tentative optimization of chunk intersection test

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

diff --git a/src/world/chunk.cpp b/src/world/chunk.cpp
index cedc532aed726a838d2b9ad10b7ea04be16eafb5..a6f1521eeeafc39bdacf7478475f21b725007104 100644 (file)
--- a/src/world/chunk.cpp
+++ b/src/world/chunk.cpp
@@ -400,13 +400,20 @@ bool Chunk::Intersection(
        const glm::mat4 &Mchunk,
        std::vector<WorldCollision> &col
 ) noexcept {
+       // box's origin relative to the chunk
+       const glm::vec3 box_coords(Mbox[3] - Mchunk[3]);
+       const float box_rad = box.OriginRadius();
+
+       if (distance_squared(box_coords, Center()) > (box_rad + Radius()) * (box_rad + Radius())) {
+               return false;
+       }
+
        bool any = false;
        float penetration;
        glm::vec3 normal;
 
-       if (!blank::Intersection(box, Mbox, Bounds(), Mchunk, penetration, normal)) {
-               return false;
-       }
+       // assume a bounding radius of 2 for blocks
+       constexpr float block_rad = 2.0f;
        for (int idx = 0, z = 0; z < side; ++z) {
                for (int y = 0; y < side; ++y) {
                        for (int x = 0; x < side; ++x, ++idx) {
@@ -414,7 +421,11 @@ bool Chunk::Intersection(
                                if (!type.collision || !type.shape) {
                                        continue;
                                }
-                               if (type.shape->Intersects(Mchunk * ToTransform(RoughLocation::Fine(x, y, z), idx), box, Mbox, penetration, normal)) {
+                               const RoughLocation::Fine block_pos(x, y, z);
+                               const ExactLocation::Fine block_coords(ToCoords(block_pos));
+                               if (distance_squared(box_coords, block_coords) <= (box_rad + block_rad) * (box_rad + block_rad)
+                                       && type.shape->Intersects(Mchunk * ToTransform(block_pos, idx), box, Mbox, penetration, normal)
+                               ) {
                                        col.emplace_back(this, idx, penetration, normal);
                                        any = true;
                                }