X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Ffreeglut_geometry.c;h=3c7a835a6ce02e9b999fdffc33dd99021d732bd6;hb=9807c5fdb2f20f098c7046786908a7f3ce1dc2d4;hp=83715bb2f8b8c2a3eb21c43ba3677bf511f2e84a;hpb=2e5dc871b7c1df472978af9811d0e97b6684707c;p=freeglut

diff --git a/src/freeglut_geometry.c b/src/freeglut_geometry.c
index 83715bb..3c7a835 100644
--- a/src/freeglut_geometry.c
+++ b/src/freeglut_geometry.c
@@ -25,11 +25,7 @@
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
 
-#ifdef HAVE_CONFIG_H
-#include "config.h"
-#endif
-
-#include "../include/GL/freeglut.h"
+#include <GL/freeglut.h>
 #include "freeglut_internal.h"
 
 /*
@@ -39,13 +35,6 @@
  *
  *      glutWireCube()          -- looks OK
  *      glutSolidCube()         -- OK
- *      glutWireSphere()        -- OK
- *      glutSolidSphere()       -- OK
- *
- * Following functions have been implemented by Pawel and modified by John Fay:
- *
- *      glutWireCone()          -- looks OK
- *      glutSolidCone()         -- looks OK
  *
  * Those functions have been implemented by John Fay.
  *
@@ -59,6 +48,14 @@
  *      glutSolidTetrahedron()  -- looks OK
  *      glutWireIcosahedron()   -- looks OK
  *      glutSolidIcosahedron()  -- looks OK
+ *
+ *  The Following functions have been updated by Nigel Stewart, based
+ *  on FreeGLUT 2.0.0 implementations:
+ *
+ *      glutWireSphere()        -- looks OK
+ *      glutSolidSphere()       -- looks OK
+ *      glutWireCone()          -- looks OK
+ *      glutSolidCone()         -- looks OK
  */
 
 
@@ -71,12 +68,12 @@ void FGAPIENTRY glutWireCube( GLdouble dSize )
 {
     double size = dSize * 0.5;
 
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireCube" );
+
 #   define V(a,b,c) glVertex3d( a size, b size, c size );
 #   define N(a,b,c) glNormal3d( a, b, c );
 
-    /*
-     * PWO: I dared to convert the code to use macros...
-     */
+    /* PWO: I dared to convert the code to use macros... */
     glBegin( GL_LINE_LOOP ); N( 1.0, 0.0, 0.0); V(+,-,+); V(+,-,-); V(+,+,-); V(+,+,+); glEnd();
     glBegin( GL_LINE_LOOP ); N( 0.0, 1.0, 0.0); V(+,+,+); V(+,+,-); V(-,+,-); V(-,+,+); glEnd();
     glBegin( GL_LINE_LOOP ); N( 0.0, 0.0, 1.0); V(+,+,+); V(-,+,+); V(-,-,+); V(+,-,+); glEnd();
@@ -95,12 +92,12 @@ void FGAPIENTRY glutSolidCube( GLdouble dSize )
 {
     double size = dSize * 0.5;
 
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCube" );
+
 #   define V(a,b,c) glVertex3d( a size, b size, c size );
 #   define N(a,b,c) glNormal3d( a, b, c );
 
-    /*
-     * PWO: Again, I dared to convert the code to use macros...
-     */
+    /* PWO: Again, I dared to convert the code to use macros... */
     glBegin( GL_QUADS );
         N( 1.0, 0.0, 0.0); V(+,-,+); V(+,-,-); V(+,+,-); V(+,+,+);
         N( 0.0, 1.0, 0.0); V(+,+,+); V(+,+,-); V(-,+,-); V(-,+,+);
@@ -115,376 +112,496 @@ void FGAPIENTRY glutSolidCube( GLdouble dSize )
 }
 
 /*
- * Draws a wire sphere. Code contributed by Andreas Umbach <marvin@dataway.ch>
+ * Compute lookup table of cos and sin values forming a cirle
+ *
+ * Notes:
+ *    It is the responsibility of the caller to free these tables
+ *    The size of the table is (n+1) to form a connected loop
+ *    The last entry is exactly the same as the first
+ *    The sign of n can be flipped to get the reverse loop
  */
-void FGAPIENTRY glutWireSphere( GLdouble dRadius, GLint slices, GLint stacks )
+
+static void fghCircleTable(double **sint,double **cost,const int n)
 {
-    double  radius = dRadius, phi, psi, dpsi, dphi;
-    double *vertex;
-    int    i, j;
-    double cphi, sphi, cpsi, spsi ;
+    int i;
+
+    /* Table size, the sign of n flips the circle direction */
+
+    const int size = abs(n);
 
-    /*
-     * Allocate the vertices array
-     */
-    vertex = (double *)calloc( sizeof(double), 3 * slices * (stacks - 1) );
+    /* Determine the angle between samples */
 
-    glPushMatrix();
-    glScaled( radius, radius, radius );
+    const double angle = 2*M_PI/(double)( ( n == 0 ) ? 1 : n );
 
-    dpsi = M_PI / (stacks + 1);
-    dphi = 2 * M_PI / slices;
-    psi  = dpsi;
+    /* Allocate memory for n samples, plus duplicate of first entry at the end */
 
-    for( j=0; j<stacks-1; j++ )
+    *sint = (double *) calloc(sizeof(double), size+1);
+    *cost = (double *) calloc(sizeof(double), size+1);
+
+    /* Bail out if memory allocation fails, fgError never returns */
+
+    if (!(*sint) || !(*cost))
+    {
+        free(*sint);
+        free(*cost);
+        fgError("Failed to allocate memory in fghCircleTable");
+    }
+
+    /* Compute cos and sin around the circle */
+
+    (*sint)[0] = 0.0;
+    (*cost)[0] = 1.0;
+
+    for (i=1; i<size; i++)
     {
-        cpsi = cos ( psi ) ;
-        spsi = sin ( psi ) ;
-        phi = 0.0;
+        (*sint)[i] = sin(angle*i);
+        (*cost)[i] = cos(angle*i);
+    }
+
+    /* Last sample is duplicate of the first */
+
+    (*sint)[size] = (*sint)[0];
+    (*cost)[size] = (*cost)[0];
+}
+
+/*
+ * Draws a solid sphere
+ */
+void FGAPIENTRY glutSolidSphere(GLdouble radius, GLint slices, GLint stacks)
+{
+    int i,j;
 
