Add camera lookahead when falling

x follows a mass-spring-damper system
y is simple lerp. Doesnt follow player when jumping

res/rres_packer.c

@@ -3,7 +3,10 @@
 #define RRES_IMPLEMENTATION
 #include "rres.h"              // Required to read rres data chunks
 
+#include <stdlib.h>
 #include <stdint.h>
+#include <stdio.h>
+#include <string.h>
 
 // Load a continuous data buffer from rresResourceChunkData struct
 static unsigned char *LoadDataBuffer(rresResourceChunkData data, unsigned int rawSize)

scenes/constants.h

@@ -15,6 +15,7 @@
 #define VIEWABLE_MAP_HEIGHT 16
 #endif
 
+#define DELTA_T 0.017
 #define GRAV_ACCEL 1500
 #define JUMP_SPEED 70
 #define MOVE_ACCEL 1300

scenes/editor_scene.c

@@ -86,13 +86,13 @@ static void level_scene_render_func(Scene_t* scene)
     TileGrid_t tilemap = data->tilemap;
 
     Entity_t* p_ent;
-    Vector2 min = GetScreenToWorld2D((Vector2){data->game_rec.x, data->game_rec.y}, data->cam);
+    Vector2 min = GetScreenToWorld2D((Vector2){data->game_rec.x, data->game_rec.y}, data->camera.cam);
     Vector2 max = GetScreenToWorld2D(
         (Vector2){
             data->game_rec.x + data->game_rec.width,
             data->game_rec.y + data->game_rec.height
         },
-        data->cam
+        data->camera.cam
     );
     min = Vector2Scale(min, 1.0f/tilemap.tile_size);
     max = Vector2Scale(max, 1.0f/tilemap.tile_size);
@@ -103,7 +103,7 @@ static void level_scene_render_func(Scene_t* scene)
 
     BeginTextureMode(data->game_viewport);
         ClearBackground(WHITE);
-        BeginMode2D(data->cam);
+        BeginMode2D(data->camera.cam);
         for (int tile_y = min.y; tile_y <= max.y; tile_y++)
         {
             for (int tile_x = min.x; tile_x <= max.x; tile_x++)
@@ -533,7 +533,7 @@ static void toggle_block_system(Scene_t* scene)
         && raw_mouse_pos.y < data->game_rec.height
     ) 
     {
-        Vector2 mouse_pos = GetScreenToWorld2D(raw_mouse_pos, data->cam);
+        Vector2 mouse_pos = GetScreenToWorld2D(raw_mouse_pos, data->camera.cam);
         unsigned int tile_idx = get_tile_idx(mouse_pos.x, mouse_pos.y, &tilemap);
         if (tile_idx >= (tilemap.n_tiles - tilemap.width)) return;
         if (tile_idx == last_tile_idx) return;

scenes/engine/AABB.c

@@ -23,7 +23,7 @@ uint8_t find_AABB_overlap(const Vector2 tl1, const Vector2 sz1, const Vector2 tl
     // Note that we include one extra pixel for checking
     // This avoid overlapping on the border
     Vector2 l1, l2;
-    Vector2 tmp;
+    Vector2 tmp = {0,0};
     uint8_t overlap_x, overlap_y;
     l1.x = tl1.x;
     l1.y = tl1.x + sz1.x;

scenes/game_scene.c

@@ -19,7 +19,7 @@ static void level_scene_render_func(Scene_t* scene)
 
