fast-nuclear-sim/src/graphics/data/mesh.cpp

375 lines
7.1 KiB
C++

#include "mesh.hpp"
#include "arrays.hpp"
#include "../shader.hpp"
#include "../camera.hpp"
#include "../input/focus.hpp"
#include "../../util/math.hpp"
#include "../../util/streams.hpp"
#include <iostream>
using namespace Sim::Graphics::Data;
Mesh::Mesh()
{
}
Mesh& Mesh::set_texture_id(unsigned int id)
{
for(unsigned int i = 0; i < vertices.size(); i++)
{
vertices[i].texid = id;
}
return *this;
}
Mesh& Mesh::set_blank_transform()
{
transforms = {glm::mat4(1)};
for(unsigned int i = 0; i < vertices.size(); i++)
{
vertices[i].transform_id = 0;
}
return *this;
}
Mesh& Mesh::add(const Mesh& o, glm::mat4 mat, bool bake)
{
int off = vertices.size();
indices.reserve(indices.size() + o.indices.size());
vertices.reserve(vertices.size() + o.vertices.size());
if(bake)
{
for(int i = 0; i < o.vertices.size(); i++)
{
Arrays::Vertex v = o.vertices[i];
int t_id = (int)v.transform_id;
glm::mat4 t_mat = t_id >= 0 ? transforms[t_id] : glm::mat4(1);
t_mat = mat * t_mat;
v.pos = t_mat * glm::vec4(v.pos, 1);
v.normal = glm::normalize(glm::mat3(t_mat) * v.normal);
v.transform_id = -1;
vertices.push_back(v);
}
for(int i = 0; i < o.indices.size(); i++)
{
indices.push_back(o.indices[i] + off);
}
return *this;
}
glm::mat3 mat3(mat);
float t_off = transforms.size();
float t_new = -1;
if(mat != glm::mat4(1))
{
t_new = transforms.size() + o.transforms.size();
}
transforms.reserve(transforms.size() + o.transforms.size() + (t_new >= 0 ? 1 : 0));
for(int i = 0; i < o.vertices.size(); i++)
{
Arrays::Vertex v = o.vertices[i];
if(v.transform_id >= 0)
{
v.transform_id += t_off;
}
else
{
v.transform_id = t_new;
}
vertices.push_back(v);
}
for(int i = 0; i < o.transforms.size(); i++)
{
transforms.push_back(o.transforms[i] * mat);
}
for(int i = 0; i < o.indices.size(); i++)
{
indices.push_back(o.indices[i] + off);
}
if(t_new >= 0)
{
transforms.push_back(mat);
}
return *this;
}
Mesh& Mesh::bake_transforms()
{
for(unsigned int i = 0; i < vertices.size(); i++)
{
int id = (int)vertices[i].transform_id;
if(id >= 0)
{
glm::mat4 transform = transforms[id];
vertices[i].pos = glm::vec3(transform * glm::vec4(vertices[i].pos, 1));
vertices[i].normal = glm::normalize(glm::mat3(transform) * vertices[i].normal);
vertices[i].transform_id = -1;
}
}
transforms.clear();
return *this;
}
typedef glm::vec<3, double> vec3;
bool ray_intersects_triangle(vec3 ray_origin,
vec3 ray_vector,
const vec3* triangle,
vec3& out_intersection_point)
{
constexpr double epsilon = std::numeric_limits<double>::epsilon();
vec3 edge1 = triangle[1] - triangle[0];
vec3 edge2 = triangle[2] - triangle[0];
vec3 ray_cross_e2 = cross(ray_vector, edge2);
double det = dot(edge1, ray_cross_e2);
if (det > -epsilon && det < epsilon)
return false; // This ray is parallel to this triangle.
double inv_det = 1.0 / det;
vec3 s = ray_origin - triangle[0];
double u = inv_det * dot(s, ray_cross_e2);
if (u < 0 || u > 1)
return false;
vec3 s_cross_e1 = cross(s, edge1);
double v = inv_det * dot(ray_vector, s_cross_e1);
if (v < 0 || u + v > 1)
return false;
// At this stage we can compute t to find out where the intersection point is on the line.
double t = inv_det * dot(edge2, s_cross_e1);
out_intersection_point = ray_origin + ray_vector * t;
if (t > epsilon) // ray intersection
{
return true;
}
else // This means that there is a line intersection but not a ray intersection.
