From c8d2ee540830dc1bef7d67740b27c23ef2065c37 Mon Sep 17 00:00:00 2001
From: En Yi <en.yi@tutanota.com>
Date: Wed, 21 Jun 2023 21:27:13 +0800
Subject: [PATCH] Improve crushing using edge testing

Changelog:
- Add len reduction to edge checking to give leeway in crushing
---
 scenes/editor_scene.c |  2 +-
 scenes/game_systems.c | 65 +++++++++++--------------------------------
 2 files changed, 17 insertions(+), 50 deletions(-)

diff --git a/scenes/editor_scene.c b/scenes/editor_scene.c
index 4b8819d..f107d5f 100644
--- a/scenes/editor_scene.c
+++ b/scenes/editor_scene.c
@@ -477,7 +477,7 @@ void init_level_scene(LevelScene_t* scene)
     sc_array_add(&scene->scene.systems, &tile_collision_system);
     sc_array_add(&scene->scene.systems, &update_tilemap_system);
     sc_array_add(&scene->scene.systems, &hitbox_update_system);
-    //sc_array_add(&scene->scene.systems, &player_crushing_system);
+    sc_array_add(&scene->scene.systems, &player_crushing_system);
     sc_array_add(&scene->scene.systems, &state_transition_update_system);
     sc_array_add(&scene->scene.systems, &player_ground_air_transition_system);
     sc_array_add(&scene->scene.systems, &sprite_animation_system);
diff --git a/scenes/game_systems.c b/scenes/game_systems.c
index 6ea31d2..6f8670b 100644
--- a/scenes/game_systems.c
+++ b/scenes/game_systems.c
@@ -298,14 +298,19 @@ collision_end:
 
 static uint8_t check_bbox_edges(
     TileGrid_t* tilemap,
-    Entity_t* p_ent, Vector2 pos, Vector2 prev_pos, Vector2 bbox
+    Entity_t* p_ent, Vector2 pos, Vector2 prev_pos, Vector2 bbox,
+    int8_t len_reduction
 )
 {
     uint8_t detected = 0;
+
+    bbox.x -= 2 * len_reduction;
+    bbox.y -= 2 * len_reduction;
+
     CollideEntity_t ent = 
     {
         .p_ent = p_ent,
-        .bbox = (Rectangle){pos.x - 1, pos.y, 1, bbox.y},
+        .bbox = (Rectangle){pos.x - 1, pos.y + len_reduction, 1, bbox.y},
         .prev_bbox = (Rectangle){pos.x, pos.y, bbox.x, bbox.y},
         .area = (TileArea_t){
             .tile_x1 = (pos.x - 1) / TILE_SIZE,
@@ -327,8 +332,8 @@ static uint8_t check_bbox_edges(
     detected |= (check_collision_line(&ent, tilemap, false) ? 1 : 0) << 2;
 
     // Up
-    ent.bbox.x = pos.x;
-    ent.bbox.y--;
+    ent.bbox.x = pos.x + len_reduction;
+    ent.bbox.y = pos.y - 1;
     ent.bbox.width = bbox.x;
     ent.bbox.height = 1;
     ent.area.tile_x1 = (pos.x) / TILE_SIZE,
@@ -672,57 +677,19 @@ void player_bbox_update_system(Scene_t* scene)
 void player_crushing_system(Scene_t* scene)
 {
     LevelSceneData_t* data = &(CONTAINER_OF(scene, LevelScene_t, scene)->data);
-    TileGrid_t tilemap = data->tilemap;
 
     Entity_t* p_player;
     sc_map_foreach_value(&scene->ent_manager.entities_map[PLAYER_ENT_TAG], p_player)
     {
         CTransform_t* p_ctransform = get_component(p_player, CTRANSFORM_COMP_T);
         CBBox_t* p_bbox = get_component(p_player, CBBOX_COMP_T);
-        CollideEntity_t ent = 
-        {
-            .p_ent = p_player,
-            .bbox = (Rectangle){p_ctransform->position.x, p_ctransform->position.y, p_bbox->size.x, p_bbox->size.y},
-            .prev_bbox = (Rectangle){p_ctransform->prev_velocity.x, p_ctransform->prev_position.y, p_bbox->size.x, p_bbox->size.y},
-            .area = (TileArea_t){
-                .tile_x1 = (p_ctransform->position.x) / TILE_SIZE,
-                .tile_y1 = (p_ctransform->position.y) / TILE_SIZE,
-                .tile_x2 = (p_ctransform->position.x) / TILE_SIZE,
-                .tile_y2 = (p_ctransform->position.y + p_bbox->size.y - 1) / TILE_SIZE,
-            },
-        };
 
-        // Mostly identical to edge check function
-        // Except we want collision instead of just touching
-        uint8_t detected = 0;
-        // Left
-        detected |= (check_collision(&ent, &tilemap, false) ? 1 : 0);
+        uint8_t edges = check_bbox_edges(
+            &data->tilemap, p_player,
+            p_ctransform->position, p_ctransform->prev_position, p_bbox->size, 2
+        );
 
-        //Right
-        ent.area.tile_x1 = (p_ctransform->position.x + p_bbox->size.x - 1) / TILE_SIZE;
-        ent.area.tile_x2 = ent.area.tile_x1;
-        detected |= (check_collision(&ent, &tilemap, false) ? 1 : 0) << 1;
-
-        if (detected == 0b11)
-        {
-            p_player->m_alive = false;
-            return;
-        }
-
-        detected = 0;
-        // Up
-        ent.area.tile_x1 = (p_ctransform->position.x) / TILE_SIZE,
-        ent.area.tile_y1 = (p_ctransform->position.y - 1) / TILE_SIZE,
-        ent.area.tile_y2 = ent.area.tile_y1;
-        detected |= (check_collision(&ent, &tilemap, false) ? 1 : 0) << 1;
-
-        // Down
-        ent.area.tile_y1 = (p_ctransform->position.y + p_bbox->size.y - 1) / TILE_SIZE,
-        ent.area.tile_y2 = ent.area.tile_y1;
-        detected |= (check_collision(&ent, &tilemap, true) ? 1 : 0);
-
-        //if (check_collision(&ent, &tilemap, false) == 1)
-        if (detected == 0b11)
+        if ((edges & 0b1100) == 0b1100 || (edges & 0b0011) == 0b0011)
         {
             p_player->m_alive = false;
             return;
@@ -801,7 +768,7 @@ void tile_collision_system(Scene_t* scene)
         // Post movement edge check to zero out velocity
         uint8_t edges = check_bbox_edges(
             &data->tilemap, p_ent,
-            p_ctransform->position, p_ctransform->prev_position, p_bbox->size
+            p_ctransform->position, p_ctransform->prev_position, p_bbox->size, 0
         );
         if (edges & (1<<3))
         {
@@ -927,7 +894,7 @@ void global_external_forces_system(Scene_t* scene)
         // Zero out acceleration for contacts with sturdy entites and tiles
         uint8_t edges = check_bbox_edges(
             &data->tilemap, p_ent,
-            p_ctransform->position, p_ctransform->prev_position, p_bbox->size
+            p_ctransform->position, p_ctransform->prev_position, p_bbox->size, 0
         );
         if (edges & (1<<3))
         {