From cbdef8b3b99a3a95d2347317bdec4dc77fc20da8 Mon Sep 17 00:00:00 2001
From: Michael Fitzmayer <mail@michael-fitzmayer.de>
Date: Thu, 10 Mar 2022 21:58:27 +0100
Subject: [PATCH] Add basic collision detection, it's not perfect but it works

---
 res/entry.tmj | 266 ++++++++++++++++++++++++++++++++++++++++++--------
 src/core.c    |  77 ++++++++++++++-
 2 files changed, 295 insertions(+), 48 deletions(-)

diff --git a/res/entry.tmj b/res/entry.tmj
index 5389cc7..7d6a396 100644
--- a/res/entry.tmj
+++ b/res/entry.tmj
@@ -154,6 +154,24 @@
          "tilecount":832,
          "tileheight":16,
          "tiles":[
+                {
+                 "id":8,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":10,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
                 {
                  "id":11,
                  "properties":[
@@ -1585,6 +1603,15 @@
                          "value":true
                         }]
                 }, 
+                {
+                 "id":340,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
                 {
                  "id":341,
                  "properties":[
@@ -1685,7 +1712,7 @@
                         }]
                 }, 
                 {
-                 "id":375,
+                 "id":370,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1694,7 +1721,7 @@
                         }]
                 }, 
                 {
-                 "id":392,
+                 "id":373,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1703,7 +1730,7 @@
                         }]
                 }, 
                 {
-                 "id":393,
+                 "id":374,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1712,25 +1739,7 @@
                         }]
                 }, 
                 {
-                 "id":394,
-                 "properties":[
-                        {
-                         "name":"is_solid",
-                         "type":"bool",
-                         "value":true
-                        }]
-                }, 
-                {
-                 "id":395,
-                 "properties":[
-                        {
-                         "name":"is_solid",
-                         "type":"bool",
-                         "value":true
-                        }]
-                }, 
-                {
-                 "id":396,
+                 "id":375,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1739,7 +1748,7 @@
                         }]
                 }, 
                 {
-                 "id":397,
+                 "id":392,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1748,7 +1757,7 @@
                         }]
                 }, 
                 {
-                 "id":398,
+                 "id":393,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1757,7 +1766,7 @@
                         }]
                 }, 
                 {
-                 "id":399,
+                 "id":394,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1766,7 +1775,7 @@
                         }]
                 }, 
                 {
-                 "id":408,
+                 "id":395,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1775,7 +1784,7 @@
                         }]
                 }, 
                 {
-                 "id":409,
+                 "id":396,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1784,7 +1793,7 @@
                         }]
                 }, 
                 {
-                 "id":411,
+                 "id":397,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1793,7 +1802,7 @@
                         }]
                 }, 
                 {
-                 "id":412,
+                 "id":398,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1802,7 +1811,7 @@
                         }]
                 }, 
                 {
-                 "id":413,
+                 "id":399,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1811,7 +1820,7 @@
                         }]
                 }, 
                 {
-                 "id":414,
+                 "id":408,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1820,7 +1829,7 @@
                         }]
                 }, 
                 {
-                 "id":415,
+                 "id":409,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1829,7 +1838,7 @@
                         }]
                 }, 
                 {
-                 "id":418,
+                 "id":411,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1838,7 +1847,7 @@
                         }]
                 }, 
                 {
-                 "id":419,
+                 "id":412,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1847,7 +1856,7 @@
                         }]
                 }, 
                 {
-                 "id":420,
+                 "id":413,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1856,7 +1865,7 @@
                         }]
                 }, 
                 {
-                 "id":421,
+                 "id":414,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1865,7 +1874,7 @@
                         }]
                 }, 
                 {
-                 "id":422,
+                 "id":415,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1874,7 +1883,7 @@
                         }]
                 }, 
                 {
-                 "id":423,
+                 "id":418,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1883,7 +1892,7 @@
                         }]
                 }, 
                 {
-                 "id":424,
+                 "id":419,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1892,7 +1901,7 @@
                         }]
                 }, 
                 {
-                 "id":428,
+                 "id":420,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1901,7 +1910,7 @@
                         }]
                 }, 
                 {
-                 "id":429,
+                 "id":421,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1910,7 +1919,7 @@
                         }]
                 }, 
                 {
-                 "id":430,
+                 "id":422,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -1919,7 +1928,7 @@
                         }]
                 }, 
                 {
-                 "id":431,
+                 "id":423,
                  "properties":[
                         {
                          "name":"is_solid",
@@ -2638,6 +2647,24 @@
                          "value":true
                         }]
                 }, 
+                {
+                 "id":680,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":684,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
                 {
                  "id":688,
                  "properties":[
@@ -2665,6 +2692,42 @@
                          "value":true
                         }]
                 }, 
+                {
+                 "id":696,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":697,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":699,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":700,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
                 {
                  "id":708,
                  "properties":[
@@ -2701,6 +2764,51 @@
                          "value":true
                         }]
                 }, 
+                {
+                 "id":712,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":713,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":714,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":715,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":716,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
                 {
                  "id":723,
                  "properties":[
@@ -2754,6 +2862,78 @@
                          "type":"bool",
                          "value":true
                         }]
+                }, 
+                {
+                 "id":747,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":748,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":750,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":751,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":779,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":780,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":782,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
+                }, 
+                {
+                 "id":783,
+                 "properties":[
+                        {
+                         "name":"is_solid",
+                         "type":"bool",
+                         "value":true
+                        }]
                 }],
          "tilewidth":16,
          "transparentcolor":"#ff00ff"
diff --git a/src/core.c b/src/core.c
index 28bd768..87d8fe5 100644
--- a/src/core.c
+++ b/src/core.c
@@ -101,6 +101,69 @@ static void update_camera(core_t* core)
     }
 }
 
