Babylon.js/src/Physics/Plugins/babylon.oimoJSPlugin.ts

module BABYLON {
    declare var OIMO;

    export class OimoJSPlugin implements IPhysicsEnginePlugin {
        private _world;
        private _registeredMeshes = [];

        private _checkWithEpsilon(value: number): number {
            return value < PhysicsEngine.Epsilon ? PhysicsEngine.Epsilon : value;
        }

        public initialize(iterations?: number): void {
            this._world = new OIMO.World();
            this._world.clear();
        }

        public setGravity(gravity: Vector3): void {
            this._world.gravity = gravity;
        }

        public registerMesh(mesh: AbstractMesh, impostor: number, options: PhysicsBodyCreationOptions): any {
            this.unregisterMesh(mesh);
            
            if (!mesh.rotationQuaternion) {
                mesh.rotationQuaternion = Quaternion.RotationYawPitchRoll(mesh.rotation.y, mesh.rotation.x, mesh.rotation.z);
            }
            
            mesh.computeWorldMatrix(true);

            var bbox = mesh.getBoundingInfo().boundingBox;

            // The delta between the mesh position and the mesh bounding box center
            var deltaPosition = mesh.position.subtract(bbox.center);
            
            //calculate rotation to fit Oimo's needs (Euler...)
            var rot = OIMO.MatrixToEuler(mesh.getWorldMatrix().asArray());

            var bodyConfig : any = {
                pos: [bbox.center.x, bbox.center.y, bbox.center.z],
                rot: rot,
                move: options.mass != 0,
                config: [options.mass, options.friction, options.restitution],
                world: this._world
            };

            // register mesh
            switch (impostor) {
                case PhysicsEngine.SphereImpostor:
                    var radiusX = bbox.maximumWorld.x - bbox.minimumWorld.x;
                    var radiusY = bbox.maximumWorld.y - bbox.minimumWorld.y;
                    var radiusZ = bbox.maximumWorld.z - bbox.minimumWorld.z;

                    var size = Math.max(
                        this._checkWithEpsilon(radiusX),
                        this._checkWithEpsilon(radiusY),
                        this._checkWithEpsilon(radiusZ)) / 2;

                    bodyConfig.type = 'sphere';
                    bodyConfig.size = [size];
                    break;

                case PhysicsEngine.PlaneImpostor:
                //Oimo "fakes" a cylinder as a box, so why don't we!
                case PhysicsEngine.CylinderImpostor:
                case PhysicsEngine.BoxImpostor:

                    var min = bbox.minimumWorld;
                    var max = bbox.maximumWorld;
                    var box = max.subtract(min);
                    var sizeX = this._checkWithEpsilon(box.x);
                    var sizeY = this._checkWithEpsilon(box.y);
                    var sizeZ = this._checkWithEpsilon(box.z);

                    bodyConfig.type = 'box';
                    bodyConfig.size = [sizeX, sizeY, sizeZ];
                    break;
            }
            
            var body = new OIMO.Body(bodyConfig);

            //We have to access the rigid body's properties to set the quaternion. 
            //The setQuaternion function of Oimo only sets the newOrientation that is only set after an impulse is given or a collision.
            //body.body.orientation = new OIMO.Quat(mesh.rotationQuaternion.w, mesh.rotationQuaternion.x, mesh.rotationQuaternion.y, mesh.rotationQuaternion.z);
            //TEST
            //body.body.resetQuaternion(new OIMO.Quat(mesh.rotationQuaternion.w, mesh.rotationQuaternion.x, mesh.rotationQuaternion.y, mesh.rotationQuaternion.z));
            //update the internal rotation matrix
            //body.body.syncShapes();
            
            this._registeredMeshes.push({
                mesh: mesh,
                body: body,
                delta: deltaPosition
            });

            return body;
        }

        public registerMeshesAsCompound(parts: PhysicsCompoundBodyPart[], options: PhysicsBodyCreationOptions): any {
            var types = [],
                sizes = [],
                positions = [],
                rotations = [];

            var initialMesh = parts[0].mesh;

