Et enkelt rammeverk for kjøring av OpenGL-programmer i Java

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1 1 Et enkelt rammeverk for kjøring av OpenGL-programmer i Java JOGL2 API og dokumentasjon kan lastes ned fra siden: I det etterfølgende er det gitt et eksempel på et Java-rammeverk for uttegning av en trekant på dataskjermen vha OpenGL2 med Java-binding. /* OpenGL_Ov1.java JHN Draws one triangle JOGL versjon 2 binding towards OpenGL import javax.swing.*; //import java.awt.dimension; // klassene JFrame og JPanel class Vindu extends JFrame { public Vindu(String tittel) { settitle(tittel); setdefaultcloseoperation(jframe.exit_on_close); //GLCanvas canvas = new TegningIv1(); //canvas.setpreferredsize(new Dimension(800,600)); TegningOv1 tegningen = new TegningOv1(); tegningen.setsize(800, 600); add(tegningen); pack(); // Vindu public class OpenGL_Ov1 { public static void main(string args[]){ Vindu etvindu = new Vindu("Øving 1"); etvindu.setvisible(true); /* For animasjon - trengs ikke her final FPSAnimator animator = new FPSAnimator(canvas, FPS, true); animator.start(); // start the animation loop // OpenGL_Ov1

2 2 Klassen som generer tegningen: TegningOv1_1JOGL: /* TegningOv1.java JHN Draw one triangle. JOGL versjon 2 binding towards OpenGL // Java classes: import javax.swing.*; // klassene JFrame og JPanel //import java.awt.dimension; //JOGL2 classes: import static com.jogamp.opengl.gl2.*;//slipper å bruke GL2.konstant import com.jogamp.opengl.gl2; import com.jogamp.opengl.glu.glu; import com.jogamp.opengl.gleventlistener; import com.jogamp.opengl.glautodrawable; import com.jogamp.opengl.glcapabilities; import com.jogamp.opengl.awt.glcanvas; import static com.jogamp.opengl.fixedfunc.glmatrixfunc.gl_modelview; import static com.jogamp.opengl.fixedfunc.glmatrixfunc.gl_projection; import com.jogamp.opengl.util.fpsanimator; public class TegningOv1 extends GLCanvas implements GLEventListener{ /* interfacet GLEventListener innholder de 5 metodene som må implemeenteres: - display(gldrawable drawable) Called by the drawable to initiate OpenGL rendering by the client - dispose(glautodrawable d) Notifies the listener to perform the release of all OpenGL resources per GLContext, such as memory buffers and GLSL programs. - init(gldrawable drawable) Called by the drawable immediately after the OpenGL context is initialized. - reshape(gldrawable drawable, int x, int y, int width, int height) Called by the drawable during the first repaint after the component has been resized. private float angle; private GLU glu = new GLU(); private float number = 1.0f;

3 3 //Konstruktor public TegningOv1() { this.addgleventlistener(this); //et objekt av klassen TegningOv1 fungerer som lytter. Det lytter på objektet selv public void init(glautodrawable gldrawable) { // System.out.println("init()"); GL2 gl = gldrawable.getgl().getgl2(); //Get the GL2 object from gldrawable gl.glclearcolor(1.0f, 1.0f, 1.0f, 1.0f); // Sets the background color to white gl.glmatrixmode(gl_projection); // Select The Projection Matrix // Reset the view matrix to the identity matrix glu.gluperspective(60.0,1.25,1.0,15.0); // Spesifize the projection matrix (fov, w/h, near plane, far plane) //gl.glfrustum(- 3, 3, -3, 3, 1, 9); // Definerer synsvolum for en perspektivprojeksjon //gl.glortho(- 3, 3, -3, 3, -10, 10); // Ortogonalprojeksjon //glu.glulookat(0, 0, 4, 0, 0, 0, 0, 1, 0); // Øyeposisjon, siktepunkt, up-vektor kamera(øye) gl.glmatrixmode(gl_modelview); public void reshape(glautodrawable gldrawable, int i, int i1, int width, int height) { public void dispose(glautodrawable d){;//lagt til /* Draw one triangle public void drawglscene(glautodrawable gldrawable) { GL2 gl = gldrawable.getgl().getgl2();//gl gl = gldrawable.getgl(); TOMAS gl.glclear(gl_color_buffer_bit GL_DEPTH_BUFFER_BIT); //Clear The Screen And The Depth Buffer // Reset The View matrix gl.gltranslatef(-1.5f,0.0f,-8.0f); // Move Left 1.5 Units and into The Screen 7 units gl.glcolor3f(1.0f,0.0f,0.0f); // Set the Color to Red gl.glbegin(gl_triangles); // Start drawing using the polygon primitiv GL.GL_TRIANGLES gl.glvertex3f( 0.0f, 1.0f, 0.0f); // Top gl.glvertex3f(-1.0f,-1.0f, 0.0f); // Bottom Left gl.glvertex3f( 1.0f,-1.0f, 0.0f); // Bottom Right gl.glend(); // Finished Drawing The Triangle // drawglscene

4 4 /** void display() Draw to the canvas. public void display(glautodrawable gldrawable) { // System.out.println("display()"); GL2 gl = gldrawable.getgl().getgl2(); drawglscene(gldrawable); gl.glflush(); // display() // TegningOv1

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