no lol

src/main.cpp

@@ -9,6 +9,7 @@
 #include "blt/gfx/renderer/batch_2d_renderer.h"
 #include "blt/std/assert.h"
 #include "imgui.h"
+#include "shifting.h"
 #include <variant>
 #include <random>
 #include <queue>
@@ -343,8 +344,8 @@ void update(std::int32_t w, std::int32_t h)
     
     if (ImGui::Button("Eval"))
     {
-        if (root && root->hasImage())
-            BLT_DEBUG(eval_AMF(root->getImage()));
+        //if (root && root->hasImage())
+            //BLT_DEBUG(eval_AMF(root->getImage()));
     }
     
     auto lw = 512.0f;

src/shifting.cpp

@@ -15,6 +15,7 @@
  *  You should have received a copy of the GNU General Public License
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
+#include "blt/std/logging.h"
 #include <shifting.h>
 #include <blt/math/vectors.h>
 #include <vector>
@@ -22,35 +23,145 @@
 
 inline constexpr char from_char(char c)
 {
-    return c - 'a';
+    return c;
 }
 
-struct vertex
+struct vertex_data
 {
     char name;
     HASHSET<char> neighbours;
+    blt::vec2 pos;
     
-    vertex(char name, const HASHSET<char>& n): name(from_char(name))
+    vertex_data(char name, const HASHSET<char>& n): name(from_char(name))
     {
         for (const auto& v : n)
             neighbours.insert(from_char(v));
     }
+    
+    vertex_data(char name, const blt::vec2& pos): name(from_char(name)), pos(pos)
+    {}
 };
 
-std::vector<vertex> edges = {
-        vertex{'a', {'i', 'e', 'b', 'j', 'h'}},
-        vertex{'b', {'a', 'e', 'c', 'j'}},
-        vertex{'c', {'e', 'd', 'f', 'j', 'b'}},
-        vertex{'d', {'e', 'f', 'c'}},
-        vertex{'e', {'h', 'f', 'd', 'c', 'b', 'a', 'i'}},
-        vertex{'f', {'d', 'e', 'h', 'g', 'j', 'c'}},
-        vertex{'g', {'j', 'f', 'h'}},
-        vertex{'h', {'j', 'g', 'f', 'e', 'i', 'a'}},
-        vertex{'i', {'e', 'a', 'h'}},
-        vertex{'j', {'a', 'b', 'c', 'f', 'g', 'h'}},
+using Point = const blt::vec2&;
+
+bool onSegment(Point p, Point q, Point r)
+{
+    if (q.x() <= std::max(p.x(), r.x()) && q.x() >= std::min(p.x(), r.x()) &&
+        q.y() <= std::max(p.y(), r.y()) && q.y() >= std::min(p.y(), r.y()))
+        return true;
+    return false;
+}
+
+int orientation(Point p, Point q, Point r)
+{
+    // for details of below formula.
+    int val = (q.y() - p.y()) * (r.x() - q.x()) -
+              (q.x() - p.x()) * (r.y() - q.y());
+    
+    if (val == 0) return 0;  // collinear
+    
+    return (val > 0) ? 1 : 2; // clock or counterclock wise
+}
+
+bool doIntersect(Point p1, Point q1, Point p2, Point q2)
+{
+    // Find the four orientations needed for general and
+    // special cases
+    int o1 = orientation(p1, q1, p2);
+    int o2 = orientation(p1, q1, q2);
+    int o3 = orientation(p2, q2, p1);
+    int o4 = orientation(p2, q2, q1);
+    
+    // General case
+    if (o1 != o2 && o3 != o4)
+        return true;
+    
+    // Special Cases
+    // p1, q1 and p2 are collinear and p2 lies on segment p1q1
+    if (o1 == 0 && onSegment(p1, p2, q1)) return true;
+    
+    // p1, q1 and q2 are collinear and q2 lies on segment p1q1
+    if (o2 == 0 && onSegment(p1, q2, q1)) return true;
+    
+    // p2, q2 and p1 are collinear and p1 lies on segment p2q2
+    if (o3 == 0 && onSegment(p2, p1, q2)) return true;
+    
+    // p2, q2 and q1 are collinear and q1 lies on segment p2q2
+    if (o4 == 0 && onSegment(p2, q1, q2)) return true;
+    
+    return false; // Doesn't fall in any of the above cases
+}
+
+float ccw(const blt::vec2& A, const blt::vec2& B, const blt::vec2& C)
+{
+    return (C.y() - A.y()) * (B.x() - A.x()) > (B.y() - A.y()) * (C.x() - A.x());
+}
+
+// Return true if line segments AB and CD intersect
+bool intersects(const blt::vec2& A, const blt::vec2& B, const blt::vec2& C, const blt::vec2& D)
+{
+    return ccw(A, C, D) != ccw(B, C, D) and ccw(A, B, C) != ccw(A, B, D);
+}
+
+std::vector<vertex_data> edges = {
+        vertex_data{'a', HASHSET<char>{'i', 'e', 'b', 'j', 'h'}},
+        vertex_data{'b', HASHSET<char>{'a', 'e', 'c', 'j'}},
+        vertex_data{'c', HASHSET<char>{'e', 'd', 'f', 'j', 'b'}},
+        vertex_data{'d', HASHSET<char>{'e', 'f', 'c'}},
+        vertex_data{'e', HASHSET<char>{'h', 'f', 'd', 'c', 'b', 'a', 'i'}},
+        vertex_data{'f', HASHSET<char>{'d', 'e', 'h', 'g', 'j', 'c'}},
+        vertex_data{'g', HASHSET<char>{'j', 'f', 'h'}},
+        vertex_data{'h', HASHSET<char>{'j', 'g', 'f', 'e', 'i', 'a'}},
+        vertex_data{'i', HASHSET<char>{'e', 'a', 'h'}},
+        vertex_data{'j', HASHSET<char>{'a', 'b', 'c', 'f', 'g', 'h'}},
 };
 
-void calculate_ordering()
+HASHSET<char>& getEdges(char c)
+{
+    for (auto& e : edges)
+        if (e.name == c)
+            return e.neighbours;
+    BLT_FATAL("Failed to find character in edge set");
+    std::exit(2);
+}
+
+std::vector<char> order = {
+        from_char('f'),
+        from_char('d'),
+        from_char('c'),
+        from_char('g'),
+        from_char('j'),
+        from_char('b'),
+        from_char('e'),
+        from_char('i'),
+        from_char('a'),
+        from_char('h'),
+};
+
+std::vector<vertex_data> out;
+
+bool has_intersection(Point p, char c)
 {
 
 }
+
+void shift_right(int units)
+{
+
+}
+
+void calculate_ordering()
+{
+    out.push_back(vertex_data{order.back(), blt::vec2{0, 0}});
+    out.back().neighbours = getEdges(out.back().name);
+    order.pop_back();
+    
+    out.push_back(vertex_data{order.back(), blt::vec2{2, 0}});
+    out.back().neighbours = getEdges(out.back().name);
+    order.pop_back();
+    
+    while (!order.empty())
+    {
+    
+    }
+}