#include <limits>
#include <glm/gtx/euler_angles.hpp>
#include <glm/gtx/io.hpp>
+#include <glm/gtx/projection.hpp>
#include <glm/gtx/quaternion.hpp>
#include <glm/gtx/rotate_vector.hpp>
#include <glm/gtx/transform.hpp>
}
glm::vec3 Entity::ControlForce(const EntityState &s) const noexcept {
+ glm::vec3 force;
if (HasController()) {
- return GetController().ControlForce(*this, s);
+ force = GetController().ControlForce(*this, s);
} else {
- return -s.velocity;
+ force = -s.velocity;
}
+ limit(force, max_force);
+ return force;
}
void Entity::Position(const glm::ivec3 &c, const glm::vec3 &b) noexcept {
return Ray{ glm::vec3(transform[3]), -glm::vec3(transform[2]) };
}
-void Entity::Update(float dt) {
- UpdateTransforms();
- UpdateHeading();
+void Entity::Update(World &world, float dt) {
if (HasController()) {
GetController().Update(*this, dt);
}
+ UpdatePhysics(world, dt);
+ UpdateTransforms();
+ UpdateHeading();
UpdateModel(dt);
}
+void Entity::UpdatePhysics(World &world, float dt) {
+ EntityState s(state);
+
+ EntityDerivative a(CalculateStep(world, s, 0.0f, EntityDerivative()));
+ EntityDerivative b(CalculateStep(world, s, dt * 0.5f, a));
+ EntityDerivative c(CalculateStep(world, s, dt * 0.5f, b));
+ EntityDerivative d(CalculateStep(world, s, dt, c));
+
+ EntityDerivative f;
+ constexpr float sixth = 1.0f / 6.0f;
+ f.position = sixth * (a.position + 2.0f * (b.position + c.position) + d.position);
+ f.velocity = sixth * (a.velocity + 2.0f * (b.velocity + c.velocity) + d.velocity);
+
+ s.pos.block += f.position * dt;
+ s.velocity += f.velocity * dt;
+ limit(s.velocity, max_vel);
+ world.ResolveWorldCollision(*this, s);
+ s.AdjustPosition();
+
+ SetState(s);
+}
+
+EntityDerivative Entity::CalculateStep(
+ World &world,
+ const EntityState &cur,
+ float dt,
+ const EntityDerivative &delta
+) const {
+ EntityState next(cur);
+ next.pos.block += delta.position * dt;
+ next.velocity += delta.velocity * dt;
+ limit(next.velocity, max_vel);
+ world.ResolveWorldCollision(*this, next);
+ next.AdjustPosition();
+
+ EntityDerivative out;
+ out.position = next.velocity;
+ out.velocity = ControlForce(next) + world.GravityAt(next.pos); // by mass = 1kg
+ return out;
+}
+
+
void Entity::UpdateTransforms() noexcept {
// model transform is the one given by current state
model_transform = state.Transform(state.pos.chunk);
std::cout << "direction: " << direction << std::endl;
std::cout << "difference: " << glm::degrees(relative_difference) << "°" << std::endl;
std::cout << "correction: " << glm::degrees(correction) << "°" << std::endl;
- std::cout << std::endl;
+ std::cout << std::endl;
}
// now rotate body by correction and head by -correction
state.orient = rotate(state.orient, correction, up);
}
void Entity::OrientHead(float dt) noexcept {
- // maximum yaw of head (90°)
- constexpr float max_head_yaw = PI_0p5;
+ // maximum yaw of head (60°)
+ constexpr float max_head_yaw = PI / 3.0f;
// use local Y as up
const glm::vec3 up(model_transform[1]);
// if yaw is bigger than max, rotate the body to accomodate
}
bool World::Intersection(const Entity &e, const EntityState &s, std::vector<WorldCollision> &col) {