-        for( i=0; i<slices; i++ )
+    /* Adjust z and radius as stacks are drawn. */
+
+    double z0,z1;
+    double r0,r1;
+
+    /* Pre-computed circle */
+
+    double *sint1,*cost1;
+    double *sint2,*cost2;
+
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidSphere" );
+
+    fghCircleTable(&sint1,&cost1,-slices);
+    fghCircleTable(&sint2,&cost2,stacks*2);
+
+    /* The top stack is covered with a triangle fan */
+
+    z0 = 1.0;
+    z1 = cost2[(stacks>0)?1:0];
+    r0 = 0.0;
+    r1 = sint2[(stacks>0)?1:0];
+
+    glBegin(GL_TRIANGLE_FAN);
+
+        glNormal3d(0,0,1);
+        glVertex3d(0,0,radius);
+
+        for (j=slices; j>=0; j--)
         {
-          int offset = 3 * ( j * slices + i ) ;
-          cphi = cos ( phi ) ;
-          sphi = sin ( phi ) ;
-            *(vertex + offset + 0) = sphi * spsi ;
-            *(vertex + offset + 1) = cphi * spsi ;
-            *(vertex + offset + 2) = cpsi ;
-            phi += dphi;
+            glNormal3d(cost1[j]*r1,        sint1[j]*r1,        z1       );
+            glVertex3d(cost1[j]*r1*radius, sint1[j]*r1*radius, z1*radius);
         }
 
-        psi += dpsi;
-    }
+    glEnd();
 
-    for( i=0; i<slices; i++ )
+    /* Cover each stack with a quad strip, except the top and bottom stacks */
+
+    for( i=1; i<stacks-1; i++ )
     {
-        glBegin( GL_LINE_STRIP );
-        glNormal3d( 0, 0, 1 );
-        glVertex3d( 0, 0, 1 );
+        z0 = z1; z1 = cost2[i+1];
+        r0 = r1; r1 = sint2[i+1];
+
+        glBegin(GL_QUAD_STRIP);
+
+            for(j=0; j<=slices; j++)
+            {
+                glNormal3d(cost1[j]*r1,        sint1[j]*r1,        z1       );
+                glVertex3d(cost1[j]*r1*radius, sint1[j]*r1*radius, z1*radius);
+                glNormal3d(cost1[j]*r0,        sint1[j]*r0,        z0       );
+                glVertex3d(cost1[j]*r0*radius, sint1[j]*r0*radius, z0*radius);
+            }
 
-        for( j=0; j<stacks - 1; j++ )
+        glEnd();
+    }
+
+    /* The bottom stack is covered with a triangle fan */
+
+    z0 = z1;
+    r0 = r1;
+
+    glBegin(GL_TRIANGLE_FAN);
+
+        glNormal3d(0,0,-1);
+        glVertex3d(0,0,-radius);
+
+        for (j=0; j<=slices; j++)
         {
-          int offset = 3 * ( j * slices + i ) ;
-            glNormal3dv( vertex + offset );
-            glVertex3dv( vertex + offset );
+            glNormal3d(cost1[j]*r0,        sint1[j]*r0,        z0       );
+            glVertex3d(cost1[j]*r0*radius, sint1[j]*r0*radius, z0*radius);
         }
 
-        glNormal3d(0, 0, -1);
-        glVertex3d(0, 0, -1);
+    glEnd();
+
+    /* Release sin and cos tables */
+
+    free(sint1);
+    free(cost1);
+    free(sint2);
+    free(cost2);
+}
+
+/*
+ * Draws a wire sphere
+ */
+void FGAPIENTRY glutWireSphere(GLdouble radius, GLint slices, GLint stacks)
+{
+    int i,j;
+
+    /* Adjust z and radius as stacks and slices are drawn. */
+
+    double r;
+    double x,y,z;
+
+    /* Pre-computed circle */
+
+    double *sint1,*cost1;
+    double *sint2,*cost2;
+
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireSphere" );
+
+    fghCircleTable(&sint1,&cost1,-slices  );
+    fghCircleTable(&sint2,&cost2, stacks*2);
+
+    /* Draw a line loop for each stack */
+
+    for (i=1; i<stacks; i++)
+    {
+        z = cost2[i];
+        r = sint2[i];
+
+        glBegin(GL_LINE_LOOP);
+
+            for(j=0; j<=slices; j++)
+            {
+                x = cost1[j];
+                y = sint1[j];
+
+                glNormal3d(x,y,z);
+                glVertex3d(x*r*radius,y*r*radius,z*radius);
+            }
+
         glEnd();
     }
 
-    for( j=0; j<stacks-1; j++ )
+    /* Draw a line loop for each slice */
+
+    for (i=0; i<slices; i++)
     {
-        glBegin(GL_LINE_LOOP);
+        glBegin(GL_LINE_STRIP);
 
-        for( i=0; i<slices; i++ )
-        {
-          int offset = 3 * ( j * slices + i ) ;
-            glNormal3dv( vertex + offset );
-            glVertex3dv( vertex + offset );
-        }
+            for(j=0; j<=stacks; j++)
+            {
+                x = cost1[i]*sint2[j];
+                y = sint1[i]*sint2[j];
+                z = cost2[j];
+
+                glNormal3d(x,y,z);
+                glVertex3d(x*radius,y*radius,z*radius);
+            }
 
         glEnd();
     }
 
-    free( vertex );
-    glPopMatrix();
+    /* Release sin and cos tables */
+
+    free(sint1);
+    free(cost1);
+    free(sint2);
+    free(cost2);
 }
 
 /*
- * Draws a solid sphere. Code contributed by Andreas Umbach <marvin@dataway.ch>
+ * Draws a solid cone
  */
-void FGAPIENTRY glutSolidSphere( GLdouble dRadius, GLint slices, GLint stacks )
+void FGAPIENTRY glutSolidCone( GLdouble base, GLdouble height, GLint slices, GLint stacks )
 {
-    double  radius = dRadius, phi, psi, dpsi, dphi;
-    double *next, *tmp, *row;
-    int    i, j;
-    double cphi, sphi, cpsi, spsi ;
+    int i,j;
 
-    glPushMatrix();
-    /* glScalef( radius, radius, radius ); */
+    /* Step in z and radius as stacks are drawn. */
 
-    row  = (double *)calloc( sizeof(double), slices * 3 );
-    next = (double *)calloc( sizeof(double), slices * 3 );
+    double z0,z1;
+    double r0,r1;
 
-    dpsi = M_PI / (stacks + 1);
-    dphi = 2 * M_PI / slices;
-    psi  = dpsi;
-    phi  = 0;
+    const double zStep = height / ( ( stacks > 0 ) ? stacks : 1 );
+    const double rStep = base / ( ( stacks > 0 ) ? stacks : 1 );
 
-    /* init first line + do polar cap */
-    glBegin( GL_TRIANGLE_FAN );
-    glNormal3d( 0.0, 0.0, 1.0 );
-    glVertex3d( 0.0, 0.0, radius );
+    /* Scaling factors for vertex normals */
 