     BeginTextureMode(data->game_viewport);
         ClearBackground(WHITE);
-        BeginMode2D(data->cam);
+        BeginMode2D(data->camera.cam);
         for (size_t i = 0; i < tilemap.n_tiles; ++i)
         {
             char buffer[6] = {0};

scenes/game_systems.c

@@ -362,11 +362,10 @@ void player_movement_input_system(Scene_t* scene)
         // Check if possible to jump when jump is pressed
         if (p_cjump->jump_released && p_pstate->jump_pressed && p_cjump->jumps > 0 && p_cjump->jump_ready)
         {
-            p_pstate->ladder_state = false;
             p_cjump->jumps--;
             if (!in_water)
             {
-                if (p_mstate->ground_state & 1)
+                if (p_mstate->ground_state & 1 || p_cjump->coyote_timer > 0)
                 {
                     p_ctransform->velocity.y = -p_cjump->jump_speed;
                 }
@@ -380,6 +379,7 @@ void player_movement_input_system(Scene_t* scene)
                 p_ctransform->velocity.y = -p_cjump->jump_speed / 1.75;
             }
 
+            p_pstate->ladder_state = false;
             p_cjump->coyote_timer = 0;
             p_cjump->jumped = true;
             p_cjump->jump_ready = false;
@@ -1125,7 +1125,7 @@ void movement_update_system(Scene_t* scene)
     LevelSceneData_t* data = &(CONTAINER_OF(scene, LevelScene_t, scene)->data);
     TileGrid_t tilemap = data->tilemap;
     // Update movement
-    float delta_time = 0.017; // TODO: Will need to think about delta time handling
+    float delta_time = DELTA_T; // TODO: Will need to think about delta time handling
     CTransform_t * p_ctransform;
     unsigned long ent_idx;
     sc_map_foreach(&scene->ent_manager.component_map[CTRANSFORM_COMP_T], ent_idx, p_ctransform)
@@ -1795,29 +1795,77 @@ void sprite_animation_system(Scene_t* scene)
 
 void camera_update_system(Scene_t* scene)
 {
-    LevelScene_t* lvl_scene = CONTAINER_OF(scene, LevelScene_t, scene);
+    LevelSceneData_t* data = &CONTAINER_OF(scene, LevelScene_t, scene)->data;
     Entity_t* p_player;
-    const int width = lvl_scene->data.game_rec.width;
-    const int height = lvl_scene->data.game_rec.height;
+    const int width = data->game_rec.width;
+    const int height =data->game_rec.height;
+    data->camera.cam.offset = (Vector2){ width/2.0f, height/2.0f };
+
+    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);
-        lvl_scene->data.cam.offset = (Vector2){ width/2.0f, height/2.0f };
-        lvl_scene->data.cam.target = p_ctransform->position;
+        data->camera.target_pos.x = p_ctransform->position.x;
+        target_vel = p_ctransform->velocity;
+        CMovementState_t* p_movement = get_component(p_player, CMOVEMENTSTATE_T);
+        CPlayerState_t* p_pstate = get_component(p_player, CPLAYERSTATE_T);
+        data->camera.target_pos.x += (p_movement->x_dir == 1) ? width/6: -width/6;
+
+        if (p_movement->ground_state == 0b01
+            || (p_movement->water_state & 1)
+            || (p_pstate->ladder_state & 1)
+        )
+        {
+            data->camera.base_y  = p_ctransform->position.y;
+        }
+        if (p_ctransform->position.y >= data->camera.base_y)
+        {
+            data->camera.target_pos.y = p_ctransform->position.y;
+            data->camera.target_pos.y += p_ctransform->velocity.y * 0.2;
+        }
     }
+    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 = 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;
+    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){
-            fmax(lvl_scene->data.tilemap.width * TILE_SIZE, lvl_scene->data.game_rec.width),
-            fmax(lvl_scene->data.tilemap.height * TILE_SIZE, lvl_scene->data.game_rec.height)
+            fmax(data->tilemap.width * TILE_SIZE, data->game_rec.width),
+            fmax(data->tilemap.height * TILE_SIZE, data->game_rec.height)
         },
-        lvl_scene->data.cam
+        data->camera.cam
     );
-    Vector2 min = GetWorldToScreen2D((Vector2){0, 0}, lvl_scene->data.cam);
+    Vector2 min = GetWorldToScreen2D((Vector2){0, 0}, data->camera.cam);
+
+    if (max.x < width)
+    {
+        data->camera.cam.offset.x = width - (max.x - width/2.0f);
+        data->camera.cam.target.x = fmax(data->tilemap.width * TILE_SIZE, data->game_rec.width) - width / 2;
+        data->camera.current_vel.x = 0;
+    }
+    if (min.x > 0)
+    {
+        data->camera.cam.offset.x = width/2.0f - min.x;
+        data->camera.cam.target.x = width / 2;
+        data->camera.current_vel.x = 0;
+    }
 
