round_rect_geometry.cc

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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
 
#include "flutter/impeller/entity/geometry/round_rect_geometry.h"
 
namespace impeller {
 
RoundRectGeometry::RoundRectGeometry(const Rect& bounds, const Size& radii)
    : bounds_(bounds), radii_(radii) {}
 
GeometryResult RoundRectGeometry::GetPositionBuffer(
    const ContentContext& renderer,
    const Entity& entity,
    RenderPass& pass) const {
  return ComputePositionGeometry(renderer,
                                 renderer.GetTessellator()->FilledRoundRect(
                                     entity.GetTransform(), bounds_, radii_),
                                 entity, pass);
}
 
std::optional<Rect> RoundRectGeometry::GetCoverage(
    const Matrix& transform) const {
  return bounds_.TransformBounds(transform);
}
 
bool RoundRectGeometry::CoversArea(const Matrix& transform,
                                   const Rect& rect) const {
  if (!transform.IsTranslationScaleOnly()) {
    return false;
  }
  bool flat_on_tb = bounds_.GetWidth() > radii_.width * 2;
  bool flat_on_lr = bounds_.GetHeight() > radii_.height * 2;
  if (!flat_on_tb && !flat_on_lr) {
    return false;
  }
  // We either transform the bounds and delta-transform the radii,
  // or we compute the vertical and horizontal bounds and then
  // transform each. Either way there are 2 transform operations.
  // We could also get a weaker answer by computing just the
  // "inner rect" and only doing a coverage analysis on that,
  // but this process will produce more culling results.
  if (flat_on_tb) {
    Rect vertical_bounds = bounds_.Expand(Size{-radii_.width, 0});
    Rect coverage = vertical_bounds.TransformBounds(transform);
    if (coverage.Contains(rect)) {
      return true;
    }
  }
  if (flat_on_lr) {
    Rect horizontal_bounds = bounds_.Expand(Size{0, -radii_.height});
    Rect coverage = horizontal_bounds.TransformBounds(transform);
    if (coverage.Contains(rect)) {
      return true;
    }
  }
  return false;
}
 
bool RoundRectGeometry::IsAxisAlignedRect() const {
  return false;
}
 
}  // namespace impeller