Hi, i'm trying to get the arbitrary clip planes working, ie GL_CLIP_PLANE0 but am having some trouble. Firstly, are these actually implemented? Because I really thought I had the code going to make it happen and it just isnt - i'm using the gears demo as my basis and altering that.
I have altered the code so only one cog is drawn at the origin, so theoretically any extra clipping plane should alter the scene and I won't be able to miss it, I have tried every combination of plane and nothing has shown up.
I've added the code below and all in all i'm a bit confused - any help would be much appreciated!
/*
* Copyright (c) 2002-2005 LWJGL Project
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* met:
*
* * Redistributions of source code must retain the above copyright
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* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of 'LWJGL' nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* 3-D gear wheels. Originally by Brian Paul
*/
package operator;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import org.lwjgl.BufferUtils;
import org.lwjgl.LWJGLException;
import org.lwjgl.opengl.ARBTransposeMatrix;
import org.lwjgl.opengl.Display;
import org.lwjgl.opengl.PixelFormat;
import org.lwjgl.opengl.DisplayMode;
import org.lwjgl.opengl.GL11;
import org.lwjgl.opengl.GLContext;
/**
* <p>
* This is the OpenGL "standard" Gears demo, originally by Brian Paul
* </p>
* @author Brian Matzon <brian@matzon.dk>
* @version $Revision$
* $Id$
*/
public class Gears {
private float view_rotx = 20.0f;
private float view_roty = 45.0f;
private float view_rotz = 0.0f;
private int gear1;
private int gear2;
private int gear3;
private float angle = 0.0f;
private DoubleBuffer myDB;
private ByteBuffer myBB;
public static void main(String[] args) {
new Gears().execute();
System.exit(0);
}
/**
*
*/
private void execute() {
try {
init();
} catch (LWJGLException le) {
le.printStackTrace();
System.out.println("Failed to initialize Gears.");
return;
}
loop();
destroy();
}
/**
*
*/
private void destroy() {
Display.destroy();
}
/**
*
*/
private void loop() {
long startTime = System.currentTimeMillis() + 5000;
long fps = 0;
while (!Display.isCloseRequested()) {
angle += 2.0f;
GL11.glClear(GL11.GL_COLOR_BUFFER_BIT | GL11.GL_DEPTH_BUFFER_BIT);
GL11.glLoadIdentity();
GL11.glTranslatef(0.0f, 0.0f, -40.0f);
//byte eqn[] = {-1, 0, -1, 0};
//myBB = ByteBuffer.allocateDirect(64);
//myBB.order(ByteOrder.nativeOrder());
//myBB.put(eqn);
//myDB = (DoubleBuffer)myBB.asDoubleBuffer();
myDB = BufferUtils.createDoubleBuffer(8).put(new double[] { 0.0f, 1.0f, 0.0f, 0.0f});
GL11.glClipPlane(GL11.GL_CLIP_PLANE0, myDB);
GL11.glEnable(GL11.GL_CLIP_PLANE0);
GL11.glPushMatrix();
GL11.glRotatef(view_rotx, 1.0f, 0.0f, 0.0f);
GL11.glRotatef(view_roty, 0.0f, 1.0f, 0.0f);
GL11.glRotatef(view_rotz, 0.0f, 0.0f, 1.0f);
GL11.glPushMatrix();
//GL11.glTranslatef(-3.0f, -2.0f, 0.0f);
GL11.glRotatef(angle, 0.0f, 0.0f, 1.0f);
//GL11.glCallList(gear1);
GL11.glPopMatrix();
GL11.glPushMatrix();
//GL11.glTranslatef(3.1f, -2.0f, 0.0f);
GL11.glRotatef(-2.0f * angle - 9.0f, 0.0f, 0.0f, 1.0f);
//GL11.glCallList(gear2);
GL11.glPopMatrix();
