Erase rows (incomplete)

5 files changed, 171 insertions, 52 deletions

diff --git a/src/eetg.c b/src/eetg.c
index 890f659..6bc2129 100644
--- a/src/eetg.c
+++ b/src/eetg.c
@@ -202,6 +202,26 @@ eetg_layer_remove(struct eetg_layer *layer, struct eetg_object *object)
     return false;
 }
 
+static struct eetg_object *
+eetg_layer_lookup(struct eetg_layer *layer, int x, int y)
+{
+    assert(layer);
+
+    for (struct eetg_object *object = layer->objects;
+         object;
+         object = object->next) {
+        char c;
+
+        c = eetg_object_get_char(object, x, y);
+
+        if ((c > 0) && (c != ' ')) {
+            return object;
+        }
+    }
+
+    return NULL;
+}
+
 static void
 eetg_view_cell_set(struct eetg_view_cell *view_cell,
                    char c, int color)
@@ -309,12 +329,11 @@ eetg_world_clear(struct eetg_world *world)
 }
 
 void
-eetg_world_register_collision_fn(struct eetg_world *world,
-                                 eetg_handle_collision_fn handle_collision_fn,
-                                 void *arg)
+eetg_world_set_collision_fn(struct eetg_world *world,
+                            eetg_handle_collision_fn handle_collision_fn,
+                            void *arg)
 {
     assert(world);
-    assert(handle_collision_fn);
 
     world->handle_collision_fn = handle_collision_fn;
     world->handle_collision_fn_arg = arg;
@@ -386,6 +405,27 @@ eetg_world_add(struct eetg_world *world, struct eetg_object *object,
     return hit;
 }
 
+struct eetg_object *
+eetg_world_lookup(struct eetg_world *world, int x, int y, int layer_id)
+{
+    assert(world);
+
+    for (int i = ARRAY_SIZE(world->layers) - 1; i >= 0; i--) {
+        if ((layer_id < 0) || (i == layer_id)) {
+            struct eetg_layer *layer = &world->layers[i];
+            struct eetg_object *object;
+
+            object = eetg_layer_lookup(layer, x, y);
+
+            if (object) {
+                return object;
+            }
+        }
+    }
+
+    return NULL;
+}
+
 void
 eetg_world_remove(struct eetg_world *world, struct eetg_object *object)
 {
@@ -664,31 +704,22 @@ eetg_world_render(struct eetg_world *world, bool sync)
     eetg_world_swap_views(world);
 }
 
-void
-eetg_object_init(struct eetg_object *object, int type, const char *sprite)
+static void
+eetg_object_compute_dimensions(struct eetg_object *object)
 {
     size_t width;
     char *ptr;
 
     assert(object);
 
-    object->world = NULL;
-    object->next = NULL;
-    object->sprite = sprite;
-    object->type = type;
-    object->x = 0;
-    object->y = 0;
-    object->color = EETG_FG_COLOR;
-
-    ptr = strchr(sprite, '\n');
+    ptr = strchr(object->sprite, '\n');
     assert(ptr);
 
-    width = ptr - sprite;
+    width = ptr - object->sprite;
     assert(width <= INT_MAX);
 
     object->width = (int)width;
     object->height = 1;
-    object->layer_id = -1;
 
     for (;;) {
         char *next;
@@ -712,6 +743,23 @@ eetg_object_init(struct eetg_object *object, int type, const char *sprite)
 }
 
 void
+eetg_object_init(struct eetg_object *object, int type, const char *sprite)
+{
+    assert(object);
+
+    object->world = NULL;
+    object->next = NULL;
+    object->sprite = sprite;
+    object->color = EETG_FG_COLOR;
+    object->type = type;
+    object->x = 0;
+    object->y = 0;
+    object->layer_id = -1;
+
+    eetg_object_compute_dimensions(object);
+}
+
+void
 eetg_object_set_color(struct eetg_object *object, int color)
 {
     assert(object);
@@ -823,6 +871,7 @@ eetg_object_update(struct eetg_object *object)
 {
     assert(object);
 
+    eetg_object_compute_dimensions(object);
     return eetg_object_move(object, object->x, object->y);
 }
 
diff --git a/src/eetg.h b/src/eetg.h
index ee4582e..2ad9436 100644
--- a/src/eetg.h
+++ b/src/eetg.h
@@ -96,10 +96,12 @@ struct eetg_world {
 void eetg_world_init(struct eetg_world *world,
                      eetg_write_fn write_fn, void *arg);
 void eetg_world_clear(struct eetg_world *world);
-void eetg_world_register_collision_fn(struct eetg_world *world,
+void eetg_world_set_collision_fn(struct eetg_world *world,
          eetg_handle_collision_fn handle_collision_fn, void *arg);
 bool eetg_world_add(struct eetg_world *world, struct eetg_object *object,
                     int x, int y, int layer_id);
+struct eetg_object *eetg_world_lookup(struct eetg_world *world,
+                                      int x, int y, int layer_id);
 void eetg_world_remove(struct eetg_world *world, struct eetg_object *object);
 void eetg_world_render(struct eetg_world *world, bool sync);
 