-    if (max.x < width) lvl_scene->data.cam.offset.x = width - (max.x - width/2.0f);
-    if (max.y < height) lvl_scene->data.cam.offset.y = height - (max.y - height/2.0f);
-    if (min.x > 0) lvl_scene->data.cam.offset.x = width/2.0f - min.x;
-    if (min.y > 0) lvl_scene->data.cam.offset.y = height/2.0f - min.y;
 }
 
 void level_end_detection_system(Scene_t* scene)

scenes/scene_impl.h

@@ -27,11 +27,23 @@ typedef struct CoinCounter
     uint16_t total;
 }CoinCounter_t;
 
+typedef struct LevelCamera {
+    Camera2D cam;
+    Vector2 target_pos;
+    float base_y;
+    //Vector2 prev_pos;
+    Vector2 current_vel;
+    float mass;
+    float c; // damping factor
+    float k; // spring constant
+}LevelCamera_t;
+
 typedef struct LevelSceneData {
     TileGrid_t tilemap;
     RenderTexture2D game_viewport;
     Rectangle game_rec;
-    Camera2D cam;
+    //Camera2D cam;
+    LevelCamera_t camera;
     Sprite_t* tile_sprites[MAX_TILE_SPRITES];
     LevelPack_t* level_pack;
     unsigned int current_level;

scenes/scene_systems.c

@@ -10,9 +10,13 @@ void init_level_scene_data(LevelSceneData_t* data, uint32_t max_tiles, Tile_t* t
     //data->game_rec = (Rectangle){25, 25, VIEWABLE_MAP_WIDTH*TILE_SIZE, VIEWABLE_MAP_HEIGHT*TILE_SIZE};
     data->game_viewport = LoadRenderTexture(view_zone.width, view_zone.height);
     data->game_rec = view_zone;
-    data->cam = (Camera2D){0};
-    data->cam.rotation = 0.0f;
-    data->cam.zoom = 1.0f;
+    //data->camera.cam = (Camera2D){0};
+    memset(&data->camera, 0, sizeof(LevelCamera_t));
+    data->camera.cam.rotation = 0.0f;
+    data->camera.cam.zoom = 1.0f;
+    data->camera.mass = 0.2f;
+    data->camera.k = 6.2f;
+    data->camera.c = 2.2f;
 
     data->tilemap.max_tiles = max_tiles;
     if (tiles != NULL)

water_test.c

@@ -34,7 +34,7 @@ static void level_scene_render_func(Scene_t* scene)
 
     BeginTextureMode(data->game_viewport);
         ClearBackground(WHITE);
-        BeginMode2D(data->cam);
+        BeginMode2D(data->camera.cam);
         for (size_t i = 0; i < tilemap.n_tiles; ++i)
         {
             char buffer[6] = {0};
@@ -240,7 +240,7 @@ static void toggle_block_system(Scene_t* scene)
         && raw_mouse_pos.y < data->game_rec.height
     ) 
     {
-        Vector2 mouse_pos = GetScreenToWorld2D(raw_mouse_pos, data->cam);
+        Vector2 mouse_pos = GetScreenToWorld2D(raw_mouse_pos, data->camera.cam);
         unsigned int tile_idx = get_tile_idx(mouse_pos.x, mouse_pos.y, &tilemap);
         if (tile_idx >= MAX_N_TILES) return;
         if (tile_idx == last_tile_idx) return;