The following program is modified from JOGL unit tests programs or sample programs.

/** * @author Zhikai Wang/www.heteroclinic.net * Science and technology promotion license applied (third party licenses automatically cascaded). * Non-commercial usage of this file is not limited (Zhikai Wang/www.heteroclinic.net's rights). * Commercial usage is allowed, given this file is not modified. Inheritance/overriding/re-factoring is suggested at higher level. * This is a good-will software. Users' liability always. * (c) Zhikai Wang/www.heteroclinic.net **/ package net.heteroclinic.examples; import java.awt.Frame; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import java.util.ArrayList; import java.util.List; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.Future; import javax.media.opengl.GLCapabilities; import javax.media.opengl.GLProfile; import javax.media.opengl.awt.GLCanvas; import net.heteroclinic.computergraphics.derivedfromopengl.derivedfromjogl.SmoothShadingRendererEventListener; import com.jogamp.opengl.util.FPSAnimator; public class SmoothShadingRenderer { public static final String static_graphics_path = "/home/graphics/Desktop/workspace/images"; static private List<Future<?>> fl = new ArrayList<Future<?>>(); static private ExecutorService exec = Executors.newCachedThreadPool(); public static void oncloseDoSomething () { exec.shutdown(); for (Future<?> f : fl) f.cancel(true); } public static void showThreadId(String arg) { System.out.println(arg + " Thread.currentThread().getId():" + Thread.currentThread().getId()); } public static String status_message = "Starting..."; //public static ThreadedServer foaken = null; public static void main(String[] args) { //DrawableCollection.getInstance().init(); GLProfile glp = GLProfile.getDefault(); GLCapabilities caps = new GLCapabilities(glp); GLCanvas canvas = new GLCanvas(caps); showThreadId("Main() "); Frame frame = new Frame("Jgts Demo 1.0 Smooth Rendering of GTS models"); frame.setSize(800, 800); frame.add(canvas); frame.setVisible(true); frame.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { oncloseDoSomething () ; System.exit(0); } }); canvas.addGLEventListener(new SmoothShadingRendererEventListener()); FPSAnimator animator = new FPSAnimator(canvas, 20); //animator.add(canvas); animator.start(); } }

The program will read and parse a mesh file, compute the scale to fit a model in a camera with fixed settings, compute the triangles' normals, then render the model with smooth shading.

For model bunny.gts, we would achieve the following:

From the code in (1) we will not see much typical OpenGL structure as most C/C++ programs have. (1) will call SmoothShadingRendererEventListener as the following. It is basically showing how Java JOGL provides an interface for the underlying libraries to talk to the graphical hardware.

/** * @author Zhikai Wang/www.heteroclinic.net * Science and technology promotion license applied (third party licenses automatically cascaded). * Non-commercial usage of this file is not limited (Zhikai Wang/www.heteroclinic.net's rights). * Commercial usage is allowed, given this file is not modified. Inheritance/overriding/re-factoring is suggested at higher level. * This is a good-will software. Users' liability always. * (c) Zhikai Wang/www.heteroclinic.net **/ package net.heteroclinic.computergraphics.derivedfromopengl.derivedfromjogl; import