262 lines
6.0 KiB
C
262 lines
6.0 KiB
C
#include <stdlib.h>
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#include <math.h>
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#include <GL/gl.h>
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#include "glu.h"
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void drawTorus(float rc, int numc, float rt, int numt)
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{
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int i, j, k;
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double s, t;
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double x, y, z;
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double pi, twopi;
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pi = 3.14159265358979323846;
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twopi = 2 * pi;
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for (i = 0; i < numc; i++) {
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glBegin(GL_QUAD_STRIP);
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for (j = 0; j <= numt; j++) {
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for (k = 1; k >= 0; k--) {
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s = (i + k) % numc + 0.5;
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t = j % numt;
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x = cos(t*twopi/numt) * cos(s*twopi/numc);
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y = sin(t*twopi/numt) * cos(s*twopi/numc);
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z = sin(s*twopi/numc);
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glNormal3f(x, y, z);
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x = (rt + rc * cos(s*twopi/numc)) * cos(t*twopi/numt);
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y = (rt + rc * cos(s*twopi/numc)) * sin(t*twopi/numt);
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z = rc * sin(s*twopi/numc);
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glVertex3f(x, y, z);
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}
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}
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glEnd();
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}
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}
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static void normal3f( GLfloat x, GLfloat y, GLfloat z )
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{
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GLdouble mag;
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mag = sqrt( x*x + y*y + z*z );
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if (mag>0.00001F) {
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x /= mag;
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y /= mag;
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z /= mag;
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}
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glNormal3f( x, y, z );
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}
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void gluPerspective( GLdouble fovy, GLdouble aspect,
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GLdouble zNear, GLdouble zFar )
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{
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GLdouble xmin, xmax, ymin, ymax;
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ymax = zNear * tan( fovy * M_PI / 360.0 );
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ymin = -ymax;
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xmin = ymin * aspect;
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xmax = ymax * aspect;
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glFrustum( xmin, xmax, ymin, ymax, zNear, zFar );
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}
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GLUquadricObj *gluNewQuadric(void)
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{
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return NULL;
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}
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void gluQuadricDrawStyle(GLUquadricObj *obj, int style)
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{
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}
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void gluCylinder( GLUquadricObj *qobj,
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GLdouble baseRadius, GLdouble topRadius, GLdouble height,
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GLint slices, GLint stacks )
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{
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GLdouble da, r, dr, dz;
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GLfloat z, nz, nsign;
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GLint i, j;
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GLfloat du = 1.0 / slices;
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GLfloat dv = 1.0 / stacks;
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GLfloat tcx = 0.0, tcy = 0.0;
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nsign = 1.0;
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da = 2.0*M_PI / slices;
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dr = (topRadius-baseRadius) / stacks;
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dz = height / stacks;
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nz = (baseRadius-topRadius) / height; /* Z component of normal vectors */
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for (i=0;i<slices;i++) {
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GLfloat x1 = -sin(i*da);
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GLfloat y1 = cos(i*da);
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GLfloat x2 = -sin((i+1)*da);
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GLfloat y2 = cos((i+1)*da);
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z = 0.0;
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r = baseRadius;
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tcy = 0.0;
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glBegin( GL_QUAD_STRIP );
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for (j=0;j<=stacks;j++) {
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if (nsign==1.0) {
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normal3f( x1*nsign, y1*nsign, nz*nsign );
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glTexCoord2f(tcx, tcy);
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glVertex3f( x1*r, y1*r, z );
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normal3f( x2*nsign, y2*nsign, nz*nsign );
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glTexCoord2f(tcx+du, tcy);
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glVertex3f( x2*r, y2*r, z );
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}
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else {
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normal3f( x2*nsign, y2*nsign, nz*nsign );
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glTexCoord2f(tcx, tcy);
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glVertex3f( x2*r, y2*r, z );
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normal3f( x1*nsign, y1*nsign, nz*nsign );
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glTexCoord2f(tcx+du, tcy);
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glVertex3f( x1*r, y1*r, z );
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}
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z += dz;
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r += dr;
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tcy += dv;
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}
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glEnd();
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tcx += du;
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}
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}
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/* Disk (adapted from Mesa) */
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void gluDisk( GLUquadricObj *qobj,
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GLdouble innerRadius, GLdouble outerRadius,
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GLint slices, GLint loops )
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{
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GLdouble a, da;
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GLfloat dr;