            for (var index = 0; index < parts.length; index++) {
                var part = parts[index];
                var bodyParameters = this._createBodyAsCompound(part, options, initialMesh);
                types.push(bodyParameters.type);
                sizes.push.apply(sizes, bodyParameters.size);
                positions.push.apply(positions, bodyParameters.pos);
                //Hack for Oimo's rotation. Quaternion will be used later.
                rotations.push.apply(rotations, bodyParameters.rot);
            }

            var body = new OIMO.Body({
                type: types,
                size: sizes,
                pos: positions,
                rot: rotations,
                move: options.mass != 0,
                config: [options.mass, options.friction, options.restitution],
                world: this._world
            });
            
            
            this._registeredMeshes.push({
                mesh: initialMesh,
                body: body
            });

            return body;
        }

        private _createBodyAsCompound(part: PhysicsCompoundBodyPart, options: PhysicsBodyCreationOptions, initialMesh: AbstractMesh): any {
            var mesh = part.mesh;
            // We need the bounding box/sphere info to compute the physics body
            mesh.computeWorldMatrix();

            var rot = OIMO.MatrixToEuler(mesh.getWorldMatrix().asArray());
            
            var bodyParameters : any = {
                pos: [mesh.position.x, mesh.position.y, mesh.position.z],
                rot: rot
            };
            
            switch (part.impostor) {
                case PhysicsEngine.SphereImpostor:
                    var bbox = mesh.getBoundingInfo().boundingBox;
                    var radiusX = bbox.maximumWorld.x - bbox.minimumWorld.x;
                    var radiusY = bbox.maximumWorld.y - bbox.minimumWorld.y;
                    var radiusZ = bbox.maximumWorld.z - bbox.minimumWorld.z;

                    var size = Math.max(
                        this._checkWithEpsilon(radiusX),
                        this._checkWithEpsilon(radiusY),
                        this._checkWithEpsilon(radiusZ)) / 2;
                    
                    bodyParameters.type = 'sphere';
                    bodyParameters.size = [size, size, size];
                    
                    break;

                case PhysicsEngine.PlaneImpostor:
                case PhysicsEngine.CylinderImpostor:
                case PhysicsEngine.BoxImpostor:
                    bbox = mesh.getBoundingInfo().boundingBox;
                    var min = bbox.minimumWorld;
                    var max = bbox.maximumWorld;
                    var box = max.subtract(min);
                    var sizeX = this._checkWithEpsilon(box.x);
                    var sizeY = this._checkWithEpsilon(box.y);
                    var sizeZ = this._checkWithEpsilon(box.z);
                    
                    bodyParameters.type = 'sphere';
                    bodyParameters.size = [sizeX, sizeY, sizeZ];
                    
                    break;
            }

            return bodyParameters;
        }

        public unregisterMesh(mesh: AbstractMesh): void {
            for (var index = 0; index < this._registeredMeshes.length; index++) {
                var registeredMesh = this._registeredMeshes[index];
                if (registeredMesh.mesh === mesh || registeredMesh.mesh === mesh.parent) {
                    if (registeredMesh.body) {
                        this._world.removeRigidBody(registeredMesh.body.body);
                        this._unbindBody(registeredMesh.body);
                    }
                    this._registeredMeshes.splice(index, 1);
                    return;
                }
            }
        }

        private _unbindBody(body: any): void {
            for (var index = 0; index < this._registeredMeshes.length; index++) {
                var registeredMesh = this._registeredMeshes[index];
                if (registeredMesh.body === body) {
                    registeredMesh.body = null;
                }
            }
        }

