1 files changed, 30 insertions, 0 deletions
diff --git a/src/shared/math/coords.cc b/src/shared/math/coords.cc
new file mode 100644
index 0000000..37fb19a
--- /dev/null
+++ b/src/shared/math/coords.cc
@@ -0,0 +1,30 @@
+#include "shared/math/coords.hh"
+
+namespace shared {
+namespace math {
+
+bool coords::is_inside_draw(const coords& a, const coords& b,
+                            const std::int32_t draw_distance) noexcept {
+    const auto x2 = (a.x - b.x) * (a.x - b.x);
+    const auto z2 = (a.z - b.z) * (a.z - b.z);
+    const auto dd2 = draw_distance * draw_distance;
+
+    return (x2 < dd2 - z2) && (z2 < dd2 - x2);
+}
+
+coords coords::operator+(const coords& c) const noexcept {
+    auto ret = *this;
+    ret.x += c.x;
+    ret.z += c.z;
+    return ret;
+}
+
+coords coords::operator-(const coords& c) const noexcept {
+    auto ret = *this;
+    ret.x -= c.x;
+    ret.z -= c.z;
+    return ret;
+}
+
+} // namespace math
+} // namespace shared