-    for( i=0; i<slices; i++ )
-    {
-        row[ i * 3 + 0 ] = sin( phi ) * sin( psi );
-        row[ i * 3 + 1 ] = cos( phi ) * sin( psi );
-        row[ i * 3 + 2 ] = cos( psi );
-
-        glNormal3dv( row + 3 * i );
-        glVertex3d(
-            radius * *(row + 3 * i + 0),
-            radius * *(row + 3 * i + 1),
-                  radius * *(row + 3 * i + 2)
-            );
-        
-        phi += dphi;
-    }
+    const double cosn = ( height / sqrt ( height * height + base * base ));
+    const double sinn = ( base   / sqrt ( height * height + base * base ));
+
+    /* Pre-computed circle */
+
+    double *sint,*cost;
+
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCone" );
+
+    fghCircleTable(&sint,&cost,-slices);
+
+    /* Cover the circular base with a triangle fan... */
+
+    z0 = 0.0;
+    z1 = zStep;
+
+    r0 = base;
+    r1 = r0 - rStep;
+
+    glBegin(GL_TRIANGLE_FAN);
+
+        glNormal3d(0.0,0.0,-1.0);
+        glVertex3d(0.0,0.0, z0 );
+
+        for (j=0; j<=slices; j++)
+            glVertex3d(cost[j]*r0, sint[j]*r0, z0);
 
-    glNormal3dv( row );
-    glVertex3d( radius * *(row + 0), radius * *(row + 1), radius * *(row + 2) );
     glEnd();
 
-    for( j=0; j<stacks-1; j++ )
+    /* Cover each stack with a quad strip, except the top stack */
+
+    for( i=0; i<stacks-1; i++ )
     {
-        phi = 0.0;
-        psi += dpsi;
-        cpsi = cos ( psi ) ;
-        spsi = sin ( psi ) ;
+        glBegin(GL_QUAD_STRIP);
+
+            for(j=0; j<=slices; j++)
+            {
+                glNormal3d(cost[j]*sinn, sint[j]*sinn, cosn);
+                glVertex3d(cost[j]*r0,   sint[j]*r0,   z0  );
+                glVertex3d(cost[j]*r1,   sint[j]*r1,   z1  );
+            }
 
-        /* get coords */
-        glBegin( GL_QUAD_STRIP );
+            z0 = z1; z1 += zStep;
+            r0 = r1; r1 -= rStep;
 
-        /* glBegin(GL_LINE_LOOP); */
-        for( i=0; i<slices; i++ )
+        glEnd();
+    }
+
+    /* The top stack is covered with individual triangles */
+
+    glBegin(GL_TRIANGLES);
+
+        glNormal3d(cost[0]*sinn, sint[0]*sinn, cosn);
+
+        for (j=0; j<slices; j++)
         {
-          cphi = cos ( phi ) ;
-          sphi = sin ( phi ) ;
-            next[ i * 3 + 0 ] = sphi * spsi ;
-            next[ i * 3 + 1 ] = cphi * spsi ;
-            next[ i * 3 + 2 ] = cpsi ;
-
-            glNormal3dv( row + i * 3 );
-            glVertex3d(
-                radius * *(row + 3 * i + 0),
-                radius * *(row + 3 * i + 1),
-                        radius * *(row + 3 * i + 2)
-                    );
-
-            glNormal3dv( next + i * 3 );
-            glVertex3d(
-                radius * *(next + 3 * i + 0),
-                radius * *(next + 3 * i + 1),
-                radius * *(next + 3 * i + 2)
-            );
-
-            phi += dphi;
+            glVertex3d(cost[j+0]*r0,   sint[j+0]*r0,   z0    );
+            glVertex3d(0,              0,              height);
+            glNormal3d(cost[j+1]*sinn, sint[j+1]*sinn, cosn  );
+            glVertex3d(cost[j+1]*r0,   sint[j+1]*r0,   z0    );
         }
 
-        glNormal3dv( row );
-        glVertex3d( radius * *(row + 0), radius * *(row + 1), radius * *(row + 2) );
-        glNormal3dv( next );
-        glVertex3d( radius * *(next + 0), radius * *(next + 1), radius * *(next + 2) );
-        glEnd();
+    glEnd();
 
-        tmp = row;
-        row = next;
-        next = tmp;
-    }
+    /* Release sin and cos tables */
+
+    free(sint);
+    free(cost);
+}
+
+/*
+ * Draws a wire cone
+ */
+void FGAPIENTRY glutWireCone( GLdouble base, GLdouble height, GLint slices, GLint stacks)
+{
+    int i,j;
+
+    /* Step in z and radius as stacks are drawn. */
+
+    double z = 0.0;
+    double r = base;
+
+    const double zStep = height / ( ( stacks > 0 ) ? stacks : 1 );
+    const double rStep = base / ( ( stacks > 0 ) ? stacks : 1 );
+
+    /* Scaling factors for vertex normals */
+
+    const double cosn = ( height / sqrt ( height * height + base * base ));
+    const double sinn = ( base   / sqrt ( height * height + base * base ));
+
+    /* Pre-computed circle */
+
+    double *sint,*cost;
+
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireCone" );
 
-    /* south pole */
-    glBegin( GL_TRIANGLE_FAN );
-    glNormal3d( 0.0, 0.0, -1.0 );
-    glVertex3d( 0.0, 0.0, -radius );
-    glNormal3dv( row );
-    glVertex3d( radius * *(row + 0), radius * *(row + 1), radius * *(row + 2) );
+    fghCircleTable(&sint,&cost,-slices);
 
-    for( i=slices-1; i>=0; i-- )
+    /* Draw the stacks... */
+
+    for (i=0; i<stacks; i++)
     {
-        glNormal3dv(row + 3 * i);
-        glVertex3d(
-            radius * *(row + 3 * i + 0),
-            radius * *(row + 3 * i + 1),
-                  radius * *(row + 3 * i + 2)
-           );
+        glBegin(GL_LINE_LOOP);
+
+            for( j=0; j<slices; j++ )
+            {
+                glNormal3d(cost[j]*sinn, sint[j]*sinn, cosn);
+                glVertex3d(cost[j]*r,    sint[j]*r,    z   );
+            }
+
+        glEnd();
+
+        z += zStep;
+        r -= rStep;
     }
 
+    /* Draw the slices */
+
+    r = base;
+
+    glBegin(GL_LINES);
+
+        for (j=0; j<slices; j++)
+        {
+            glNormal3d(cost[j]*sinn, sint[j]*sinn, cosn  );
+            glVertex3d(cost[j]*r,    sint[j]*r,    0.0   );
+            glVertex3d(0.0,          0.0,          height);
+        }
+
     glEnd();
 
-    free(row);
-    free(next);
-    glPopMatrix();
+    /* Release sin and cos tables */
+
+    free(sint);
+    free(cost);
 }
 
+
 /*
- * Draws a wire cone
+ * Draws a solid cylinder
  */
-void FGAPIENTRY glutWireCone( GLdouble base, GLdouble height, GLint slices, GLint stacks )
+void FGAPIENTRY glutSolidCylinder(GLdouble radius, GLdouble height, GLint slices, GLint stacks)
 {
-  double  alt   = height / (double) (stacks + 1);
-  double  angle = M_PI / (double) slices * 2.0;
-  double  slope = ( height / base );
-  double  sBase = base ;
-  double  sinNormal = ( base   / sqrt ( height * height + base * base )) ;
-  double  cosNormal = ( height / sqrt ( height * height + base * base )) ;
-
-  double *vertices = NULL;
-  int    i, j;
+    int i,j;
 