java.util.Calendar; import java.util.concurrent.atomic.AtomicLong; import javax.media.opengl.GL; import javax.media.opengl.GL2; import javax.media.opengl.GL2ES1; import javax.media.opengl.GLAutoDrawable; import javax.media.opengl.GLCapabilities; import javax.media.opengl.GLCapabilitiesImmutable; import javax.media.opengl.GLContext; import javax.media.opengl.GLDrawableFactory; import javax.media.opengl.GLEventListener; import javax.media.opengl.GLOffscreenAutoDrawable; import javax.media.opengl.GLProfile; import javax.media.opengl.fixedfunc.GLLightingFunc; import javax.media.opengl.fixedfunc.GLMatrixFunc; import javax.media.opengl.glu.GLU; import net.heteroclinic.bunny.Model; import net.heteroclinic.computergraphics.derivedfromopengl.UnlightedAxis; import net.heteroclinic.computergraphics.math.MathConstants; import net.heteroclinic.computergraphics.math.MathPoint3; import net.heteroclinic.computergraphics.math.MathVector3; import net.heteroclinic.computergraphics.math.glcomputable.SimpleGLCamera; import com.jogamp.newt.Window; import com.jogamp.newt.event.KeyAdapter; import com.jogamp.newt.event.KeyEvent; import com.jogamp.newt.event.KeyListener; import com.jogamp.newt.event.MouseAdapter; import com.jogamp.newt.event.MouseEvent; import com.jogamp.newt.event.MouseListener; import com.jogamp.newt.event.awt.AWTKeyAdapter; import com.jogamp.newt.event.awt.AWTMouseAdapter; import com.jogamp.opengl.util.GLReadBufferUtil; public class SmoothShadingRendererEventListener implements GLEventListener { public static boolean makeScreenShot = false; public static boolean alignObjectswithViewVector = false; public static boolean alignObjectswithViewVector_lastvalue = alignObjectswithViewVector; final GLProfile offscreen_glp; final GLCapabilities offscreen_caps; final GLDrawableFactory offscreen_factory; final GLOffscreenAutoDrawable.FBO offscreen_glad; int offscreen_width = 600; int offscreen_height = 400; GLContext offscreen_context; GLCapabilitiesImmutable offscreen_chosenCaps; final String fn = "bunny.gts"; Model model = new Model(); public SmoothShadingRendererEventListener() { offscreen_glp = GLProfile.getGL2ES2(); offscreen_caps = new GLCapabilities(offscreen_glp); offscreen_caps.setDoubleBuffered(false); offscreen_caps.setFBO(true); offscreen_factory = GLDrawableFactory.getFactory(offscreen_caps .getGLProfile()); offscreen_glad = (GLOffscreenAutoDrawable.FBO) offscreen_factory .createOffscreenAutoDrawable(null, offscreen_caps, null, offscreen_width, offscreen_height); offscreen_context = offscreen_glad.getContext(); offscreen_chosenCaps = offscreen_glad.getChosenGLCapabilities(); initModel (); } void initModel () { model.initFromFile(fn); model.OBJ_SIZE =10.0f; //model.print(); model.calculateScale(); model.offSet(); model.calculateTrianglesNormals(); } private GLU glu; //TODO align photos by view vector's project at X-Z plane SimpleGLCamera glcamera = new SimpleGLCamera ( new MathPoint3 (5.0f,10f,20f), new MathPoint3 (0f,0f,0f),1 ); // float orthoganal_clip_size2 = 10.0f; // float orthoganal_clip_size = 10.0f; // float eyex = 5.0f, eyey = 10.0f, eyez = 20f; // float lookatx = 0f, lookaty = 0f, lookatz = 0f; // float NEAR_Z = 1.0f; // float FAR_Z = 300.0f; KeyListener gearsKeys = new GearsKeyAdapter(); class GearsKeyAdapter extends KeyAdapter { public void keyPressed(KeyEvent e) { int kc = e.getKeyCode(); if (KeyEvent.VK_F5 == kc) { System.out.println("Print