quad.c

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/*
** License Applicability. Except to the extent portions of this file are
** made subject to an alternative license as permitted in the SGI Free
** Software License B, Version 1.1 (the "License"), the contents of this
** file are subject only to the provisions of the License. You may not use
** this file except in compliance with the License. You may obtain a copy
** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
**
** http://oss.sgi.com/projects/FreeB
**
** Note that, as provided in the License, the Software is distributed on an
** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
**
** Original Code. The Original Code is: OpenGL Sample Implementation,
** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
** Copyright in any portions created by third parties is as indicated
** elsewhere herein. All Rights Reserved.
**
** Additional Notice Provisions: The application programming interfaces
** established by SGI in conjunction with the Original Code are The
** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
** Window System(R) (Version 1.3), released October 19, 1998. This software
** was created using the OpenGL(R) version 1.2.1 Sample Implementation
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
**
*/

#include "gluos.h"
#include "gluint.h"
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/gl.h>
#include <GL/glu.h>

#ifndef GLU_ERROR
#define GLU_ERROR                          100103
#endif

/* Make it not a power of two to avoid cache thrashing on the chip */
#define CACHE_SIZE  240

#undef  PI
#define PI        3.14159265358979323846

struct GLUquadric {
    GLint   normals;
    GLboolean   textureCoords;
    GLint   orientation;
    GLint   drawStyle;
    void    (GLAPIENTRY *errorCallback)( GLint );
};

GLUquadric * GLAPIENTRY
gluNewQuadric(void)
{
    GLUquadric *newstate;

    newstate = (GLUquadric *) malloc(sizeof(GLUquadric));
    if (newstate == NULL) {
    /* Can't report an error at this point... */
    return NULL;
    }
    newstate->normals = GLU_SMOOTH;
    newstate->textureCoords = GL_FALSE;
    newstate->orientation = GLU_OUTSIDE;
    newstate->drawStyle = GLU_FILL;
    newstate->errorCallback = NULL;
    return newstate;
}


void GLAPIENTRY
gluDeleteQuadric(GLUquadric *state)
{
    free(state);
}

static void gluQuadricError(GLUquadric *qobj, GLenum which)
{
    if (qobj->errorCallback) {
    qobj->errorCallback(which);
    }
}

void GLAPIENTRY
gluQuadricCallback(GLUquadric *qobj, GLenum which, _GLUfuncptr fn)
{
    switch (which) {
      case GLU_ERROR:
    qobj->errorCallback = (void (GLAPIENTRY *)(GLint)) fn;
    break;
      default:
    gluQuadricError(qobj, GLU_INVALID_ENUM);
    return;
    }
}

void GLAPIENTRY
gluQuadricNormals(GLUquadric *qobj, GLenum normals)
{
    switch (normals) {
      case GLU_SMOOTH:
      case GLU_FLAT:
      case GLU_NONE:
    break;
      default:
    gluQuadricError(qobj, GLU_INVALID_ENUM);
    return;
    }
    qobj->normals = normals;
}

void GLAPIENTRY
gluQuadricTexture(GLUquadric *qobj, GLboolean textureCoords)
{
    qobj->textureCoords = textureCoords;
}

void GLAPIENTRY
gluQuadricOrientation(GLUquadric *qobj, GLenum orientation)
{
    switch(orientation) {
      case GLU_OUTSIDE:
      case GLU_INSIDE:
    break;
      default:
    gluQuadricError(qobj, GLU_INVALID_ENUM);
    return;
    }
    qobj->orientation = orientation;
}

void GLAPIENTRY
gluQuadricDrawStyle(GLUquadric *qobj, GLenum drawStyle)
{
    switch(drawStyle) {
      case GLU_POINT:
      case GLU_LINE:
      case GLU_FILL:
      case GLU_SILHOUETTE:
    break;
      default:
    gluQuadricError(qobj, GLU_INVALID_ENUM);
    return;
    }
    qobj->drawStyle = drawStyle;
}

