From e4018f1ad6311bfbbb82b27afa1706256a63f140 Mon Sep 17 00:00:00 2001 From: En Yi Date: Sat, 4 Feb 2023 17:22:01 +0800 Subject: [PATCH] Fix edge case in handling horizontal movement Changelog: - Zero out acceleration when colliding with solid tile or strong entities - This is to prevent continuous overlap after a single collision horizontally, similar to the gravity handling --- engine/game_systems.c | 82 +++++++++++++++++++++++++------------------ 1 file changed, 48 insertions(+), 34 deletions(-) diff --git a/engine/game_systems.c b/engine/game_systems.c index 2eda818..a604938 100644 --- a/engine/game_systems.c +++ b/engine/game_systems.c @@ -25,17 +25,19 @@ static inline unsigned int get_tile_idx(int x, int y, unsigned int tilemap_width return tile_y * tilemap_width + tile_x; } -static bool check_collision_at(Vector2 pos, Vector2 bbox_sz, TileGrid_t* grid, Vector2 point, EntityManager_t* p_manager) +typedef struct TileArea { - Vector2 new_pos = Vector2Add(pos, point); - unsigned int tile_x1 = (new_pos.x) / TILE_SIZE; - unsigned int tile_x2 = (new_pos.x + bbox_sz.x - 1) / TILE_SIZE; - unsigned int tile_y1 = (new_pos.y) / TILE_SIZE; - unsigned int tile_y2 = (new_pos.y + bbox_sz.y - 1) / TILE_SIZE; + unsigned int tile_x1; + unsigned int tile_y1; + unsigned int tile_x2; + unsigned int tile_y2; +}TileArea_t; - for(unsigned int tile_y = tile_y1; tile_y <= tile_y2; tile_y++) +static bool check_collision(Vector2 pos, Vector2 bbox_sz, TileArea_t area_to_check, TileGrid_t* grid, EntityManager_t* p_manager) +{ + for(unsigned int tile_y = area_to_check.tile_y1; tile_y <= area_to_check.tile_y2; tile_y++) { - for(unsigned int tile_x = tile_x1; tile_x <= tile_x2; tile_x++) + for(unsigned int tile_x = area_to_check.tile_x1; tile_x <= area_to_check.tile_x2; tile_x++) { unsigned int tile_idx = tile_y*grid->width + tile_x; if (grid->tiles[tile_idx].solid) return true; @@ -52,34 +54,32 @@ static bool check_collision_at(Vector2 pos, Vector2 bbox_sz, TileGrid_t* grid, V } } return false; + } -static inline bool check_on_ground(unsigned int ent_idx, Vector2 pos, Vector2 bbox_sz, TileGrid_t* grid, Scene_t* scene) +static bool check_collision_at(Vector2 pos, Vector2 bbox_sz, TileGrid_t* grid, Vector2 point, EntityManager_t* p_manager) +{ + Vector2 new_pos = Vector2Add(pos, point); + TileArea_t area = { + .tile_x1 = (new_pos.x) / TILE_SIZE, + .tile_y1 = (new_pos.y) / TILE_SIZE, + .tile_x2 = (new_pos.x + bbox_sz.x - 1) / TILE_SIZE, + .tile_y2 = (new_pos.y + bbox_sz.y - 1) / TILE_SIZE + }; + + return check_collision(new_pos, bbox_sz, area, grid, p_manager); +} + +static inline bool check_on_ground(unsigned int ent_idx, Vector2 pos, Vector2 bbox_sz, TileGrid_t* grid, EntityManager_t* p_manager) { pos.y += 1; - unsigned int tile_x1 = (pos.x) / TILE_SIZE; - unsigned int tile_x2 = (pos.x + bbox_sz.x - 1) / TILE_SIZE; - unsigned int tile_y = (pos.y + bbox_sz.y - 1) / TILE_SIZE; - - for(unsigned int tile_x = tile_x1; tile_x <= tile_x2; tile_x++) - { - unsigned int tile_idx = tile_y*grid->width + tile_x; - if (grid->tiles[tile_idx].solid) return true; - - unsigned int other_ent_idx; - sc_map_foreach_key(&grid->tiles[tile_idx].entities_set, other_ent_idx) - { - Vector2 overlap; - if (other_ent_idx == ent_idx) continue; - Entity_t *p_other_ent = get_entity(&scene->ent_manager, other_ent_idx); - CBBox_t *p_other_bbox = get_component(&scene->ent_manager, p_other_ent, CBBOX_COMP_T); - if (p_other_bbox == NULL || !p_other_bbox->solid || p_other_bbox->fragile) continue; - - CTransform_t *p_other_ct = get_component(&scene->ent_manager, p_other_ent, CTRANSFORM_COMP_T); - if (find_AABB_overlap(pos, bbox_sz, p_other_ct->position, p_other_bbox->size, &overlap)) return true; - } - } - return false; + TileArea_t area = { + .tile_x1 = (pos.x) / TILE_SIZE, + .tile_y1 = (pos.y + bbox_sz.y - 1) / TILE_SIZE, + .tile_x2 = (pos.x + bbox_sz.x - 1) / TILE_SIZE, + .tile_y2 = (pos.y + bbox_sz.y - 1) / TILE_SIZE, + }; + return check_collision(pos, bbox_sz, area, grid, p_manager); } static Vector2 shift_bbox(Vector2 bbox, Vector2 new_bbox, AnchorPoint_t anchor) { @@ -187,7 +187,6 @@ void player_movement_input_system(Scene_t* scene) } } - //else { bool hit = false; @@ -561,6 +560,21 @@ void global_external_forces_system(Scene_t *scene) p_ctransform->accel.x += p_ctransform->velocity.x * -3.3; p_ctransform->accel.y += p_ctransform->velocity.y * -1; } + Vector2 new_pos = p_ctransform->position; + new_pos.x--; + TileArea_t area = { + .tile_x1 = (p_ctransform->position.x - 1) / TILE_SIZE, + .tile_y1 = (p_ctransform->position.y) / TILE_SIZE, + .tile_x2 = (p_ctransform->position.x - 1) / TILE_SIZE, + .tile_y2 = (p_ctransform->position.y + p_bbox->size.y - 1) / TILE_SIZE, + }; + if (check_collision(new_pos, p_bbox->size, area, &data->tilemap, &scene->ent_manager) && p_ctransform->accel.x < 0) p_ctransform->accel.x = 0; + + new_pos.x += p_bbox->size.x + 2; // 2 to account for the previous subtraction + area.tile_x1 = (p_ctransform->position.x + p_bbox->size.x + 1) / TILE_SIZE; + area.tile_x2 = area.tile_x1; + if (check_collision(new_pos, p_bbox->size, area, &data->tilemap, &scene->ent_manager) && p_ctransform->accel.x > 0) p_ctransform->accel.x = 0; + } } @@ -641,7 +655,7 @@ void state_transition_update_system(Scene_t *scene) CBBox_t *p_bbox = get_component(&scene->ent_manager, p_ent, CBBOX_COMP_T); if (p_ctransform == NULL || p_bbox == NULL) continue; - bool on_ground = check_on_ground(ent_idx, p_ctransform->position, p_bbox->size, &data->tilemap, scene); + bool on_ground = check_on_ground(ent_idx, p_ctransform->position, p_bbox->size, &data->tilemap, &scene->ent_manager); bool in_water = false; if (!(p_mstate->water_state & 1)) {