        /**
         * Update the body position according to the mesh position
         * @param mesh
         */
        public updateBodyPosition = function (mesh: AbstractMesh): void {

            for (var index = 0; index < this._registeredMeshes.length; index++) {
                var registeredMesh = this._registeredMeshes[index];
                if (registeredMesh.mesh === mesh || registeredMesh.mesh === mesh.parent) {
                    var body = registeredMesh.body.body;
                    mesh.computeWorldMatrix(true);

                    var center = mesh.getBoundingInfo().boundingBox.center;
                    body.setPosition(new OIMO.Vec3(center.x, center.y, center.z));
                    body.setQuaternion(mesh.rotationQuaternion);
                    body.sleeping = false;
                    return;
                }
                // Case where the parent has been updated
                if (registeredMesh.mesh.parent === mesh) {
                    mesh.computeWorldMatrix(true);
                    registeredMesh.mesh.computeWorldMatrix(true);

                    var absolutePosition = registeredMesh.mesh.getAbsolutePosition();

                    body = registeredMesh.body.body;
                    body.setPosition(new OIMO.Vec3(absolutePosition.x, absolutePosition.y, absolutePosition.z));
                    body.setQuaternion(mesh.rotationQuaternion);
                    body.sleeping = false;
                    return;
                }
            }
        }

        public applyImpulse(mesh: AbstractMesh, force: Vector3, contactPoint: Vector3): void {
            for (var index = 0; index < this._registeredMeshes.length; index++) {
                var registeredMesh = this._registeredMeshes[index];
                if (registeredMesh.mesh === mesh || registeredMesh.mesh === mesh.parent) {
                    // Get object mass to have a behaviour similar to cannon.js
                    var mass = registeredMesh.body.body.massInfo.mass;
                    // The force is scaled with the mass of object
                    registeredMesh.body.body.applyImpulse(contactPoint.scale(OIMO.INV_SCALE), force.scale(OIMO.INV_SCALE * mass));
                    return;
                }
            }
        }

        public createLink(mesh1: AbstractMesh, mesh2: AbstractMesh, pivot1: Vector3, pivot2: Vector3, options?: any): boolean {
            var body1 = null,
                body2 = null;
            for (var index = 0; index < this._registeredMeshes.length; index++) {
                var registeredMesh = this._registeredMeshes[index];
                if (registeredMesh.mesh === mesh1) {
                    body1 = registeredMesh.body.body;
                } else if (registeredMesh.mesh === mesh2) {
                    body2 = registeredMesh.body.body;
                }
            }
            if (!body1 || !body2) {
                return false;
            }
            if (!options) {
                options = {};
            }

            new OIMO.Link({
                type: options.type,
                body1: body1,
                body2: body2,
                min: options.min,
                max: options.max,
                axe1: options.axe1,
                axe2: options.axe2,
                pos1: [pivot1.x, pivot1.y, pivot1.z],
                pos2: [pivot2.x, pivot2.y, pivot2.z],
                collision: options.collision,
                spring: options.spring,
                world: this._world
            });

            return true;

        }

        public dispose(): void {
            this._world.clear();
            while (this._registeredMeshes.length) {
                this.unregisterMesh(this._registeredMeshes[0].mesh);
            }
        }

        public isSupported(): boolean {
            return OIMO !== undefined;
        }
        
        public getWorldObject() : any {
            return this._world;
        }

        private _getLastShape(body: any): any {
            var lastShape = body.shapes;
            while (lastShape.next) {
                lastShape = lastShape.next;
            }
            return lastShape;
        }

        public runOneStep(time: number): void {
            this._world.step();

            // Update the position of all registered meshes
            var i = this._registeredMeshes.length;
            var m;
            while (i--) {

                var body = this._registeredMeshes[i].body.body;
                var mesh = this._registeredMeshes[i].mesh;
                
                if(!this._registeredMeshes[i].delta) {
                    this._registeredMeshes[i].delta = Vector3.Zero();
                }

                if (!body.sleeping) {
                    //TODO check that
                    if (body.shapes.next) {
                        var parentShape = this._getLastShape(body);
                        mesh.position.x = parentShape.position.x * OIMO.WORLD_SCALE;
                        mesh.position.y = parentShape.position.y * OIMO.WORLD_SCALE;
                        mesh.position.z = parentShape.position.z * OIMO.WORLD_SCALE;
                    } else {
                        mesh.position.copyFrom(body.getPosition()).addInPlace(this._registeredMeshes[i].delta);
                        
                    }
                    mesh.rotationQuaternion.copyFrom(body.getQuaternion());
                    mesh.computeWorldMatrix();
                }
            }
        }
    }
}