/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_ShapeUtils_h

#define mozilla_ShapeUtils_h

#include "nsCoord.h"

#include "nsSize.h"

#include "nsStyleConsts.h"

struct nsPoint;

struct nsRect;

namespace mozilla {

class StyleBasicShape;

// ShapeUtils is a namespace class containing utility functions related to

// processing basic shapes in the CSS Shapes Module.

// https://drafts.csswg.org/css-shapes/#basic-shape-functions

//

struct ShapeUtils final {

  // Compute the length of a keyword <shape-radius>, i.e. closest-side or

  // farthest-side, for a circle or an ellipse on a single dimension. The

  // caller needs to call for both dimensions and combine the result.

  // https://drafts.csswg.org/css-shapes/#typedef-shape-radius.

  // @return The length of the radius in app units.

  static nscoord ComputeShapeRadius(const StyleShapeRadius aType,

                                    const nscoord aCenter,

                                    const nscoord aPosMin,

                                    const nscoord aPosMax);

  // Compute the center of a circle or an ellipse.

  // @param aRefBox The reference box of the basic shape.

  // @return The point of the center.

  static nsPoint ComputeCircleOrEllipseCenter(

      const UniquePtr<StyleBasicShape>& aBasicShape, const nsRect& aRefBox);

  // Compute the radius for a circle.

  // @param aCenter the center of the circle.

  // @param aRefBox the reference box of the circle.

  // @return The length of the radius in app units.

  static nscoord ComputeCircleRadius(

      const UniquePtr<StyleBasicShape>& aBasicShape, const nsPoint& aCenter,

      const nsRect& aRefBox);

  // Compute the radii for an ellipse.

  // @param aCenter the center of the ellipse.

  // @param aRefBox the reference box of the ellipse.

  // @return The radii of the ellipse in app units. The width and height

  // represent the x-axis and y-axis radii of the ellipse.

  static nsSize ComputeEllipseRadii(

      const UniquePtr<StyleBasicShape>& aBasicShape, const nsPoint& aCenter,

      const nsRect& aRefBox);

  // Compute the rect for an inset.

  // @param aRefBox the reference box of the inset.

  // @return The inset rect in app units.

  static nsRect ComputeInsetRect(const UniquePtr<StyleBasicShape>& aBasicShape,

                                 const nsRect& aRefBox);

  // Compute the radii for an inset.

  // @param aRefBox the reference box of the inset.

  // @param aInsetRect the inset rect computed by ComputeInsetRect().

  // @param aRadii the returned radii in app units.

  // @return true if any of the radii is nonzero; false otherwise.

  static bool ComputeInsetRadii(const UniquePtr<StyleBasicShape>& aBasicShape,

                                const nsRect& aInsetRect, const nsRect& aRefBox,

                                nscoord aRadii[8]);

  // Compute the vertices for a polygon.

  // @param aRefBox the reference box of the polygon.

  // @return The vertices in app units; the coordinate space is the same

  //         as aRefBox.

  static nsTArray<nsPoint> ComputePolygonVertices(

      const UniquePtr<StyleBasicShape>& aBasicShape, const nsRect& aRefBox);

};

}  // namespace mozilla

#endif  // mozilla_ShapeUtils_h