/******************************************************************************\
Adjusts globe vertices to show the tile's height. Updates the globe with data
from the [r_tiles] array.
\******************************************************************************/
void R_configure_globe(void)
{
c_vec2_t tile;
float left, right, top, bottom, tmp;
int i, tx, ty, terrain;
C_debug("Configuring globe");
C_var_unlatch(&r_globe_transitions);
/* UV dimensions of tile boundary box */
tile.x = 2.f * (r_terrain_tex->surface->w / R_TILE_SHEET_W) /
r_terrain_tex->surface->w;
tile.y = 2.f * (int)(C_SIN_60 * r_terrain_tex->surface->h /
R_TILE_SHEET_H / 2) / r_terrain_tex->surface->h;
for (i = 0; i < r_tiles_max; i++) {
set_tile_height(i, r_tiles[i].height);
/* Tile terrain texture */
terrain = tile_terrain(i);
ty = terrain / R_TILE_SHEET_W;
tx = terrain - ty * R_TILE_SHEET_W;
left = tx / 2 * tile.x + C_SIN_60 * R_TILE_BORDER;
right = (tx / 2 + 1) * tile.x - C_SIN_60 * R_TILE_BORDER;
if (tx & 1) {
bottom = ty * tile.y + C_SIN_30 * R_TILE_BORDER;
top = (ty + 1.f) * tile.y - C_SIN_60 * R_TILE_BORDER;
left += tile.x / 2.f;
right += tile.x / 2.f;
} else {
top = ty * tile.y + R_TILE_BORDER;
bottom = (ty + 1.f) * tile.y - C_SIN_30 * R_TILE_BORDER;
}
/* Flip tiles are mirrored over the middle */
if (i < flip_limit) {
tmp = left;
left = right;
right = tmp;
}
r_globe_verts[3 * i].v.uv = C_vec2((left + right) / 2.f, top);
r_globe_verts[3 * i + 1].v.uv = C_vec2(left, bottom);
r_globe_verts[3 * i + 2].v.uv = C_vec2(right, bottom);
}
for (i = 0; i < r_tiles_max; i++)
compute_tile_vectors(i);
smooth_normals();
/* We can update normals dynamically from now on */
r_globe_smooth.edit = C_VE_FUNCTION;
r_globe_smooth.update = globe_smooth_update;
/* If Vertex Buffer Objects are supported, upload the vertices now */
R_vbo_cleanup(&r_globe_vbo);
R_vbo_init(&r_globe_vbo, &r_globe_verts[0].v,
3 * r_tiles_max, sizeof (*r_globe_verts),
R_VERTEX3_FORMAT, NULL, 0);
}
/******************************************************************************\
Called when [r_globe_smooth] changes.
\******************************************************************************/
static int globe_smooth_update(c_var_t *var, c_var_value_t value)
{
int i;
if (value.f > 0.f) {
r_globe_smooth.value.f = value.f;
smooth_normals();
} else
for (i = 0; i < r_tiles_max * 3; i++)
r_globe_verts[i].v.no = r_tiles[i / 3].normal;
R_vbo_update(&r_globe_vbo);
return TRUE;
}
// particle simulation
void simulate(Scene* scene) {
//put_your_code_here("Implement simulation");
// for each mesh
for(auto m : scene->meshes){
// skip if no simulation
if(!m->simulation){continue;}
// compute time per step
float timeperstep = scene->animation->dt/scene->animation->simsteps;
// foreach simulation steps
for(int step = 0; step < scene->animation->simsteps; step++){
// foreach particle, compute external forces
for(int particle: range(0, m->simulation->force.size())){
// initialize particle forces to zero3f
m->simulation->force[particle] = zero3f;
// compute force of gravity
auto g = scene->animation->gravity;
// compute force of wind
//EXTRA CREDIT DON"T DO WIND
// accumulate sum of forces on particle
m->simulation->force[particle] += g;
}
//SPRING EXTRA CREDIT
// for each spring, compute spring force on points
// compute spring distance and length
// compute static force
// accumulate static force on points
// compute dynamic force
// accumulate dynamic force on points
// foreach particle, integrate using newton laws
for(int particle: range(0, m->simulation->force.size())){
// if pinned, skip
if(m->simulation->pinned[particle]){continue;}
// compute acceleration
auto acceleration = m->simulation->force[particle]/m->simulation->mass[particle];
// update velocity and positions using Euler's method
m->simulation->vel[particle] = m->simulation->vel[particle] + acceleration*timeperstep ;
m->pos[particle] = m->pos[particle] + m->simulation->vel[particle]*timeperstep + acceleration*timeperstep*timeperstep*.5;
// for each surface, check for collision
bool inside;
for(auto surface : scene->surfaces){
inside = false;
// compute local position
auto L_pos = transform_point_to_local(surface->frame, m->pos[particle]);
auto R = surface->radius;
// if quad
vec3f col_pos;
vec3f col_norm;
if(surface->isquad){
// perform inside test
if(L_pos.x < R && L_pos.x > -R && L_pos.z < 0 && L_pos.y < R && L_pos.y > -R){
inside = true;
// vec3f col_pos = m->pos[particle];
col_norm = surface->frame.z;
col_pos = transform_point_from_local(surface->frame, vec3f(L_pos.x, L_pos.y, 0));
}
}
// if sphere
if(!surface->isquad){
// inside test
if(dist(zero3f, L_pos) < R){
// // if inside, compute a collision position and normal
inside = true;
// vec3f col_pos = m->pos[particle];
vec3f C = surface->frame.o; //sphere center
vec3f E = surface->frame.o; //camera origin
float a = lengthSqr(C - m->pos[particle]);
float b = dot(2*(C - m->pos[particle]), C-E);
float c = lengthSqr(C - m->pos[particle])-sqr(R);
float det = sqr(b) - 4*a*c;
//if(det < 0){continue;}
//calculate t1 and t2
float t1 = (-b + sqrt(det))/(2*a);
float t2 = (-b - sqrt(det))/(2*a);
// just grab only the first hit
float t = fminf(t1, t2);
//check if computed param is within ray.tmin and ray.tmax
col_pos = m->pos[particle] + t*(C - m->pos[particle]); //find intersection point with quad
col_norm = normalize(col_pos - C);
}
}
// if inside
if(inside == true){
m->pos[particle]=col_pos;
// update velocity (particle bounces), taking into account loss of kinetic energy
vec3f ref = reflect(m->simulation->vel[particle], col_norm);
auto v1 = ref - dot(ref, col_norm)*col_norm;
auto v2 = dot(ref, col_norm)*col_norm;
m->simulation->vel[particle] = (1 - scene->animation->bounce_dump.x)*v1 +(1 - scene->animation->bounce_dump.y)*v2;
}
}
}
}
// smooth normals if it has triangles or quads
if(m->quad.size() != 0 || m->triangle.size() != 0){
smooth_normals(m);
}
}
}