optimize chunk intersection tests a little

[blank.git] / src / chunk.cpp

diff --git a/src/chunk.cpp b/src/chunk.cpp
index 10031e77e359deb60145bdefe24d2195baecfa6e..e61a3a70ba0260a2600f8498fb4c24996c1c89d3 100644 (file)
--- a/src/chunk.cpp
+++ b/src/chunk.cpp
@@ -6,6 +6,12 @@
 #include <glm/gtx/transform.hpp>
 
 
+namespace {
+
+blank::Model::Buffer buf;
+
+}
+
 namespace blank {
 
 Chunk::Chunk(const BlockTypeRegistry &types)
@@ -50,24 +56,14 @@ void Chunk::Draw() {
 bool Chunk::Intersection(
        const Ray &ray,
        const glm::mat4 &M,
-       int *blkid,
-       float *dist,
-       glm::vec3 *normal) const {
-       { // rough check
-               if (!blank::Intersection(ray, Bounds(), M)) {
-                       return false;
-               }
-       }
-
-       if (!blkid && !dist && !normal) {
-               return true;
-       }
-
+       int &blkid,
+       float &dist,
+       glm::vec3 &normal
+) const {
        // TODO: should be possible to heavily optimize this
        int id = 0;
-       int closest_id = -1;
-       float closest_dist = std::numeric_limits<float>::infinity();
-       glm::vec3 closest_normal(0, 1, 0);
+       blkid = -1;
+       dist = std::numeric_limits<float>::infinity();
        for (int z = 0; z < Depth(); ++z) {
                for (int y = 0; y < Height(); ++y) {
                        for (int x = 0; x < Width(); ++x, ++id) {
@@ -76,32 +72,23 @@ bool Chunk::Intersection(
                                }
                                float cur_dist;
                                glm::vec3 cur_norm;
-                               Block::Pos pos(float(x) + 0.5f, float(y) + 0.5f, float(z) + 0.5f);
-                               if (Type(blocks[id]).shape->Intersects(ray, glm::translate(M, pos), cur_dist, cur_norm)) {
-                                       if (cur_dist < closest_dist) {
-                                               closest_id = id;
-                                               closest_dist = cur_dist;
-                                               closest_normal = cur_norm;
+                               if (Type(blocks[id]).shape->Intersects(ray, M * ToTransform(id), cur_dist, cur_norm)) {
+                                       if (cur_dist < dist) {
+                                               blkid = id;
+                                               dist = cur_dist;
+                                               normal = cur_norm;
                                        }
                                }
                        }
                }
        }
 
-       if (closest_id < 0) {
+       if (blkid < 0) {
                return false;
+       } else {
+               normal = glm::vec3(BlockAt(blkid).Transform() * glm::vec4(normal, 0.0f));
+               return true;
        }
-
-       if (blkid) {
-               *blkid = closest_id;
-       }
-       if (dist) {
-               *dist = closest_dist;
-       }
-       if (normal) {
-               *normal = closest_normal;
-       }
-       return true;
 }
 
 void Chunk::Position(const Pos &pos) {
@@ -117,7 +104,6 @@ void Chunk::CheckUpdate() {
        if (dirty) {
                Update();
        }
-       model.CheckUpdate();
 }
 
 void Chunk::Update() {
@@ -127,20 +113,54 @@ void Chunk::Update() {
                vtx_count += shape->VertexCount();
                idx_count += shape->VertexIndexCount();
        }
-       model.Clear();
-       model.Reserve(vtx_count, idx_count);
+       buf.Clear();
+       buf.Reserve(vtx_count, idx_count);
 
        Model::Index vtx_counter = 0;
        for (size_t i = 0; i < Size(); ++i) {
+               if (Obstructed(i)) continue;
+
                const BlockType &type = Type(blocks[i]);
-               type.FillModel(model, ToCoords(i), vtx_counter);
+               type.FillModel(buf, ToTransform(i), vtx_counter);
                vtx_counter += type.shape->VertexCount();
        }
 
-       model.Invalidate();
+       model.Update(buf);
        dirty = false;
 }
 
+bool Chunk::Obstructed(int idx) const {
+       if (IsBorder(idx)) return false;
+
+       // not checking neighbor visibility here, so all
+       // invisible blocks must have their fill set to 6x false
+       // (the default, so should be okay)
+
+       const BlockType &right = Type(blocks[idx + 1]);
+       if (!right.fill.left) return false;
+
+       const BlockType &left = Type(blocks[idx - 1]);
+       if (!left.fill.right) return false;
+
+       const BlockType &up = Type(blocks[idx + Width()]);
+       if (!up.fill.down) return false;
+
+       const BlockType &down = Type(blocks[idx - Width()]);
+       if (!down.fill.up) return false;
+
+       const BlockType &front = Type(blocks[idx + Width() * Height()]);
+       if (!front.fill.back) return false;
+
+       const BlockType &back = Type(blocks[idx - Width() * Height()]);
+       if (!back.fill.front) return false;
+
+       return true;
+}
+
+glm::mat4 Chunk::ToTransform(int idx) const {
+       return glm::translate(glm::mat4(1.0f), ToCoords(idx)) * blocks[idx].Transform();
+}
+
 
 ChunkLoader::ChunkLoader(const BlockTypeRegistry &reg, const Generator &gen)
 : base(0, 0, 0)
@@ -186,6 +206,15 @@ void ChunkLoader::Generate(const Chunk::Pos &from, const Chunk::Pos &to) {
                                        loaded.emplace_back(reg);
                                        loaded.back().Position(pos);
                                        gen(loaded.back());
+
+                               //      orientation testing
+                               //      for (int i = 0; i < Block::FACE_COUNT; ++i) {
+                               //              for (int j = 0; j < Block::TURN_COUNT; ++j) {
+                               //                      loaded.back().BlockAt(512 * j + 2 * i) = Block(3 * (j + 1), Block::Face(i), Block::Turn(j));
+                               //              }
+                               //      }
+                               //      loaded.back().Invalidate();
+                               //      loaded.back().CheckUpdate();
                                } else {
                                        to_generate.emplace_back(pos);
                                }