From ae730ce029914c45e16dbb5ca13d4356e45ff52e Mon Sep 17 00:00:00 2001
From: En Yi <en.yi@tutanota.com>
Date: Sat, 7 Oct 2023 22:35:15 +0800
Subject: [PATCH] Finish initial camera behaviour

x follows a mass-spring-damper system
y is simple lerp. Doesnt follow player when jumping
---
 scenes/game_systems.c | 82 +++++++++++++------------------------------
 scenes/scene_impl.h   |  1 +
 2 files changed, 25 insertions(+), 58 deletions(-)

diff --git a/scenes/game_systems.c b/scenes/game_systems.c
index 1917415..0ebdc6a 100644
--- a/scenes/game_systems.c
+++ b/scenes/game_systems.c
@@ -1801,69 +1801,47 @@ void camera_update_system(Scene_t* scene)
     const int height =data->game_rec.height;
     data->camera.cam.offset = (Vector2){ width/2.0f, height/2.0f };
 
-    Vector2 target_pos = {0, data->camera.cam.target.y};
     Vector2 target_vel = {0};
     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);
-        target_pos.x = p_ctransform->position.x;
+        data->camera.target_pos.x = p_ctransform->position.x;
         target_vel = p_ctransform->velocity;
         CMovementState_t* p_movement = get_component(p_player, CMOVEMENTSTATE_T);
-        target_pos.x += (p_movement->x_dir == 1) ? width/6: -width/6;
-        //target_pos.y += p_ctransform->velocity.y * 0.08;
+        CPlayerState_t* p_pstate = get_component(p_player, CPLAYERSTATE_T);
+        data->camera.target_pos.x += (p_movement->x_dir == 1) ? width/6: -width/6;
 
-        //else if (p_ctransform->velocity.y > 0)
+        if (p_movement->ground_state == 0b01
+            || (p_movement->water_state & 1)
+            || (p_pstate->ladder_state & 1)
+        )
         {
-            //target_pos.y = p_ctransform->position.y;
-            target_pos.y = p_ctransform->position.y + Clamp(p_ctransform->velocity.y * 0.1, -height/6, height /6);
+            data->camera.base_y  = p_ctransform->position.y;
         }
-
-        if (p_movement->ground_state & 1)
+        if (p_ctransform->position.y >= data->camera.base_y)
         {
-            target_pos.y -= height / 8;
+            data->camera.target_pos.y = p_ctransform->position.y;
         }
     }
-    //target_pos.x = Clamp(target_pos.x, 0,
-    //       fmax(data->tilemap.width * TILE_SIZE, data->game_rec.width));
+    data->camera.target_pos.x = Clamp(data->camera.target_pos.x, data->game_rec.width / 2,
+           fmax(data->tilemap.width * TILE_SIZE, data->game_rec.width) - data->game_rec.width / 2);
+    data->camera.target_pos.y = Clamp(data->camera.target_pos.y, data->game_rec.height / 2,
+           fmax(data->tilemap.height * TILE_SIZE, data->game_rec.width) - data->game_rec.height / 2);
     
     // Mass-Spring damper update in x direction
-    //float x = target_pos.x - data->camera.cam.target.x;
-    //float v = data->camera.current_vel.x - target_vel.x; 
-    //float F = data->camera.k * x - data->camera.c * v;
-    //// Kinematics update
-    //const float dt = DELTA_T;
-    //float a_dt = F * dt / data->camera.mass;
-    //data->camera.cam.target.x += (data->camera.current_vel.x + a_dt * 0.5) * dt;
-
-    //data->camera.current_vel.x += a_dt;
-
-    //// Simple lerp for y direction
-    //float dy = target_pos.y - data->camera.cam.target.y;
-    //data->camera.cam.target.y += dy * (dy < 0 ? 0.01 : 0.2);
-
-    // Mass-Spring damper update
-    Vector2 x = Vector2Subtract(target_pos, data->camera.cam.target);
-    Vector2 v = Vector2Subtract(data->camera.current_vel, target_vel); 
-    //Vector2 v = data->camera.current_vel;
-    Vector2 F = 
-        Vector2Subtract(
-            Vector2Scale(x, data->camera.k),
-            Vector2Scale(v, data->camera.c)
-        );
-
+    float x = data->camera.target_pos.x - data->camera.cam.target.x;
+    float v = data->camera.current_vel.x - target_vel.x; 
+    float F = data->camera.k * x - data->camera.c * v;
     // Kinematics update
     const float dt = DELTA_T;
-    Vector2 a_dt = Vector2Scale(F, dt/data->camera.mass);
-    data->camera.cam.target =
-        Vector2Add(
-            data->camera.cam.target,
-                Vector2Add(
-                    Vector2Scale(data->camera.current_vel, dt),
-                    Vector2Scale(a_dt, dt*0.5f)
-                )
-        );
-    data->camera.current_vel = Vector2Add(data->camera.current_vel, a_dt);
+    float a_dt = F * dt / data->camera.mass;
+    data->camera.cam.target.x += (data->camera.current_vel.x + a_dt * 0.5) * dt;
 
+    data->camera.current_vel.x += a_dt;
+
+    // Simple lerp for y direction
+    float dy = data->camera.target_pos.y - data->camera.cam.target.y;
+    data->camera.cam.target.y += dy * 0.1;
 
     Vector2 max = GetWorldToScreen2D(
         (Vector2){
@@ -1887,18 +1865,6 @@ void camera_update_system(Scene_t* scene)
         data->camera.current_vel.x = 0;
     }
 
-    if (max.y < height)
-    {
-        data->camera.cam.offset.y = height - (max.y - height/2.0f);
-        data->camera.cam.target.y = fmax(data->tilemap.height * TILE_SIZE, data->game_rec.height) - height / 2;
-        data->camera.current_vel.y = 0;
-    }
-    if (min.y > 0)
-    {
-        data->camera.cam.offset.y = height/2.0f - min.y;
-        data->camera.cam.target.y = height / 2;
-        data->camera.current_vel.y = 0;
-    }
 }
 
 void level_end_detection_system(Scene_t* scene)
diff --git a/scenes/scene_impl.h b/scenes/scene_impl.h
index e5fb873..a13e964 100644
--- a/scenes/scene_impl.h
+++ b/scenes/scene_impl.h
@@ -30,6 +30,7 @@ typedef struct CoinCounter
 typedef struct LevelCamera {
     Camera2D cam;
     Vector2 target_pos;
+    float base_y;
     //Vector2 prev_pos;
     Vector2 current_vel;
     float mass;