source: 2014/30/MiskaK/The Reclaim/The Reclaim/Jypeli/FrictionLogic.cs @ 5555

Revision 5480, 4.8 KB checked in by anlakane, 6 years ago (diff)

Lisätty Reclaim versionhallintaan

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1#region MIT License
2/*
3 * Copyright (c) 2009 University of Jyväskylä, Department of Mathematical
4 * Information Technology.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24#endregion
25
26/*
27 * Authors: Tero Jäntti, Tomi Karppinen, Janne Nikkanen.
28 */
29
30using System;
31using AdvanceMath;
32using AdvanceMath.Geometry2D;
33using Physics2DDotNet;
34using Physics2DDotNet.PhysicsLogics;
35
36namespace Jypeli
37{
38    /// <summary>
39    /// Fysiikkalogiikkaluokka ylhäältä päin kuvattuihin peleihin, joissa tarvitaan kitkaa.
40    /// </summary>
41#if !XBOX && !WINDOWS_PHONE
42    [Serializable]
43#endif
44    internal sealed class FrictionLogic : PhysicsLogic
45    {
46        private TopDownPhysicsGame parent;
47
48        public FrictionLogic( TopDownPhysicsGame parent, Lifespan lifetime )
49            : base( lifetime )
50        {
51            this.parent = parent;
52        }
53
54        private bool Overlap( Body b, Body surface )
55        {
56            if ( !b.Shape.CanGetIntersection || !surface.Shape.CanGetIntersection )
57                return false;
58
59            Vector2D offset = b.State.Position.Linear - surface.State.Position.Linear;
60            IntersectionInfo ii;
61            var rect = surface.Rectangle;
62            double surfaceWidth = Math.Abs( rect.Max.X - rect.Min.X );
63            double surfaceHeight = Math.Abs( rect.Max.Y - rect.Min.Y );
64            double targetRadius = Math.Sqrt( Math.Pow( surfaceWidth, 2 ) + Math.Pow( surfaceHeight, 2 ) );
65
66            for ( int i = 0; i < b.Shape.Vertexes.Length; i++ )
67            {
68                Vector2D vec = b.Shape.Vertexes[i] + offset + Vector2D.FromLengthAndAngle( 10, b.Shape.Vertexes[i].Angle );
69
70                if ( surface.Shape.TryGetIntersection( vec, out ii ) )
71                    return true;
72            }
73
74            return false;
75        }
76
77        /// <summary>
78        /// Käyttää kitkalogiikkaa pelitilanteeseen.
79        /// </summary>
80        /// <param name="step">Aika viimeisestä päivityksestä.</param>
81        protected internal override void RunLogic( TimeStep step )
82        {
83            double surfaceFriction = parent.KineticFriction;
84            double gravityNormal = parent.Gravity;
85
86            foreach ( Body e in Bodies )
87            {
88                if ( e.IgnoresPhysicsLogics ) continue;
89                if ( !( e.Tag is PhysicsObject ) ) continue;
90
91                double frictionCoefficient = 0;
92                if ( Game.Instance is TopDownPhysicsGame )
93                    frictionCoefficient = ( (TopDownPhysicsGame)Game.Instance ).KineticFriction;
94
95                foreach ( var surface in parent.Surfaces )
96                {
97                    if ( surface.Body == e )
98                        continue;
99
100                    if ( Overlap( e, surface.Body ) )
101                    {
102                        // Use the object's friction
103                        frictionCoefficient = Math.Sqrt( surface.KineticFriction * e.Coefficients.DynamicFriction );
104
105                        // TODO: Instead of stopping on the first surface found, look for
106                        // the surface with highest Z value.
107                        break;
108                    }
109                    else
110                    {
111                        // Use the global friction
112                        frictionCoefficient = Math.Sqrt( surfaceFriction * e.Coefficients.DynamicFriction );
113                    }
114                }
115
116                float friction = (float)( frictionCoefficient * gravityNormal * e.Mass.MassInv * step.Dt );
117                if ( e.State.Velocity.Linear.Magnitude <= friction )
118                    e.State.Velocity.Linear = Vector2D.Zero;
119                else
120                    e.State.Velocity.Linear.Magnitude -= friction;
121            }
122        }
123    }
124}
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