/*
* Farseer Physics Engine based on Box2D.XNA port:
* Copyright (c) 2010 Ian Qvist
* 
* Box2D.XNA port of Box2D:
* Copyright (c) 2009 Brandon Furtwangler, Nathan Furtwangler
*
* Original source Box2D:
* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com 
* 
* This software is provided 'as-is', without any express or implied 
* warranty.  In no event will the authors be held liable for any damages 
* arising from the use of this software. 
* Permission is granted to anyone to use this software for any purpose, 
* including commercial applications, and to alter it and redistribute it 
* freely, subject to the following restrictions: 
* 1. The origin of this software must not be misrepresented; you must not 
* claim that you wrote the original software. If you use this software 
* in a product, an acknowledgment in the product documentation would be 
* appreciated but is not required. 
* 2. Altered source versions must be plainly marked as such, and must not be 
* misrepresented as being the original software. 
* 3. This notice may not be removed or altered from any source distribution. 
*/

using System;
using FarseerPhysics.Common;
using FarseerPhysics.Dynamics;
using Vortex.Drawing;

namespace FarseerPhysics
{
    [Flags]
    public enum DebugViewFlags
    {
        /// <summary>
        /// Draw shapes.
        /// </summary>
        Shape = (1 << 0),

        /// <summary>
        /// Draw joint connections.
        /// </summary>
        Joint = (1 << 1),

        /// <summary>
        /// Draw axis aligned bounding boxes.
        /// </summary>
        AABB = (1 << 2),

        /// <summary>
        /// Draw broad-phase pairs.
        /// </summary>
        Pair = (1 << 3),

        /// <summary>
        /// Draw center of mass frame.
        /// </summary>
        CenterOfMass = (1 << 4),

        /// <summary>
        /// Draw useful debug data such as timings and number of bodies, joints, contacts and more.
        /// </summary>
        DebugPanel = (1 << 5),

        /// <summary>
        /// Draw contact points between colliding bodies.
        /// </summary>
        ContactPoints = (1 << 6),

        /// <summary>
        /// Draw contact normals. Need ContactPoints to be enabled first.
        /// </summary>
        ContactNormals = (1 << 7),

        /// <summary>
        /// Draws the vertices of polygons
        /// </summary>
        PolygonPoints = (1 << 8),
    }

    /// Implement and register this class with a World to provide debug drawing of physics
    /// entities in your game.
    public abstract class DebugView
    {
        protected DebugView(World world)
        {
            World = world;
        }

        protected World World { get; private set; }

        /// <summary>
        /// Gets or sets the debug view flags.
        /// </summary>
        /// <value>The flags.</value>
        public DebugViewFlags Flags { get; set; }

        /// <summary>
        /// Append flags to the current flags.
        /// </summary>
        /// <param name="flags">The flags.</param>
        public void AppendFlags(DebugViewFlags flags)
        {
            Flags |= flags;
        }

        /// <summary>
        /// Remove flags from the current flags.
        /// </summary>
        /// <param name="flags">The flags.</param>
        public void RemoveFlags(DebugViewFlags flags)
        {
            Flags &= ~flags;
        }

        /// <summary>
        /// Draw a closed polygon provided in CCW order.
        /// </summary>
        /// <param name="vertices">The vertices.</param>
        /// <param name="count">The vertex count.</param>
        /// <param name="red">The red value.</param>
        /// <param name="blue">The blue value.</param>
        /// <param name="green">The green value.</param>
        public abstract void DrawPolygon(Vector2[] vertices, int count, float red, float blue, float green);

        /// <summary>
        /// Draw a solid closed polygon provided in CCW order.
        /// </summary>
        /// <param name="vertices">The vertices.</param>
        /// <param name="count">The vertex count.</param>
        /// <param name="red">The red value.</param>
        /// <param name="blue">The blue value.</param>
        /// <param name="green">The green value.</param>
        public abstract void DrawSolidPolygon(Vector2[] vertices, int count, float red, float blue, float green);

        /// <summary>
        /// Draw a circle.
        /// </summary>
        /// <param name="center">The center.</param>
        /// <param name="radius">The radius.</param>
        /// <param name="red">The red value.</param>
        /// <param name="blue">The blue value.</param>
        /// <param name="green">The green value.</param>
        public abstract void DrawCircle(Vector2 center, float radius, float red, float blue, float green);

        /// <summary>
        /// Draw a solid circle.
        /// </summary>
        /// <param name="center">The center.</param>
        /// <param name="radius">The radius.</param>
        /// <param name="axis">The axis.</param>
        /// <param name="red">The red value.</param>
        /// <param name="blue">The blue value.</param>
        /// <param name="green">The green value.</param>
        public abstract void DrawSolidCircle(Vector2 center, float radius, Vector2 axis, float red, float blue,
                                             float green);

        /// <summary>
        /// Draw a line segment.
        /// </summary>
        /// <param name="start">The start.</param>
        /// <param name="end">The end.</param>
        /// <param name="red">The red value.</param>
        /// <param name="blue">The blue value.</param>
        /// <param name="green">The green value.</param>
        public abstract void DrawSegment(Vector2 start, Vector2 end, float red, float blue, float green);

        /// <summary>
        /// Draw a transform. Choose your own length scale.
        /// </summary>
        /// <param name="transform">The transform.</param>
        public abstract void DrawTransform(ref Transform transform);
    }
}