X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2Ffg_geometry.c;h=66659a46f1b7725f46de1a6bb871a7043e735d34;hb=ba18146fd9c60026c42e2dac896222b781fb588b;hp=de1cbadae2e27c1d4e847042e8146c6c06fc7052;hpb=1b5ee849ba61b667aeba474a7e03406196478bee;p=freeglut diff --git a/src/fg_geometry.c b/src/fg_geometry.c index de1cbad..66659a4 100644 --- a/src/fg_geometry.c +++ b/src/fg_geometry.c @@ -31,6 +31,8 @@ /* * TODO BEFORE THE STABLE RELEASE: * + * See fghTetrahedron + * * Following functions have been contributed by Andreas Umbach. * * glutWireCube() -- looks OK @@ -59,58 +61,223 @@ */ -/* -- INTERFACE FUNCTIONS -------------------------------------------------- */ - -/* - * Draws a wireframed cube. Code contributed by Andreas Umbach +/* 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 + * versions (TRUE) of the geometry you pass */ -void FGAPIENTRY glutWireCube( GLdouble dSize ) +static void fghDrawGeometry(GLenum vertexMode, double* vertices, double* normals, GLsizei numVertices, GLboolean useWireMode) { - double size = dSize * 0.5; + if (useWireMode) + { + glPushAttrib(GL_POLYGON_BIT); + glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); + } - FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutWireCube" ); + glEnableClientState(GL_VERTEX_ARRAY); + glEnableClientState(GL_NORMAL_ARRAY); + + glVertexPointer(3, GL_DOUBLE, 0, vertices); + glNormalPointer(GL_DOUBLE, 0, normals); + glDrawArrays(vertexMode,0,numVertices); -# define V(a,b,c) glVertex3d( a size, b size, c size ); -# define N(a,b,c) glNormal3d( a, b, c ); + glDisableClientState(GL_VERTEX_ARRAY); + glDisableClientState(GL_NORMAL_ARRAY); + + if (useWireMode) + { + glPopAttrib(); + } +} + +static void fghGenerateGeometry(int numFaces, int numVertPerFace, GLdouble *vertices, GLubyte* vertIndices, GLdouble *normals, GLdouble *vertOut, GLdouble *normOut) +{ + 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 (i=0; i + * 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. */ -void FGAPIENTRY glutSolidCube( GLdouble dSize ) + +/* -- Cube -- */ +#define CUBE_NUM_VERT 8 +#define CUBE_NUM_FACES 6 +#define CUBE_NUM_VERT_PER_FACE 4 +#define CUBE_VERT_PER_CUBE CUBE_NUM_FACES*CUBE_NUM_VERT_PER_FACE +#define CUBE_VERT_ELEM_PER_CUBE CUBE_VERT_PER_CUBE*3 +/* Vertex Coordinates */ +static GLdouble cube_v[CUBE_NUM_VERT*3] = { - double size = dSize * 0.5; + .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 +}; - FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidCube" ); +/* 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 +}; -# define V(a,b,c) glVertex3d( a size, b size, c size ); -# define N(a,b,c) glNormal3d( a, b, c ); +/* Cache of input to glDrawArrays */ +static GLboolean cubeCached = FALSE; +static double cube_verts[CUBE_VERT_ELEM_PER_CUBE]; +static double cube_norms[CUBE_VERT_ELEM_PER_CUBE]; - /* 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(); +static void fghCubeGenerate() +{ + fghGenerateGeometry(CUBE_NUM_FACES, CUBE_NUM_VERT_PER_FACE, cube_v, cube_vi, cube_n, cube_verts, cube_norms); +} + +/* -- Tetrahedron -- */ +/* 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 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 tetr_v[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 tetr_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 +}; -# undef V -# undef N +/* Vertex indices */ +static GLubyte tetr_vi[TETR_NUM_FACES*TETR_NUM_VERT_PER_FACE] = +{ + 1, 3, 2, + 0, 2, 3, + 0, 3, 1, + 0, 1, 2 +}; + +/* Cache of input to glDrawArrays */ +static GLboolean tetrCached = FALSE; +static double tetr_verts[TETR_VERT_ELEM_PER_TETR]; +static double tetr_norms[TETR_VERT_ELEM_PER_TETR]; + +static void fghTetrahedronGenerate() +{ + fghGenerateGeometry(TETR_NUM_FACES, TETR_NUM_VERT_PER_FACE, tetr_v, tetr_vi, tetr_n, tetr_verts, tetr_norms); +} + +/* -- 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 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++ ) + { + int idx = i*3; + local_offset[0] = offset[0] + scale * tetr_v[idx ]; + local_offset[1] = offset[1] + scale * tetr_v[idx+1]; + local_offset[2] = offset[2] + scale * tetr_v[idx+2]; + fghSierpinskiSpongeGenerate ( numLevels, local_offset, scale, vertices+i*stride, normals+i*stride ); + } + } } +/* -- Now the various shapes involving circles -- */ /* * Compute lookup table of cos and sin values forming a cirle * @@ -120,7 +287,6 @@ void FGAPIENTRY glutSolidCube( GLdouble dSize ) * The last entry is exactly the same as the first * The sign of n can be flipped to get the reverse loop */ - static void fghCircleTable(double **sint,double **cost,const int n) { int i; @@ -164,6 +330,70 @@ static void fghCircleTable(double **sint,double **cost,const int n) (*cost)[size] = (*cost)[0]; } + +/* -- INTERNAL DRAWING functions to avoid code duplication ------------- */ + +static void fghCube( GLdouble dSize, GLboolean useWireMode ) +{ + if (!cubeCached) + { + fghCubeGenerate(); + cubeCached = TRUE; + } + + if (dSize!=1.) + { + int i; + + /* Need to build new vertex list containing vertices for cube of different size */ + GLdouble *vertices = malloc(CUBE_VERT_ELEM_PER_CUBE * sizeof(double)); + for (i=0; i 0 ) - { - GLdouble local_offset[3] ; /* Use a local variable to avoid buildup of roundoff errors */ - num_levels -- ; - scale /= 2.0 ; - 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 ) ; - } - } +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 ) { - int i, j ; - - FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidSierpinskiSponge" ); - - if ( num_levels == 0 ) - { - glBegin ( GL_TRIANGLES ) ; - - for ( i = 0 ; i < NUM_TETR_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 < 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 ) ; - } - } + FREEGLUT_EXIT_IF_NOT_INITIALISED ( "glutSolidSierpinskiSponge" ); + fghSierpinskiSponge ( num_levels, offset, scale, FALSE ); } + /*** END OF FILE ***/