Examples with ShapeHull com.bulletphysics.collision.shapes.ShapeHull used on opensource projects

Example 1 with ShapeHull

use of com.bulletphysics.collision.shapes.ShapeHull in project jmonkeyengine by jMonkeyEngine.

the class BufferedTriangleCallback method getVertices.

/**
     *  Processes the given convex shape to retrieve a correctly ordered FloatBuffer to
     *  construct the shape from with a TriMesh.
     *
     * @param convexShape the shape to retreieve the vertices from.
     * @return the vertices as a FloatBuffer, ordered as Triangles.
     */
private static FloatBuffer getVertices(ConvexShape convexShape) {
    // Check there is a hull shape to render
    if (convexShape.getUserPointer() == null) {
        // create a hull approximation
        ShapeHull hull = new ShapeHull(convexShape);
        float margin = convexShape.getMargin();
        hull.buildHull(margin);
        convexShape.setUserPointer(hull);
    }
    // Assert state - should have a pointer to a hull (shape) that'll be drawn
    assert convexShape.getUserPointer() != null : "Should have a shape for the userPointer, instead got null";
    ShapeHull hull = (ShapeHull) convexShape.getUserPointer();
    // Assert we actually have a shape to render
    assert hull.numTriangles() > 0 : "Expecting the Hull shape to have triangles";
    int numberOfTriangles = hull.numTriangles();
    // The number of bytes needed is: (floats in a vertex) * (vertices in a triangle) * (# of triangles) * (size of float in bytes)
    final int numberOfFloats = 3 * 3 * numberOfTriangles;
    FloatBuffer vertices = BufferUtils.createFloatBuffer(numberOfFloats);
    // Force the limit, set the cap - most number of floats we will use the buffer for
    vertices.limit(numberOfFloats);
    // Loop variables
    final IntArrayList hullIndicies = hull.getIndexPointer();
    final List<Vector3f> hullVertices = hull.getVertexPointer();
    Vector3f vertexA, vertexB, vertexC;
    int index = 0;
    for (int i = 0; i < numberOfTriangles; i++) {
        // Grab the data for this triangle from the hull
        vertexA = hullVertices.get(hullIndicies.get(index++));
        vertexB = hullVertices.get(hullIndicies.get(index++));
        vertexC = hullVertices.get(hullIndicies.get(index++));
        // Put the verticies into the vertex buffer
        vertices.put(vertexA.x).put(vertexA.y).put(vertexA.z);
        vertices.put(vertexB.x).put(vertexB.y).put(vertexB.z);
        vertices.put(vertexC.x).put(vertexC.y).put(vertexC.z);
    }
    vertices.clear();
    return vertices;
}