/* $Id: quad.c,v 1.2 2000-03-11 09:05:04 jeroen Exp $ */
/*
** 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 1.0 (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.
**
** $Date: 2000-03-11 09:05:04 $ $Revision: 1.2 $
** $Header: /home/ktk/tmp/odin/2007/netlabs.cvs/odin32/src/opengl/glu/util/quad.c,v 1.2 2000-03-11 09:05:04 jeroen Exp $
*/

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

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

#define PI            3.14159265358979323846

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

GLUquadric * GLAPI
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 GLAPI
gluDeleteQuadric(GLUquadric *state)
{
    free(state);
}

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

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

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

void GLAPI
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 GLAPI
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 GLAPI
gluCylinder(GLUquadric *qobj, GLdouble baseRadius, GLdouble topRadius,
                GLdouble height, GLint slices, GLint stacks)
{
    GLint i,j,max;
    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 x, y, 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 GLAPI
gluDisk(GLUquadric *qobj, GLdouble innerRadius, GLdouble outerRadius,
            GLint slices, GLint loops)
{
    gluPartialDisk(qobj, innerRadius, outerRadius, slices, loops, 0.0, 360.0);
}

void GLAPI
gluPartialDisk(GLUquadric *qobj, GLdouble innerRadius,
                   GLdouble outerRadius, GLint slices, GLint loops,
                   GLdouble startAngle, GLdouble sweepAngle)
{
    GLint i,j,max;
    GLfloat sinCache[CACHE_SIZE];
    GLfloat cosCache[CACHE_SIZE];
    GLfloat angle;
    GLfloat x, y;
    GLfloat sintemp, costemp;
    GLfloat deltaRadius;
    GLfloat radiusLow, radiusHigh;
    GLfloat texLow, texHigh;
    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 GLAPI
gluSphere(GLUquadric *qobj, GLdouble radius, GLint slices, GLint stacks)
{
    GLint i,j,max;
    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 x, y, zLow, zHigh;
    GLfloat sintemp1, sintemp2, sintemp3, sintemp4;
    GLfloat costemp1, costemp2, costemp3, costemp4;
    GLfloat zNormal;
    GLfloat xyNormalRatio;
    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;
    }
}