-added slider constraint, bugfixed object removal

include/irrDynamics.h

@@ -66,6 +66,14 @@ class irrDynamics
       * \param pivotInB A position relative to nodeB where the hinge relation will be placed.
       * \return True, when both nodes were found in the physics representation and the relation was created.*/
     static bool createPoint2PointConstraint(irr::scene::ISceneNode* nodeA, irr::scene::ISceneNode* nodeB, const irr::core::vector3df& pivotInA, const irr::core::vector3df& pivotInB);
+    //! Create a slider relation between two objects
+    /** The slider constraint allows a rigid body to rotate around and translate along an axis. This
+      * method uses to the two nodes' current rotation to compute this axis.
+      * \note Both scene nodes have to be already added to the sim.
+      * \param nodeA The "parent" node the constraint is computed from.
+      * \param nodeB The child element that will be animated by that relation.
+      * \return True, when both nodes were found in the physics representation and the relation was created.*/
+    static bool createSliderConstraint(irr::scene::ISceneNode* nodeA, irr::scene::ISceneNode* nodeB, const irr::core::vector3df& posInA, const irr::core::vector3df& rotInA, const irr::core::vector3df& posInB, const irr::core::vector3df& rotInB);
     //! Remove an object from the physics
     /** Call this whenever you either remove the corresponding scene node from the ISceneManager or you don't want
       * to have it animated by the physics anymore.

src/irrDynamics.cpp

@@ -136,7 +136,7 @@ void irrDynamics::removeObject(scene::ISceneNode* node)
 {
     irrDynamics* inst = getInstance();
     std::map<scene::ISceneNode*, btRigidBody*>::iterator iter = inst->objects.find(node);
-    if (iter == inst->objects.end())
+    if (iter != inst->objects.end())
     {
         inst->world->removeRigidBody(iter->second);
 
@@ -288,6 +288,54 @@ bool irrDynamics::createPoint2PointConstraint(scene::ISceneNode* nodeA, scene::I
     return true;
 }
 
+bool irrDynamics::createSliderConstraint(scene::ISceneNode* nodeA,
+                                         scene::ISceneNode* nodeB,
+                                         const core::vector3df& posInA,
+                                         const core::vector3df& rotInA,
+                                         const core::vector3df& posInB,
+                                         const core::vector3df& rotInB)
+{
+    irrDynamics* inst = getInstance();
+    //find the corresponding rigid bodies:
+    std::map<scene::ISceneNode*, btRigidBody*>::iterator iterA, iterB;
+    iterA = inst->objects.find(nodeA);
+    iterB = inst->objects.find(nodeB);
+
+    if (iterA == inst->objects.end())
+    {
+        printf("irrdynamics: Unable to find first node for constraint!\n");
+        return false;
+    }
+
+    if (iterB == inst->objects.end())
+    {
+        printf("irrdynamics: Unable to find second node for constraint!\n");
+        return false;
+    }
+
+    btTransform matA, matB;
+    core::vector3df rotationRadians = rotInA;
+    rotationRadians *= core::DEGTORAD;
+    core::quaternion rotA(rotationRadians);
+
+    rotationRadians = rotInB;
+    rotationRadians *= core::DEGTORAD;
+    core::quaternion rotB(rotationRadians);
+
+    matA.setIdentity();
+    matA.setOrigin(btVector3(posInA.X, posInA.Y, posInA.Z));
+    matA.setRotation(btQuaternion(rotA.X, rotA.Y, rotA.Z, rotA.W));
+
+    matB.setIdentity();
+    matB.setOrigin(btVector3(posInB.X, posInB.Y, posInB.Z));
+    matB.setRotation(btQuaternion(rotB.X, rotB.Y, rotB.Z, rotB.W));
+
+
+    btSliderConstraint* constraint = new btSliderConstraint(*(iterA->second), *(iterB->second), matA, matB, true);
+    inst->world->addConstraint(constraint);
+    return true;
+}
+
 void irrDynamics::applyCentralForce(scene::ISceneNode* node, const core::vector3df& force)
 {
     irrDynamics* inst = getInstance();