UIGridPathfinding: clear and separate A-star and Djikstra path systems

src/UIGridPathfinding.h

@@ -0,0 +1,152 @@
+#pragma once
+#include "Common.h"
+#include "Python.h"
+#include "UIBase.h"  // For PyUIGridObject typedef
+#include <libtcod.h>
+#include <SFML/System/Vector2.hpp>
+#include <vector>
+#include <memory>
+#include <map>
+
+// Forward declarations
+class UIGrid;
+
+//=============================================================================
+// AStarPath - A computed A* path result, consumed like an iterator
+//=============================================================================
+
+struct PyAStarPathObject {
+    PyObject_HEAD
+    std::vector<sf::Vector2i> path;  // Pre-computed path positions
+    size_t current_index;            // Next step to return
+    sf::Vector2i origin;             // Fixed at creation
+    sf::Vector2i destination;        // Fixed at creation
+};
+
+//=============================================================================
+// DijkstraMap - A Dijkstra distance field from a fixed root
+//=============================================================================
+
+class DijkstraMap {
+public:
+    DijkstraMap(TCODMap* map, int root_x, int root_y, float diagonal_cost);
+    ~DijkstraMap();
+
+    // Non-copyable (owns TCODDijkstra)
+    DijkstraMap(const DijkstraMap&) = delete;
+    DijkstraMap& operator=(const DijkstraMap&) = delete;
+
+    // Queries
+    float getDistance(int x, int y) const;
+    std::vector<sf::Vector2i> getPathFrom(int x, int y) const;
+    sf::Vector2i stepFrom(int x, int y, bool* valid = nullptr) const;
+
+    // Accessors
+    sf::Vector2i getRoot() const { return root; }
+    float getDiagonalCost() const { return diagonal_cost; }
+
+private:
+    TCODDijkstra* tcod_dijkstra;  // Owned by this object
+    TCODMap* tcod_map;            // Borrowed from Grid
+    sf::Vector2i root;
+    float diagonal_cost;
+};
+
+struct PyDijkstraMapObject {
+    PyObject_HEAD
+    std::shared_ptr<DijkstraMap> data;  // Shared with Grid's collection
+};
+
+//=============================================================================
+// Helper Functions
+//=============================================================================
+
+namespace UIGridPathfinding {
+    // Extract grid position from Vector, Entity, or tuple
+    // Sets Python error and returns false on failure
+    // If expected_grid is provided and obj is Entity, validates grid membership
+    bool ExtractPosition(PyObject* obj, int* x, int* y,
+                         UIGrid* expected_grid = nullptr,
+                         const char* arg_name = "position");
+
+    //=========================================================================
+    // AStarPath Python Type Methods
+    //=========================================================================
+
+    PyObject* AStarPath_new(PyTypeObject* type, PyObject* args, PyObject* kwds);
+    int AStarPath_init(PyAStarPathObject* self, PyObject* args, PyObject* kwds);
+    void AStarPath_dealloc(PyAStarPathObject* self);
+    PyObject* AStarPath_repr(PyAStarPathObject* self);
+
+    // Methods
+    PyObject* AStarPath_walk(PyAStarPathObject* self, PyObject* args);
+    PyObject* AStarPath_peek(PyAStarPathObject* self, PyObject* args);
+
+    // Properties
+    PyObject* AStarPath_get_origin(PyAStarPathObject* self, void* closure);
+    PyObject* AStarPath_get_destination(PyAStarPathObject* self, void* closure);
+    PyObject* AStarPath_get_remaining(PyAStarPathObject* self, void* closure);
+
+    // Sequence protocol
+    Py_ssize_t AStarPath_len(PyAStarPathObject* self);
+    int AStarPath_bool(PyObject* self);
+    PyObject* AStarPath_iter(PyAStarPathObject* self);
+    PyObject* AStarPath_iternext(PyAStarPathObject* self);
+
+    //=========================================================================
+    // DijkstraMap Python Type Methods
+    //=========================================================================
+
+    PyObject* DijkstraMap_new(PyTypeObject* type, PyObject* args, PyObject* kwds);
+    int DijkstraMap_init(PyDijkstraMapObject* self, PyObject* args, PyObject* kwds);
+    void DijkstraMap_dealloc(PyDijkstraMapObject* self);
+    PyObject* DijkstraMap_repr(PyDijkstraMapObject* self);
+
+    // Methods
+    PyObject* DijkstraMap_distance(PyDijkstraMapObject* self, PyObject* args, PyObject* kwds);
+    PyObject* DijkstraMap_path_from(PyDijkstraMapObject* self, PyObject* args, PyObject* kwds);
+    PyObject* DijkstraMap_step_from(PyDijkstraMapObject* self, PyObject* args, PyObject* kwds);
+
+    // Properties
+    PyObject* DijkstraMap_get_root(PyDijkstraMapObject* self, void* closure);
+
+    //=========================================================================
+    // Grid Factory Methods (called from UIGrid Python bindings)
+    //=========================================================================
+
+    // Grid.find_path() -> AStarPath | None
+    PyObject* Grid_find_path(PyUIGridObject* self, PyObject* args, PyObject* kwds);
+
+    // Grid.get_dijkstra_map() -> DijkstraMap
+    PyObject* Grid_get_dijkstra_map(PyUIGridObject* self, PyObject* args, PyObject* kwds);
+
+    // Grid.clear_dijkstra_maps() -> None
+    PyObject* Grid_clear_dijkstra_maps(PyUIGridObject* self, PyObject* args);
+}
+
+//=============================================================================
+// Python Type Definitions
+//=============================================================================
+
+namespace mcrfpydef {
+
+    // AStarPath iterator type
+    struct PyAStarPathIterObject {
+        PyObject_HEAD
+        PyAStarPathObject* path;  // Reference to path being iterated
+        size_t iter_index;        // Current iteration position
+    };
+
+    extern PyNumberMethods PyAStarPath_as_number;
+    extern PySequenceMethods PyAStarPath_as_sequence;
+    extern PyMethodDef PyAStarPath_methods[];
+    extern PyGetSetDef PyAStarPath_getsetters[];
+
+    extern PyTypeObject PyAStarPathType;
+    extern PyTypeObject PyAStarPathIterType;
+
+    extern PyMethodDef PyDijkstraMap_methods[];
+    extern PyGetSetDef PyDijkstraMap_getsetters[];
+
+    extern PyTypeObject PyDijkstraMapType;
+}