- // TODO: make special case for entities here and in Chunk::Intersection so entity's bounding radius
- // doesn't have to be calculated over and over again (sqrt)
glm::ivec3 reference = s.pos.chunk;
glm::mat4 M = s.Transform(reference);
if (manhattan_radius(cur_chunk.Position() - reference) > 1) {
// chunk is not one of the 3x3x3 surrounding the entity
// since there's no entity which can extent over 16 blocks, they can be skipped
+ // TODO: change to indexed (like with entity)
continue;
}
if (cur_chunk.Intersection(box, M, cur_chunk.Transform(reference), col)) {
void World::Update(int dt) {
float fdt(dt * 0.001f);
for (Entity &entity : entities) {
- Update(entity, fdt);
- }
- for (Entity &entity : entities) {
- entity.Update(fdt);
+ entity.Update(*this, fdt);
}
for (Player &player : players) {
player.Update(dt);
}
}
-void World::Update(Entity &entity, float dt) {
- EntityState state(entity.GetState());
-
- EntityDerivative a(CalculateStep(entity, state, 0.0f, EntityDerivative()));
- EntityDerivative b(CalculateStep(entity, state, dt * 0.5f, a));
- EntityDerivative c(CalculateStep(entity, state, dt * 0.5f, b));
- EntityDerivative d(CalculateStep(entity, state, dt, c));
-
- EntityDerivative f;
- constexpr float sixth = 1.0f / 6.0f;
- f.position = sixth * ((a.position + 2.0f * (b.position + c.position)) + d.position);
- f.velocity = sixth * ((a.velocity + 2.0f * (b.velocity + c.velocity)) + d.velocity);
+namespace {
- state.pos.block += f.position * dt;
- state.velocity += f.velocity * dt;
- state.AdjustPosition();
+std::vector<WorldCollision> col;
- entity.SetState(state);
}
-EntityDerivative World::CalculateStep(
+void World::ResolveWorldCollision(
const Entity &entity,
- const EntityState &cur,
- float dt,
- const EntityDerivative &delta
+ EntityState &state
) {
- EntityState next(cur);
- next.pos.block += delta.position * dt;
- next.velocity += delta.velocity * dt;
- next.AdjustPosition();
-
- if (dot(next.velocity, next.velocity) > entity.MaxVelocity() * entity.MaxVelocity()) {
- next.velocity = normalize(next.velocity) * entity.MaxVelocity();
+ col.clear();
+ if (!entity.WorldCollidable() || !Intersection(entity, state, col)) {
+ // no collision, no fix
+ return;
}
-
- EntityDerivative out;
- out.position = next.velocity;
- out.velocity = CalculateForce(entity, next); // by mass = 1kg
- return out;
-}
-
-glm::vec3 World::CalculateForce(
- const Entity &entity,
- const EntityState &state
-) {
- glm::vec3 force(ControlForce(entity, state) + CollisionForce(entity, state) + Gravity(entity, state));
- if (dot(force, force) > entity.MaxControlForce() * entity.MaxControlForce()) {
- return normalize(force) * entity.MaxControlForce();
- } else {
- return force;
+ glm::vec3 correction = CombinedInterpenetration(state, col);
+ // correction may be zero in which case normalize() returns NaNs
+ if (iszero(correction)) {
+ return;
}
+ // if entity is already going in the direction of correction,
+ // let the problem resolve itself
+ if (dot(state.velocity, correction) >= 0.0f) {
+ return;
+ }
+ // apply correction, maybe could use some damping, gotta test
+ state.pos.block += correction;
+ // kill velocity?