-  /*
-   * We need 'slices' points on a circle
-   */
-  vertices = (double *)calloc( sizeof(double), 2 * (slices + 1) );
+    /* Step in z and radius as stacks are drawn. */
 
-  for( j=0; j<slices+1; j++ )
-  {
-    vertices[ j*2 + 0 ] = cos( angle * j );
-    vertices[ j*2 + 1 ] = sin( angle * j );
-  }
+    double z0,z1;
+    const double zStep = height / ( ( stacks > 0 ) ? stacks : 1 );
 
-  /*
-   * First the cone's bottom...
-   */
-  for( j=0; j<slices; j++ )
-  {
-    glBegin( GL_LINE_LOOP );
-      glNormal3d( 0.0, 0.0, -1.0 );
-      glVertex3d( vertices[ (j+0)*2+0 ] * sBase, vertices[ (j+0)*2+1 ] * sBase, 0 );
-      glVertex3d( vertices[ (j+1)*2+0 ] * sBase, vertices[ (j+1)*2+1 ] * sBase, 0 );
-      glVertex3d( 0.0, 0.0, 0.0 );
+    /* Pre-computed circle */
+
+    double *sint,*cost;
+
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCylinder" );
+
+    fghCircleTable(&sint,&cost,-slices);
+
+    /* Cover the base and top */
+
+    glBegin(GL_TRIANGLE_FAN);
+        glNormal3d(0.0, 0.0, -1.0 );
+        glVertex3d(0.0, 0.0,  0.0 );
+        for (j=0; j<=slices; j++)
+          glVertex3d(cost[j]*radius, sint[j]*radius, 0.0);
     glEnd();
-  }
 
-  /*
-   * Then all the stacks between the bottom and the top
-   */
-  for( i=0; i<stacks; i++ )
-  {
-    double alt_a = i * alt, alt_b = (i + 1) * alt;
-    double scl_a = (height - alt_a) / slope;
-    double scl_b = (height - alt_b) / slope;
+    glBegin(GL_TRIANGLE_FAN);
+        glNormal3d(0.0, 0.0, 1.0   );
+        glVertex3d(0.0, 0.0, height);
+        for (j=slices; j>=0; j--)
+          glVertex3d(cost[j]*radius, sint[j]*radius, height);
+    glEnd();
+
+    /* Do the stacks */
 
-    for( j=0; j<slices; j++ )
+    z0 = 0.0;
+    z1 = zStep;
+
+    for (i=1; i<=stacks; i++)
     {
-      glBegin( GL_LINE_LOOP );
-        glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+0)*2+0] * scl_a, vertices[(j+0)*2+1] * scl_a, alt_a );
-        glNormal3d( sinNormal * vertices[(j+1)*2+0], sinNormal * vertices[(j+1)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+1)*2+0] * scl_a, vertices[(j+1)*2+1] * scl_a, alt_a );
-        glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+0)*2+0] * scl_b, vertices[(j+0)*2+1] * scl_b, alt_b );
-      glEnd();
-
-      glBegin( GL_LINE_LOOP );
-        glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+0)*2+0] * scl_b, vertices[(j+0)*2+1] * scl_b, alt_b );
-        glNormal3d( sinNormal * vertices[(j+1)*2+0], sinNormal * vertices[(j+1)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+1)*2+0] * scl_b, vertices[(j+1)*2+1] * scl_b, alt_b );
-        glVertex3d( vertices[(j+1)*2+0] * scl_a, vertices[(j+1)*2+1] * scl_a, alt_a );
-      glEnd();
+        if (i==stacks)
+            z1 = height;
+
+        glBegin(GL_QUAD_STRIP);
+            for (j=0; j<=slices; j++ )
+            {
+                glNormal3d(cost[j],        sint[j],        0.0 );
+                glVertex3d(cost[j]*radius, sint[j]*radius, z0  );
+                glVertex3d(cost[j]*radius, sint[j]*radius, z1  );
+            }
+        glEnd();
+
+        z0 = z1; z1 += zStep;
     }
-  }
 
-  /*
-   * Finally have the top part drawn...
-   */
-  for( j=0; j<slices; j++ )
-  {
-    double scl = alt / slope;
+    /* Release sin and cos tables */
 
-    glBegin( GL_LINE_LOOP );
-      glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-      glVertex3d( vertices[ (j+0)*2+0 ] * scl, vertices[ (j+0)*2+1 ] * scl, height - alt );
-      glNormal3d( sinNormal * vertices[(j+1)*2+0], sinNormal * vertices[(j+1)*2+1], cosNormal ) ;
-      glVertex3d( vertices[ (j+1)*2+0 ] * scl, vertices[ (j+1)*2+1 ] * scl, height - alt );
-      glVertex3d( 0, 0, height );
-    glEnd();
-  }
+    free(sint);
+    free(cost);
 }
 
 /*
- * Draws a solid cone
+ * Draws a wire cylinder
  */
-void FGAPIENTRY glutSolidCone( GLdouble base, GLdouble height, GLint slices, GLint stacks )
+void FGAPIENTRY glutWireCylinder(GLdouble radius, GLdouble height, GLint slices, GLint stacks)
 {
-  double  alt   = height / (double) (stacks + 1);
-  double  angle = M_PI / (double) slices * 2.0f;
-  double  slope = ( height / base );
-  double  sBase = base ;
-  double  sinNormal = ( base   / sqrt ( height * height + base * base )) ;
-  double  cosNormal = ( height / sqrt ( height * height + base * base )) ;
-
-  double *vertices = NULL;
-  int    i, j;
+    int i,j;
 
-  /*
-   * We need 'slices' points on a circle
-   */
-  vertices = (double *)calloc( sizeof(double), 2 * (slices + 1) );
+    /* Step in z and radius as stacks are drawn. */
 
-  for( j=0; j<slices+1; j++ )
-  {
-    vertices[ j*2 + 0 ] = cos( angle * j );
-    vertices[ j*2 + 1 ] = sin( angle * j );
-  }
+          double z = 0.0;
+    const double zStep = height / ( ( stacks > 0 ) ? stacks : 1 );
 
-  /*
-   * First the cone's bottom...
-   */
-  for( j=0; j<slices; j++ )
-  {
-    double scl = height / slope;
+    /* Pre-computed circle */
 
-    glBegin( GL_TRIANGLES );
-      glNormal3d( 0.0, 0.0, -1.0 );
-      glVertex3d( vertices[ (j+0)*2+0 ] * sBase, vertices[ (j+0)*2+1 ] * sBase, 0 );
-      glVertex3d( vertices[ (j+1)*2+0 ] * sBase, vertices[ (j+1)*2+1 ] * sBase, 0 );
-      glVertex3d( 0.0, 0.0, 0.0 );
-    glEnd();
-  }
+    double *sint,*cost;
 
-  /*
-   * Then all the stacks between the bottom and the top
-   */
-  for( i=0; i<stacks; i++ )
-  {
-    double alt_a = i * alt, alt_b = (i + 1) * alt;
-    double scl_a = (height - alt_a) / slope;
-    double scl_b = (height - alt_b) / slope;
+    FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireCylinder" );
 
