chromium/src/third_party/blink/renderer/modules/canvas/canvas2d/canvas_gradient.cc

/*
 * Copyright (C) 2006, 2007, 2008 Apple Inc. All rights reserved.
 * Copyright (C) 2007 Alp Toker <alp@atoker.com>
 *
 * 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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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 "third_party/blink/renderer/modules/canvas/canvas2d/canvas_gradient.h"

#include "third_party/blink/renderer/modules/canvas/canvas2d/canvas_pattern.h"
#include "third_party/blink/renderer/modules/canvas/canvas2d/canvas_style.h"
#include "third_party/blink/renderer/platform/bindings/exception_state.h"

namespace blink {

CanvasGradient::CanvasGradient(const FloatPoint& p0, const FloatPoint& p1)
    : gradient_(
          Gradient::CreateLinear(p0,
                                 p1,
                                 kSpreadMethodPad,
                                 Gradient::ColorInterpolation::kUnpremultiplied,
                                 Gradient::DegenerateHandling::kDisallow)) {
  identifiability_study_helper_.MaybeUpdateBuilder(
      CanvasOps::kCreateLinearGradient, p0.X(), p0.Y(), p1.X(), p1.Y());
}

CanvasGradient::CanvasGradient(const FloatPoint& p0,
                               float r0,
                               const FloatPoint& p1,
                               float r1)
    : gradient_(
          Gradient::CreateRadial(p0,
                                 r0,
                                 p1,
                                 r1,
                                 1,
                                 kSpreadMethodPad,
                                 Gradient::ColorInterpolation::kUnpremultiplied,
                                 Gradient::DegenerateHandling::kDisallow)) {
  identifiability_study_helper_.MaybeUpdateBuilder(
      CanvasOps::kCreateRadialGradient, p0.X(), p0.Y(), r0, p1.X(), p1.Y(), r1);
}

// CanvasRenderingContext2D.createConicGradient only takes one angle argument
// it makes sense to make that rotation here and always make the angles 0 -> 2pi
CanvasGradient::CanvasGradient(float startAngle, const FloatPoint& center)
    : gradient_(
          Gradient::CreateConic(center,
                                startAngle,
                                0,
                                360,
                                kSpreadMethodPad,
                                Gradient::ColorInterpolation::kUnpremultiplied,
                                Gradient::DegenerateHandling::kDisallow)) {}

void CanvasGradient::addColorStop(double value,
                                  const String& color_string,
                                  ExceptionState& exception_state) {
  if (!(value >= 0 && value <= 1.0)) {
    exception_state.ThrowDOMException(DOMExceptionCode::kIndexSizeError,
                                      "The provided value (" +
                                          String::Number(value) +
                                          ") is outside the range (0.0, 1.0).");
    return;
  }

  Color color = 0;
  if (!ParseColorOrCurrentColor(color, color_string, nullptr /*canvas*/)) {
    exception_state.ThrowDOMException(DOMExceptionCode::kSyntaxError,
                                      "The value provided ('" + color_string +
                                          "') could not be parsed as a color.");
    return;
  }
  identifiability_study_helper_.MaybeUpdateBuilder(CanvasOps::kAddColorStop,
                                                   value, color.Rgb());

  gradient_->AddColorStop(value, color);
}

IdentifiableToken CanvasGradient::GetIdentifiableToken() const {
  return identifiability_study_helper_.GetToken();
}

}  // namespace blink