| /* |
| * 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) Research In Motion Limited 2010. All rights reserved. |
| * Copyright (C) 2013 Google 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 "third_party/blink/renderer/platform/graphics/filters/fe_component_transfer.h" |
| |
| #include <algorithm> |
| |
| #include "SkTableColorFilter.h" |
| |
| #include "base/stl_util.h" |
| #include "third_party/blink/renderer/platform/graphics/filters/paint_filter_builder.h" |
| #include "third_party/blink/renderer/platform/wtf/math_extras.h" |
| #include "third_party/blink/renderer/platform/wtf/text/text_stream.h" |
| |
| namespace blink { |
| |
| typedef void (*TransferType)(unsigned char*, const ComponentTransferFunction&); |
| |
| FEComponentTransfer::FEComponentTransfer( |
| Filter* filter, |
| const ComponentTransferFunction& red_func, |
| const ComponentTransferFunction& green_func, |
| const ComponentTransferFunction& blue_func, |
| const ComponentTransferFunction& alpha_func) |
| : FilterEffect(filter), |
| red_func_(red_func), |
| green_func_(green_func), |
| blue_func_(blue_func), |
| alpha_func_(alpha_func) {} |
| |
| FEComponentTransfer* FEComponentTransfer::Create( |
| Filter* filter, |
| const ComponentTransferFunction& red_func, |
| const ComponentTransferFunction& green_func, |
| const ComponentTransferFunction& blue_func, |
| const ComponentTransferFunction& alpha_func) { |
| return MakeGarbageCollected<FEComponentTransfer>(filter, red_func, green_func, |
| blue_func, alpha_func); |
| } |
| |
| static void Identity(unsigned char*, const ComponentTransferFunction&) {} |
| |
| static void Table(unsigned char* values, |
| const ComponentTransferFunction& transfer_function) { |
| const Vector<float>& table_values = transfer_function.table_values; |
| unsigned n = table_values.size(); |
| if (n < 1) |
| return; |
| for (unsigned i = 0; i < 256; ++i) { |
| double c = i / 255.0; |
| unsigned k = static_cast<unsigned>(c * (n - 1)); |
| double v1 = table_values[k]; |
| double v2 = table_values[std::min((k + 1), (n - 1))]; |
| double val = 255.0 * (v1 + (c * (n - 1) - k) * (v2 - v1)); |
| val = clampTo(val, 0.0, 255.0); |
| values[i] = static_cast<unsigned char>(val); |
| } |
| } |
| |
| static void Discrete(unsigned char* values, |
| const ComponentTransferFunction& transfer_function) { |
| const Vector<float>& table_values = transfer_function.table_values; |
| unsigned n = table_values.size(); |
| if (n < 1) |
| return; |
| for (unsigned i = 0; i < 256; ++i) { |
| unsigned k = static_cast<unsigned>((i * n) / 255.0); |
| k = std::min(k, n - 1); |
| double val = 255 * table_values[k]; |
| val = clampTo(val, 0.0, 255.0); |
| values[i] = static_cast<unsigned char>(val); |
| } |
| } |
| |
| static void Linear(unsigned char* values, |
| const ComponentTransferFunction& transfer_function) { |
| for (unsigned i = 0; i < 256; ++i) { |
| double val = |
| transfer_function.slope * i + 255 * transfer_function.intercept; |
| val = clampTo(val, 0.0, 255.0); |
| values[i] = static_cast<unsigned char>(val); |
| } |
| } |
| |
| static void Gamma(unsigned char* values, |
| const ComponentTransferFunction& transfer_function) { |
| for (unsigned i = 0; i < 256; ++i) { |
| double exponent = transfer_function.exponent; |
| double val = |
| 255.0 * (transfer_function.amplitude * pow((i / 255.0), exponent) + |
| transfer_function.offset); |
| val = clampTo(val, 0.0, 255.0); |
| values[i] = static_cast<unsigned char>(val); |
| } |
| } |
| |
| bool FEComponentTransfer::AffectsTransparentPixels() const { |
| double intercept = 0; |
| switch (alpha_func_.type) { |
