Vec3 barycentric(const Vec3& value1, const Vec3& value2, const Vec3& value3,
const float& amount1, const float& amount2)
{
return Vec3(barycentric(value1.x, value2.x, value3.x, amount1, amount2),
barycentric(value1.y, value2.y, value3.y, amount1, amount2),
barycentric(value1.z, value2.z, value3.z, amount1, amount2));
}
bool collides( SphereBody& body1, TriangleBody& body2, real_t collision_damping )
{
// Normal vector of trangle body.
Vector3 normal = normalize(cross(body2.vertices[1] - body2.vertices[0],
body2.vertices[2] - body2.vertices[0]));
real_t distance = dot(normal, body1.position - body2.position);
// Sphere may come from the opposition direction of normal.
if (std::abs(distance) <= body1.radius) {
Vector3 projection = body1.position - distance * normal;
Vector3 sphere_v = body1.velocity - body2.velocity;
// If sphere moves toward the triangle, check whether it hits the surface or
// edges of the triangle.
if (dot(sphere_v, distance * normal) < 0 && (barycentric(projection, body2) ||
collides_vertices_axes(body1.position, body1.radius, body2))) {
// Since the triangle is fixed, use the same formula with plane collision.
real_t v_projection = dot(body1.velocity, normal);
body1.velocity = body1.velocity - 2 * v_projection * normal;
body1.velocity = (1 - collision_damping) * body1.velocity;
return true;
}
}
return false;
}
Foam::vector Foam::barycentricParticle::position() const
{
vector centre;
tensor A;
tetTransform(centre, A);
return fromBarycentric(A, centre, barycentric());
}
void Foam::barycentricParticle::position(const vector& position)
{
vector centre;
scalar detA;
tensor T;
tetReverseTransform(centre, detA, T);
barycentric() = toBarycentric(T/detA, centre, position);
}
FT extrapolate(const Point &p,
const Point &a, FT fa,
const Point &b, FT fb,
const Point &c, FT fc)
{
FT u, v, w;
barycentric(p, a, b, c, u, v, w);
return u * fa + v * fb + w * fc;
}
void draw_triangle_gradient_new(point p[],vect_t zv[],double zs[],rgb c[]){
double minx=DBL_MAX,miny=DBL_MAX,maxx=-DBL_MAX,maxy=-DBL_MAX;
for(int i=0;i<3;i++){
if( p[i].x < minx) minx=p[i].x;
if( p[i].y < miny) miny=p[i].y;
if( p[i].x > maxx) maxx=p[i].x;
if( p[i].y > maxy) maxy=p[i].y;
}
vect_t t[3];
// printf("%f %f %f %f\n",minx,miny,maxx,maxy);
for(int i=0;i<3;i++){
t[i].x=p[i].x;
t[i].y=p[i].y;
t[i].z=0;
}
#if BARY_INLINE
// barycentric part one!
vect_t u=v_sub(t[1],t[0]);
vect_t v=v_sub(t[2],t[0]);
double d=u.x*v.y-v.x*u.y,a,bb,cc;
a=(u.y-v.y);
bb=(v.x-u.x);
cc=(u.x*v.y-v.x*u.y);
#endif
for(int y=miny;y<maxy;y++){
for(int x=minx;x<maxx;x++){
#if BARY_INLINE
vect_t pt=v_sub((vect_t){(double)x,(double)y,0},t[0]);
vect_t b;
b.x=(pt.x*a+pt.y*bb+cc)/d;
b.y=(pt.x*v.y-pt.y*v.x)/d;
b.z=(pt.y*u.x-pt.x*u.y)/d;
#else
vect_t b=barycentric(t,(vect_t){(double)x,(double)y,0.0});
#endif
// Fun effect if you put this at 0
#if 1