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GLfloat r1, r2, dtc;
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GLint s, l;
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GLfloat sa,ca;
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/* Normal vectors */
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glNormal3f( 0.0, 0.0, +1.0 );
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da = 2.0*M_PI / slices;
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dr = (outerRadius-innerRadius) / (GLfloat) loops;
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/* texture of a gluDisk is a cut out of the texture unit square */
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/* x, y in [-outerRadius, +outerRadius]; s, t in [0, 1] (linear mapping) */
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dtc = 2.0f * outerRadius;
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r1 = innerRadius;
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for (l=0;l<loops;l++) {
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r2 = r1 + dr;
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glBegin( GL_QUAD_STRIP );
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for (s=0;s<=slices;s++) {
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if (s==slices) a = 0.0;
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else a = s * da;
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sa = sin(a); ca = cos(a);
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glTexCoord2f(0.5+sa*r2/dtc,0.5+ca*r2/dtc);
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glVertex2f( r2*sa, r2*ca );
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glTexCoord2f(0.5+sa*r1/dtc,0.5+ca*r1/dtc);
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glVertex2f( r1*sa, r1*ca );
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}
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glEnd();
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r1 = r2;
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}
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}
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/*
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* Sph<70>re (adapted from Mesa)
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*/
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void gluSphere(GLUquadricObj *qobj,
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float radius,int slices,int stacks)
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{
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float rho, drho, theta, dtheta;
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float x, y, z;
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float s, t, ds, dt;
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int i, j, imin, imax;
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int normals;
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float nsign;
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normals=1;
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nsign=1;
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drho = M_PI / (float) stacks;
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dtheta = 2.0 * M_PI / (float) slices;
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/* draw +Z end as a triangle fan */
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glBegin( GL_TRIANGLE_FAN );
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glNormal3f( 0.0, 0.0, 1.0 );
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glTexCoord2f(0.5,0.0);
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glVertex3f( 0.0, 0.0, nsign * radius );
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for (j=0;j<=slices;j++) {
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theta = (j==slices) ? 0.0 : j * dtheta;
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x = -sin(theta) * sin(drho);
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y = cos(theta) * sin(drho);
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z = nsign * cos(drho);
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if (normals) glNormal3f( x*nsign, y*nsign, z*nsign );
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glVertex3f( x*radius, y*radius, z*radius );
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}
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glEnd();
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ds = 1.0 / slices;
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dt = 1.0 / stacks;
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t = 1.0; /* because loop now runs from 0 */
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if (1) {
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imin = 0;
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imax = stacks;
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}
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else {
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imin = 1;
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imax = stacks-1;
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}
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/* draw intermediate stacks as quad strips */
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for (i=imin;i<imax;i++) {
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rho = i * drho;
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glBegin( GL_QUAD_STRIP );
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s = 0.0;
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for (j=0;j<=slices;j++) {
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theta = (j==slices) ? 0.0 : j * dtheta;
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x = -sin(theta) * sin(rho);
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y = cos(theta) * sin(rho);
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z = nsign * cos(rho);
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if (normals) glNormal3f( x*nsign, y*nsign, z*nsign );
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glTexCoord2f(s,1-t);
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glVertex3f( x*radius, y*radius, z*radius );
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x = -sin(theta) * sin(rho+drho);
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y = cos(theta) * sin(rho+drho);
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z = nsign * cos(rho+drho);
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if (normals) glNormal3f( x*nsign, y*nsign, z*nsign );
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glTexCoord2f(s,1-(t-dt));
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s += ds;
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glVertex3f( x*radius, y*radius, z*radius );
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}
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glEnd();
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t -= dt;
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}
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/* draw -Z end as a triangle fan */
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glBegin( GL_TRIANGLE_FAN );
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glNormal3f( 0.0, 0.0, -1.0 );
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glTexCoord2f(0.5,1.0);
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glVertex3f( 0.0, 0.0, -radius*nsign );
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rho = M_PI - drho;
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s = 1.0;
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t = dt;
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for (j=slices;j>=0;j--) {
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theta = (j==slices) ? 0.0 : j * dtheta;
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x = -sin(theta) * sin(rho);
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y = cos(theta) * sin(rho);
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z = nsign * cos(rho);
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if (normals) glNormal3f( x*nsign, y*nsign, z*nsign );
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glTexCoord2f(s,1-t);
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s -= ds;
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glVertex3f( x*radius, y*radius, z*radius );
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}
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glEnd();
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}
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