void GLAPIENTRY
gluCylinder(GLUquadric *qobj, GLdouble baseRadius, GLdouble topRadius,
        GLdouble height, GLint slices, GLint stacks)
{
    GLint i,j;
    GLfloat sinCache[CACHE_SIZE];
    GLfloat cosCache[CACHE_SIZE];
    GLfloat sinCache2[CACHE_SIZE];
    GLfloat cosCache2[CACHE_SIZE];
    GLfloat sinCache3[CACHE_SIZE];
    GLfloat cosCache3[CACHE_SIZE];
    GLfloat angle;
    GLfloat zLow, zHigh;
    GLfloat sintemp, costemp;
    GLfloat length;
    GLfloat deltaRadius;
    GLfloat zNormal;
    GLfloat xyNormalRatio;
    GLfloat radiusLow, radiusHigh;
    int needCache2, needCache3;

    if (slices >= CACHE_SIZE) slices = CACHE_SIZE-1;

    if (slices < 2 || stacks < 1 || baseRadius < 0.0 || topRadius < 0.0 ||
        height < 0.0) {
    gluQuadricError(qobj, GLU_INVALID_VALUE);
    return;
    }

    /* Compute length (needed for normal calculations) */
    deltaRadius = baseRadius - topRadius;
    length = SQRT(deltaRadius*deltaRadius + height*height);
    if (length == 0.0) {
    gluQuadricError(qobj, GLU_INVALID_VALUE);
    return;
    }

    /* Cache is the vertex locations cache */
    /* Cache2 is the various normals at the vertices themselves */
    /* Cache3 is the various normals for the faces */
    needCache2 = needCache3 = 0;
    if (qobj->normals == GLU_SMOOTH) {
    needCache2 = 1;
    }

    if (qobj->normals == GLU_FLAT) {
    if (qobj->drawStyle != GLU_POINT) {
        needCache3 = 1;
    }
    if (qobj->drawStyle == GLU_LINE) {
        needCache2 = 1;
    }
    }

    zNormal = deltaRadius / length;
    xyNormalRatio = height / length;

    for (i = 0; i < slices; i++) {
    angle = 2 * PI * i / slices;
    if (needCache2) {
        if (qobj->orientation == GLU_OUTSIDE) {
        sinCache2[i] = xyNormalRatio * SIN(angle);
        cosCache2[i] = xyNormalRatio * COS(angle);
        } else {
        sinCache2[i] = -xyNormalRatio * SIN(angle);
        cosCache2[i] = -xyNormalRatio * COS(angle);
        }
    }
    sinCache[i] = SIN(angle);
    cosCache[i] = COS(angle);
    }

    if (needCache3) {
    for (i = 0; i < slices; i++) {
        angle = 2 * PI * (i-0.5) / slices;
        if (qobj->orientation == GLU_OUTSIDE) {
        sinCache3[i] = xyNormalRatio * SIN(angle);
        cosCache3[i] = xyNormalRatio * COS(angle);
        } else {
        sinCache3[i] = -xyNormalRatio * SIN(angle);
        cosCache3[i] = -xyNormalRatio * COS(angle);
        }
    }
    }

    sinCache[slices] = sinCache[0];
    cosCache[slices] = cosCache[0];
    if (needCache2) {
    sinCache2[slices] = sinCache2[0];
    cosCache2[slices] = cosCache2[0];
    }
    if (needCache3) {
    sinCache3[slices] = sinCache3[0];
    cosCache3[slices] = cosCache3[0];
    }

    switch (qobj->drawStyle) {
      case GLU_FILL:
    /* Note:
    ** An argument could be made for using a TRIANGLE_FAN for the end
    ** of the cylinder of either radii is 0.0 (a cone).  However, a
    ** TRIANGLE_FAN would not work in smooth shading mode (the common
    ** case) because the normal for the apex is different for every
    ** triangle (and TRIANGLE_FAN doesn't let me respecify that normal).
    ** Now, my choice is GL_TRIANGLES, or leave the GL_QUAD_STRIP and
    ** just let the GL trivially reject one of the two triangles of the
    ** QUAD.  GL_QUAD_STRIP is probably faster, so I will leave this code
    ** alone.
    */
    for (j = 0; j < stacks; j++) {
        zLow = j * height / stacks;
        zHigh = (j + 1) * height / stacks;
        radiusLow = baseRadius - deltaRadius * ((float) j / stacks);
        radiusHigh = baseRadius - deltaRadius * ((float) (j + 1) / stacks);

