simplify ray/chunk intersection test

[blank.git] / src / world / chunk.cpp

diff --git a/src/world/chunk.cpp b/src/world/chunk.cpp
index cedc532aed726a838d2b9ad10b7ea04be16eafb5..9e95458ef45ac7b9b818cd40d32193bc52fc9f51 100644 (file)
--- a/src/world/chunk.cpp
+++ b/src/world/chunk.cpp
@@ -359,7 +359,7 @@ bool Chunk::IsSurface(const RoughLocation::Fine &pos) const noexcept {
 
 bool Chunk::Intersection(
        const Ray &ray,
-       const glm::mat4 &M,
+       const ExactLocation::Coarse &reference,
        WorldCollision &coll
 ) noexcept {
        int idx = 0;
@@ -375,7 +375,7 @@ bool Chunk::Intersection(
                                }
                                float cur_dist;
                                glm::vec3 cur_norm;
-                               if (type.shape->Intersects(ray, M * ToTransform(RoughLocation::Fine(x, y, z), idx), cur_dist, cur_norm)) {
+                               if (type.shape->Intersects(ray, ToTransform(reference, RoughLocation::Fine(x, y, z), idx), cur_dist, cur_norm)) {
                                        if (cur_dist < coll.depth) {
                                                coll.block = idx;
                                                coll.depth = cur_dist;
@@ -407,14 +407,82 @@ bool Chunk::Intersection(
        if (!blank::Intersection(box, Mbox, Bounds(), Mchunk, penetration, normal)) {
                return false;
        }
-       for (int idx = 0, z = 0; z < side; ++z) {
-               for (int y = 0; y < side; ++y) {
-                       for (int x = 0; x < side; ++x, ++idx) {
+
+       // box's origin relative to the chunk
+       const glm::vec3 box_coords(Mbox[3] - Mchunk[3]);
+       const float box_rad = box.OriginRadius();
+
+       // assume a bounding radius of 2 for blocks
+       constexpr float block_rad = 2.0f;
+       const float bb_radius = box_rad + block_rad;
+
+       const RoughLocation::Fine begin(max(
+               RoughLocation::Fine(0),
+               RoughLocation::Fine(floor(box_coords - bb_radius))
+       ));
+       const RoughLocation::Fine end(min(
+               RoughLocation::Fine(side - 1),
+               RoughLocation::Fine(ceil(box_coords + bb_radius))
+       ) - 1);
+
+       for (RoughLocation::Fine pos(begin); pos.z < end.y; ++pos.z) {
+               for (pos.y = begin.y; pos.y < end.y; ++pos.y) {
+                       for (pos.x = begin.x; pos.x < end.x; ++pos.x) {
+                               int idx = ToIndex(pos);
                                const BlockType &type = Type(idx);
                                if (!type.collision || !type.shape) {
                                        continue;
                                }
-                               if (type.shape->Intersects(Mchunk * ToTransform(RoughLocation::Fine(x, y, z), idx), box, Mbox, penetration, normal)) {
+                               if (type.shape->Intersects(Mchunk * ToTransform(pos, idx), box, Mbox, penetration, normal)) {
+                                       col.emplace_back(this, idx, penetration, normal);
+                                       any = true;
+                               }
+                       }
+               }
+       }
+       return any;
+}
+
+bool Chunk::Intersection(
+       const Entity &entity,
+       const glm::mat4 &Mentity,
+       const glm::mat4 &Mchunk,
+       std::vector<WorldCollision> &col
+) noexcept {
+       // entity's origin relative to the chunk
+       const glm::vec3 entity_coords(Mentity[3] - Mchunk[3]);
+       const float ec_radius = entity.Radius() + Radius();
+
+       if (distance_squared(entity_coords, Center()) > ec_radius * ec_radius) {
+               return false;
+       }
+
+       bool any = false;
+       float penetration;
+       glm::vec3 normal;
+
+       // assume a bounding radius of 2 for blocks
+       constexpr float block_rad = 2.0f;
+       const float eb_radius = entity.Radius() + block_rad;
+
+       const RoughLocation::Fine begin(max(
+               RoughLocation::Fine(0),
+               RoughLocation::Fine(floor(entity_coords - eb_radius))
+       ));
+       const RoughLocation::Fine end(min(
+               RoughLocation::Fine(side),
+               RoughLocation::Fine(ceil(entity_coords + eb_radius))
+       ));
+
+       for (RoughLocation::Fine 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) {
+                               int idx = ToIndex(pos);
+                               const BlockType &type = Type(idx);
+                               if (!type.collision || !type.shape) {
+                                       continue;
+                               }
+                               if (type.shape->Intersects(Mchunk * ToTransform(pos, idx), entity.Bounds(), Mentity, penetration, normal)) {
                                        col.emplace_back(this, idx, penetration, normal);
                                        any = true;
                                }
@@ -492,6 +560,10 @@ glm::mat4 Chunk::ToTransform(const RoughLocation::Fine &pos, int idx) const noex
        return glm::translate(ToCoords(pos)) * BlockAt(idx).Transform();
 }
 
+glm::mat4 Chunk::ToTransform(const ExactLocation::Coarse &ref, const RoughLocation::Fine &pos, int idx) const noexcept {
+       return glm::translate(ExactLocation::Fine((position - ref) * ExactLocation::Extent()) + ToCoords(pos)) * BlockAt(idx).Transform();
+}
+
 
 BlockLookup::BlockLookup(Chunk *c, const RoughLocation::Fine &p) noexcept
 : chunk(c), pos(p) {