Screen to working directory."); SmoothShadingRendererEventListener.makeScreenShot = true; } if (KeyEvent.VK_F6 == kc) { SmoothShadingRendererEventListener.alignObjectswithViewVector = !SmoothShadingRendererEventListener.alignObjectswithViewVector; System.out.println("Align objects with view vector: "+ SmoothShadingRendererEventListener.alignObjectswithViewVector); } } } float scale = 1.0f; public void init(GLAutoDrawable drawable) { GL2 gl = drawable.getGL().getGL2(); glu = new GLU(); gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f); ((GLLightingFunc) gl).glShadeModel(GLLightingFunc.GL_SMOOTH); gl.glEnable(GL.GL_DEPTH_TEST); gl.glDisable(GL.GL_CULL_FACE); ((GL2) gl).glLightModeli(GL2.GL_LIGHT_MODEL_TWO_SIDE, GL.GL_TRUE); float ambient[] = { 0.2f, 0.2f, 0.2f, 1 }; float position[] = { 1.0f, 10.0f, 5.7f, 1 }; float intensity[] = { 1, 1, 1, 1 }; float specColor[] = { 1, 1, 1, 1 }; gl.glEnable(GLLightingFunc.GL_LIGHTING); ((GL2ES1) gl).glLightModelfv(GLLightingFunc.GL_AMBIENT, ambient, 0); gl.glEnable(GLLightingFunc.GL_LIGHT0); ((GLLightingFunc) gl).glLightfv(GLLightingFunc.GL_LIGHT0, GLLightingFunc.GL_POSITION, position, 0); ((GLLightingFunc) gl).glLightfv(GLLightingFunc.GL_LIGHT0, GLLightingFunc.GL_DIFFUSE, intensity, 0); ((GLLightingFunc) gl).glLightfv(GLLightingFunc.GL_LIGHT0, GLLightingFunc.GL_SPECULAR, specColor, 0); gl.glEnable(GLLightingFunc.GL_COLOR_MATERIAL); ((GL) gl).glClearColor(1.0f, 1.0f, 1.0f, 1.0f); MouseListener colorclickMouse = new ColorClickMouseAdapter(); if (drawable instanceof Window) { //System.out.println("drawable instanceof Window "); Window window = (Window) drawable; window.addMouseListener(colorclickMouse); window.addKeyListener(gearsKeys); } else if (GLProfile.isAWTAvailable() && drawable instanceof java.awt.Component) { //System.out.println("NOT drawable instanceof Window "); java.awt.Component comp = (java.awt.Component) drawable; new AWTMouseAdapter(colorclickMouse, drawable).addTo(comp); new AWTKeyAdapter(gearsKeys, drawable).addTo(comp); } offscreen_glad.display(); // initial display incl. init! { offscreen_context = offscreen_glad.getContext(); // System.out.println("Context :"+context); } // offscreen_chosenCaps = offscreen_glad.getChosenGLCapabilities(); // offscreen_clickcolorGLEventListener = new ClickedColorGLEventListener(); // offscreen_glad.addGLEventListener(offscreen_clickcolorGLEventListener); // drawable.display(); drawable.getContext(); //TextureCollection.getInstance().init(); //TODO draw model here //TextureCollection.getInstance(); // hints_renderer = new TextRenderer(new Font("SansSerif", Font.BOLD, 16)); // // Rectangle2D hintsBounds = hints_renderer.getBounds(hints_string); // hints_renderer.setColor(0f, 0f, 0f, 1.0f); //// hints_width = (int) hintsBounds.getWidth(); //// hints_height = (int) hintsBounds.getHeight(); // //// for (int i = 0; i<1000; i++) { //// System.out.println(DrawableCollection.getInstance().getATitle()); //// } } // private int hints_width ; // private int hints_height; private MathPoint3 hints_position = new MathPoint3(25f,15f,0f); public void dispose(GLAutoDrawable drawable) { } public void display(GLAutoDrawable drawable) { // System.out.println("SecondpassFriendsTorusGLEventListener display tid="+Thread.currentThread().getId()); GL2 gl = drawable.getGL().getGL2(); if (GLProfile.isAWTAvailable() && (drawable instanceof javax.media.opengl.awt.GLJPanel) && !