        glBegin(GL_QUAD_STRIP);
        for (i = 0; i <= slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
            glNormal3f(sinCache3[i], cosCache3[i], zNormal);
            break;
          case GLU_SMOOTH:
            glNormal3f(sinCache2[i], cosCache2[i], zNormal);
            break;
          case GLU_NONE:
          default:
            break;
        }
        if (qobj->orientation == GLU_OUTSIDE) {
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) j / stacks);
            }
            glVertex3f(radiusLow * sinCache[i],
                radiusLow * cosCache[i], zLow);
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) (j+1) / stacks);
            }
            glVertex3f(radiusHigh * sinCache[i],
                radiusHigh * cosCache[i], zHigh);
        } else {
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) (j+1) / stacks);
            }
            glVertex3f(radiusHigh * sinCache[i],
                radiusHigh * cosCache[i], zHigh);
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) j / stacks);
            }
            glVertex3f(radiusLow * sinCache[i],
                radiusLow * cosCache[i], zLow);
        }
        }
        glEnd();
    }
    break;
      case GLU_POINT:
    glBegin(GL_POINTS);
    for (i = 0; i < slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
          case GLU_SMOOTH:
        glNormal3f(sinCache2[i], cosCache2[i], zNormal);
        break;
          case GLU_NONE:
          default:
        break;
        }
        sintemp = sinCache[i];
        costemp = cosCache[i];
        for (j = 0; j <= stacks; j++) {
        zLow = j * height / stacks;
        radiusLow = baseRadius - deltaRadius * ((float) j / stacks);

        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) j / stacks);
        }
        glVertex3f(radiusLow * sintemp,
            radiusLow * costemp, zLow);
        }
    }
    glEnd();
    break;
      case GLU_LINE:
    for (j = 1; j < stacks; j++) {
        zLow = j * height / stacks;
        radiusLow = baseRadius - deltaRadius * ((float) j / stacks);

        glBegin(GL_LINE_STRIP);
        for (i = 0; i <= slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
            glNormal3f(sinCache3[i], cosCache3[i], zNormal);
            break;
          case GLU_SMOOTH:
            glNormal3f(sinCache2[i], cosCache2[i], zNormal);
            break;
          case GLU_NONE:
          default:
            break;
        }
        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) j / stacks);
        }
        glVertex3f(radiusLow * sinCache[i],
            radiusLow * cosCache[i], zLow);
        }
        glEnd();
    }
    /* Intentionally fall through here... */
      case GLU_SILHOUETTE:
    for (j = 0; j <= stacks; j += stacks) {
        zLow = j * height / stacks;
        radiusLow = baseRadius - deltaRadius * ((float) j / stacks);

        glBegin(GL_LINE_STRIP);
        for (i = 0; i <= slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
            glNormal3f(sinCache3[i], cosCache3[i], zNormal);
            break;
          case GLU_SMOOTH:
            glNormal3f(sinCache2[i], cosCache2[i], zNormal);
            break;
          case GLU_NONE:
          default:
            break;
        }
        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) j / stacks);
        }
        glVertex3f(radiusLow * sinCache[i], radiusLow * cosCache[i],
            zLow);
        }
        glEnd();
    }
    for (i = 0; i < slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
          case GLU_SMOOTH:
        glNormal3f(sinCache2[i], cosCache2[i], 0.0);
        break;
          case GLU_NONE:
          default:
        break;
        }
        sintemp = sinCache[i];
        costemp = cosCache[i];
        glBegin(GL_LINE_STRIP);
        for (j = 0; j <= stacks; j++) {
        zLow = j * height / stacks;
        radiusLow = baseRadius - deltaRadius * ((float) j / stacks);

        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                (float) j / stacks);
        }
        glVertex3f(radiusLow * sintemp,
            radiusLow * costemp, zLow);
        }
        glEnd();
    }
    break;
      default:
    break;
    }
}

void GLAPIENTRY
gluDisk(GLUquadric *qobj, GLdouble innerRadius, GLdouble outerRadius,
        GLint slices, GLint loops)
{
    gluPartialDisk(qobj, innerRadius, outerRadius, slices, loops, 0.0, 360.0);
}

void GLAPIENTRY
gluPartialDisk(GLUquadric *qobj, GLdouble innerRadius,
           GLdouble outerRadius, GLint slices, GLint loops,
           GLdouble startAngle, GLdouble sweepAngle)
{
    GLint i,j;
    GLfloat sinCache[CACHE_SIZE];
    GLfloat cosCache[CACHE_SIZE];
    GLfloat angle;
    GLfloat sintemp, costemp;
    GLfloat deltaRadius;
    GLfloat radiusLow, radiusHigh;
    GLfloat texLow = 0, texHigh = 0;
    GLfloat angleOffset;
    GLint slices2;
    GLint finish;

