/* ====================================================================== balls.c Ernie Wright 01 Jun 05 This version has been modified to fit your TV. ====================================================================== */ /* * balls.c - Also known as "sphereflake". Create a set of shiny spheres, with * each sphere blooming sets of 9 more spheres with 1/3rd radius. * A square floor polygon is added. Three light sources. * * Author: Eric Haines * * size_factor determines the number of objects output. * Total spheres = sum of n=0,SF of (9**SF). * * size_factor # spheres # squares * 1 10 1 * 2 91 1 * 3 820 1 * * 4 7381 1 */ #include #include #include "lwmod.h" #include "def.h" #include "lib.h" static int size_factor; static COORD4 objset[9]; static char *spdName = "Sphereflake"; /* ====================================================================== output_object() Output the parent sphere, then output the children of the sphere. Uses global 'objset'. ====================================================================== */ static void output_object( int depth, COORD4 center, COORD4 direction ) { double angle; COORD4 axis, z_axis; COORD4 child_pt, child_dir; MATRIX mx; long num_vert; double scale; /* output sphere at location & radius defined by center */ lib_output_sphere(center, 0); /* check if children should be generated */ if (depth > 0) { --depth ; /* rotation matrix to new axis from +Z axis */ if ( direction[Z] >= 1.0 ) { /* identity matrix */ lib_create_identity_matrix(mx); } else if ( direction[Z] <= -1.0 ) { lib_create_rotate_matrix(mx, Y_AXIS, PI); } else { SET_COORD3(z_axis, 0.0, 0.0, 1.0); CROSS(axis, z_axis, direction); lib_normalize_vector(axis); angle = acos((double)DOT_PRODUCT(z_axis, direction)); lib_create_axis_rotate_matrix(mx, axis, angle); } /* scale down location of new spheres */ scale = center[W] * (1.0 + direction[W]); for ( num_vert = 0 ; num_vert < 9 ; ++num_vert ) { /* only do progress for top-level objects of recursion */ if (depth==size_factor-1) if ( lwMonitorStep( 1 )) return; lib_transform_coord(child_pt, objset[num_vert], mx); child_pt[X] = child_pt[X] * scale + center[X]; child_pt[Y] = child_pt[Y] * scale + center[Y]; child_pt[Z] = child_pt[Z] * scale + center[Z]; /* scale down radius */ child_pt[W] = center[W] * direction[W]; SUB3_COORD3( child_dir, child_pt, center); child_dir[X] /= scale; child_dir[Y] /= scale; child_dir[Z] /= scale; child_dir[W] = direction[W]; output_object(depth, child_pt, child_dir); } } } /* ====================================================================== create_objset() Create the set of 9 vectors needed to generate the sphere set. Uses global 'objset' ====================================================================== */ static void create_objset( void ) { COORD4 axis, temp_pt, trio_dir[3]; double dist; MATRIX mx; long num_set, num_vert; dist = 1.0 / sqrt((double)2.0); SET_COORD4(trio_dir[0], dist, dist, 0.0, 0.0); SET_COORD4(trio_dir[1], dist, 0.0, -dist, 0.0); SET_COORD4(trio_dir[2], 0.0, dist, -dist, 0.0); SET_COORD3(axis, 1.0, -1.0, 0.0); lib_normalize_vector(axis); lib_create_axis_rotate_matrix(mx, axis, asin((double)(2.0/sqrt((double)6.0)))); for (num_vert=0;num_vert<3;++num_vert) { lib_transform_coord(temp_pt, trio_dir[num_vert], mx); COPY_COORD4(trio_dir[num_vert], temp_pt); } for (num_set=0;num_set<3;++num_set) { lib_create_rotate_matrix(mx, Z_AXIS, num_set*2.0*PI/3.0); for (num_vert=0;num_vert<3;++num_vert) { lib_transform_coord(objset[num_set*3+num_vert], trio_dir[num_vert], mx); } } } /* ====================================================================== spdBalls() Create a sphereflake. ====================================================================== */ void spdBalls( int sf ) { COORD3 back_color, obj_color; COORD3 backg[5], bvec; COORD3 from, at, up; COORD4 light; COORD4 center_pt, direction; double radius, lscale; size_factor = sf; /* set radius of sphere which would enclose entire object */ radius = 1.0 ; /* output background color - UNC sky blue */ /* NOTE: Do this BEFORE lib_output_viewpoint(), for display_init() */ SET_COORD3(back_color, 0.078, 0.361, 0.753); lib_output_background_color(back_color); /* output viewpoint */ SET_COORD3(from, 2.1, 1.3, 1.7); SET_COORD3(at, 0.0, 0.0, 0.0); SET_COORD3(up, 0.0, 0.0, 1.0); lib_output_viewpoint(from, at, up, 45.0, 1.0, 0.01, 512, 512); /* * For raytracers that don't scale the light intensity, * we will do it for them */ #define NUM_LIGHTS 3 lscale = 1.0 / sqrt(NUM_LIGHTS); /* output light sources */ SET_COORD4(light, 4.0, 3.0, 2.0, lscale); lib_output_light(light); SET_COORD4(light, 1.0, -4.0, 4.0, lscale); lib_output_light(light); SET_COORD4(light, -3.0, 1.0, 5.0, lscale); lib_output_light(light); /* output floor polygon - beige */ SET_COORD3(back_color, 1.0, 0.75, 0.33); lib_output_color(spdName, 1, back_color, 0.2, 0.8, 0.0, 0.0, 0.0, 0.0, 1.0); SET_COORD3(bvec, 12.0 * radius, 12.0 * radius, -radius / 2.0); SET_COORD3(backg[0], bvec[X], bvec[Y], bvec[Z]); SET_COORD3(backg[1], -bvec[X], bvec[Y], bvec[Z]); SET_COORD3(backg[2], -bvec[X], -bvec[Y], bvec[Z]); SET_COORD3(backg[3], bvec[X], -bvec[Y], bvec[Z]); SET_COORD3(backg[4], bvec[X], bvec[Y], bvec[Z]); lib_output_polygon(4, backg); /* set up object color - mirrored */ SET_COORD3(obj_color, 1.0, 0.9, 0.7); lib_output_color(spdName, 2, obj_color, 0.0, 0.5, 0.5, 0.5, 37.0, 0.0, 1.0); /* create set of spawned points */ create_objset(); /* compute and output object */ SET_COORD4(center_pt, 0.0, 0.0, 0.0, radius / 2.0); SET_COORD4(direction, 0.0, 0.0, 1.0, 1.0/3.0); lwMonitorBegin( spdName, "Creating spheres.", 9 ); output_object(size_factor, center_pt, direction); lwMonitorDone(); }