+ glm::vec3 normal_velocity(proj(state.velocity, correction));
+ state.velocity -= normal_velocity;
}
-glm::vec3 World::ControlForce(
- const Entity &entity,
- const EntityState &state
-) {
- return entity.ControlForce(state);
+glm::vec3 World::CombinedInterpenetration(
+ const EntityState &state,
+ const std::vector<WorldCollision> &col
+) noexcept {
+ // determine displacement for each cardinal axis and move entity accordingly
+ glm::vec3 min_pen(0.0f);
+ glm::vec3 max_pen(0.0f);
+ for (const WorldCollision &c : col) {
+ if (!c.Blocks()) continue;
+ glm::vec3 normal(c.normal);
+ // swap if neccessary (normal may point away from the entity)
+ if (dot(normal, state.RelativePosition(c.ChunkPos()) - c.BlockCoords()) < 0) {
+ normal = -normal;
+ }
+ // check if block surface is "inside"
+ Block::Face coll_face = Block::NormalFace(normal);
+ BlockLookup neighbor(c.chunk, c.BlockPos(), coll_face);
+ if (neighbor && neighbor.FaceFilled(Block::Opposite(coll_face))) {
+ // yep, so ignore this contact
+ continue;
+ }
+ glm::vec3 local_pen(normal * c.depth);
+ min_pen = min(min_pen, local_pen);
+ max_pen = max(max_pen, local_pen);
+ }
+ glm::vec3 pen(0.0f);
+ // only apply correction for axes where penetration is only in one direction
+ for (std::size_t i = 0; i < 3; ++i) {
+ if (min_pen[i] < -std::numeric_limits<float>::epsilon()) {
+ if (max_pen[i] < std::numeric_limits<float>::epsilon()) {
+ pen[i] = min_pen[i];
+ }
+ } else {
+ pen[i] = max_pen[i];
+ }
+ }
+ return pen;
}
-namespace {
+glm::vec3 World::GravityAt(const ExactLocation &loc) const noexcept {
+ glm::vec3 force(0.0f);
+ ExactLocation::Coarse begin(loc.chunk - 1);
+ ExactLocation::Coarse end(loc.chunk + 2);
-std::vector<WorldCollision> col;
-
-}
-
-glm::vec3 World::CollisionForce(
- const Entity &entity,
- const EntityState &state
-) {
- col.clear();
- if (entity.WorldCollidable() && Intersection(entity, state, col)) {
- // determine displacement for each cardinal axis and move entity accordingly
- glm::vec3 min_pen(0.0f);
- glm::vec3 max_pen(0.0f);
- for (const WorldCollision &c : col) {
- if (!c.Blocks()) continue;
- glm::vec3 local_pen(c.normal * c.depth);
- // swap if neccessary (normal may point away from the entity)
- if (dot(c.normal, state.RelativePosition(c.ChunkPos()) - c.BlockCoords()) > 0) {
- local_pen *= -1;
- }
- min_pen = min(min_pen, local_pen);
- max_pen = max(max_pen, local_pen);
- }
- glm::vec3 correction(0.0f);
- // only apply correction for axes where penetration is only in one direction
- for (std::size_t i = 0; i < 3; ++i) {
- if (min_pen[i] < -std::numeric_limits<float>::epsilon()) {
- if (max_pen[i] < std::numeric_limits<float>::epsilon()) {
- correction[i] = -min_pen[i];
+ for (ExactLocation::Coarse pos(begin); pos.z < end.z; ++pos.z) {
+ for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
+ for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
+ const Chunk *chunk = chunks.Get(pos);
+ if (chunk) {
+ force += chunk->GravityAt(loc);
}
- } else {
- correction[i] = -max_pen[i];
}
}
- // correction may be zero in which case normalize() returns NaNs
- if (dot(correction, correction) < std::numeric_limits<float>::epsilon()) {
- return glm::vec3(0.0f);
- }
- glm::vec3 normal(normalize(correction));
- glm::vec3 normal_velocity(normal * dot(state.velocity, normal));
- // apply force proportional to penetration
- // use velocity projected onto normal as damper
- constexpr float k = 1000.0f; // spring constant
- constexpr float b = 10.0f; // damper constant
- const glm::vec3 x(-correction); // endpoint displacement from equilibrium in m
- const glm::vec3 v(normal_velocity); // relative velocity between endpoints in m/s
- return (((-k) * x) - (b * v)); // times 1kg/s, in kg*m/s²
- } else {
- return glm::vec3(0.0f);
}
-}
-glm::vec3 World::Gravity(
- const Entity &entity,
- const EntityState &state
-) {
- return glm::vec3(0.0f);
+ return force;
}
World::EntityHandle World::RemoveEntity(EntityHandle &eh) {