    if (slices >= CACHE_SIZE) slices = CACHE_SIZE-1;
    if (slices < 2 || loops < 1 || outerRadius <= 0.0 || innerRadius < 0.0 ||
        innerRadius > outerRadius) {
    gluQuadricError(qobj, GLU_INVALID_VALUE);
    return;
    }

    if (sweepAngle < -360.0) sweepAngle = 360.0;
    if (sweepAngle > 360.0) sweepAngle = 360.0;
    if (sweepAngle < 0) {
    startAngle += sweepAngle;
    sweepAngle = -sweepAngle;
    }

    if (sweepAngle == 360.0) {
    slices2 = slices;
    } else {
    slices2 = slices + 1;
    }

    /* Compute length (needed for normal calculations) */
    deltaRadius = outerRadius - innerRadius;

    /* Cache is the vertex locations cache */

    angleOffset = startAngle / 180.0 * PI;
    for (i = 0; i <= slices; i++) {
    angle = angleOffset + ((PI * sweepAngle) / 180.0) * i / slices;
    sinCache[i] = SIN(angle);
    cosCache[i] = COS(angle);
    }

    if (sweepAngle == 360.0) {
    sinCache[slices] = sinCache[0];
    cosCache[slices] = cosCache[0];
    }

    switch(qobj->normals) {
      case GLU_FLAT:
      case GLU_SMOOTH:
    if (qobj->orientation == GLU_OUTSIDE) {
        glNormal3f(0.0, 0.0, 1.0);
    } else {
        glNormal3f(0.0, 0.0, -1.0);
    }
    break;
      default:
      case GLU_NONE:
    break;
    }

    switch (qobj->drawStyle) {
      case GLU_FILL:
    if (innerRadius == 0.0) {
        finish = loops - 1;
        /* Triangle strip for inner polygons */
        glBegin(GL_TRIANGLE_FAN);
        if (qobj->textureCoords) {
        glTexCoord2f(0.5, 0.5);
        }
        glVertex3f(0.0, 0.0, 0.0);
        radiusLow = outerRadius -
            deltaRadius * ((float) (loops-1) / loops);
        if (qobj->textureCoords) {
        texLow = radiusLow / outerRadius / 2;
        }

        if (qobj->orientation == GLU_OUTSIDE) {
        for (i = slices; i >= 0; i--) {
            if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
            }
            glVertex3f(radiusLow * sinCache[i],
                radiusLow * cosCache[i], 0.0);
        }
        } else {
        for (i = 0; i <= slices; i++) {
            if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
            }
            glVertex3f(radiusLow * sinCache[i],
                radiusLow * cosCache[i], 0.0);
        }
        }
        glEnd();
    } else {
        finish = loops;
    }
    for (j = 0; j < finish; j++) {
        radiusLow = outerRadius - deltaRadius * ((float) j / loops);
        radiusHigh = outerRadius - deltaRadius * ((float) (j + 1) / loops);
        if (qobj->textureCoords) {
        texLow = radiusLow / outerRadius / 2;
        texHigh = radiusHigh / outerRadius / 2;
        }

        glBegin(GL_QUAD_STRIP);
        for (i = 0; i <= slices; i++) {
        if (qobj->orientation == GLU_OUTSIDE) {
            if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
            }
            glVertex3f(radiusLow * sinCache[i],
                radiusLow * cosCache[i], 0.0);

            if (qobj->textureCoords) {
            glTexCoord2f(texHigh * sinCache[i] + 0.5,
                texHigh * cosCache[i] + 0.5);
            }
            glVertex3f(radiusHigh * sinCache[i],
                radiusHigh * cosCache[i], 0.0);
        } else {
            if (qobj->textureCoords) {
            glTexCoord2f(texHigh * sinCache[i] + 0.5,
                texHigh * cosCache[i] + 0.5);
            }
            glVertex3f(radiusHigh * sinCache[i],
                radiusHigh * cosCache[i], 0.0);

            if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
            }
            glVertex3f(radiusLow * sinCache[i],
                radiusLow * cosCache[i], 0.0);
        }
        }
        glEnd();
    }
    break;
      case GLU_POINT:
    glBegin(GL_POINTS);
    for (i = 0; i < slices2; i++) {
        sintemp = sinCache[i];
        costemp = cosCache[i];
        for (j = 0; j <= loops; j++) {
        radiusLow = outerRadius - deltaRadius * ((float) j / loops);

        if (qobj->textureCoords) {
            texLow = radiusLow / outerRadius / 2;

