From 4df96acf3b42eb117c3b30db38894fb6bb791922 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Sat, 19 Feb 2011 16:53:27 +0000
Subject: [PATCH] Connect up diagonal track

---
 include/Maths.hpp |  4 ++++
 src/Editor.cpp    | 24 +++++++++++++++++++++---
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/include/Maths.hpp b/include/Maths.hpp
index 276768b..1b1f4ed 100644
--- a/include/Maths.hpp
+++ b/include/Maths.hpp
@@ -244,6 +244,10 @@ struct Point {
    Point right() const { return Point(x + 1, y); }
    Point up() const { return Point(x, y + 1); }
    Point down() const { return Point(x, y - 1); }
+   Point up_left() const { return Point(x - 1, y + 1); }
+   Point up_right() const { return Point(x + 1, y + 1); }
+   Point down_left() const { return Point(x - 1, y - 1); }
+   Point down_right() const { return Point(x + 1, y - 1); }
 
    bool operator==(const Point<T>& a_point) const
    {
diff --git a/src/Editor.cpp b/src/Editor.cpp
index 5498cc0..89a4ed2 100644
--- a/src/Editor.cpp
+++ b/src/Editor.cpp
@@ -243,6 +243,18 @@ bool Editor::guess_track_dir(const Point<int>& p, track::Direction& d) const
    else if (can_connect(p.down(), p)) {
       d = axis::Y;
    }
+   else if (can_connect(p.up_left(), p)) {
+      d = -make_vector(-1, 0, 1);
+   }
+   else if (can_connect(p.up_right(), p)) {
+      d = -make_vector(1, 0, 1);
+   }
+   else if (can_connect(p.down_left(), p)) {
+      d = -make_vector(-1, 0, -1);
+   }
+   else if (can_connect(p.down_right(), p)) {
+      d = -make_vector(1, 0, -1);
+   }
    else
       return false;
    
@@ -442,15 +454,21 @@ void Editor::draw_dragged_track()
            << " drag_end=" << drag_end;
    debug() << "start_dir=" << start_dir << " end_dir=" << end_dir;
 
-   if (xlen == 1 && ylen == 1) {
+   const bool simple =
+      (start_dir.x + start_dir.z == 1)
+      && (end_dir.x + end_dir.z == 1);
+
+   debug() << "simple=" << simple;
+
+   if (simple && xlen == 1 && ylen == 1) {
       // A single tile
       draw_track_tile(drag_begin, start_dir);
    }
-   else if (xlen == 1) {
+   else if (simple && xlen == 1) {
       draw_dragged_straight(drag_begin.y < drag_end.y ? axis::Y : -axis::Y,
                             ylen);
    }
-   else if (ylen == 1) {
+   else if (simple && ylen == 1) {
       draw_dragged_straight(drag_begin.x < drag_end.x ? axis::X : -axis::X,
                             xlen);
    }
-- 
2.39.2