WebCore/ChangeLog

2010-09-30  Alejandro G. Castro  <alex@igalia.com>

        Reviewed by NOBODY (OOPS!).

        ContextShadow should not use the blur radius as kernel size of the

        box blurs

        https://bugs.webkit.org/show_bug.cgi?id=46918

        Calculate the size of the kernel in the blur algorihtm using the

        radius instead of using directly.

        * platform/graphics/ContextShadow.cpp:

        (WebCore::ContextShadow::blurLayerImage):

        (WebCore::ContextShadow::calculateLayerBoundingRect):

2010-09-29  Kent Tamura  <tkent@chromium.org>

        Reviewed by Dimitri Glazkov.

WebCore/platform/graphics/ContextShadow.cpp

@@static const int BlurSumShift = 15;

void ContextShadow::blurLayerImage(unsigned char* imageData, const IntSize& size, int rowStride)

{

    int channels[4] = { 3, 0, 1, 3 };

88 int dmax = m_blurRadius >> 1;

89 int dmin = dmax - 1 + (m_blurRadius & 1);

    unsigned kernelSize = max(2.f, (2 / 3.f) * m_blurRadius);

    int dmax = kernelSize >> 1;

    int dmin = dmax - 1 + (kernelSize & 1);

    if (dmin < 0)

        dmin = 0;

@@void ContextShadow::calculateLayerBoundingRect(const FloatRect& layerArea, const

    destinationRect.move(m_offset);

    m_layerRect = enclosingIntRect(destinationRect);

156 // We expand the area by the blur radius * 2 to give extra space for the blur transition.

157 m_layerRect.inflate((m_type == BlurShadow) ? ceil(m_blurRadius * 2) : 0);

157 // We expand the area by the blur radius to give extra space for the blur transition.

158 m_layerRect.inflate((m_type == BlurShadow) ? ceil(m_blurRadius) : 0);

    if (!clipRect.contains(m_layerRect)) {

        // No need to have the buffer larger than the clip.

@@void ContextShadow::calculateLayerBoundingRect(const FloatRect& layerArea, const

        // We adjust again because the pixels at the borders are still

        // potentially affected by the pixels outside the buffer.

        if (m_type == BlurShadow)

170 m_layerRect.inflate((m_type == BlurShadow) ? ceil(m_blurRadius * 2) : 0);

171 m_layerRect.inflate((m_type == BlurShadow) ? ceil(m_blurRadius) : 0);

    }

}