            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
        }
        glVertex3f(radiusLow * sintemp, radiusLow * costemp, 0.0);
        }
    }
    glEnd();
    break;
      case GLU_LINE:
    if (innerRadius == outerRadius) {
        glBegin(GL_LINE_STRIP);

        for (i = 0; i <= slices; i++) {
        if (qobj->textureCoords) {
            glTexCoord2f(sinCache[i] / 2 + 0.5,
                cosCache[i] / 2 + 0.5);
        }
        glVertex3f(innerRadius * sinCache[i],
            innerRadius * cosCache[i], 0.0);
        }
        glEnd();
        break;
    }
    for (j = 0; j <= loops; j++) {
        radiusLow = outerRadius - deltaRadius * ((float) j / loops);
        if (qobj->textureCoords) {
        texLow = radiusLow / outerRadius / 2;
        }

        glBegin(GL_LINE_STRIP);
        for (i = 0; i <= slices; i++) {
        if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
        }
        glVertex3f(radiusLow * sinCache[i],
            radiusLow * cosCache[i], 0.0);
        }
        glEnd();
    }
    for (i=0; i < slices2; i++) {
        sintemp = sinCache[i];
        costemp = cosCache[i];
        glBegin(GL_LINE_STRIP);
        for (j = 0; j <= loops; j++) {
        radiusLow = outerRadius - deltaRadius * ((float) j / loops);
        if (qobj->textureCoords) {
            texLow = radiusLow / outerRadius / 2;
        }

        if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
        }
        glVertex3f(radiusLow * sintemp, radiusLow * costemp, 0.0);
        }
        glEnd();
    }
    break;
      case GLU_SILHOUETTE:
    if (sweepAngle < 360.0) {
        for (i = 0; i <= slices; i+= slices) {
        sintemp = sinCache[i];
        costemp = cosCache[i];
        glBegin(GL_LINE_STRIP);
        for (j = 0; j <= loops; j++) {
            radiusLow = outerRadius - deltaRadius * ((float) j / loops);

            if (qobj->textureCoords) {
            texLow = radiusLow / outerRadius / 2;
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
            }
            glVertex3f(radiusLow * sintemp, radiusLow * costemp, 0.0);
        }
        glEnd();
        }
    }
    for (j = 0; j <= loops; j += loops) {
        radiusLow = outerRadius - deltaRadius * ((float) j / loops);
        if (qobj->textureCoords) {
        texLow = radiusLow / outerRadius / 2;
        }

        glBegin(GL_LINE_STRIP);
        for (i = 0; i <= slices; i++) {
        if (qobj->textureCoords) {
            glTexCoord2f(texLow * sinCache[i] + 0.5,
                texLow * cosCache[i] + 0.5);
        }
        glVertex3f(radiusLow * sinCache[i],
            radiusLow * cosCache[i], 0.0);
        }
        glEnd();
        if (innerRadius == outerRadius) break;
    }
    break;
      default:
    break;
    }
}

void GLAPIENTRY
gluSphere(GLUquadric *qobj, GLdouble radius, GLint slices, GLint stacks)
{
    GLint i,j;
    GLfloat sinCache1a[CACHE_SIZE];
    GLfloat cosCache1a[CACHE_SIZE];
    GLfloat sinCache2a[CACHE_SIZE];
    GLfloat cosCache2a[CACHE_SIZE];
    GLfloat sinCache3a[CACHE_SIZE];
    GLfloat cosCache3a[CACHE_SIZE];
    GLfloat sinCache1b[CACHE_SIZE];
    GLfloat cosCache1b[CACHE_SIZE];
    GLfloat sinCache2b[CACHE_SIZE];
    GLfloat cosCache2b[CACHE_SIZE];
    GLfloat sinCache3b[CACHE_SIZE];
    GLfloat cosCache3b[CACHE_SIZE];
    GLfloat angle;
    GLfloat zLow, zHigh;
    GLfloat sintemp1, sintemp2=0, sintemp3=0, sintemp4=0;
    GLfloat costemp1, costemp2=0, costemp3=0, costemp4=0;
    GLboolean needCache2, needCache3;
    GLint start, finish;

    if (slices >= CACHE_SIZE) slices = CACHE_SIZE-1;
    if (stacks >= CACHE_SIZE) stacks = CACHE_SIZE-1;
    if (slices < 2 || stacks < 1 || radius < 0.0) {
    gluQuadricError(qobj, GLU_INVALID_VALUE);
    return;
    }

