1 files changed, 59 insertions, 0 deletions
diff --git a/connection.cpp b/connection.cpp
new file mode 100644
index 0000000..3b5076c
--- /dev/null
+++ b/connection.cpp
@@ -0,0 +1,59 @@
+#include "connection.h"
+#include "vector.h"
+
+using std::min;
+using std::max;
+
+Connection::Connection(boost::asio::io_service& io_service_) : io_service(io_service_), socket(io_service_) {
+}
+
+float Connection::distance(float px, float pz) {
+	bool in_width = px > pos.x && px < pos.x+1;
+	bool in_height = pz > pos.z && pz < pos.z+1;
+
+	if(in_width && in_height)
+		return 0;
+
+	Vector2 p(px, pz);
+
+	float a = (p - pos.xz()).length();
+	float b = (p - (pos.xz() + Vector2(1, 0))).length();
+	float c = (p - (pos.xz() + Vector2(0, 1))).length();
+	float d = (p - (pos.xz() + Vector2(1, 1))).length();
+
+	float dist = min(min(min(a, b), c), d);
+
+	if(in_width)
+		dist = min(dist, (float)min(abs(pos.z - pz), abs(pos.z+1 - pz)));
+	if(in_height)
+		dist = min(dist, (float)min(abs(pos.x - px), abs(pos.x+1 - px)));
+
+	return dist;
+}
+
+std::set<std::pair<int64_t, int64_t> > Connection::check_chunks() {
+	// TODO: make configurable
+	const int chunk_size = 32;
+	const int chunk_dist_threshold = chunk_size*4;
+
+	// list of chunks client should hold
+	std::set<std::pair<int64_t, int64_t> > new_chunks;
+	int i = pos.x - chunk_dist_threshold;
+	i -= i % chunk_size;
+	for(; i < pos.x + chunk_dist_threshold; i += chunk_size) {
+		int j = pos.z - chunk_dist_threshold;
+		j -= j % chunk_size;
+		for(; j < pos.z + chunk_dist_threshold; j += chunk_size) {
+			if(chunk_indices.find(std::pair<int64_t, int64_t>(i, j)) != chunk_indices.end())
+				continue;
+			float a = i - pos.x + chunk_size/2;
+			float b = j - pos.z + chunk_size/2;
+			if(sqrtf(a*a + b*b) < chunk_dist_threshold) {
+				chunk_indices.insert(std::pair<int64_t, int64_t>(i, j));
+				new_chunks.insert(std::pair<int64_t, int64_t>(i, j));
+			}
+		}
+	}
+
+	return new_chunks;
+}