((javax.media.opengl.awt.GLJPanel) drawable).isOpaque() && ((javax.media.opengl.awt.GLJPanel) drawable) .shouldPreserveColorBufferIfTranslucent()) { gl.glClear(GL2.GL_DEPTH_BUFFER_BIT); } else { gl.glClear(GL2.GL_COLOR_BUFFER_BIT | GL2.GL_DEPTH_BUFFER_BIT); } gl.glClearColor(1.0f, 1.0f, 1.0f, 1.0f); gl.glEnable(GL.GL_DEPTH_TEST); gl.glDisable(GL.GL_CULL_FACE); gl.glShadeModel(GLLightingFunc.GL_SMOOTH); gl.glCullFace(GL.GL_FRONT); gl.glFrontFace(GL.GL_CCW); gl.glMatrixMode(GLMatrixFunc.GL_PROJECTION); gl.glLoadIdentity(); // gl.glOrtho(-orthoganal_clip_size, orthoganal_clip_size, // -orthoganal_clip_size2, orthoganal_clip_size2, NEAR_Z, FAR_Z); this.glcamera.applyProjection(gl,glu); gl.glScalef(scale, scale, scale); gl.glMatrixMode(GLMatrixFunc.GL_MODELVIEW); gl.glLoadIdentity(); //glu.gluLookAt(eyex, eyey, eyez, lookatx, lookaty, lookatz, 0, 1, 0); this.glcamera.applyLookat(glu); gl.glEnable(GLLightingFunc.GL_LIGHTING); // hints_renderer.endRendering(); // // hints_renderer.beginRendering(drawable.getSurfaceWidth(), drawable.getSurfaceHeight()); // // hints_renderer.draw(hints_string2 // , // (int) hints_position.getX(), (int)hints_position.getY()+20); // hints_renderer.endRendering(); UnlightedAxis.draw(gl); //model.drawByEdges(gl); model.drawSmoothShading(gl); /* void Model::drawByEdges() { float scale1,scale2,scale3; scale1 = OBJ_SIZE/(xmax - xmin); scale2 = OBJ_SIZE/(ymax - ymin); scale3 = OBJ_SIZE/(zmax - zmin); float scale = ( ((OBJ_SIZE/(xmax - xmin)<OBJ_SIZE/(ymax - ymin)) ?OBJ_SIZE/(xmax - xmin):OBJ_SIZE/(ymax - ymin))<OBJ_SIZE/(zmax - zmin) ) ? ((OBJ_SIZE/(xmax - xmin)<OBJ_SIZE/(ymax - ymin)) ?OBJ_SIZE/(xmax - xmin):OBJ_SIZE/(ymax - ymin)):OBJ_SIZE/(zmax - zmin); glPushMatrix(); glScalef(scale,scale,scale); glTranslatef(-(xmin+xmax)/2,-(ymin+ymax)/2,-(zmin+zmax)/2); int tmp = 0; glPointSize(1.0); glBegin(GL_LINES ); int i = 0; modeledge * mlp; Vertex * vp; for (i = 0; i< edgesCount;i++) { //glVertex3f(vertices[i]->p.x,vertices[i]->p.y,vertices[i]->p.z); //edges[i] mlp = edges[i]; vp = vertices[mlp->gp.beg-1]; glVertex3f(vp->p.x,vp->p.y,vp->p.z); vp = vertices[mlp->gp.fin-1]; glVertex3f(vp->p.x,vp->p.y,vp->p.z); } glEnd(); glPopMatrix(); } */ // offscreen_glad.display(); // actual screenshot // // if ( MeshRendererEventListener.makeScreenShot == true) { // if (getcolor.readPixels(gl, false)) { // // String filename = "FriendsTorus"+filestamp+String.format("%03d",sequence.incrementAndGet()); // getcolor.write(new File(filename+".png")); // } // MeshRendererEventListener.makeScreenShot = false; // } } private final GLReadBufferUtil getcolor = new GLReadBufferUtil(false, false); static final long filestamp = Calendar.getInstance().getTimeInMillis(); static protected AtomicLong sequence = new AtomicLong(0l); public static final long photoid_expiring_at = 5000l; // five seconds protected boolean filesaved = false; public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) { // System.out.println("TwoFriendsTorusGLEventListener reshape "+ width+ // " "+ height); offscreen_glad.setSurfaceSize(width, height); GL2 gl = drawable.getGL().getGL2(); gl.glViewport(x, y, width, height); this.glcamera.setScreenWidthHeight(width, height); // // ((GL2ES1) gl).glOrtho(-orthoganal_clip_size, orthoganal_clip_size, // -orthoganal_clip_size2, orthoganal_clip_size2, NEAR_Z, FAR_Z); gl.glScalef(scale, scale, scale); this.glcamera.applyProjection(gl,glu); gl.glMatrixMode(GLMatrixFunc.GL_MODELVIEW); gl.glLoadIdentity(); //glu.gluLookAt(eyex, eyey, eyez, lookatx, lookaty, lookatz, 