Add chipmunk source code

And upgrade it to 7.0.2

thirdparty/src/chipmunk/cpRotaryLimitJoint.c

@@ -0,0 +1,160 @@
+/* Copyright (c) 2013 Scott Lembcke and Howling Moon Software
+ * 
+ * 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.
+ */
+
+#include "chipmunk/chipmunk_private.h"
+
+static void
+preStep(cpRotaryLimitJoint *joint, cpFloat dt)
+{
+	cpBody *a = joint->constraint.a;
+	cpBody *b = joint->constraint.b;
+	
+	cpFloat dist = b->a - a->a;
+	cpFloat pdist = 0.0f;
+	if(dist > joint->max) {
+		pdist = joint->max - dist;
+	} else if(dist < joint->min) {
+		pdist = joint->min - dist;
+	}
+	
+	// calculate moment of inertia coefficient.
+	joint->iSum = 1.0f/(a->i_inv + b->i_inv);
+	
+	// calculate bias velocity
+	cpFloat maxBias = joint->constraint.maxBias;
+	joint->bias = cpfclamp(-bias_coef(joint->constraint.errorBias, dt)*pdist/dt, -maxBias, maxBias);
+
+	// If the bias is 0, the joint is not at a limit. Reset the impulse.
+	if(!joint->bias) joint->jAcc = 0.0f;
+}
+
+static void
+applyCachedImpulse(cpRotaryLimitJoint *joint, cpFloat dt_coef)
+{
+	cpBody *a = joint->constraint.a;
+	cpBody *b = joint->constraint.b;
+	
+	cpFloat j = joint->jAcc*dt_coef;
+	a->w -= j*a->i_inv;
+	b->w += j*b->i_inv;
+}
+
+static void
+applyImpulse(cpRotaryLimitJoint *joint, cpFloat dt)
+{
+	if(!joint->bias) return; // early exit
+
+	cpBody *a = joint->constraint.a;
+	cpBody *b = joint->constraint.b;
+	
+	// compute relative rotational velocity
+	cpFloat wr = b->w - a->w;
+	
+	cpFloat jMax = joint->constraint.maxForce*dt;
+	
+	// compute normal impulse	
+	cpFloat j = -(joint->bias + wr)*joint->iSum;
+	cpFloat jOld = joint->jAcc;
+	if(joint->bias < 0.0f){
+		joint->jAcc = cpfclamp(jOld + j, 0.0f, jMax);
+	} else {
+		joint->jAcc = cpfclamp(jOld + j, -jMax, 0.0f);
+	}
+	j = joint->jAcc - jOld;
+	
+	// apply impulse
+	a->w -= j*a->i_inv;
+	b->w += j*b->i_inv;
+}
+
+static cpFloat
+getImpulse(cpRotaryLimitJoint *joint)
+{
+	return cpfabs(joint->jAcc);
+}
+
+static const cpConstraintClass klass = {
+	(cpConstraintPreStepImpl)preStep,
+	(cpConstraintApplyCachedImpulseImpl)applyCachedImpulse,
+	(cpConstraintApplyImpulseImpl)applyImpulse,
+	(cpConstraintGetImpulseImpl)getImpulse,
+};
+
+cpRotaryLimitJoint *
+cpRotaryLimitJointAlloc(void)
+{
+	return (cpRotaryLimitJoint *)cpcalloc(1, sizeof(cpRotaryLimitJoint));
+}
+
+cpRotaryLimitJoint *
+cpRotaryLimitJointInit(cpRotaryLimitJoint *joint, cpBody *a, cpBody *b, cpFloat min, cpFloat max)
+{
+	cpConstraintInit((cpConstraint *)joint, &klass, a, b);
+	
+	joint->min = min;
+	joint->max  = max;
+	
+	joint->jAcc = 0.0f;
+	
+	return joint;
+}
+
+cpConstraint *
+cpRotaryLimitJointNew(cpBody *a, cpBody *b, cpFloat min, cpFloat max)
+{
+	return (cpConstraint *)cpRotaryLimitJointInit(cpRotaryLimitJointAlloc(), a, b, min, max);
+}
+
+cpBool
+cpConstraintIsRotaryLimitJoint(const cpConstraint *constraint)
+{
+	return (constraint->klass == &klass);
+}
+
+cpFloat
+cpRotaryLimitJointGetMin(const cpConstraint *constraint)
+{
+	cpAssertHard(cpConstraintIsRotaryLimitJoint(constraint), "Constraint is not a rotary limit joint.");
+	return ((cpRotaryLimitJoint *)constraint)->min;
+}
+
+void
+cpRotaryLimitJointSetMin(cpConstraint *constraint, cpFloat min)
+{
+	cpAssertHard(cpConstraintIsRotaryLimitJoint(constraint), "Constraint is not a rotary limit joint.");
+	cpConstraintActivateBodies(constraint);
+	((cpRotaryLimitJoint *)constraint)->min = min;
+}
+
+cpFloat
+cpRotaryLimitJointGetMax(const cpConstraint *constraint)
+{
+	cpAssertHard(cpConstraintIsRotaryLimitJoint(constraint), "Constraint is not a rotary limit joint.");
+	return ((cpRotaryLimitJoint *)constraint)->max;
+}
+
+void
+cpRotaryLimitJointSetMax(cpConstraint *constraint, cpFloat max)
+{
+	cpAssertHard(cpConstraintIsRotaryLimitJoint(constraint), "Constraint is not a rotary limit joint.");
+	cpConstraintActivateBodies(constraint);
+	((cpRotaryLimitJoint *)constraint)->max = max;
+}