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#include "rail.h"
#include "network.h"
#include <array>
#include <cmath>
#include <collection.h>
#include <cstddef>
#include <game/network/link.h>
#include <game/network/network.impl.h> // IWYU pragma: keep
#include <gfx/models/vertex.h>
#include <glad/gl.h>
#include <glm/gtx/transform.hpp>
#include <maths.h>
#include <utility>
#include <vector>
template class NetworkOf<RailLink, RailLinkStraight, RailLinkCurve>;
constexpr auto RAIL_CROSSSECTION_VERTICES {5U};
constexpr Size3D RAIL_HEIGHT {0, 0, 250.F};
RailLinks::RailLinks() : NetworkOf<RailLink, RailLinkStraight, RailLinkCurve> {"rails.jpg"} { }
void
RailLinks::tick(TickDuration)
{
}
std::shared_ptr<RailLink>
RailLinks::addLinksBetween(GlobalPosition3D start, GlobalPosition3D end)
{
auto node1ins = newNodeAt(start), node2ins = newNodeAt(end);
if (node1ins.second == NodeIs::NotInNetwork && node2ins.second == NodeIs::NotInNetwork) {
// Both nodes are new, direct link, easy
return addLink<RailLinkStraight>(start, end);
}
if (node1ins.second == NodeIs::NotInNetwork && node2ins.second == NodeIs::InNetwork) {
// node1 is new, node2 exists, but we build from existing outwards
std::swap(node1ins, node2ins);
std::swap(start, end);
}
// Find start link/end - opposite entry dir to existing link; so pi +...
const Angle dir = pi + findNodeDirection(node1ins.first);
if (dir == vector_yaw(end - start)) {
return addLink<RailLinkStraight>(start, end);
}
const auto flatStart {start.xy()}, flatEnd {end.xy()};
if (node2ins.second == NodeIs::InNetwork) {
auto midheight = [&](auto mid) {
const auto sm = glm::length(RelativePosition2D(flatStart - mid)),
em = glm::length(RelativePosition2D(flatEnd - mid));
return start.z + GlobalDistance(RelativeDistance(end.z - start.z) * (sm / (sm + em)));
};
const float dir2 = pi + findNodeDirection(node2ins.first);
if (const auto radii = find_arcs_radius(flatStart, dir, flatEnd, dir2); radii.first < radii.second) {
const auto radius {radii.first};
const auto c1 = flatStart + GlobalPosition2D(sincosf(dir + half_pi) * radius);
const auto c2 = flatEnd + GlobalPosition2D(sincosf(dir2 + half_pi) * radius);
const auto mid = (c1 + c2) / 2;
const auto midh = mid || midheight(mid);
addLink<RailLinkCurve>(start, midh, c1);
return addLink<RailLinkCurve>(end, midh, c2);
}
else {
const auto radius {radii.second};
const auto c1 = flatStart + GlobalPosition2D(sincosf(dir - half_pi) * radius);
const auto c2 = flatEnd + GlobalPosition2D(sincosf(dir2 - half_pi) * radius);
const auto mid = (c1 + c2) / 2;
const auto midh = mid || midheight(mid);
addLink<RailLinkCurve>(midh, start, c1);
return addLink<RailLinkCurve>(midh, end, c2);
}
}
const auto diff {end - start};
const auto vy {vector_yaw(diff)};
const auto n2ed {(vy * 2) - dir - pi};
const auto centre {find_arc_centre(flatStart, dir, flatEnd, n2ed)};
if (centre.second) { // right hand arc
std::swap(start, end);
}
return addLink<RailLinkCurve>(start, end, centre.first);
}
Mesh::Ptr
RailLink::defaultMesh(const std::span<Vertex> vertices)
{
std::vector<unsigned int> indices;
for (auto n = RAIL_CROSSSECTION_VERTICES; n < vertices.size(); n += 1) {
indices.push_back(n - RAIL_CROSSSECTION_VERTICES);
indices.push_back(n);
}
return std::make_unique<Mesh>(vertices, indices, GL_TRIANGLE_STRIP);
}
void
RailLink::render(const SceneShader &) const
{
mesh->Draw();
}
constexpr const std::array<std::pair<RelativePosition3D, float>, RAIL_CROSSSECTION_VERTICES> railCrossSection {{
// ___________
// _/ \_
// left to right
{{-1900.F, 0.F, 0.F}, 0.F},
{{-608.F, 0.F, RAIL_HEIGHT.z}, .34F},
{{0, 0.F, RAIL_HEIGHT.z * .7F}, .5F},
{{608.F, 0.F, RAIL_HEIGHT.z}, .66F},
{{1900.F, 0.F, 0.F}, 1.F},
}};
constexpr auto sleepers {5.F}; // There are 5 repetitions of sleepers in the texture
inline auto
round_sleepers(const float v)
{
return round_frac(v, sleepers);