GL11.glPushMatrix();
//GL11.glTranslatef(-3.1f, 4.2f, 0.0f);
GL11.glRotatef(-2.0f * angle - 25.0f, 0.0f, 0.0f, 1.0f);
GL11.glCallList(gear3);
GL11.glPopMatrix();
GL11.glPopMatrix();
Display.update();
if (startTime > System.currentTimeMillis()) {
fps++;
} else {
long timeUsed = 5000 + (startTime - System.currentTimeMillis());
startTime = System.currentTimeMillis() + 5000;
System.out.println(fps + " frames in " + (float) (timeUsed / 1000f) + " seconds = "
+ (fps / (timeUsed / 1000f)));
fps = 0;
}
}
}
/**
*
*/
private void init() throws LWJGLException {
// create Window of size 300x300
Display.setLocation((Display.getDisplayMode().getWidth() - 300) / 2,
(Display.getDisplayMode().getHeight() - 300) / 2);
Display.setDisplayMode(new DisplayMode(600, 600));
Display.setTitle("Gears");
Display.create(new PixelFormat(0, 16, 1));
// setup ogl
FloatBuffer pos = BufferUtils.createFloatBuffer(4).put(new float[] { 5.0f, 5.0f, 10.0f, 0.0f});
FloatBuffer red = BufferUtils.createFloatBuffer(4).put(new float[] { 0.8f, 0.1f, 0.0f, 1.0f});
FloatBuffer green = BufferUtils.createFloatBuffer(4).put(new float[] { 0.0f, 0.8f, 0.2f, 1.0f});
FloatBuffer blue = BufferUtils.createFloatBuffer(4).put(new float[] { 0.2f, 0.2f, 1.0f, 1.0f});
pos.flip();
red.flip();
green.flip();
blue.flip();
GL11.glLight(GL11.GL_LIGHT0, GL11.GL_POSITION, pos);
GL11.glEnable(GL11.GL_CULL_FACE);
GL11.glEnable(GL11.GL_LIGHTING);
GL11.glEnable(GL11.GL_LIGHT0);
GL11.glEnable(GL11.GL_DEPTH_TEST);
/* make the gears */
gear1 = GL11.glGenLists(1);
GL11.glNewList(gear1, GL11.GL_COMPILE);
GL11.glMaterial(GL11.GL_FRONT, GL11.GL_AMBIENT_AND_DIFFUSE, red);
gear(1.0f, 4.0f, 1.0f, 20, 0.7f);
GL11.glEndList();
gear2 = GL11.glGenLists(1);
GL11.glNewList(gear2, GL11.GL_COMPILE);
GL11.glMaterial(GL11.GL_FRONT, GL11.GL_AMBIENT_AND_DIFFUSE, green);
gear(0.5f, 2.0f, 2.0f, 10, 0.7f);
GL11.glEndList();
gear3 = GL11.glGenLists(1);
GL11.glNewList(gear3, GL11.GL_COMPILE);
GL11.glMaterial(GL11.GL_FRONT, GL11.GL_AMBIENT_AND_DIFFUSE, blue);
gear(1.3f, 2.0f, 0.5f, 10, 0.7f);
GL11.glEndList();
GL11.glEnable(GL11.GL_NORMALIZE);
GL11.glMatrixMode(GL11.GL_PROJECTION);
System.err.println("GL_VENDOR: " + GL11.glGetString(GL11.GL_VENDOR));
System.err.println("GL_RENDERER: " + GL11.glGetString(GL11.GL_RENDERER));
System.err.println("GL_VERSION: " + GL11.glGetString(GL11.GL_VERSION));
System.err.println();
System.err.println("glLoadTransposeMatrixfARB() supported: " + GLContext.getCapabilities().GL_ARB_transpose_matrix);
if (!GLContext.getCapabilities().GL_ARB_transpose_matrix) {
// --- not using extensions
GL11.glLoadIdentity();
} else {
// --- using extensions
final FloatBuffer identityTranspose = BufferUtils.createFloatBuffer(16).put(
new float[] { 1, 0, 0, 0, 0, 1, 0, 0,
0, 0, 1, 0, 0, 0, 0, 1});
identityTranspose.flip();
ARBTransposeMatrix.glLoadTransposeMatrixARB(identityTranspose);
}
float h = (float) 300 / (float) 300;
GL11.glFrustum(-1.0f, 1.0f, -h, h, 5.0f, 60.0f);
GL11.glMatrixMode(GL11.GL_MODELVIEW);
GL11.glLoadIdentity();
GL11.glTranslatef(0.0f, 0.0f, -40.0f);
}
/**
* Draw a gear wheel. You'll probably want to call this function when
* building a display list since we do a lot of trig here.