-    for( j=0; j<slices; j++ )
+    fghCircleTable(&sint,&cost,-slices);
+
+    /* Draw the stacks... */
+
+    for (i=0; i<=stacks; i++)
     {
-      glBegin( GL_TRIANGLES );
-        glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+0)*2+0] * scl_a, vertices[(j+0)*2+1] * scl_a, alt_a );
-        glNormal3d( sinNormal * vertices[(j+1)*2+0], sinNormal * vertices[(j+1)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+1)*2+0] * scl_a, vertices[(j+1)*2+1] * scl_a, alt_a );
-        glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+0)*2+0] * scl_b, vertices[(j+0)*2+1] * scl_b, alt_b );
-      glEnd();
-
-      glBegin( GL_TRIANGLES );
-        glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+0)*2+0] * scl_b, vertices[(j+0)*2+1] * scl_b, alt_b );
-        glNormal3d( sinNormal * vertices[(j+1)*2+0], sinNormal * vertices[(j+1)*2+1], cosNormal ) ;
-        glVertex3d( vertices[(j+1)*2+0] * scl_b, vertices[(j+1)*2+1] * scl_b, alt_b );
-        glVertex3d( vertices[(j+1)*2+0] * scl_a, vertices[(j+1)*2+1] * scl_a, alt_a );
-      glEnd();
+        if (i==stacks)
+            z = height;
+
+        glBegin(GL_LINE_LOOP);
+
+            for( j=0; j<slices; j++ )
+            {
+                glNormal3d(cost[j],        sint[j],        0.0);
+                glVertex3d(cost[j]*radius, sint[j]*radius, z  );
+            }
+
+        glEnd();
+
+        z += zStep;
     }
-  }
 
-  /*
-   * Finally have the top part drawn...
-   */
-  for( j=0; j<slices; j++ )
-  {
-    double scl = alt / slope;
-
-    glBegin( GL_TRIANGLES );
-      glNormal3d( sinNormal * vertices[(j+0)*2+0], sinNormal * vertices[(j+0)*2+1], cosNormal ) ;
-      glVertex3d( vertices[ (j+0)*2+0 ] * scl, vertices[ (j+0)*2+1 ] * scl, height - alt );
-      glNormal3d( sinNormal * vertices[(j+1)*2+0], sinNormal * vertices[(j+1)*2+1], cosNormal ) ;
-      glVertex3d( vertices[ (j+1)*2+0 ] * scl, vertices[ (j+1)*2+1 ] * scl, height - alt );
-      glVertex3d( 0, 0, height );
+    /* Draw the slices */
+
+    glBegin(GL_LINES);
+
+        for (j=0; j<slices; j++)
+        {
+            glNormal3d(cost[j],        sint[j],        0.0   );
+            glVertex3d(cost[j]*radius, sint[j]*radius, 0.0   );
+            glVertex3d(cost[j]*radius, sint[j]*radius, height);
+        }
+
     glEnd();
-  }
+
+    /* Release sin and cos tables */
+
+    free(sint);
+    free(cost);
 }
 
 /*
- *
+ * Draws a wire torus
  */
 void FGAPIENTRY glutWireTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GLint nSides, GLint nRings )
 {
@@ -493,16 +610,19 @@ void FGAPIENTRY glutWireTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GLi
   int    i, j;
   double spsi, cpsi, sphi, cphi ;
 
-  /*
-   * Allocate the vertices array
-   */
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireTorus" );
+
+  if ( nSides < 1 ) nSides = 1;
+  if ( nRings < 1 ) nRings = 1;
+
+  /* Allocate the vertices array */
   vertex = (double *)calloc( sizeof(double), 3 * nSides * nRings );
   normal = (double *)calloc( sizeof(double), 3 * nSides * nRings );
 
   glPushMatrix();
 
-  dpsi = 2.0 * M_PI / (double)nRings ;
-  dphi = 2.0 * M_PI / (double)nSides ;
+  dpsi =  2.0 * M_PI / (double)nRings ;
+  dphi = -2.0 * M_PI / (double)nSides ;
   psi  = 0.0;
 
   for( j=0; j<nRings; j++ )
@@ -518,7 +638,7 @@ void FGAPIENTRY glutWireTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GLi
       sphi = sin ( phi ) ;
       *(vertex + offset + 0) = cpsi * ( oradius + cphi * iradius ) ;
       *(vertex + offset + 1) = spsi * ( oradius + cphi * iradius ) ;
-      *(vertex + offset + 2) =                    sphi * iradius   ;
+      *(vertex + offset + 2) =                    sphi * iradius  ;
       *(normal + offset + 0) = cpsi * cphi ;
       *(normal + offset + 1) = spsi * cphi ;
       *(normal + offset + 2) =        sphi ;
@@ -562,7 +682,7 @@ void FGAPIENTRY glutWireTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GLi
 }
 
 /*
- *
+ * Draws a solid torus
  */
 void FGAPIENTRY glutSolidTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GLint nSides, GLint nRings )
 {
@@ -571,22 +691,23 @@ void FGAPIENTRY glutSolidTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GL
   int    i, j;
   double spsi, cpsi, sphi, cphi ;
 
-  /*
-   * Increment the number of sides and rings to allow for one more point than surface
-   */
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidTorus" );
+
+  if ( nSides < 1 ) nSides = 1;
+  if ( nRings < 1 ) nRings = 1;
+
+  /* Increment the number of sides and rings to allow for one more point than surface */
   nSides ++ ;
   nRings ++ ;
 
-  /*
-   * Allocate the vertices array
-   */
+  /* Allocate the vertices array */
   vertex = (double *)calloc( sizeof(double), 3 * nSides * nRings );
   normal = (double *)calloc( sizeof(double), 3 * nSides * nRings );
 
   glPushMatrix();
 
-  dpsi = 2.0 * M_PI / (double)(nRings - 1) ;
-  dphi = 2.0 * M_PI / (double)(nSides - 1) ;
+  dpsi =  2.0 * M_PI / (double)(nRings - 1) ;
+  dphi = -2.0 * M_PI / (double)(nSides - 1) ;
   psi  = 0.0;
 