| case FECOMPONENTTRANSFER_TYPE_UNKNOWN: |
| case FECOMPONENTTRANSFER_TYPE_IDENTITY: |
| break; |
| case FECOMPONENTTRANSFER_TYPE_TABLE: |
| case FECOMPONENTTRANSFER_TYPE_DISCRETE: |
| if (alpha_func_.table_values.size() > 0) |
| intercept = alpha_func_.table_values[0]; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_LINEAR: |
| intercept = alpha_func_.intercept; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_GAMMA: |
| intercept = alpha_func_.offset; |
| break; |
| } |
| return 255 * intercept >= 1; |
| } |
| |
| sk_sp<PaintFilter> FEComponentTransfer::CreateImageFilter() { |
| sk_sp<PaintFilter> input(paint_filter_builder::Build( |
| InputEffect(0), OperatingInterpolationSpace())); |
| |
| unsigned char r_values[256], g_values[256], b_values[256], a_values[256]; |
| GetValues(r_values, g_values, b_values, a_values); |
| |
| PaintFilter::CropRect crop_rect = GetCropRect(); |
| sk_sp<SkColorFilter> color_filter = |
| SkTableColorFilter::MakeARGB(a_values, r_values, g_values, b_values); |
| return sk_make_sp<ColorFilterPaintFilter>(std::move(color_filter), |
| std::move(input), &crop_rect); |
| } |
| |
| void FEComponentTransfer::GetValues(unsigned char r_values[256], |
| unsigned char g_values[256], |
| unsigned char b_values[256], |
| unsigned char a_values[256]) { |
| for (unsigned i = 0; i < 256; ++i) |
| r_values[i] = g_values[i] = b_values[i] = a_values[i] = i; |
| unsigned char* tables[] = {r_values, g_values, b_values, a_values}; |
| ComponentTransferFunction transfer_function[] = {red_func_, green_func_, |
| blue_func_, alpha_func_}; |
| TransferType call_effect[] = {Identity, Identity, Table, |
| Discrete, Linear, Gamma}; |
| |
| for (unsigned channel = 0; channel < 4; channel++) { |
| SECURITY_DCHECK(static_cast<size_t>(transfer_function[channel].type) < |
| base::size(call_effect)); |
| (*call_effect[transfer_function[channel].type])(tables[channel], |
| transfer_function[channel]); |
| } |
| } |
| |
| static WTF::TextStream& operator<<(WTF::TextStream& ts, |
| const ComponentTransferType& type) { |
| switch (type) { |
| case FECOMPONENTTRANSFER_TYPE_UNKNOWN: |
| ts << "UNKNOWN"; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_IDENTITY: |
| ts << "IDENTITY"; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_TABLE: |
| ts << "TABLE"; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_DISCRETE: |
| ts << "DISCRETE"; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_LINEAR: |
| ts << "LINEAR"; |
| break; |
| case FECOMPONENTTRANSFER_TYPE_GAMMA: |
| ts << "GAMMA"; |
| break; |
| } |
| return ts; |
| } |
| |
| static WTF::TextStream& operator<<(WTF::TextStream& ts, |
| const ComponentTransferFunction& function) { |
| ts << "type=\"" << function.type << "\" slope=\"" << function.slope |
| << "\" intercept=\"" << function.intercept << "\" amplitude=\"" |
| << function.amplitude << "\" exponent=\"" << function.exponent |
| << "\" offset=\"" << function.offset << "\""; |
| return ts; |
| } |
| |
| WTF::TextStream& FEComponentTransfer::ExternalRepresentation( |
| WTF::TextStream& ts, |
| int indent) const { |
| WriteIndent(ts, indent); |
| ts << "[feComponentTransfer"; |
| FilterEffect::ExternalRepresentation(ts); |
| ts << " \n"; |
| WriteIndent(ts, indent + 2); |
| ts << "{red: " << red_func_ << "}\n"; |
| WriteIndent(ts, indent + 2); |
| ts << "{green: " << green_func_ << "}\n"; |
| WriteIndent(ts, indent + 2); |
| ts << "{blue: " << blue_func_ << "}\n"; |
| WriteIndent(ts, indent + 2); |
| ts << "{alpha: " << alpha_func_ << "}]\n"; |
| InputEffect(0)->ExternalRepresentation(ts, indent + 1); |
| return ts; |
| } |
| |
| } // namespace blink |