    /* Cache is the vertex locations cache */
    /* Cache2 is the various normals at the vertices themselves */
    /* Cache3 is the various normals for the faces */
    needCache2 = needCache3 = GL_FALSE;

    if (qobj->normals == GLU_SMOOTH) {
    needCache2 = GL_TRUE;
    }

    if (qobj->normals == GLU_FLAT) {
    if (qobj->drawStyle != GLU_POINT) {
        needCache3 = GL_TRUE;
    }
    if (qobj->drawStyle == GLU_LINE) {
        needCache2 = GL_TRUE;
    }
    }

    for (i = 0; i < slices; i++) {
    angle = 2 * PI * i / slices;
    sinCache1a[i] = SIN(angle);
    cosCache1a[i] = COS(angle);
    if (needCache2) {
        sinCache2a[i] = sinCache1a[i];
        cosCache2a[i] = cosCache1a[i];
    }
    }

    for (j = 0; j <= stacks; j++) {
    angle = PI * j / stacks;
    if (needCache2) {
        if (qobj->orientation == GLU_OUTSIDE) {
        sinCache2b[j] = SIN(angle);
        cosCache2b[j] = COS(angle);
        } else {
        sinCache2b[j] = -SIN(angle);
        cosCache2b[j] = -COS(angle);
        }
    }
    sinCache1b[j] = radius * SIN(angle);
    cosCache1b[j] = radius * COS(angle);
    }
    /* Make sure it comes to a point */
    sinCache1b[0] = 0;
    sinCache1b[stacks] = 0;

    if (needCache3) {
    for (i = 0; i < slices; i++) {
        angle = 2 * PI * (i-0.5) / slices;
        sinCache3a[i] = SIN(angle);
        cosCache3a[i] = COS(angle);
    }
    for (j = 0; j <= stacks; j++) {
        angle = PI * (j - 0.5) / stacks;
        if (qobj->orientation == GLU_OUTSIDE) {
        sinCache3b[j] = SIN(angle);
        cosCache3b[j] = COS(angle);
        } else {
        sinCache3b[j] = -SIN(angle);
        cosCache3b[j] = -COS(angle);
        }
    }
    }

    sinCache1a[slices] = sinCache1a[0];
    cosCache1a[slices] = cosCache1a[0];
    if (needCache2) {
    sinCache2a[slices] = sinCache2a[0];
    cosCache2a[slices] = cosCache2a[0];
    }
    if (needCache3) {
    sinCache3a[slices] = sinCache3a[0];
    cosCache3a[slices] = cosCache3a[0];
    }

    switch (qobj->drawStyle) {
      case GLU_FILL:
    /* Do ends of sphere as TRIANGLE_FAN's (if not texturing)
    ** We don't do it when texturing because we need to respecify the
    ** texture coordinates of the apex for every adjacent vertex (because
    ** it isn't a constant for that point)
    */
    if (!(qobj->textureCoords)) {
        start = 1;
        finish = stacks - 1;

