/*
* Copyright (c) 2002-2008 LWJGL Project
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*
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*
* * Redistributions in binary form must reproduce the above copyright
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* documentation and/or other materials provided with the distribution.
*
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* 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,
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package org.lwjgl.util.glu;
import org.lwjgl.opengl.GL11;
/**
* Cylinder.java
*
*
* Created 23-dec-2003
* @author Erik Duijs
*/
public class Cylinder extends Quadric {
/**
* Constructor for Cylinder.
*/
public Cylinder() {
super();
}
/**
* draws a cylinder oriented along the z axis. The base of the
* cylinder is placed at z = 0, and the top at z=height. Like a sphere, a
* cylinder is subdivided around the z axis into slices, and along the z axis
* into stacks.
*
* Note that if topRadius is set to zero, then this routine will generate a
* cone.
*
* If the orientation is set to GLU.OUTSIDE (with glu.quadricOrientation), then
* any generated normals point away from the z axis. Otherwise, they point
* toward the z axis.
*
* If texturing is turned on (with glu.quadricTexture), then texture
* coordinates are generated so that t ranges linearly from 0.0 at z = 0 to
* 1.0 at z = height, and s ranges from 0.0 at the +y axis, to 0.25 at the +x
* axis, to 0.5 at the -y axis, to 0.75 at the -x axis, and back to 1.0 at the
* +y axis.
*
* @param baseRadius Specifies the radius of the cylinder at z = 0.
* @param topRadius Specifies the radius of the cylinder at z = height.
* @param height Specifies the height of the cylinder.
* @param slices Specifies the number of subdivisions around the z axis.
* @param stacks Specifies the number of subdivisions along the z axis.
*/
public void draw(float baseRadius, float topRadius, float height, int slices, int stacks) {
float da, r, dr, dz;
float x, y, z, nz, nsign;
int i, j;
if (super.orientation == GLU.GLU_INSIDE) {
nsign = -1.0f;
} else {
nsign = 1.0f;
}
da = 2.0f * GLU.PI / slices;
dr = (topRadius - baseRadius) / stacks;
dz = height / stacks;
nz = (baseRadius - topRadius) / height;
// Z component of normal vectors
if (super.drawStyle == GLU.GLU_POINT) {
GL11.glBegin(GL11.GL_POINTS);
for (i = 0; i < slices; i++) {
x = cos((i * da));
y = sin((i * da));
normal3f(x * nsign, y * nsign, nz * nsign);
z = 0.0f;
r = baseRadius;
for (j = 0; j <= stacks; j++) {
GL11.glVertex3f((x * r), (y * r), z);
z += dz;
r += dr;
}
}
GL11.glEnd();
} else if (super.drawStyle == GLU.GLU_LINE || super.drawStyle == GLU.GLU_SILHOUETTE) {
// Draw rings
if (super.drawStyle == GLU.GLU_LINE) {
z = 0.0f;
r = baseRadius;
for (j = 0; j <= stacks; j++) {
GL11.glBegin(GL11.GL_LINE_LOOP);
for (i = 0; i < slices; i++) {
x = cos((i * da));
y = sin((i * da));
normal3f(x * nsign, y * nsign, nz * nsign);
GL11.glVertex3f((x * r), (y * r), z);
}
GL11.glEnd();
z += dz;
r += dr;
}
} else {
// draw one ring at each end
if (baseRadius != 0.0) {
GL11.glBegin(GL11.GL_LINE_LOOP);
for (i = 0; i < slices; i++) {
x = cos((i * da));
y = sin((i * da));
normal3f(x * nsign, y * nsign, nz * nsign);
GL11.glVertex3f((x * baseRadius), (y * baseRadius), 0.0f);
}
GL11.glEnd();
GL11.glBegin(GL11.GL_LINE_LOOP);
for (i = 0; i < slices; i++) {
x = cos((i * da));
y = sin((i * da));
normal3f(x * nsign, y * nsign, nz * nsign);
GL11.glVertex3f((x * topRadius), (y * topRadius), height);
}
GL11.glEnd();
}
}
// draw length lines
GL11.glBegin(GL11.GL_LINES);
for (i = 0; i < slices; i++) {
x = cos((i * da));
y = sin((i * da));
normal3f(x * nsign, y * nsign, nz * nsign);
GL11.glVertex3f((x * baseRadius), (y * baseRadius), 0.0f);
GL11.glVertex3f((x * topRadius), (y * topRadius), (height));
}
GL11.glEnd();
} else if (super.drawStyle == GLU.GLU_FILL) {
float ds = 1.0f / slices;
float dt = 1.0f / stacks;
float t = 0.0f;
z = 0.0f;
r = baseRadius;
for (j = 0; j < stacks; j++) {
float s = 0.0f;
GL11.glBegin(GL11.GL_QUAD_STRIP);
for (i = 0; i <= slices; i++) {
if (i == slices) {
x = sin(0.0f);
y = cos(0.0f);
} else {
x = sin((i * da));
y = cos((i * da));
}
if (nsign == 1.0f) {
normal3f((x * nsign), (y * nsign), (nz * nsign));
TXTR_COORD(s, t);
GL11.glVertex3f((x * r), (y * r), z);
normal3f((x * nsign), (y * nsign), (nz * nsign));
TXTR_COORD(s, t + dt);
GL11.glVertex3f((x * (r + dr)), (y * (r + dr)), (z + dz));
} else {
normal3f(x * nsign, y * nsign, nz * nsign);
TXTR_COORD(s, t);
GL11.glVertex3f((x * r), (y * r), z);
normal3f(x * nsign, y * nsign, nz * nsign);
TXTR_COORD(s, t + dt);
GL11.glVertex3f((x * (r + dr)), (y * (r + dr)), (z + dz));
}
s += ds;
} // for slices
GL11.glEnd();
r += dr;
t += dt;
z += dz;
} // for stacks
}
}
}
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