outline pointed-at block

[blank.git] / src / world.cpp

diff --git a/src/world.cpp b/src/world.cpp
index 96b48ee120d96ee4e79bec833936fb7ae310c2e8..c958a65cf3144942f8d47af09576872fd48aae9c 100644 (file)
--- a/src/world.cpp
+++ b/src/world.cpp
@@ -1,5 +1,7 @@
 #include "world.hpp"
 
+#include <limits>
+
 
 namespace blank {
 
@@ -87,6 +89,54 @@ void Chunk::Draw() {
 }
 
 
+bool Chunk::Intersection(const Ray &ray, const glm::mat4 &M, int *blkid, float *dist) const {
+       { // rough check
+               const AABB bb{{0, 0, 0}, {Width(), Height(), Depth()}};
+               if (!blank::Intersection(ray, bb, M)) {
+                       return false;
+               }
+       }
+
+       if (!blkid && !dist) {
+               return true;
+       }
+
+       // TODO: should be possible to heavily optimize this
+       int id = 0;
+       int closest_id = -1;
+       float closest_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) {
+                               if (!blocks[id].type->visible) {
+                                       continue;
+                               }
+                               const AABB bb{{x, y, z}, {x+1, y+1, z+1}};
+                               float cur_dist;
+                               if (blank::Intersection(ray, bb, M, &cur_dist)) {
+                                       if (cur_dist < closest_dist) {
+                                               closest_id = id;
+                                               closest_dist = cur_dist;
+                                       }
+                               }
+                       }
+               }
+       }
+
+       if (closest_id < 0) {
+               return false;
+       }
+
+       if (blkid) {
+               *blkid = closest_id;
+       }
+       if (dist) {
+               *dist = closest_dist;
+       }
+       return true;
+}
+
+
 int Chunk::VertexCount() const {
        // TODO: query blocks as soon as type shapes are implemented
        return Size() * 6 * 6;