*/
-/*
- * General function for drawing geometry. As for all geometry we have no
+/* General function for drawing geometry. As for all geometry we have no
* redundancy (or hardly any in the case of cones and cylinders) in terms
* of the vertex/normal combinations, we just use glDrawArrays.
* useWireMode controls the drawing of solids (false) or wire frame
/* -- INTERNAL SETUP OF GEOMETRY --------------------------------------- */
-/* -- first the cachable ones -- */
+static unsigned int ipow (int x, unsigned int y)
+{
+ return y==0? 1: y==1? x: (y%2? x: 1) * ipow(x*x, y/2);
+}
+
+/* -- stuff that can be cached -- */
+/*
+ * In general, we build arrays with all vertices or normals.
+ * We cant compress this and use glDrawElements as all combinations of
+ * vertex and normals are unique.
+ */
+
+/* -- Cube -- */
+#define CUBE_NUM_VERT 8
+#define CUBE_NUM_FACES 6
+#define CUBE_NUM_VERT_PER_FACE 4
+#define CUBE_VERT_PER_TETR CUBE_NUM_FACES*CUBE_NUM_VERT_PER_FACE
+#define CUBE_VERT_ELEM_PER_TETR CUBE_VERT_PER_TETR*3
+/* Vertex Coordinates */
+static GLdouble cube_v[CUBE_NUM_VERT][3] =
+{
+ { .5, .5, .5},
+ {-.5, .5, .5},
+ {-.5,-.5, .5},
+ { .5,-.5, .5},
+ { .5,-.5,-.5},
+ { .5, .5,-.5},
+ {-.5, .5,-.5},
+ {-.5,-.5,-.5}
+};
+/* Normal Vectors */
+static GLdouble cube_n[CUBE_NUM_FACES][3] =
+{
+ { 0.0, 0.0, 1.0},
+ { 1.0, 0.0, 0.0},
+ { 0.0, 1.0, 0.0},
+ {-1.0, 0.0, 0.0},
+ { 0.0,-1.0, 0.0},
+ { 0.0, 0.0,-1.0}
+};
+
+/* Vertex indices */
+static GLubyte cube_vi[CUBE_NUM_FACES][CUBE_NUM_VERT_PER_FACE] =
+{
+ {0,1,2,3}, {0,3,4,5}, {0,5,6,1}, {1,6,7,2}, {7,4,3,2}, {4,7,6,5}
+};
+/* Cache of input to glDrawArrays */
+static GLboolean cubeCached = FALSE;
+static double cube_verts[CUBE_VERT_ELEM_PER_TETR];
+static double cube_norms[CUBE_VERT_ELEM_PER_TETR];
+
+static void fghCubeGenerate()
+{
+ int i,j;
+ for (i=0; i<CUBE_NUM_FACES; i++)
+ {
+ for (j=0; j<CUBE_NUM_VERT_PER_FACE; j++)
+ {
+ int idx = i*CUBE_NUM_VERT_PER_FACE*3+j*3;
+ cube_verts[idx ] = cube_v[cube_vi[i][j]][0];
+ cube_verts[idx+1] = cube_v[cube_vi[i][j]][1];
+ cube_verts[idx+2] = cube_v[cube_vi[i][j]][2];
+
+ cube_norms[idx ] = cube_n[i][0];
+ cube_norms[idx+1] = cube_n[i][1];
+ cube_norms[idx+2] = cube_n[i][2];
+ }
+ }
+}
+
+/* -- Tetrahedron -- */
/* Magic Numbers: r0 = ( 1, 0, 0 )
* r1 = ( -1/3, 2 sqrt(2) / 3, 0 )
* r2 = ( -1/3, - sqrt(2) / 3, sqrt(6) / 3 )
* 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.
-*/
-
-/* -- TetraHedron -- */
+ */
+#define TETR_NUM_VERT 4
#define TETR_NUM_FACES 4
#define TETR_NUM_VERT_PER_FACE 3
+#define TETR_VERT_PER_TETR TETR_NUM_FACES*TETR_NUM_VERT_PER_FACE
+#define TETR_VERT_ELEM_PER_TETR TETR_VERT_PER_TETR*3
/* Vertex Coordinates */
-static GLdouble tet_r[TETR_NUM_FACES][TETR_NUM_VERT_PER_FACE] =
+static GLdouble tet_r[TETR_NUM_VERT][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 }
};
+/* Normal Vectors */
+static GLdouble tet_n[CUBE_NUM_FACES][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 }
+};
/* Vertex indices */
static GLubyte tet_i[TETR_NUM_FACES][TETR_NUM_VERT_PER_FACE] =
{
{ 1, 3, 2 }, { 0, 2, 3 }, { 0, 3, 1 }, { 0, 1, 2 }
};
-/* Normal indices */
-static GLubyte tet_n[TETR_NUM_FACES] =
-{
- 0, 1, 2, 3
-};
/* Cache of input to glDrawArrays */
static GLboolean tetrCached = FALSE;
-static double tetr_verts[TETR_NUM_FACES * TETR_NUM_VERT_PER_FACE * 3];
-static double tetr_norms[TETR_NUM_FACES * TETR_NUM_VERT_PER_FACE * 3];
+static double tetr_verts[TETR_VERT_ELEM_PER_TETR];
+static double tetr_norms[TETR_VERT_ELEM_PER_TETR];
-static void fghTetrahedronCache()
+static void fghTetrahedronGenerate()
{
- int p,q;
+ int i,j;
/*
- * Build array with vertices from vertex coordinates and vertex indices
- * Do same for normals.
