| /* |
| * Copyright (C) 2004, 2005, 2006, 2007 Nikolas Zimmermann <zimmermann@kde.org> |
| * Copyright (C) 2004, 2005 Rob Buis <buis@kde.org> |
| * Copyright (C) 2005 Eric Seidel <eric@webkit.org> |
| * Copyright (C) 2009 Dirk Schulze <krit@webkit.org> |
| * Copyright (C) 2010 Igalia, S.L. |
| * Copyright (C) Research In Motion Limited 2010. All rights reserved. |
| * Copyright (C) 2015-2021 Apple, Inc. All rights reserved. |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Library General Public |
| * License as published by the Free Software Foundation; either |
| * version 2 of the License, or (at your option) any later version. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Library General Public License for more details. |
| * |
| * You should have received a copy of the GNU Library General Public License |
| * along with this library; see the file COPYING.LIB. If not, write to |
| * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| */ |
| |
| #include "config.h" |
| #include "FEGaussianBlur.h" |
| |
| #include "FEGaussianBlurSoftwareApplier.h" |
| #include "Filter.h" |
| #include <wtf/text/TextStream.h> |
| |
| namespace WebCore { |
| |
| Ref<FEGaussianBlur> FEGaussianBlur::create(float x, float y, EdgeModeType edgeMode) |
| { |
| return adoptRef(*new FEGaussianBlur(x, y, edgeMode)); |
| } |
| |
| FEGaussianBlur::FEGaussianBlur(float x, float y, EdgeModeType edgeMode) |
| : FilterEffect(FilterEffect::Type::FEGaussianBlur) |
| , m_stdX(x) |
| , m_stdY(y) |
| , m_edgeMode(edgeMode) |
| { |
| } |
| |
| void FEGaussianBlur::setStdDeviationX(float x) |
| { |
| m_stdX = x; |
| } |
| |
| void FEGaussianBlur::setStdDeviationY(float y) |
| { |
| m_stdY = y; |
| } |
| |
| void FEGaussianBlur::setEdgeMode(EdgeModeType edgeMode) |
| { |
| m_edgeMode = edgeMode; |
| } |
| |
| static inline float gaussianKernelFactor() |
| { |
| return 3 / 4.f * sqrtf(2 * piFloat); |
| } |
| |
| static int clampedToKernelSize(float value) |
| { |
| static constexpr unsigned maxKernelSize = 500; |
| |
| // Limit the kernel size to 500. A bigger radius won't make a big difference for the result image but |
| // inflates the absolute paint rect too much. This is compatible with Firefox' behavior. |
| unsigned size = std::max<unsigned>(2, static_cast<unsigned>(floorf(value * gaussianKernelFactor() + 0.5f))); |
| return clampTo<int>(std::min(size, maxKernelSize)); |
| } |
| |
| IntSize FEGaussianBlur::calculateUnscaledKernelSize(FloatSize stdDeviation) |
| { |
| ASSERT(stdDeviation.width() >= 0 && stdDeviation.height() >= 0); |
| IntSize kernelSize; |
| |
| if (stdDeviation.width()) |
| kernelSize.setWidth(clampedToKernelSize(stdDeviation.width())); |
| |
| if (stdDeviation.height()) |
| kernelSize.setHeight(clampedToKernelSize(stdDeviation.height())); |
| |
| return kernelSize; |
| } |
| |
| IntSize FEGaussianBlur::calculateKernelSize(const Filter& filter, FloatSize stdDeviation) |
| { |
| stdDeviation = filter.resolvedSize(stdDeviation); |
| return calculateUnscaledKernelSize(filter.scaledByFilterScale(stdDeviation)); |
| } |
| |
| IntSize FEGaussianBlur::calculateOutsetSize(FloatSize stdDeviation) |
| { |
| auto kernelSize = calculateUnscaledKernelSize(stdDeviation); |
| |
| // We take the half kernel size and multiply it with three, because we run box blur three times. |
| return { 3 * kernelSize.width() / 2, 3 * kernelSize.height() / 2 }; |
| } |
| |
| FloatRect FEGaussianBlur::calculateImageRect(const Filter& filter, const FilterImageVector& inputs, const FloatRect& primitiveSubregion) const |
| { |
| auto imageRect = inputs[0]->imageRect(); |
| |
| // Edge modes other than 'none' do not inflate the affected paint rect. |
| if (m_edgeMode != EdgeModeType::None) |
| return enclosingIntRect(imageRect); |
| |
| auto kernelSize = calculateUnscaledKernelSize(filter.resolvedSize({ m_stdX, m_stdY })); |
| |
| // We take the half kernel size and multiply it with three, because we run box blur three times. |
| imageRect.inflateX(3 * kernelSize.width() * 0.5f); |
| imageRect.inflateY(3 * kernelSize.height() * 0.5f); |
| |
| return filter.clipToMaxEffectRect(imageRect, primitiveSubregion); |
| } |
| |
| IntOutsets FEGaussianBlur::outsets() const |
| { |
| IntSize outsetSize = calculateOutsetSize({ m_stdX, m_stdY }); |
| return { outsetSize.height(), outsetSize.width(), outsetSize.height(), outsetSize.width() }; |
| } |
| |
| bool FEGaussianBlur::resultIsAlphaImage(const FilterImageVector& inputs) const |
| { |
| return inputs[0]->isAlphaImage(); |
| } |
| |
| std::unique_ptr<FilterEffectApplier> FEGaussianBlur::createApplier(const Filter&) const |
| { |
| return FilterEffectApplier::create<FEGaussianBlurSoftwareApplier>(*this); |
| } |
| |
| TextStream& FEGaussianBlur::externalRepresentation(TextStream& ts, FilterRepresentation representation) const |
| { |
| ts << indent << "[feGaussianBlur"; |
| FilterEffect::externalRepresentation(ts, representation); |
| |
| ts << " stdDeviation=\"" << m_stdX << ", " << m_stdY << "\""; |
| |
| ts << "]\n"; |
| return ts; |
| } |
| |
| } // namespace WebCore |