0, 1, 0); this.glcamera.applyLookat(glu); gl.glEnable(GLLightingFunc.GL_LIGHTING); } private int prevMouseX, prevMouseY; @SuppressWarnings("unused") private boolean mouseRButtonDown = false; private MathPoint3 mousepoint = new MathPoint3(-1f, 0f, 0f); class ColorClickMouseAdapter extends MouseAdapter { @SuppressWarnings("static-access") public void mousePressed(MouseEvent e) { // System.out // .println("ColorClickMouseAdapter mousePressed Thread.currentThread().getId():" // + Thread.currentThread().getId()); prevMouseX = e.getX(); prevMouseY = e.getY(); if ((e.getModifiers() & e.BUTTON3_MASK) != 0) { mouseRButtonDown = true; } mousepoint.setX(prevMouseX); mousepoint.setY(prevMouseY); //System.out.println("ColorClickMouseAdapter mousePressed " + mousepoint); // display(); } @SuppressWarnings("static-access") public void mouseReleased(MouseEvent e) { if ((e.getModifiers() & e.BUTTON3_MASK) != 0) { mouseRButtonDown = false; } } public static final float mouse_move_scope_in_angle = 180f;//orginal 360f public void mouseDragged(MouseEvent e) { //FriendsTorus.showThreadId(" mouseDragged"); int x = e.getX(); int y = e.getY(); int width = 0, height = 0; Object source = e.getSource(); if (source instanceof Window) { Window window = (Window) source; width = window.getWidth(); height = window.getHeight(); } else if (GLProfile.isAWTAvailable() && source instanceof java.awt.Component) { java.awt.Component comp = (java.awt.Component) source; width = comp.getWidth(); height = comp.getHeight(); } else { throw new RuntimeException( "Event source neither Window nor Component: " + source); } // float thetaY = mouse_move_scope_in_angle * ((float) (x - prevMouseX) / (float) // width); // float thetaX = mouse_move_scope_in_angle * ((float) (prevMouseY - y) / (float) // height); MathVector3 v2 = new MathVector3 (x-((float)width/2.0f),y - ((float)height/2.0f),0f); MathVector3 v1 = new MathVector3 ( prevMouseX- ((float)width/2.0f),prevMouseY - ((float)height/2.0f),0f); MathVector3 vref = new MathVector3 ( 0,0,1f); float delta = MathVector3.angleBetweenVWWithAnomalyDetection(v1, v2, vref);// counter clock angle/right hand rule if ( !MathConstants.isAlmost(delta, -1000f) ){ //System.out.println("[prev_x,prev_y,x,y]:["+ prevMouseX+","+prevMouseY+","+x+","+y+","+"]=>clockwise "+ delta +"degrees."); // REMARK screen coordiate x:left->right y:upper->down, rotate ref would be Z- of opengl. the value returned would be clock-wise screen op // when rotate the torus, should be counter clock referred to torus upper vector, we use opengl y+; //DrawableCollection.getInstance().torus_delta_rotate(delta); } prevMouseX = x; prevMouseY = y; //System.out.println(TwopassFriendsTorusGLEventListener.) // //rotate the torus // view_rotx += thetaX; // view_roty += thetaY; } } }

From the program in (3), what we do with C/C++ is that we can pass function pointers so we can specify init, display functions etc. In JOGL implementation, these functions' names are fixed. We leave the camera part for future discussion, we can have a brief view as the following segment of how we handle the GTS models.

void initModel () { model.initFromFile(fn); model.OBJ_SIZE =10.0f; //model.print(); model.calculateScale(); model.offSet(); model.calculateTrianglesNormals(); }