xref: /xsrc/external/mit/glu/dist/src/libutil/quad.c

/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * shall be included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */

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

/* 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 = 0.0, texHigh = 0.0;
    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 = 0.0, sintemp2 = 0.0, sintemp3 = 0.0, sintemp4 = 0.0;
    GLfloat costemp1 = 0.0, costemp2 = 0.0, costemp3 = 0.0, costemp4 = 0.0;
    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;
    }
}