   for( j=0; j<nRings; j++ )
@@ -602,7 +723,7 @@ void FGAPIENTRY glutSolidTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GL
       sphi = sin ( phi ) ;
       *(vertex + offset + 0) = cpsi * ( oradius + cphi * iradius ) ;
       *(vertex + offset + 1) = spsi * ( oradius + cphi * iradius ) ;
-      *(vertex + offset + 2) =                    sphi * iradius   ;
+      *(vertex + offset + 2) =                    sphi * iradius  ;
       *(normal + offset + 0) = cpsi * cphi ;
       *(normal + offset + 1) = spsi * cphi ;
       *(normal + offset + 2) =        sphi ;
@@ -641,10 +762,13 @@ void FGAPIENTRY glutSolidTorus( GLdouble dInnerRadius, GLdouble dOuterRadius, GL
  */
 void FGAPIENTRY glutWireDodecahedron( void )
 {
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireDodecahedron" );
+
   /* Magic Numbers:  It is possible to create a dodecahedron by attaching two pentagons to each face of
    * of a cube.  The coordinates of the points are:
    *   (+-x,0, z); (+-1, 1, 1); (0, z, x )
-   * where x = 0.61803398875 and z = 1.61803398875.
+   * where x = (-1 + sqrt(5))/2, z = (1 + sqrt(5))/2  or
+   *       x = 0.61803398875 and z = 1.61803398875.
    */
   glBegin ( GL_LINE_LOOP ) ;
   glNormal3d (  0.0,  0.525731112119,  0.850650808354 ) ; glVertex3d (  0.0,  1.61803398875,  0.61803398875 ) ; glVertex3d ( -1.0,  1.0,  1.0 ) ; glVertex3d ( -0.61803398875, 0.0,  1.61803398875 ) ; glVertex3d (  0.61803398875, 0.0,  1.61803398875 ) ; glVertex3d (  1.0,  1.0,  1.0 ) ;
@@ -691,10 +815,13 @@ void FGAPIENTRY glutWireDodecahedron( void )
  */
 void FGAPIENTRY glutSolidDodecahedron( void )
 {
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidDodecahedron" );
+
   /* Magic Numbers:  It is possible to create a dodecahedron by attaching two pentagons to each face of
    * of a cube.  The coordinates of the points are:
    *   (+-x,0, z); (+-1, 1, 1); (0, z, x )
-   * where x = 0.61803398875 and z = 1.61803398875.
+   * where x = (-1 + sqrt(5))/2, z = (1 + sqrt(5))/2 or
+   *       x = 0.61803398875 and z = 1.61803398875.
    */
   glBegin ( GL_POLYGON ) ;
   glNormal3d (  0.0,  0.525731112119,  0.850650808354 ) ; glVertex3d (  0.0,  1.61803398875,  0.61803398875 ) ; glVertex3d ( -1.0,  1.0,  1.0 ) ; glVertex3d ( -0.61803398875, 0.0,  1.61803398875 ) ; glVertex3d (  0.61803398875, 0.0,  1.61803398875 ) ; glVertex3d (  1.0,  1.0,  1.0 ) ;
@@ -741,16 +868,18 @@ void FGAPIENTRY glutSolidDodecahedron( void )
  */
 void FGAPIENTRY glutWireOctahedron( void )
 {
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireOctahedron" );
+
 #define RADIUS    1.0f
   glBegin( GL_LINE_LOOP );
     glNormal3d( 0.577350269189, 0.577350269189, 0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
-    glNormal3d( 0.577350269189, 0.577350269189,-0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
-    glNormal3d( 0.577350269189,-0.577350269189, 0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
+    glNormal3d( 0.577350269189, 0.577350269189,-0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS ); glVertex3d( 0.0, RADIUS, 0.0 );
+    glNormal3d( 0.577350269189,-0.577350269189, 0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS ); glVertex3d( 0.0,-RADIUS, 0.0 );
     glNormal3d( 0.577350269189,-0.577350269189,-0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
-    glNormal3d(-0.577350269189, 0.577350269189, 0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
+    glNormal3d(-0.577350269189, 0.577350269189, 0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS ); glVertex3d( 0.0, RADIUS, 0.0 );
     glNormal3d(-0.577350269189, 0.577350269189,-0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
     glNormal3d(-0.577350269189,-0.577350269189, 0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
-    glNormal3d(-0.577350269189,-0.577350269189,-0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
+    glNormal3d(-0.577350269189,-0.577350269189,-0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS ); glVertex3d( 0.0,-RADIUS, 0.0 );
   glEnd();
 #undef RADIUS
 }
@@ -760,45 +889,56 @@ void FGAPIENTRY glutWireOctahedron( void )
  */
 void FGAPIENTRY glutSolidOctahedron( void )
 {
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidOctahedron" );
+
 #define RADIUS    1.0f
   glBegin( GL_TRIANGLES );
     glNormal3d( 0.577350269189, 0.577350269189, 0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
-    glNormal3d( 0.577350269189, 0.577350269189,-0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
-    glNormal3d( 0.577350269189,-0.577350269189, 0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
+    glNormal3d( 0.577350269189, 0.577350269189,-0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS ); glVertex3d( 0.0, RADIUS, 0.0 );
+    glNormal3d( 0.577350269189,-0.577350269189, 0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS ); glVertex3d( 0.0,-RADIUS, 0.0 );
     glNormal3d( 0.577350269189,-0.577350269189,-0.577350269189); glVertex3d( RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
-    glNormal3d(-0.577350269189, 0.577350269189, 0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
+    glNormal3d(-0.577350269189, 0.577350269189, 0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS ); glVertex3d( 0.0, RADIUS, 0.0 );
     glNormal3d(-0.577350269189, 0.577350269189,-0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
     glNormal3d(-0.577350269189,-0.577350269189, 0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0, RADIUS );
-    glNormal3d(-0.577350269189,-0.577350269189,-0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0,-RADIUS, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS );
+    glNormal3d(-0.577350269189,-0.577350269189,-0.577350269189); glVertex3d(-RADIUS, 0.0, 0.0 ); glVertex3d( 0.0, 0.0,-RADIUS ); glVertex3d( 0.0,-RADIUS, 0.0 );
   glEnd();
 #undef RADIUS
 }
 
+/* Magic Numbers:  r0 = ( 1, 0, 0 )
+ *                 r1 = ( -1/3, 2 sqrt(2) / 3, 0 )
+ *                 r2 = ( -1/3, -sqrt(2) / 3, sqrt(6) / 3 )
+ *                 r3 = ( -1/3, -sqrt(2) / 3, -sqrt(6) / 3 )
+ * |r0| = |r1| = |r2| = |r3| = 1
+ * Distance between any two points is 2 sqrt(6) / 3
+ *
+ * Normals:  The unit normals are simply the negative of the coordinates of the point not on the surface.
+ */
+
+#define NUM_TETR_FACES     4
+
+static GLdouble tet_r[4][3] = { {             1.0,             0.0,             0.0 },
+                                { -0.333333333333,  0.942809041582,             0.0 },
+                                { -0.333333333333, -0.471404520791,  0.816496580928 },
+                                { -0.333333333333, -0.471404520791, -0.816496580928 } } ;
+
+static GLint tet_i[4][3] =  /* Vertex indices */
+{
+  { 1, 3, 2 }, { 0, 2, 3 }, { 0, 3, 1 }, { 0, 1, 2 }
+} ;
+
 /*
  *
  */
 void FGAPIENTRY glutWireTetrahedron( void )
 {
-  /* Magic Numbers:  r0 = ( 1, 0, 0 )
-   *                 r1 = ( -1/3, 2 sqrt(2) / 3, 0 )
-   *                 r2 = ( -1/3, -sqrt(2) / 3, sqrt(6) / 3 )
-   *                 r3 = ( -1/3, -sqrt(2) / 3, -sqrt(6) / 3 )
-   * |r0| = |r1| = |r2| = |r3| = 1
-   * Distance between any two points is 2 sqrt(6) / 3
-   *
-   * Normals:  The unit normals are simply the negative of the coordinates of the point not on the surface.
-   */
-
-  double r0[3] = {             1.0,             0.0,             0.0 } ;
-  double r1[3] = { -0.333333333333,  0.942809041582,             0.0 } ;
-  double r2[3] = { -0.333333333333, -0.471404520791,  0.816496580928 } ;
-  double r3[3] = { -0.333333333333, -0.471404520791, -0.816496580928 } ;
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireTetrahedron" );
 
