Add initial prototype.

3-mid/physics/implement/box2d/contrib/include/box2d/b2_common.h

@@ -0,0 +1,138 @@
+// MIT License
+
+// Copyright (c) 2019 Erin Catto
+
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+#ifndef B2_COMMON_H
+#define B2_COMMON_H
+
+#include "b2_settings.h"
+
+#include <stddef.h>
+#include <assert.h>
+#include <float.h>
+
+#if !defined(NDEBUG)
+	#define b2DEBUG
+#endif
+
+#define B2_NOT_USED(x) ((void)(x))
+#define b2Assert(A) assert(A)
+
+#define	b2_maxFloat		FLT_MAX
+#define	b2_epsilon		FLT_EPSILON
+#define b2_pi			3.14159265359f
+
+/// @file
+/// Global tuning constants based on meters-kilograms-seconds (MKS) units.
+///
+
+// Collision
+
+/// The maximum number of contact points between two convex shapes. Do
+/// not change this value.
+#define b2_maxManifoldPoints	2
+
+/// This is used to fatten AABBs in the dynamic tree. This allows proxies
+/// to move by a small amount without triggering a tree adjustment.
+/// This is in meters.
+#define b2_aabbExtension		(0.1f * b2_lengthUnitsPerMeter)
+
+/// This is used to fatten AABBs in the dynamic tree. This is used to predict
+/// the future position based on the current displacement.
+/// This is a dimensionless multiplier.
+#define b2_aabbMultiplier		4.0f
+
+/// A small length used as a collision and constraint tolerance. Usually it is
+/// chosen to be numerically significant, but visually insignificant. In meters.
+#define b2_linearSlop			(0.005f * b2_lengthUnitsPerMeter)
+
+/// A small angle used as a collision and constraint tolerance. Usually it is
+/// chosen to be numerically significant, but visually insignificant.
+#define b2_angularSlop			(2.0f / 180.0f * b2_pi)
+
+/// The radius of the polygon/edge shape skin. This should not be modified. Making
+/// this smaller means polygons will have an insufficient buffer for continuous collision.
+/// Making it larger may create artifacts for vertex collision.
+#define b2_polygonRadius		(2.0f * b2_linearSlop)
+
+/// Maximum number of sub-steps per contact in continuous physics simulation.
+#define b2_maxSubSteps			8
+
+
+// Dynamics
+
+/// Maximum number of contacts to be handled to solve a TOI impact.
+#define b2_maxTOIContacts			32
+
+/// The maximum linear position correction used when solving constraints. This helps to
+/// prevent overshoot. Meters.
+#define b2_maxLinearCorrection		(0.2f * b2_lengthUnitsPerMeter)
+
+/// The maximum angular position correction used when solving constraints. This helps to
+/// prevent overshoot.
+#define b2_maxAngularCorrection		(8.0f / 180.0f * b2_pi)
+
+/// The maximum linear translation of a body per step. This limit is very large and is used
+/// to prevent numerical problems. You shouldn't need to adjust this. Meters.
+#define b2_maxTranslation			(2.0f * b2_lengthUnitsPerMeter)
+#define b2_maxTranslationSquared	(b2_maxTranslation * b2_maxTranslation)
+
+/// The maximum angular velocity of a body. This limit is very large and is used
+/// to prevent numerical problems. You shouldn't need to adjust this.
+#define b2_maxRotation				(0.5f * b2_pi)
+#define b2_maxRotationSquared		(b2_maxRotation * b2_maxRotation)
+
+/// This scale factor controls how fast overlap is resolved. Ideally this would be 1 so
+/// that overlap is removed in one time step. However using values close to 1 often lead
+/// to overshoot.
+#define b2_baumgarte				0.2f
+#define b2_toiBaumgarte				0.75f
+
+
+// Sleep
+
+/// The time that a body must be still before it will go to sleep.
+#define b2_timeToSleep				0.5f
+
+/// A body cannot sleep if its linear velocity is above this tolerance.
+#define b2_linearSleepTolerance		(0.01f * b2_lengthUnitsPerMeter)
+
+/// A body cannot sleep if its angular velocity is above this tolerance.
+#define b2_angularSleepTolerance	(2.0f / 180.0f * b2_pi)
+
+/// Dump to a file. Only one dump file allowed at a time.
+void b2OpenDump(const char* fileName);
+void b2Dump(const char* string, ...);
+void b2CloseDump();
+
+/// Version numbering scheme.
+/// See http://en.wikipedia.org/wiki/Software_versioning
+struct b2Version
+{
+	int32 major;		///< significant changes
+	int32 minor;		///< incremental changes
+	int32 revision;		///< bug fixes
+};
+
+/// Current version.
+extern B2_API b2Version b2_version;
+
+#endif