+static void move_actor(actor_t* actor, Sint32 offset_x, Sint32 offset_y, core_t* core)
+{
+    Sint32 tile_index;
+    Sint32 adjacent_tile;
+
+    if (! is_map_loaded(core))
+    {
+        return;
+    }
+
+    tile_index = get_tile_index(actor->pos_x, actor->pos_y, core);
+
+    // Moves right.
+    if (offset_x > 0)
+    {
+        adjacent_tile = tile_index + 1;
+        if (! core->map->tile_desc[adjacent_tile].is_solid)
+        {
+            actor->pos_x += offset_x;
+        }
+    }
+    // Moves left.
+    else if (offset_x < 0)
+    {
+        adjacent_tile = tile_index - 1;
+        if (! core->map->tile_desc[adjacent_tile].is_solid)
+        {
+            actor->pos_x += offset_x;
+        }
+    }
+
+    // Moves down.
+    if (offset_y > 0)
+    {
+        adjacent_tile = tile_index + core->map->handle->width;
+        if (adjacent_tile >= core->map->tile_desc_count)
+        {
+            adjacent_tile = core->map->tile_desc_count - 1;
+        }
+
+        if (! core->map->tile_desc[adjacent_tile].is_solid)
+        {
+            actor->pos_y += offset_y;
+        }
+    }
+    // Moves up.
+    else if (offset_y < 0)
+    {
+        adjacent_tile = tile_index - core->map->handle->width;
+        if (adjacent_tile >= 0)
+        {
+            if (! core->map->tile_desc[adjacent_tile].is_solid)
+            {
+                actor->pos_y += offset_y;
+            }
+        }
+        else
+        {
+            actor->pos_y += offset_y;
+        }
+    }
+}
+
 status_t init_core(const char* resource_file, const char* title, core_t** core)
 {
     status_t status = CORE_OK;
@@ -162,7 +225,7 @@ status_t update_core(core_t* core)
 
     if (! is_map_loaded(core))
     {
-        return;
+        return status;
     }
 
     core->time_b = core->time_a;
@@ -190,25 +253,29 @@ status_t update_core(core_t* core)
     {
         core->map->actor[target_index].show_animation      = SDL_TRUE;
         core->map->actor[target_index].animation.offset_y  = 3;
-        core->map->actor[target_index].pos_y              -= 2;
+
+        move_actor(&core->map->actor[target_index], 0, -2, core);
     }
     if (keystate[SDL_SCANCODE_DOWN])
     {
         core->map->actor[target_index].show_animation      = SDL_TRUE;
         core->map->actor[target_index].animation.offset_y  = 0;
-        core->map->actor[target_index].pos_y              += 2;
+
+        move_actor(&core->map->actor[target_index], 0, 2, core);
     }
     if (keystate[SDL_SCANCODE_LEFT])
     {
         core->map->actor[target_index].show_animation      = SDL_TRUE;
         core->map->actor[target_index].animation.offset_y  = 1;
-        core->map->actor[target_index].pos_x              -= 2;
+
+        move_actor(&core->map->actor[target_index], -2, 0, core);
     }
     if (keystate[SDL_SCANCODE_RIGHT])
     {
         core->map->actor[target_index].show_animation      = SDL_TRUE;
         core->map->actor[target_index].animation.offset_y  = 2;
-        core->map->actor[target_index].pos_x              += 2;
+
+        move_actor(&core->map->actor[target_index], 2, 0, core);
     }
 
     if (SDL_PollEvent(&event))