}
RailLinkStraight::RailLinkStraight(
NetworkLinkHolder<RailLinkStraight> & instances, const Node::Ptr & a, const Node::Ptr & b) :
RailLinkStraight(instances, a, b, b->pos - a->pos)
{
}
RailLinkStraight::RailLinkStraight(
NetworkLinkHolder<RailLinkStraight> & instances, Node::Ptr a, Node::Ptr b, const RelativePosition3D & diff) :
Link({std::move(a), vector_yaw(diff)}, {std::move(b), vector_yaw(-diff)}, glm::length(diff)),
instance {instances.vertices.acquire(
ends[0].node->pos, ends[1].node->pos, flat_orientation(diff), round_sleepers(length / 2000.F))}
{
if (glGenVertexArrays) {
std::vector<::Vertex> vertices;
vertices.reserve(2 * railCrossSection.size());
const auto len = round_sleepers(length / 2000.F);
const glm::mat3 trans {flat_orientation(diff)};
for (auto ei : {1U, 0U}) {
for (const auto & rcs : railCrossSection) {
const auto m {ends[ei].node->pos + GlobalPosition3D(trans * rcs.first)};
vertices.emplace_back(m, TextureRelCoord {rcs.second, len * static_cast<float>(ei)}, up);
}
}
mesh = defaultMesh(vertices);
}
}
RailLinkCurve::RailLinkCurve(
NetworkLinkHolder<RailLinkCurve> & instances, const Node::Ptr & a, const Node::Ptr & b, GlobalPosition2D c) :
RailLinkCurve(instances, a, b, c || a->pos.z, {c || 0, a->pos, b->pos})
{
}
RailLinkCurve::RailLinkCurve(NetworkLinkHolder<RailLinkCurve> & instances, const Node::Ptr & a, const Node::Ptr & b,
GlobalPosition3D c, const Arc arc) :
Link({a, normalize(arc.first + half_pi)}, {b, normalize(arc.second - half_pi)},
glm::length(RelativePosition3D(a->pos - c)) * arc_length(arc)),
LinkCurve {c, glm::length(RelativePosition3D(ends[0].node->pos - c)), arc},
instance {instances.vertices.acquire(ends[0].node->pos, ends[1].node->pos, c, round_sleepers(length / 2000.F))}
{
if (glGenVertexArrays) {
const auto & e0p {ends[0].node->pos};
const auto & e1p {ends[1].node->pos};
const auto slength = round_sleepers(length / 2.F);
const auto segs = std::round(slength / std::pow(radius, 0.7F));
const auto step {RelativePosition3D {arc_length(arc), e1p.z - e0p.z, slength / 1000.F} / segs};
auto segCount = static_cast<std::size_t>(std::lround(segs)) + 1;
std::vector<::Vertex> vertices;
vertices.reserve(segCount * railCrossSection.size());
for (RelativePosition3D swing = {arc.first, centreBase.z - e0p.z, 0.F}; segCount; swing += step, --segCount) {
const auto t {
glm::rotate(half_pi - swing.x, up) * glm::translate(RelativePosition3D {radius, 0.F, swing.y})};
for (const auto & rcs : railCrossSection) {
const auto m {centreBase + GlobalPosition3D(t * (rcs.first || 1.F))};
vertices.emplace_back(m, TextureRelCoord {rcs.second, swing.z}, up);
}
}
mesh = defaultMesh(vertices);
}
}
RelativePosition3D
RailLink::vehiclePositionOffset() const
{
return RAIL_HEIGHT;
}
template<> NetworkLinkHolder<RailLinkStraight>::NetworkLinkHolder()
{
VertexArrayObject {vao}
.addAttribs<RailLinkStraight::Vertex, &RailLinkStraight::Vertex::a, &RailLinkStraight::Vertex::b,
&RailLinkStraight::Vertex::rotation, &RailLinkStraight::Vertex::textureRepeats>(
vertices.bufferName());
}
template<> NetworkLinkHolder<RailLinkCurve>::NetworkLinkHolder()
{
VertexArrayObject {vao}
.addAttribs<RailLinkCurve::Vertex, &RailLinkCurve::Vertex::a, &RailLinkCurve::Vertex::b,
&RailLinkCurve::Vertex::c, &RailLinkCurve::Vertex::textureRepeats>(vertices.bufferName());
}
namespace {
template<typename LinkType>
void
renderType(const NetworkLinkHolder<LinkType> & n, auto & s)
{
if (auto count = n.vertices.size()) {
s.use();
glBindVertexArray(n.vao);
glDrawArrays(GL_POINTS, 0, static_cast<GLsizei>(count));
}
};
}
void
RailLinks::render(const SceneShader & shader) const
{
if (!links.objects.empty()) {
texture->bind();
renderType<RailLinkStraight>(*this, shader.networkStraight);
renderType<RailLinkCurve>(*this, shader.networkCurve);
glBindVertexArray(0);
}
}
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