From a45a2a5bd738e44ae862b548e1a01e12fcd36dca Mon Sep 17 00:00:00 2001
From: Dominic Masters <dominic@domsplace.com>
Date: Wed, 17 Sep 2025 18:54:12 -0500
Subject: [PATCH] Basic interaction

---
 src/rpg/entity/direction.c | 25 +++++++-----------
 src/rpg/entity/direction.h | 12 +++------
 src/rpg/entity/entity.c    |  4 +++
 src/rpg/entity/player.c    | 53 ++++++++++++++++++++++++++++++++++++++
 src/rpg/entity/player.h    | 11 +++++++-
 5 files changed, 81 insertions(+), 24 deletions(-)

diff --git a/src/rpg/entity/direction.c b/src/rpg/entity/direction.c
index e4f0e5e..aa04586 100644
--- a/src/rpg/entity/direction.c
+++ b/src/rpg/entity/direction.c
@@ -18,36 +18,31 @@ float_t directionToAngle(const direction_t dir) {
   }
 }
 
-void directionGetCoordinates(
-  const direction_t dir,
-  int8_t *x, int8_t *y
-) {
-  assertNotNull(x, "X coordinate pointer cannot be NULL");
-  assertNotNull(y, "Y coordinate pointer cannot be NULL");
+void directionGetVec2(const direction_t dir, vec2 out) {
+  assertNotNull(out, "Output vector cannot be NULL");
 
   switch(dir) {
     case DIRECTION_NORTH:
-      *x = 0;
-      *y = -1;
+      out[0] = 0.0f;
+      out[1] = 1.0f;
       break;
 
     case DIRECTION_SOUTH:
-      *x = 0;
-      *y = 1;
+      out[0] = 0.0f;
+      out[1] = -1.0f;
       break;
 
     case DIRECTION_EAST:
-      *x = 1;
-      *y = 0;
+      out[0] = 1.0f;
+      out[1] = 0.0f;
       break;
 
     case DIRECTION_WEST:
-      *x = -1;
-      *y = 0;
+      out[0] = -1.0f;
+      out[1] = 0.0f;
       break;
 
     default:
       assertUnreachable("Invalid direction");
-      break;
   }
 }
\ No newline at end of file
diff --git a/src/rpg/entity/direction.h b/src/rpg/entity/direction.h
index 65d6f2e..54b9c11 100644
--- a/src/rpg/entity/direction.h
+++ b/src/rpg/entity/direction.h
@@ -29,13 +29,9 @@ typedef enum {
 float_t directionToAngle(const direction_t dir);
 
 /**
- * Gets the relative coordinates for a given direction.
+ * Converts a direction to a vec2 unit vector.
  * 
- * @param dir The direction to get coordinates for.
- * @param x Pointer to store the x coordinate.
- * @param y Pointer to store the y coordinate.
+ * @param dir The direction to convert.
+ * @param out Pointer to the vec2 array to populate.
  */
-void directionGetCoordinates(
-  const direction_t dir,
-  int8_t *x, int8_t *y
-);
\ No newline at end of file
+void directionGetVec2(const direction_t dir, vec2 out);
\ No newline at end of file
diff --git a/src/rpg/entity/entity.c b/src/rpg/entity/entity.c
index 6a65885..c9ab810 100644
--- a/src/rpg/entity/entity.c
+++ b/src/rpg/entity/entity.c
@@ -100,4 +100,8 @@ void entityUpdate(entity_t *entity) {
       entity->velocity[1] = 0.0f;
     }
   }
+
+  if(entity->type == ENTITY_TYPE_PLAYER) {
+    playerInteraction(entity);
+  }
 }
\ No newline at end of file
diff --git a/src/rpg/entity/player.c b/src/rpg/entity/player.c
index 63257b0..1246e35 100644
--- a/src/rpg/entity/player.c
+++ b/src/rpg/entity/player.c
@@ -59,4 +59,57 @@ void playerMovement(entity_t *entity) {
   } else if(dir[1] > 0) {
     entity->direction = DIRECTION_DOWN;
   }
+}
+
+void playerInteraction(entity_t *entity) {
+  assertNotNull(entity, "Entity pointer cannot be NULL");
+
+  if(!inputPressed(INPUT_ACTION_ACCEPT)) return;
+  
+  physicsbox_t interactBox;
+
+  // Get direction vector
+  directionGetVec2(entity->direction, interactBox.min);
+
+  // Scale by interact range
+  glm_vec2_scale(interactBox.min, PLAYER_INTERACTION_RANGE, interactBox.min);
+
+  // Add entity position, this makes the center of the box.
+  glm_vec2_add(interactBox.min, entity->position, interactBox.min);
+
+  // Copy to max
+  glm_vec2_copy(interactBox.min, interactBox.max);
+  
+  // Size of the hitbox
+  vec2 halfSize = {
+    TILESET_ENTITIES.tileWidth * PLAYER_INTERACTION_SIZE * 0.5f,
+    TILESET_ENTITIES.tileHeight * PLAYER_INTERACTION_SIZE * 0.5f
+  };
+
+  // Subtract from min, add to max.
+  glm_vec2_sub(interactBox.min, halfSize, interactBox.min);
+  glm_vec2_add(interactBox.max, halfSize, interactBox.max);
+
+  // For each entity
+  entity_t *start = entity->map->entities;
+  entity_t *end = &entity->map->entities[entity->map->entityCount];
+  vec2 otherSize = { TILESET_ENTITIES.tileWidth, TILESET_ENTITIES.tileHeight };
+  physicsbox_t otherBox;
+  physicsboxboxresult_t result;
+
+  do {
+    if(start->type != ENTITY_TYPE_NPC) continue;
+
+    // Setup other box.
+    glm_vec2_copy(start->position, otherBox.min);
+    glm_vec2_copy(start->position, otherBox.max);
+    glm_vec2_sub(otherBox.min, otherSize, otherBox.min);
+    glm_vec2_add(otherBox.min, otherSize, otherBox.max);
+    
+    physicsBoxCheckBox(interactBox, otherBox, &result);
+    if(!result.hit) continue;
+    
+    printf("Interacted with entity at (%.2f, %.2f)\n", start->position[0], start->position[1]);
+    break;
+  } while(++start != end);
 }
\ No newline at end of file
diff --git a/src/rpg/entity/player.h b/src/rpg/entity/player.h
index ea88ef6..efb3326 100644
--- a/src/rpg/entity/player.h
+++ b/src/rpg/entity/player.h
@@ -9,6 +9,8 @@
 #include "dusk.h"
 
 #define PLAYER_SPEED 64.0f
+#define PLAYER_INTERACTION_RANGE 1.0f
+#define PLAYER_INTERACTION_SIZE 0.5f
 
 typedef struct entity_s entity_t;
 
@@ -28,4 +30,11 @@ void playerInit(entity_t *entity);
  * 
  * @param entity Pointer to the player entity structure.
  */
-void playerMovement(entity_t *entity);
\ No newline at end of file
+void playerMovement(entity_t *entity);
+
+/**
+ * Handles interaction logic for the player entity.
+ * 
+ * @param entity Pointer to the player entity structure.
+ */
+void playerInteraction(entity_t *entity);
\ No newline at end of file