadow()) {
        GraphicsContextStateSaver stateSaver(context);
        context.clearShadow();
        context.fillRect(m_fillBoundingBox);
        return;
    }
#endif

    context.fillRect(m_fillBoundingBox);
}

void RenderSVGRect::strokeShape(GraphicsContext& context) const
{
    if (!style().hasVisibleStroke())
        return;

    if (m_usePathFallback) {
        RenderSVGShape::strokeShape(context);
        return;
    }

    context.strokeRect(m_fillBoundingBox, strokeWidth());
}

bool RenderSVGRect::shapeDependentStrokeContains(const FloatPoint& point, PointCoordinateSpace pointCoordinateSpace)
{
    // The optimized contains code below does not support non-smooth strokes so we need
    // to fall back to RenderSVGShape::shapeDependentStrokeContains in these cases.
    if (m_usePathFallback || !hasSmoothStroke()) {
        if (!hasPath())
            RenderSVGShape::updateShapeFromElement();
        return RenderSVGShape::shapeDependentStrokeContains(point, pointCoordinateSpace);
    }

    return m_outerStrokeRect.contains(point, FloatRect::InsideOrOnStroke) && !m_innerStrokeRect.contains(point, FloatRect::InsideButNotOnStroke);
}

bool RenderSVGRect::shapeDependentFillContains(const FloatPoint& point, const WindRule fillRule) const
{
    if (m_usePathFallback)
        return RenderSVGShape::shapeDependentFillContains(point, fillRule);
    return m_fillBoundingBox.contains(point.x(), point.y());
}

bool RenderSVGRect::isRenderingDisabled() const
{
    // A width or height of zero disables rendering for the element, and results in an empty bounding box.
    return m_fillBoundingBox.isEmpty();
}

}