// A basic OpenGL program. // Displays a wireframe house, viewed along the z axis. import java.awt.*; import java.awt.event.*; import com.hermetica.magician.*; import geometry.*; public class TeaPotLid extends Frame implements GLEventListener { static int subdivision = 5; // init number of subdivisions static int mode = 2; // 1: Shaded 2: Wireframe static boolean control = false; // if the control poits should be displayed float[][] vertices = { {0,0,3.15f}, {0.8f,0,3.15f}, {0.8f,-0.45f,3.15f}, {0.45f,-0.8f,3.15f}, {0,-0.8f,3.15f}, {0,0,2.85f}, {0.2f,0,2.7f}, {0.2f,-0.112f,2.7f}, {0.112f,-0.2f,2.7f}, {0,-0.2f,2.7f}, {0.4f,0,2.55f}, {0.4f,-0.224f,2.55f}, {0.224f,-0.4f,2.55f}, {0,-0.4f,2.55f}, {1.3f,0,2.55f}, {1.3f,-0.728f,2.55f}, {0.728f,-1.3f,2.55f}, {0,-1.3f,2.55f}, {1.3f,0,2.4f}, {1.3f,-0.728f,2.4f}, {0.728f,-1.3f,2.4f}, {0,-1.3f,2.4f} }; int[][] patch1 = {{1,1,1,1},{2,3,4,5},{6,6,6,6},{7,8,9,10}}; int[][] patch2 = {{7,8,9,10},{11,12,13,14},{15,16,17,18},{19,20,21,22}}; private CoreGL gl_ = new CoreGL(); private CoreGLU glu_ = new CoreGLU(); private GLComponent glc = null; private Trackball trackball; private WindowListener quitOnClose = new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }; public static void main( String argv[] ) { new TeaPotLid(); } public TeaPotLid() { super("Teapot Lid"); glc = (GLComponent) GLDrawableFactory.createGLComponent(400,400); /* setLayout(new FlowLayout()); Checkbox controlPointsDisplay = new Checkbox ("Display Control Points", true); add(controlPointsDisplay); controlPointsDisplay.addItemListener(this); */ trackball = new Trackball(glc); add( glc ); addWindowListener(quitOnClose); pack(); show(); glc.addGLEventListener( this ); glc.initialize(); } // The remaining four methods ... // ... implement the GLEventListener interface public void reshape( GLDrawable component, int x, int y, int width, int height ) { // Called at start, and whenever user resizes component int size = Math.min(width, height); gl_.glViewport(component, x, y, size, size); gl_.glLoadIdentity(); if (width <= height) { glu_.gluOrtho2D(0.0,30.0,0.0,30.0*height/width); } else glu_.gluOrtho2D(0.0,30.0*height/width,0.0,30.0); gl_.glMatrixMode(GL.GL_MODELVIEW); } // compute the b(i or j) from s or t private float B(int i, float x){ switch (i) { case 1 : return (1-x)*(1-x)*(1-x); case 2 : return 3*x*(1-x)*(1-x); case 3 : return 3*x*x*(1-x); case 4 : return x*x*x; default: { System.out.println("Failure in computation of B."); return 0.0f; } } } // compute the b'(i of j) from s or t private float Bprime(int i, float x){ switch (i) { case 1: return -3*(x-1)*(x-1); case 2: return 3*(x-1)*(3*x-1); case 3: return 3*x*(2-3*x); case 4: return 3*x*x; default: { System.out.println("Failure in computation of B'."); return 0.0f; } } } // derive a point's position using the tensor product form private Vector3f pst(int[][] patch, float s, float t) { Vector3f result = new Vector3f(0,0,0); for (int i=1; i<5; i++) { for (int j=1; j<5; j++) { result.addScaled((B(i,s)*B(j,t)),new Vector3f (vertices[patch[i-1][j-1]-1])); } } return result; } // derive a point's normal via the cross product of the derivatives in s and t directions // (must be nug inside, the output is not satisfactory) private Vector3f getNormal(int[][] patch, float s, float t) { Vector3f result = new Vector3f(0,0,0); Vector3f temp1 = new Vector3f(0,0,0); Vector3f temp2 = new Vector3f(0,0,0); for (int i=1; i<5; i++) { for (int j=1; j<5; j++) { System.out.println("i: " + i + " j: " + j); temp1.addScaled((Bprime(i,s)*B(j,t)),new Vector3f (vertices[patch[i-1][j-1]-1])); System.out.println("Temp1: " + temp1.toString()); temp2.addScaled((B(i,s)*Bprime(j,t)),new Vector3f (vertices[patch[i-1][j-1]-1])); System.out.println("Temp2: " + temp2.toString()); temp1.normalise(); temp2.normalise(); result.add(temp2.cross(temp1)); // System.out.println("i: " + i + " j: " + j + " Normal: " + result.toString()); } } return result; } // precalc polygones for surface rendering private void subdivide(int subdivision, int vertexlist){ // compile a display list for the shaded lid gl_.glNewList(1,GL.GL_COMPILE); gl_.glColor3f(1.0f, 0.5f, 0.5f); System.out.println(subdivision); for (int subd_s = 0; subd_s < subdivision; subd_s++) { // for each subdivision in s do (first patch) gl_.glBegin(GL.GL_QUADS); // 'handier' than triangle_list or quad_strip: we don't need // to handle special cases. drawback: more computations for (int subd_t=0; subd_t < subdivision; subd_t++) { gl_.glNormal3fv(getNormal(patch1, ((1.0f/subdivision)*subd_t), (1.0f/subdivision)*(subd_s+1)).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*subd_t), (1.0f/subdivision)*(subd_s+1)).get3fv()); gl_.glNormal3fv(getNormal(patch1, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glNormal3fv(getNormal(patch1, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glNormal3fv(getNormal(patch1, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*(subd_s+1))).get3fv()); } gl_.glEnd(); } for (int subd_s = 0; subd_s < subdivision; subd_s++) { // for each subdivision in s do (second patch) gl_.glBegin(GL.GL_QUADS); for (int subd_t=0; subd_t < subdivision; subd_t++) { gl_.glNormal3fv(getNormal(patch2, ((1.0f/subdivision)*subd_t), (1.0f/subdivision)*(subd_s+1)).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glNormal3fv(getNormal(patch2, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glNormal3fv(getNormal(patch2, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glNormal3fv(getNormal(patch2, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*(subd_s+1))).get3fv()); } gl_.glEnd(); } gl_.glEndList(); // compile a display list for the line representation of the lid gl_.glNewList(2,GL.GL_COMPILE); gl_.glColor3f(0.0f, 0.5f, 0.5f); for (int subd_s = 0; subd_s < subdivision; subd_s++) { // for each subdivision in s do (first patch) gl_.glBegin(GL.GL_LINES); for (int subd_t=0; subd_t < subdivision; subd_t++) { gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glVertex3fv(pst(patch1, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*(subd_s+1))).get3fv()); } gl_.glEnd(); } for (int subd_s = 0; subd_s < subdivision; subd_s++) { // for each subdivision in s do (second patch) gl_.glBegin(GL.GL_LINES); for (int subd_t=0; subd_t < subdivision; subd_t++) { gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*subd_s)).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*(subd_t+1)), ((1.0f/subdivision)*(subd_s+1))).get3fv()); gl_.glVertex3fv(pst(patch2, ((1.0f/subdivision)*subd_t), ((1.0f/subdivision)*(subd_s+1))).get3fv()); } gl_.glEnd(); } gl_.glEndList(); // the control points' net gl_.glNewList(3,GL.GL_COMPILE); gl_.glColor3f(1.0f, 0.0f, 0.0f); for (int i = 0; i < patch1.length; i++) { gl_.glBegin(GL.GL_LINE_STRIP); for (int j = 0; j < patch1[i].length; j++) { gl_.glVertex3fv(vertices[patch1[i][j]-1]); } gl_.glEnd(); } for (int i = 0; i < patch1.length; i++) { gl_.glBegin(GL.GL_LINE_STRIP); for (int j = 0; j < patch1[i].length; j++) { gl_.glVertex3fv(vertices[patch1[j][i]-1]); } gl_.glEnd(); } for (int i = 0; i < patch1.length; i++) { gl_.glBegin(GL.GL_LINE_STRIP); for (int j = 0; j < patch2[i].length; j++) { gl_.glVertex3fv(vertices[patch2[i][j]-1]); } gl_.glEnd(); } for (int i = 0; i < patch1.length; i++) { gl_.glBegin(GL.GL_LINE_STRIP); for (int j = 0; j < patch2[i].length; j++) { gl_.glVertex3fv(vertices[patch2[j][i]-1]); } gl_.glEnd(); } gl_.glEndList(); } // Called as a side-effect of the glc.initialize() call public void initialize( GLDrawable component ) { gl_.glShadeModel(GL.GL_SMOOTH); // general render mode int vertexlist = gl_.genLists(3); // allocato space for display lists subdivide(subdivision, vertexlist); // do the precalcullation for the meshes } public void display( GLDrawable component ) { // Display the 3D scene. // Called whenever component is painted. gl_.glClearColor(0f,0f,0.45f,0f); gl_.glMatrixMode ( GL.GL_PROJECTION ); gl_.glLoadIdentity(); gl_.glOrtho(-2,2,-2,2,-3,3); gl_.glMatrixMode( GL.GL_MODELVIEW ); gl_.glLoadIdentity(); gl_.glMultMatrixf(trackball.getGLRotation()); gl_.glTranslatef(-0.5f,-0.5f,-1); gl_.glClear(GL.GL_COLOR_BUFFER_BIT); gl_.glCallList(mode); if (control==true) gl_.glCallList(3); gl_.glRotatef(90.0f,0.0f,0f,1.0f); gl_.glCallList(mode); if (control==true) gl_.glCallList(3); gl_.glRotatef(90.0f,0.0f,0f,1.0f); gl_.glCallList(mode); if (control==true) gl_.glCallList(3); gl_.glRotatef(90.0f,0.0f,0,1.0f); gl_.glCallList(mode); if (control==true) gl_.glCallList(3); gl_.glFlush(); } public GL getGL() { // Return a GL object[for use by Magician code] return gl_; } } class Trackball implements MouseListener, MouseMotionListener { // Implements a virtual trackball. private Component component; // Thing to repaint after each rotation private Vector3f v0, v1; // Vectors from centre of trackball Transformation totalRotation = new Transformation(); // Identity Trackball(Component component) { this.component = component; component.addMouseListener(this); component.addMouseMotionListener(this); } float[] getGLRotation() { return totalRotation.getGLMatrix(); } // Now the code to handle the Mouse actions, i.e. the virtual trackball. // Have to implement both MouseListener and MouseMotionListener public void mousePressed(MouseEvent e) { // Save the vector from the trackball centre to the start point of the // drag (i.e. where the mouse is clicked) in instance variable v0 v0 = makeTrackballVector(e); } public void mouseDragged(MouseEvent e) { Vector3f v1 = makeTrackballVector(e); Vector3f axis = v0.cross(v1); if (axis.length() > 1.0e-5f) { // Ignore negligible drags axis = axis.normalised(); float degrees = (float) (Math.acos(v0.dot(v1)) * 180 / Math.PI); totalRotation.multiplyOnLeft(Transformation.rotation(degrees, axis)); component.repaint(); } v0 = v1; } Vector3f makeTrackballVector(MouseEvent e) { Point p = e.getPoint(); Dimension dim = e.getComponent().getSize(); int width = dim.width; int height = dim.height; float x = ( 2 * p.x - width ) / (float) width; float y = ( height - 2 * p.y ) / (float) height; float tmp = 1 - x*x - y*y; float z = tmp < 0 ? 0 : (float) Math.sqrt(tmp); return new Vector3f(x, y, z).normalised(); } // Other methods of MouseListener, MouseMotionListener are empty public void mouseReleased(MouseEvent e) {} public void mouseClicked(MouseEvent e) {} public void mouseMoved(MouseEvent e) {} public void mouseEntered(MouseEvent e) {} public void mouseExited(MouseEvent e) {} };