Knob Class for Web-Based 3D Experiment - Interactive Web-Based Virtual Reality with Java 3D - page 351

int knobFaceStripCount[] = new int[1]; // per knob vertex count
int knobVertexCount; // #(vertices) for knob

int knobStripCount[] = new int[1]; // #(vertices) in strip/strip

// Front facing normals for the knob's faces
Vector3f frontNormal = new Vector3f(0.0f, 0.0f, 1.0f);
Vector3f outNormal = new Vector3f(1.0f, 0.0f, 0.0f);

// Temporary variables for storing coordinates and vectors
Point3f coordinate = new Point3f(0.0f, 0.0f, 0.0f);
Shape3D newShape;

// The angle subtended by a single segment
double segmentAngle = 2.0 * Math.PI/segmentCount;
double tempAngle;

this.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);

// Construct the knob's front and rear face
knobFaceVertexCount = segmentCount + 2;
knobFaceStripCount[0] = knobFaceVertexCount;

TriangleFanArray frontKnobFace = new TriangleFanArray(knobFaceVertexCount,
GeometryArray.COORDINATES | GeometryArray.NORMALS, knobFaceStripCount);

coordinate.set(0.0f, 0.0f, frontZ);
frontKnobFace.setCoordinate(0, coordinate);
frontKnobFace.setNormal(0, frontNormal);

for(int index = 1; index < segmentCount+2; index++)
{
tempAngle = segmentAngle * (double)index;
coordinate.set(radius * (float)Math.cos(tempAngle), radius * (float)Math.sin(tempAngle), frontZ);
frontKnobFace.setCoordinate(index, coordinate);
frontKnobFace.setNormal(index, frontNormal);
}
TexCoordGeneration tcg = new TexCoordGeneration(TexCoordGeneration.OBJECT_LINEAR,
TexCoordGeneration.TEXTURE_COORDINATE_2);
frontfacelook.setTexCoordGeneration(tcg);
frontfacelook.setTexture(texture);
newShape = new Shape3D(frontKnobFace, frontfacelook);
PickTool.setCapabilities(newShape, PickTool.INTERSECT_FULL);
this.addChild(newShape);
// Construct knob's outer skin (the cylinder body)
knobVertexCount = 2 * segmentCount + 2;
knobStripCount[0] = knobVertexCount;

TriangleStripArray outerknobFace = new TriangleStripArray(knobVertexCount,
GeometryArray.COORDINATES|GeometryArray.NORMALS, knobStripCount);
outNormal.set(1.0f, 0.0f, 0.0f);