        /* Low end first (j == 0 iteration) */
        sintemp2 = sinCache1b[1];
        zHigh = cosCache1b[1];
        switch(qobj->normals) {
          case GLU_FLAT:
        sintemp3 = sinCache3b[1];
        costemp3 = cosCache3b[1];
        break;
          case GLU_SMOOTH:
        sintemp3 = sinCache2b[1];
        costemp3 = cosCache2b[1];
        glNormal3f(sinCache2a[0] * sinCache2b[0],
            cosCache2a[0] * sinCache2b[0],
            cosCache2b[0]);
        break;
          default:
        break;
        }
        glBegin(GL_TRIANGLE_FAN);
        glVertex3f(0.0, 0.0, radius);
        if (qobj->orientation == GLU_OUTSIDE) {
        for (i = slices; i >= 0; i--) {
            switch(qobj->normals) {
              case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp3,
                cosCache2a[i] * sintemp3,
                costemp3);
            break;
              case GLU_FLAT:
            if (i != slices) {
                glNormal3f(sinCache3a[i+1] * sintemp3,
                    cosCache3a[i+1] * sintemp3,
                    costemp3);
            }
            break;
              case GLU_NONE:
              default:
            break;
            }
            glVertex3f(sintemp2 * sinCache1a[i],
                sintemp2 * cosCache1a[i], zHigh);
        }
        } else {
        for (i = 0; i <= slices; i++) {
            switch(qobj->normals) {
              case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp3,
                cosCache2a[i] * sintemp3,
                costemp3);
            break;
              case GLU_FLAT:
            glNormal3f(sinCache3a[i] * sintemp3,
                cosCache3a[i] * sintemp3,
                costemp3);
            break;
              case GLU_NONE:
              default:
            break;
            }
            glVertex3f(sintemp2 * sinCache1a[i],
                sintemp2 * cosCache1a[i], zHigh);
        }
        }
        glEnd();

        /* High end next (j == stacks-1 iteration) */
        sintemp2 = sinCache1b[stacks-1];
        zHigh = cosCache1b[stacks-1];
        switch(qobj->normals) {
          case GLU_FLAT:
        sintemp3 = sinCache3b[stacks];
        costemp3 = cosCache3b[stacks];
        break;
          case GLU_SMOOTH:
        sintemp3 = sinCache2b[stacks-1];
        costemp3 = cosCache2b[stacks-1];
        glNormal3f(sinCache2a[stacks] * sinCache2b[stacks],
            cosCache2a[stacks] * sinCache2b[stacks],
            cosCache2b[stacks]);
        break;
          default:
        break;
        }
        glBegin(GL_TRIANGLE_FAN);
        glVertex3f(0.0, 0.0, -radius);
        if (qobj->orientation == GLU_OUTSIDE) {
        for (i = 0; i <= slices; i++) {
            switch(qobj->normals) {
              case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp3,
                cosCache2a[i] * sintemp3,
                costemp3);
            break;
              case GLU_FLAT:
            glNormal3f(sinCache3a[i] * sintemp3,
                cosCache3a[i] * sintemp3,
                costemp3);
            break;
              case GLU_NONE:
              default:
            break;
            }
            glVertex3f(sintemp2 * sinCache1a[i],
                sintemp2 * cosCache1a[i], zHigh);
        }
        } else {
        for (i = slices; i >= 0; i--) {
            switch(qobj->normals) {
              case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp3,
                cosCache2a[i] * sintemp3,
                costemp3);
            break;
              case GLU_FLAT:
            if (i != slices) {
                glNormal3f(sinCache3a[i+1] * sintemp3,
                    cosCache3a[i+1] * sintemp3,
                    costemp3);
            }
            break;
              case GLU_NONE:
              default:
            break;
            }
            glVertex3f(sintemp2 * sinCache1a[i],
                sintemp2 * cosCache1a[i], zHigh);
        }
        }
        glEnd();
    } else {
        start = 0;
        finish = stacks;
    }
    for (j = start; j < finish; j++) {
        zLow = cosCache1b[j];
        zHigh = cosCache1b[j+1];
        sintemp1 = sinCache1b[j];
        sintemp2 = sinCache1b[j+1];
        switch(qobj->normals) {
          case GLU_FLAT:
        sintemp4 = sinCache3b[j+1];
        costemp4 = cosCache3b[j+1];
        break;
          case GLU_SMOOTH:
        if (qobj->orientation == GLU_OUTSIDE) {
            sintemp3 = sinCache2b[j+1];
            costemp3 = cosCache2b[j+1];
            sintemp4 = sinCache2b[j];
            costemp4 = cosCache2b[j];
        } else {
            sintemp3 = sinCache2b[j];
            costemp3 = cosCache2b[j];
            sintemp4 = sinCache2b[j+1];
            costemp4 = cosCache2b[j+1];
        }
        break;
          default:
        break;
        }