   glBegin( GL_LINE_LOOP ) ;
-    glNormal3d (           -1.0,             0.0,             0.0 ) ; glVertex3dv ( r1 ) ; glVertex3dv ( r3 ) ; glVertex3dv ( r2 ) ;
-    glNormal3d ( 0.333333333333, -0.942809041582,             0.0 ) ; glVertex3dv ( r0 ) ; glVertex3dv ( r2 ) ; glVertex3dv ( r3 ) ;
-    glNormal3d ( 0.333333333333,  0.471404520791, -0.816496580928 ) ; glVertex3dv ( r0 ) ; glVertex3dv ( r3 ) ; glVertex3dv ( r1 ) ;
-    glNormal3d ( 0.333333333333,  0.471404520791,  0.816496580928 ) ; glVertex3dv ( r0 ) ; glVertex3dv ( r1 ) ; glVertex3dv ( r2 ) ;
+    glNormal3d ( -tet_r[0][0], -tet_r[0][1], -tet_r[0][2] ) ; glVertex3dv ( tet_r[1] ) ; glVertex3dv ( tet_r[3] ) ; glVertex3dv ( tet_r[2] ) ;
+    glNormal3d ( -tet_r[1][0], -tet_r[1][1], -tet_r[1][2] ) ; glVertex3dv ( tet_r[0] ) ; glVertex3dv ( tet_r[2] ) ; glVertex3dv ( tet_r[3] ) ;
+    glNormal3d ( -tet_r[2][0], -tet_r[2][1], -tet_r[2][2] ) ; glVertex3dv ( tet_r[0] ) ; glVertex3dv ( tet_r[3] ) ; glVertex3dv ( tet_r[1] ) ;
+    glNormal3d ( -tet_r[3][0], -tet_r[3][1], -tet_r[3][2] ) ; glVertex3dv ( tet_r[0] ) ; glVertex3dv ( tet_r[1] ) ; glVertex3dv ( tet_r[2] ) ;
   glEnd() ;
 }
 
@@ -807,26 +947,13 @@ void FGAPIENTRY glutWireTetrahedron( void )
  */
 void FGAPIENTRY glutSolidTetrahedron( void )
 {
-  /* Magic Numbers:  r0 = ( 1, 0, 0 )
-   *                 r1 = ( -1/3, 2 sqrt(2) / 3, 0 )
-   *                 r2 = ( -1/3, -sqrt(2) / 3, sqrt(6) / 3 )
-   *                 r3 = ( -1/3, -sqrt(2) / 3, -sqrt(6) / 3 )
-   * |r0| = |r1| = |r2| = |r3| = 1
-   * Distance between any two points is 2 sqrt(6) / 3
-   *
-   * Normals:  The unit normals are simply the negative of the coordinates of the point not on the surface.
-   */
-
-  double r0[3] = {             1.0,             0.0,             0.0 } ;
-  double r1[3] = { -0.333333333333,  0.942809041582,             0.0 } ;
-  double r2[3] = { -0.333333333333, -0.471404520791,  0.816496580928 } ;
-  double r3[3] = { -0.333333333333, -0.471404520791, -0.816496580928 } ;
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidTetrahedron" );
 
   glBegin( GL_TRIANGLES ) ;
-    glNormal3d (           -1.0,             0.0,             0.0 ) ; glVertex3dv ( r1 ) ; glVertex3dv ( r3 ) ; glVertex3dv ( r2 ) ;
-    glNormal3d ( 0.333333333333, -0.942809041582,             0.0 ) ; glVertex3dv ( r0 ) ; glVertex3dv ( r2 ) ; glVertex3dv ( r3 ) ;
-    glNormal3d ( 0.333333333333,  0.471404520791, -0.816496580928 ) ; glVertex3dv ( r0 ) ; glVertex3dv ( r3 ) ; glVertex3dv ( r1 ) ;
-    glNormal3d ( 0.333333333333,  0.471404520791,  0.816496580928 ) ; glVertex3dv ( r0 ) ; glVertex3dv ( r1 ) ; glVertex3dv ( r2 ) ;
+    glNormal3d ( -tet_r[0][0], -tet_r[0][1], -tet_r[0][2] ) ; glVertex3dv ( tet_r[1] ) ; glVertex3dv ( tet_r[3] ) ; glVertex3dv ( tet_r[2] ) ;
+    glNormal3d ( -tet_r[1][0], -tet_r[1][1], -tet_r[1][2] ) ; glVertex3dv ( tet_r[0] ) ; glVertex3dv ( tet_r[2] ) ; glVertex3dv ( tet_r[3] ) ;
+    glNormal3d ( -tet_r[2][0], -tet_r[2][1], -tet_r[2][2] ) ; glVertex3dv ( tet_r[0] ) ; glVertex3dv ( tet_r[3] ) ; glVertex3dv ( tet_r[1] ) ;
+    glNormal3d ( -tet_r[3][0], -tet_r[3][1], -tet_r[3][2] ) ; glVertex3dv ( tet_r[0] ) ; glVertex3dv ( tet_r[1] ) ; glVertex3dv ( tet_r[2] ) ;
   glEnd() ;
 }
 
@@ -845,6 +972,9 @@ int icos_v [20][3] = { { 0, 1, 2 }, { 0, 2, 3 }, { 0, 3, 4 }, { 0, 4, 5 }, { 0,
 void FGAPIENTRY glutWireIcosahedron( void )
 {
   int i ;
+
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireIcosahedron" );
+
   for ( i = 0; i < 20; i++ )
   {
     double normal[3] ;
@@ -867,6 +997,8 @@ void FGAPIENTRY glutSolidIcosahedron( void )
 {
   int i ;
 
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidIcosahedron" );
+
   glBegin ( GL_TRIANGLES ) ;
   for ( i = 0; i < 20; i++ )
   {
@@ -903,6 +1035,9 @@ double rdod_n[12][3] = {
 void FGAPIENTRY glutWireRhombicDodecahedron( void )
 {
   int i ;
+
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireRhombicDodecahedron" );
+
   for ( i = 0; i < 12; i++ )
   {
     glBegin ( GL_LINE_LOOP ) ;
@@ -922,6 +1057,8 @@ void FGAPIENTRY glutSolidRhombicDodecahedron( void )
 {
   int i ;
 
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidRhombicDodecahedron" );
+
   glBegin ( GL_QUADS ) ;
   for ( i = 0; i < 12; i++ )
   {
@@ -935,45 +1072,24 @@ void FGAPIENTRY glutSolidRhombicDodecahedron( void )
   glEnd () ;
 }
 