*
* @param inner_radius radius of hole at center
* @param outer_radius radius at center of teeth
* @param width width of gear
* @param teeth number of teeth
* @param tooth_depth depth of tooth
*/
private void gear(float inner_radius, float outer_radius, float width, int teeth, float tooth_depth) {
int i;
float r0, r1, r2;
float angle, da;
float u, v, len;
r0 = inner_radius;
r1 = outer_radius - tooth_depth / 2.0f;
r2 = outer_radius + tooth_depth / 2.0f;
da = 2.0f * (float) Math.PI / teeth / 4.0f;
GL11.glShadeModel(GL11.GL_FLAT);
GL11.glNormal3f(0.0f, 0.0f, 1.0f);
/* draw front face */
GL11.glBegin(GL11.GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0f * (float) Math.PI / teeth;
GL11.glVertex3f(r0 * (float) Math.cos(angle), r0 * (float) Math.sin(angle), width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle), r1 * (float) Math.sin(angle), width * 0.5f);
if (i < teeth) {
GL11.glVertex3f(r0 * (float) Math.cos(angle), r0 * (float) Math.sin(angle), width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle + 3.0f * da), r1 * (float) Math.sin(angle + 3.0f * da),
width * 0.5f);
}
}
GL11.glEnd();
/* draw front sides of teeth */
GL11.glBegin(GL11.GL_QUADS);
for (i = 0; i < teeth; i++) {
angle = i * 2.0f * (float) Math.PI / teeth;
GL11.glVertex3f(r1 * (float) Math.cos(angle), r1 * (float) Math.sin(angle), width * 0.5f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + da), r2 * (float) Math.sin(angle + da), width * 0.5f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + 2.0f * da), r2 * (float) Math.sin(angle + 2.0f * da), width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle + 3.0f * da), r1 * (float) Math.sin(angle + 3.0f * da), width * 0.5f);
}
GL11.glEnd();
/* draw back face */
GL11.glBegin(GL11.GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0f * (float) Math.PI / teeth;
GL11.glVertex3f(r1 * (float) Math.cos(angle), r1 * (float) Math.sin(angle), -width * 0.5f);
GL11.glVertex3f(r0 * (float) Math.cos(angle), r0 * (float) Math.sin(angle), -width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle + 3 * da), r1 * (float) Math.sin(angle + 3 * da), -width * 0.5f);
GL11.glVertex3f(r0 * (float) Math.cos(angle), r0 * (float) Math.sin(angle), -width * 0.5f);
}
GL11.glEnd();
/* draw back sides of teeth */
GL11.glBegin(GL11.GL_QUADS);
for (i = 0; i < teeth; i++) {
angle = i * 2.0f * (float) Math.PI / teeth;
GL11.glVertex3f(r1 * (float) Math.cos(angle + 3 * da), r1 * (float) Math.sin(angle + 3 * da), -width * 0.5f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + 2 * da), r2 * (float) Math.sin(angle + 2 * da), -width * 0.5f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + da), r2 * (float) Math.sin(angle + da), -width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle), r1 * (float) Math.sin(angle), -width * 0.5f);
}
GL11.glEnd();
/* draw outward faces of teeth */
GL11.glBegin(GL11.GL_QUAD_STRIP);
for (i = 0; i < teeth; i++) {
angle = i * 2.0f * (float) Math.PI / teeth;
GL11.glVertex3f(r1 * (float) Math.cos(angle), r1 * (float) Math.sin(angle), width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle), r1 * (float) Math.sin(angle), -width * 0.5f);
u = r2 * (float) Math.cos(angle + da) - r1 * (float) Math.cos(angle);
v = r2 * (float) Math.sin(angle + da) - r1 * (float) Math.sin(angle);
len = (float) Math.sqrt(u * u + v * v);
u /= len;
v /= len;
GL11.glNormal3f(v, -u, 0.0f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + da), r2 * (float) Math.sin(angle + da), width * 0.5f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + da), r2 * (float) Math.sin(angle + da), -width * 0.5f);
GL11.glNormal3f((float) Math.cos(angle), (float) Math.sin(angle), 0.0f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + 2 * da), r2 * (float) Math.sin(angle + 2 * da), width * 0.5f);
GL11.glVertex3f(r2 * (float) Math.cos(angle + 2 * da), r2 * (float) Math.sin(angle + 2 * da), -width * 0.5f);
u = r1 * (float) Math.cos(angle + 3 * da) - r2 * (float) Math.cos(angle + 2 * da);
v = r1 * (float) Math.sin(angle + 3 * da) - r2 * (float) Math.sin(angle + 2 * da);
GL11.glNormal3f(v, -u, 0.0f);
GL11.glVertex3f(r1 * (float) Math.cos(angle + 3 * da), r1 * (float) Math.sin(angle + 3 * da), width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(angle + 3 * da), r1 * (float) Math.sin(angle + 3 * da), -width * 0.5f);
GL11.glNormal3f((float) Math.cos(angle), (float) Math.sin(angle), 0.0f);
}
GL11.glVertex3f(r1 * (float) Math.cos(0), r1 * (float) Math.sin(0), width * 0.5f);
GL11.glVertex3f(r1 * (float) Math.cos(0), r1 * (float) Math.sin(0), -width * 0.5f);
GL11.glEnd();
GL11.glShadeModel(GL11.GL_SMOOTH);
/* draw inside radius cylinder */
GL11.glBegin(GL11.GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0f * (float) Math.PI / teeth;
GL11.glNormal3f(-(float) Math.cos(angle), -(float) Math.sin(angle), 0.0f);
GL11.glVertex3f(r0 * (float) Math.cos(angle), r0 * (float) Math.sin(angle), -width * 0.5f);
GL11.glVertex3f(r0 * (float) Math.cos(angle), r0 * (float) Math.sin(angle), width * 0.5f);
}
GL11.glEnd();
}
}
Hi, i've just worked it out, I needed to flip the buffer! Not quite as straightforward as C++ and OpenGL but i'll get there eventually.BTW I saw Jake2 and was amazed at the framerate with LWGL, even on my POS laptop, so if anyone who works on the project reads this then 2 thumbs way up :)
Andy