        glBegin(GL_QUAD_STRIP);
        for (i = 0; i <= slices; i++) {
        switch(qobj->normals) {
          case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp3,
                cosCache2a[i] * sintemp3,
                costemp3);
            break;
          case GLU_FLAT:
          case GLU_NONE:
          default:
            break;
        }
        if (qobj->orientation == GLU_OUTSIDE) {
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) (j+1) / stacks);
            }
            glVertex3f(sintemp2 * sinCache1a[i],
                sintemp2 * cosCache1a[i], zHigh);
        } else {
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) j / stacks);
            }
            glVertex3f(sintemp1 * sinCache1a[i],
                sintemp1 * cosCache1a[i], zLow);
        }
        switch(qobj->normals) {
          case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp4,
                cosCache2a[i] * sintemp4,
                costemp4);
            break;
          case GLU_FLAT:
            glNormal3f(sinCache3a[i] * sintemp4,
                cosCache3a[i] * sintemp4,
                costemp4);
            break;
          case GLU_NONE:
          default:
            break;
        }
        if (qobj->orientation == GLU_OUTSIDE) {
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) j / stacks);
            }
            glVertex3f(sintemp1 * sinCache1a[i],
                sintemp1 * cosCache1a[i], zLow);
        } else {
            if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) (j+1) / stacks);
            }
            glVertex3f(sintemp2 * sinCache1a[i],
                sintemp2 * cosCache1a[i], zHigh);
        }
        }
        glEnd();
    }
    break;
      case GLU_POINT:
    glBegin(GL_POINTS);
    for (j = 0; j <= stacks; j++) {
        sintemp1 = sinCache1b[j];
        costemp1 = cosCache1b[j];
        switch(qobj->normals) {
          case GLU_FLAT:
          case GLU_SMOOTH:
        sintemp2 = sinCache2b[j];
        costemp2 = cosCache2b[j];
        break;
          default:
        break;
        }
        for (i = 0; i < slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
          case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp2,
                cosCache2a[i] * sintemp2,
                costemp2);
            break;
          case GLU_NONE:
          default:
            break;
        }

        zLow = j * radius / stacks;

        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) j / stacks);
        }
        glVertex3f(sintemp1 * sinCache1a[i],
            sintemp1 * cosCache1a[i], costemp1);
        }
    }
    glEnd();
    break;
      case GLU_LINE:
      case GLU_SILHOUETTE:
    for (j = 1; j < stacks; j++) {
        sintemp1 = sinCache1b[j];
        costemp1 = cosCache1b[j];
        switch(qobj->normals) {
          case GLU_FLAT:
          case GLU_SMOOTH:
        sintemp2 = sinCache2b[j];
        costemp2 = cosCache2b[j];
        break;
          default:
        break;
        }

        glBegin(GL_LINE_STRIP);
        for (i = 0; i <= slices; i++) {
        switch(qobj->normals) {
          case GLU_FLAT:
            glNormal3f(sinCache3a[i] * sintemp2,
                cosCache3a[i] * sintemp2,
                costemp2);
            break;
          case GLU_SMOOTH:
            glNormal3f(sinCache2a[i] * sintemp2,
                cosCache2a[i] * sintemp2,
                costemp2);
            break;
          case GLU_NONE:
          default:
            break;
        }
        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) j / stacks);
        }
        glVertex3f(sintemp1 * sinCache1a[i],
            sintemp1 * cosCache1a[i], costemp1);
        }
        glEnd();
    }
    for (i = 0; i < slices; i++) {
        sintemp1 = sinCache1a[i];
        costemp1 = cosCache1a[i];
        switch(qobj->normals) {
          case GLU_FLAT:
          case GLU_SMOOTH:
        sintemp2 = sinCache2a[i];
        costemp2 = cosCache2a[i];
        break;
          default:
        break;
        }

        glBegin(GL_LINE_STRIP);
        for (j = 0; j <= stacks; j++) {
        switch(qobj->normals) {
          case GLU_FLAT:
            glNormal3f(sintemp2 * sinCache3b[j],
                costemp2 * sinCache3b[j],
                cosCache3b[j]);
            break;
          case GLU_SMOOTH:
            glNormal3f(sintemp2 * sinCache2b[j],
                costemp2 * sinCache2b[j],
                cosCache2b[j]);
            break;
          case GLU_NONE:
          default:
            break;
        }

        if (qobj->textureCoords) {
            glTexCoord2f(1 - (float) i / slices,
                1 - (float) j / stacks);
        }
        glVertex3f(sintemp1 * sinCache1b[j],
            costemp1 * sinCache1b[j], cosCache1b[j]);
        }
        glEnd();
    }
    break;
      default:
    break;
    }
}