-#define NUM_FACES     4
-
-static GLdouble tetrahedron_v[4][3] =  /* Vertices */
-{
-  { -0.5, -0.288675134595, -0.144337567297 },
-  {  0.5, -0.288675134595, -0.144337567297 },
-  {  0.0,  0.577350269189, -0.144337567297 },
-  {  0.0,  0.0,             0.672159013631 }
-} ;
-
-static GLint tetrahedron_i[4][3] =  /* Vertex indices */
-{
-  { 0, 1, 2 }, { 0, 2, 3 }, { 0, 3, 1 }, { 1, 3, 2 }
-} ;
-
-static GLdouble tetrahedron_n[4][3] =  /* Normals */
-{
-  {  0.0,             0.0,            -1.0 },
-  { -0.816496580928,  0.471404520791,  0.333333333333 },
-  {  0.0,            -0.942809041582,  0.333333333333 },
-  {  0.816496580928,  0.471404520791,  0.333333333333 }
-} ;
-
 void FGAPIENTRY glutWireSierpinskiSponge ( int num_levels, GLdouble offset[3], GLdouble scale )
 {
   int i, j ;
 
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireSierpinskiSponge" );
+
   if ( num_levels == 0 )
   {
 
-    for ( i = 0 ; i < NUM_FACES ; i++ )
+    for ( i = 0 ; i < NUM_TETR_FACES ; i++ )
     {
       glBegin ( GL_LINE_LOOP ) ;
-      glNormal3dv ( tetrahedron_n[i] ) ;
+      glNormal3d ( -tet_r[i][0], -tet_r[i][1], -tet_r[i][2] ) ;
       for ( j = 0; j < 3; j++ )
       {
-        double x = offset[0] + scale * tetrahedron_v[tetrahedron_i[i][j]][0] ;
-        double y = offset[1] + scale * tetrahedron_v[tetrahedron_i[i][j]][1] ;
-        double z = offset[2] + scale * tetrahedron_v[tetrahedron_i[i][j]][2] ;
+        double x = offset[0] + scale * tet_r[tet_i[i][j]][0] ;
+        double y = offset[1] + scale * tet_r[tet_i[i][j]][1] ;
+        double z = offset[2] + scale * tet_r[tet_i[i][j]][2] ;
         glVertex3d ( x, y, z ) ;
       }
 
@@ -985,18 +1101,13 @@ void FGAPIENTRY glutWireSierpinskiSponge ( int num_levels, GLdouble offset[3], G
     GLdouble local_offset[3] ;  /* Use a local variable to avoid buildup of roundoff errors */
     num_levels -- ;
     scale /= 2.0 ;
-    local_offset[0] = offset[0] + scale * tetrahedron_v[0][0] ;
-    local_offset[1] = offset[1] + scale * tetrahedron_v[0][1] ;
-    local_offset[2] = offset[2] + scale * tetrahedron_v[0][2] ;
-    glutWireSierpinskiSponge ( num_levels, local_offset, scale ) ;
-    local_offset[0] += scale ;
-    glutWireSierpinskiSponge ( num_levels, local_offset, scale ) ;
-    local_offset[0] -= 0.5            * scale ;
-    local_offset[1] += 0.866025403784 * scale ;
-    glutWireSierpinskiSponge ( num_levels, local_offset, scale ) ;
-    local_offset[1] -= 0.577350269189 * scale ;
-    local_offset[2] += 0.816496580928 * scale ;
-    glutWireSierpinskiSponge ( num_levels, local_offset, scale ) ;
+    for ( i = 0 ; i < NUM_TETR_FACES ; i++ )
+    {
+      local_offset[0] = offset[0] + scale * tet_r[i][0] ;
+      local_offset[1] = offset[1] + scale * tet_r[i][1] ;
+      local_offset[2] = offset[2] + scale * tet_r[i][2] ;
+      glutWireSierpinskiSponge ( num_levels, local_offset, scale ) ;
+    }
   }
 }
 
@@ -1004,18 +1115,20 @@ void FGAPIENTRY glutSolidSierpinskiSponge ( int num_levels, GLdouble offset[3],
 {
   int i, j ;
 
+  FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidSierpinskiSponge" );
+
   if ( num_levels == 0 )
   {
     glBegin ( GL_TRIANGLES ) ;
 
-    for ( i = 0 ; i < NUM_FACES ; i++ )
+    for ( i = 0 ; i < NUM_TETR_FACES ; i++ )
     {
-      glNormal3dv ( tetrahedron_n[i] ) ;
+      glNormal3d ( -tet_r[i][0], -tet_r[i][1], -tet_r[i][2] ) ;
       for ( j = 0; j < 3; j++ )
       {
-        double x = offset[0] + scale * tetrahedron_v[tetrahedron_i[i][j]][0] ;
-        double y = offset[1] + scale * tetrahedron_v[tetrahedron_i[i][j]][1] ;
-        double z = offset[2] + scale * tetrahedron_v[tetrahedron_i[i][j]][2] ;
+        double x = offset[0] + scale * tet_r[tet_i[i][j]][0] ;
+        double y = offset[1] + scale * tet_r[tet_i[i][j]][1] ;
+        double z = offset[2] + scale * tet_r[tet_i[i][j]][2] ;
         glVertex3d ( x, y, z ) ;
       }
     }
@@ -1027,21 +1140,14 @@ void FGAPIENTRY glutSolidSierpinskiSponge ( int num_levels, GLdouble offset[3],
     GLdouble local_offset[3] ;  /* Use a local variable to avoid buildup of roundoff errors */
     num_levels -- ;
     scale /= 2.0 ;
-    local_offset[0] = offset[0] + scale * tetrahedron_v[0][0] ;
-    local_offset[1] = offset[1] + scale * tetrahedron_v[0][1] ;
-    local_offset[2] = offset[2] + scale * tetrahedron_v[0][2] ;
-    glutSolidSierpinskiSponge ( num_levels, local_offset, scale ) ;
-    local_offset[0] += scale ;
-    glutSolidSierpinskiSponge ( num_levels, local_offset, scale ) ;
-    local_offset[0] -= 0.5            * scale ;
-    local_offset[1] += 0.866025403784 * scale ;
-    glutSolidSierpinskiSponge ( num_levels, local_offset, scale ) ;
-    local_offset[1] -= 0.577350269189 * scale ;
-    local_offset[2] += 0.816496580928 * scale ;
-    glutSolidSierpinskiSponge ( num_levels, local_offset, scale ) ;
+    for ( i = 0 ; i < NUM_TETR_FACES ; i++ )
+    {
+      local_offset[0] = offset[0] + scale * tet_r[i][0] ;
+      local_offset[1] = offset[1] + scale * tet_r[i][1] ;
+      local_offset[2] = offset[2] + scale * tet_r[i][2] ;
+      glutSolidSierpinskiSponge ( num_levels, local_offset, scale ) ;
+    }
   }
 }
 
-#undef NUM_FACES
-
 /*** END OF FILE ***/