- * Need to do this because of different normals at shared vertices
- * (and because normals' coordinates need to be negated).
- */
- for (p=0; p<TETR_NUM_FACES; p++)
+ * Build array with vertices from vertex coordinates and vertex indices
+ * Do same for normals.
+ * Need to do this because of different normals at shared vertices
+ * (and because normals' coordinates need to be negated).
+ */
+ for (i=0; i<TETR_NUM_FACES; i++)
{
- for (q=0; q<TETR_NUM_VERT_PER_FACE; q++)
+ for (j=0; j<TETR_NUM_VERT_PER_FACE; j++)
{
- int idx = p*TETR_NUM_VERT_PER_FACE*3+q*3;
- tetr_verts[idx ] = tet_r[tet_i[p][q]][0];
- tetr_verts[idx+1] = tet_r[tet_i[p][q]][1];
- tetr_verts[idx+2] = tet_r[tet_i[p][q]][2];
-
- tetr_norms[idx ] = -tet_r[tet_n[p]][0];
- tetr_norms[idx+1] = -tet_r[tet_n[p]][1];
- tetr_norms[idx+2] = -tet_r[tet_n[p]][2];
+ int idx = i*TETR_NUM_VERT_PER_FACE*3+j*3;
+ tetr_verts[idx ] = tet_r[tet_i[i][j]][0];
+ tetr_verts[idx+1] = tet_r[tet_i[i][j]][1];
+ tetr_verts[idx+2] = tet_r[tet_i[i][j]][2];
+
+ tetr_norms[idx ] = tet_n[i][0];
+ tetr_norms[idx+1] = tet_n[i][1];
+ tetr_norms[idx+2] = tet_n[i][2];
+ }
+ }
+}
+
+/* -- Sierpinski Sponge -- */
+static void fghSierpinskiSpongeGenerate ( int numLevels, GLdouble offset[3], GLdouble scale, double* vertices, double* normals )
+{
+ int i, j;
+ if ( numLevels == 0 )
+ {
+ for ( i = 0 ; i < TETR_NUM_FACES ; i++ )
+ {
+ for ( j = 0; j < TETR_NUM_VERT_PER_FACE; j++ )
+ {
+ int idx = i*TETR_NUM_VERT_PER_FACE*3+j*3;
+ vertices[idx ] = offset[0] + scale * tet_r[tet_i[i][j]][0];
+ vertices[idx+1] = offset[1] + scale * tet_r[tet_i[i][j]][1];
+ vertices[idx+2] = offset[2] + scale * tet_r[tet_i[i][j]][2];
+
+ normals [idx ] = -tet_r[i][0];
+ normals [idx+1] = -tet_r[i][1];
+ normals [idx+2] = -tet_r[i][2];
+ }
+ }
+ }
+ else if ( numLevels > 0 )
+ {
+ GLdouble local_offset[3] ; /* Use a local variable to avoid buildup of roundoff errors */
+ unsigned int stride = ipow(4,--numLevels)*TETR_VERT_ELEM_PER_TETR;
+ scale /= 2.0 ;
+ for ( i = 0 ; i < TETR_NUM_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];
+ fghSierpinskiSpongeGenerate ( numLevels, local_offset, scale, vertices+i*stride, normals+i*stride );
}
}
}
/* -- INTERNAL DRAWING functions to avoid code duplication ------------- */
-static void fghTetrahedron( GLboolean useWireMode )
+static void fghCube( GLdouble dSize, GLboolean useWireMode )
{
- if (!tetrCached)
- fghTetrahedronCache();
+ if (!cubeCached)
+ {
+ fghCubeGenerate();
+ cubeCached = TRUE;
+ }
- fghDrawGeometry(GL_TRIANGLES,tetr_verts,tetr_norms,TETR_NUM_FACES*TETR_NUM_VERT_PER_FACE,useWireMode);
+ if (dSize!=1.)