return false;
}
bool Mesh::check_focus(double len) const
{
if(!Focus::is_triggered())
{
return false;
}
auto near = Focus::get_trigger_near();
auto far = Focus::get_trigger_far();
return check_intersect(near, glm::normalize(far - near) * len);
}
bool Mesh::check_focus_hold(double len)
{
if(!Focus::is_triggered() && (!focus || Focus::is_triggered_release()))
{
return focus = false;
}
auto near = Focus::get_trigger_near();
auto far = Focus::get_trigger_far();
return focus = check_intersect(near, glm::normalize(far - near) * len);
}
bool Mesh::check_intersect(vec3 pos, vec3 path) const
{
double l = glm::length(path);
if(l == 0)
{
return false;
}
vec3 path_n = path / l;
for(unsigned int i = 0; i < indices.size(); i += 3)
{
Arrays::Vertex verts[3] = {
vertices[indices[i]],
vertices[indices[i + 1]],
vertices[indices[i + 2]]
};
vec3 v[3];
for(int j = 0; j < 3; j++)
{
int t_id = (int)verts[j].transform_id;
glm::mat4 t_mat = t_id >= 0 ? transforms[t_id] : glm::mat4(1);
v[j] = vec3(t_mat * glm::vec4(verts[j].pos, 1));
}
vec3 ipoint;
vec3 normal = glm::normalize(glm::cross(v[1] - v[0], v[2] - v[0]));
double d = glm::dot(normal, path);
if(d >= 0)
continue;
if(!ray_intersects_triangle(pos, path_n, v, ipoint))
continue;
if(l < glm::length(ipoint - pos))
continue;
return true;
}
return false;
}
static bool calc_intercept_vert(vec3 v[3], vec3 pos, vec3& path, vec3& path_n, double& l)
{
vec3 ipoint;
vec3 normal = glm::normalize(glm::cross(v[1] - v[0], v[2] - v[0]));
double d = glm::dot(path, normal);
if(d >= 0)
return false;
if(!ray_intersects_triangle(pos, path_n, v, ipoint))
return false;
if(l < glm::length(ipoint - pos))
return false;
if(d < 0)
{
path -= normal * d;
l = glm::length(path);
}
if(l > 0)
{
path_n = path / l;
}
return true;
}
vec3 Mesh::calc_intersect(vec3 pos, vec3 path) const
{
double l = glm::length(path);
if(l == 0)
{
return path;
}
vec3 path_n = path / l;
bool changing = true;
while(changing)
{
changing = false;
for(unsigned int i = 0; i < indices.size(); i += 3)
{
Arrays::Vertex verts[3] = {
vertices[indices[i]],
vertices[indices[i + 1]],
vertices[indices[i + 2]]
};
vec3 v[3];
for(int j = 0; j < 3; j++)
{
int t_id = (int)verts[j].transform_id;
glm::mat4 t_mat = t_id >= 0 ? transforms[t_id] : glm::mat4(1);
v[j] = vec3(t_mat * glm::vec4(verts[j].pos, 1));
}
if(calc_intercept_vert(v, pos, path, path_n, l))
{
changing = true;
}
if(l == 0)
{
return path;
}
}
}
return path;
}
Mesh Mesh::to_lines() const
{
Mesh m;
m.vertices = vertices;
for(int i = 0; i < indices.size(); i += 3)
{
m.indices.push_back(indices[i]);
m.indices.push_back(indices[i + 1]);
m.indices.push_back(indices[i + 1]);
m.indices.push_back(indices[i + 2]);
m.indices.push_back(indices[i]);
m.indices.push_back(indices[i + 2]);
}
return m;
}
std::ostream& Sim::Graphics::Data::operator<<(std::ostream& os, const Mesh& m)
{
os << "Mesh(\n";
os << " Vertices(\n";
for(int i = 0; i < m.vertices.size(); i++)
{
os << " " << m.vertices[i] << "\n";
}
os << " )\n";
for(int i = 0; i < m.indices.size(); i += 3)
{
os << " " << m.indices[i] << " " << m.indices[i + 1] << " " << m.indices[i + 2] << "\n";
}
os << " Transforms(\n";
for(int i = 0; i < m.transforms.size(); i++)
{
os << " " << m.transforms[i] << "\n";
}
os << " )\n";
os << ")\n";
return os;
}