if(b.x < 0 || b.y < 0 || b.z < 0) continue;
if(b.x > 1.0 || b.y > 1.0 || b.z > 1.0 ) continue;
#else
putpixel_c(x,y,c[0]);
continue;
#endif
double z=b.x*zs[0] + b.y*zs[1] + b.z*zs[2];
rgb cout;
cout.r=b.x*c[0].r + b.y*c[1].r + b.z*c[2].r;
cout.g=b.x*c[0].g + b.y*c[1].g + b.z*c[2].g;
cout.b=b.x*c[0].b + b.y*c[1].b + b.z*c[2].b;
putpixel_3d(x,y,z,cout);
// putpixel_c(x,y,c[0])
}
}
}
bool triangle_intersect(vector_t a, vector_t b, vector_t c, vector_t normal, vector_t ray_start, vector_t ray_direction, vector_t* hit, float* u, float* v, float* w)
{
vector_t plane_hit;
if (!plane_intersect((plane_t) {a, normal}, ray_start, ray_direction, &plane_hit))
return false;
float tmp_u, tmp_v, tmp_w;
barycentric(a, b, c, normal, plane_hit, &tmp_u, &tmp_v, &tmp_w);
if (tmp_u < 0.0 || tmp_v < 0.0 || tmp_w < 0.0)
return false;
*hit = plane_hit;
*u = tmp_u;
*v = tmp_v;
*w = tmp_w;
return true;
}
Vec1 barycentric(const Vec1& value1, const Vec1& value2, const Vec1& value3,
const float& amount1, const float& amount2)
{
return Vec1(barycentric(value1.x, value2.x, value3.x, amount1, amount2));
}
void draw_triangle_gradient(point p[],vect_t zv[],double zs[],rgb c[]){
int min_i=0,max_i=0,mid_i=-1;
// for(int i=0;i<3;i++) print_point(p[i]);
for(int i=1;i<3;i++){
if( p[i].x < p[min_i].x ) min_i=i;
if( p[i].x > p[max_i].x ) max_i=i;
}
/* printf("min: ");
print_point(p[min_i]);
printf("max: ");
print_point(p[max_i]);
*/
for(int i=0;i<3;i++) if( i != min_i && i != max_i ) mid_i = i;
int dx0=p[min_i].x-p[max_i].x;
int dy0=p[min_i].y-p[max_i].y;
double k0=dy0/(float)dx0;
int d0=p[min_i].y-k0*p[min_i].x;
int dx1=p[min_i].x-p[mid_i].x;
int dy1=p[min_i].y-p[mid_i].y;
double k1=dy1/(float)dx1;
int d1=p[min_i].y-k1*p[min_i].x;
int dx2=p[mid_i].x-p[max_i].x;
int dy2=p[mid_i].y-p[max_i].y;
double k2=dy2/(float)dx2;
int d2=p[mid_i].y-k2*p[mid_i].x;
for(int x=p[min_i].x ;x<p[mid_i].x;x++){
int y0 = k0*x + d0;
int y1 = k1*x + d1;
for(int y=min(y0,y1);y<=max(y0,y1);y++){
point pc={x,y};
// color cc=_tri_calc_color(p,pc,c);
vect_t b=barycentric(zv,(vect_t){x,y,0});
double z=b.x*zs[0] + b.y*zs[1] + b.z*zs[2];
if( x < 0 || x > WIDTH) continue;
if( y < 0 || y > HEIGHT) continue;
// printf("%f\n",z);
//
if((y>=0 && y<HEIGHT) && (x>0&&x<WIDTH)){
if(z_buffer[y*WIDTH+x] > z ){
putpixel_c(x,y,c[0]);
z_buffer[y*WIDTH+x]=z;
}
}
}
}
for(int x=p[mid_i].x ;x<p[max_i].x;x++){
int y0 = k0*x + d0;
int y2 = k2*x + d2;
for(int y=min(y0,y2);y<=max(y0,y2);y++){
point pc={x,y};
// color cc=_tri_calc_color(p,pc,c);
// putpixel_c(x,y,c[0]);
vect_t b=barycentric(zv,(vect_t){x,y,0});
//j double z=zv[0].z/b.x + zv[1].z/b.y + zv[2].z/b.z;
double z = b.x*zs[0] + b.y*zs[1] + b.z*zs[2];
if( x < 0 || x > WIDTH) continue;
if( y < 0 || y > HEIGHT) continue;
if((y>=0 && y<HEIGHT) && (x>0&&x<WIDTH)){
if(z_buffer[y*WIDTH+x] > z){
putpixel_c(x,y,c[0]);
z_buffer[y*WIDTH+x]=z;
}
}
}
}
}