+ {
+ /* Need to build new */
+ fghDrawGeometry(GL_QUADS,cube_verts,cube_norms,CUBE_VERT_PER_TETR,useWireMode);
+ }
+ else
+ fghDrawGeometry(GL_QUADS,cube_verts,cube_norms,CUBE_VERT_PER_TETR,useWireMode);
}
-
-/* -- INTERFACE FUNCTIONS ---------------------------------------------- */
-
-/*
- * Draws a wireframed cube. Code contributed by Andreas Umbach <marvin@dataway.ch>
- */
-void FGAPIENTRY glutWireCube( GLdouble dSize )
+static void fghTetrahedron( GLboolean useWireMode )
{
- 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... */
- 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();
- 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();
+ if (!tetrCached)
+ {
+ fghTetrahedronGenerate();
+ tetrCached = TRUE;
+ }
-# undef V
-# undef N
+ fghDrawGeometry(GL_TRIANGLES,tetr_verts,tetr_norms,TETR_VERT_PER_TETR,useWireMode);
}
-/*
- * Draws a solid cube. Code contributed by Andreas Umbach <marvin@dataway.ch>
- */
-void FGAPIENTRY glutSolidCube( GLdouble dSize )
+static void fghSierpinskiSponge ( int numLevels, GLdouble offset[3], GLdouble scale, GLboolean useWireMode )
{
- double size = dSize * 0.5;
-
- FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCube" );
+ double *vertices;
+ double * normals;
+ unsigned int numTetr = numLevels<0? 0 : ipow(4,numLevels); /* No sponge for numLevels below 0 */
+ unsigned int numVert = numTetr*TETR_VERT_PER_TETR;
-# define V(a,b,c) glVertex3d( a size, b size, c size );
-# define N(a,b,c) glNormal3d( a, b, c );
+ if (numTetr)
+ {
+ /* Allocate memory */
+ vertices = malloc(numVert*3 * sizeof(double));
+ normals = malloc(numVert*3 * sizeof(double));
- /* 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(-,+,+);
- N( 0.0, 0.0, 1.0); V(+,+,+); V(-,+,+); V(-,-,+); V(+,-,+);
- N(-1.0, 0.0, 0.0); V(-,-,+); V(-,+,+); V(-,+,-); V(-,-,-);
- N( 0.0,-1.0, 0.0); V(-,-,+); V(-,-,-); V(+,-,-); V(+,-,+);
- N( 0.0, 0.0,-1.0); V(-,-,-); V(-,+,-); V(+,+,-); V(+,-,-);
- glEnd();
+ /* Generate elements */
+ fghSierpinskiSpongeGenerate ( numLevels, offset, scale, vertices, normals );
-# undef V
-# undef N
+ /* Draw and cleanup */
+ fghDrawGeometry(GL_TRIANGLES,vertices,normals,numVert,useWireMode);
+ free(vertices);
+ free(normals );
+ }
}
+/* -- INTERFACE FUNCTIONS ---------------------------------------------- */
+
+
/*
* Draws a solid sphere
*/
glEnd () ;
}
-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 < TETR_NUM_FACES ; i++ )
- {
- glBegin ( GL_LINE_LOOP ) ;
- glNormal3d ( -tet_r[i][0], -tet_r[i][1], -tet_r[i][2] ) ;
- for ( j = 0; j < 3; j++ )
- {
- 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 ) ;
- }
-
- glEnd () ;
- }
- }
- else if ( num_levels > 0 )
- {
- GLdouble local_offset[3] ; /* Use a local variable to avoid buildup of roundoff errors */
- num_levels -- ;
- scale /= 2.0 ;
- for ( i = 0 ; i < TETR_NUM_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 ) ;
- }
- }
+/* -- INTERFACE FUNCTIONS -------------------------------------------------- */
+/*
+ * Draws a wireframed cube.
+ */
+void FGAPIENTRY glutWireCube( GLdouble dSize )
+{
+ FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireCube" );
+ fghCube( dSize, TRUE );
}
-
-void FGAPIENTRY glutSolidSierpinskiSponge ( int num_levels, GLdouble offset[3], GLdouble scale )
+void FGAPIENTRY glutSolidCube( GLdouble dSize )
{
- int i, j ;
-
- FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidSierpinskiSponge" );
-
- if ( num_levels == 0 )
- {
- glBegin ( GL_TRIANGLES ) ;
-
- for ( i = 0 ; i < TETR_NUM_FACES ; 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 * 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 ) ;
- }
- }
-
- glEnd () ;
- }
- else if ( num_levels > 0 )
- {
- GLdouble local_offset[3] ; /* Use a local variable to avoid buildup of roundoff errors */
- num_levels -- ;
- scale /= 2.0 ;
- for ( i = 0 ; i < TETR_NUM_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 ) ;
- }
- }
+ FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCube" );
+ fghCube( dSize, FALSE );
}
-
-
-/* -- INTERFACE FUNCTIONS -------------------------------------------------- */
-
-
void FGAPIENTRY glutWireTetrahedron( void )
{
FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireTetrahedron" );
-
fghTetrahedron( TRUE );
}
void FGAPIENTRY glutSolidTetrahedron( void )
{
FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidTetrahedron" );
-
fghTetrahedron( FALSE );
}
+void FGAPIENTRY glutWireSierpinskiSponge ( int num_levels, GLdouble offset[3], GLdouble scale )
+{
+ FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireSierpinskiSponge" );
+ fghSierpinskiSponge ( num_levels, offset, scale, TRUE );
+}
+void FGAPIENTRY glutSolidSierpinskiSponge ( int num_levels, GLdouble offset[3], GLdouble scale )
+{
+ FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidSierpinskiSponge" );
+ fghSierpinskiSponge ( num_levels, offset, scale, FALSE );
+}
+
/*** END OF FILE ***/
projects / freeglut / blobdiff