diff --git a/src/ei/ei.c b/src/ei/ei.c
index f55e648..665ebf0 100644
--- a/src/ei/ei.c
+++ b/src/ei/ei.c
@@ -1103,9 +1103,7 @@ ei_game_init(struct ei_game *game, eetg_write_fn write_fn, void *arg)
     ei_game_reset_history(game);
 
     eetg_world_init(&game->world, write_fn, arg);
-    eetg_world_register_collision_fn(&game->world,
-                                     ei_game_handle_collision,
-                                     game);
+    eetg_world_set_collision_fn(&game->world, ei_game_handle_collision, game);
 
     eetg_object_init(&game->title, EI_TYPE_TITLE, EI_TITLE_SPRITE);
     eetg_object_set_color(&game->title, EETG_COLOR_BLUE);
diff --git a/src/et/et.c b/src/et/et.c
index f8758c4..bc1b673 100644
--- a/src/et/et.c
+++ b/src/et/et.c
@@ -192,6 +192,14 @@ et_piece_init(struct et_piece *piece)
     piece->type = -1;
 }
 
+static struct et_piece *
+et_piece_get(struct eetg_object *object)
+{
+    assert(eetg_object_get_type(object) == ET_TYPE_PIECE);
+
+    return structof(object, struct et_piece, object);
+}
+
 static struct eetg_object *
 et_piece_get_object(struct et_piece *piece)
 {
@@ -574,6 +582,40 @@ et_piece_move_right(struct et_piece *piece)
                      eetg_object_get_y(object));
 }
 
+static bool
+et_piece_erase_row(struct et_piece *piece, int row)
+{
+    struct eetg_object *object;
+    int width, height, src_index, dest_index;
+    char *src, *dest;
+    bool empty = false;
+
+    assert(piece);
+
+    object = &piece->object;
+
+    row -= eetg_object_get_y(object);
+    width = eetg_object_get_width(object);
+    height = eetg_object_get_height(object);
+
+    assert((row >= 0) && (row < eetg_object_get_height(object)));
+
+    dest_index = row * (width + 1);
+    src_index = dest_index + width + 1;
+    src = &piece->sprite[src_index];
+    dest = &piece->sprite[dest_index];
+
+    memmove(dest, src, ((height - row - 1) * (width + 1)) + 1);
+
+    if (piece->sprite[0] == '\0') {
+        empty = true;
+    } else {
+        eetg_object_update(object);
+    }
+
+    return empty;
+}
+
 static struct et_piece *
 et_game_alloc_piece(struct et_game *game)
 {
@@ -747,35 +789,79 @@ et_game_switch_to_next_piece(struct et_game *game)
 }
 
 static bool
+et_game_handle_collision(struct eetg_object *object1,
+                         struct eetg_object *object2,
+                         int x, int y, void *arg)
+{
+    (void)x;
+    (void)y;
+    (void)arg;
+
+    if (et_has_type(object1, object2, ET_TYPE_BG)) {
+        return false;
+    }
+
+    return true;
+}
+
+static bool
 et_game_scan_row(struct et_game *game, int row)
 {
-#if 0
-    for (int i = 0; i < ET_FRAME_WIDTH; i += 2) {
-        int cell;
+    struct et_piece *pieces[ET_FRAME_WIDTH], *prev;
+
+    for (int i = 0; i < (int)ARRAY_SIZE(pieces); i++) {
+        struct eetg_object *object;
+
+        object = eetg_world_lookup(&game->world, ET_FRAME_X + (i * 2), row, 1);
 
-        cell = eetg_object_get_cell(
+        if (!object) {
+            return false;
+        }
+
+        pieces[i] = et_piece_get(object);
     }
-#endif
 
-    return false;
+    eetg_world_set_collision_fn(&game->world, NULL, NULL);
+
+    for (int i = 0; i < (int)ARRAY_SIZE(pieces); i++) {
+        struct et_piece *piece = pieces[i];
+        bool empty;
+
+        if (piece == prev) {
+            continue;
+        }
+
+        empty = et_piece_erase_row(piece, row);
+
+        if (empty) {
+            eetg_world_remove(&game->world, et_piece_get_object(piece));
+            /* TODO Free piece. */
+        } else {
+            et_piece_move_down(piece);
+        }
+
+        prev = piece;
+    }
+
+    eetg_world_set_collision_fn(&game->world, et_game_handle_collision, game);
+
+    return true;
 }
 
 static void
 et_game_scan_rows(struct et_game *game)
 {
-    int cleared_rows[4];
     int nr_cleared_rows = 0;
 
     for (int i = 0; i < ET_FRAME_HEIGHT; i++) {
         bool cleared;
 
-        cleared = et_game_scan_row(game, i);
+        cleared = et_game_scan_row(game, ET_FRAME_Y + i);
 
         if (cleared) {
-            cleared_rows[nr_cleared_rows] = i;
             nr_cleared_rows++;
 
-            if (nr_cleared_rows == ARRAY_SIZE(cleared_rows)) {
+            if (nr_cleared_rows == 4) {
                 break;
             }
         }
@@ -847,22 +933,6 @@ et_game_start_lockdown(struct et_game *game, bool nodelay)
     }
 }
 
-static bool
-et_game_handle_collision(struct eetg_object *object1,
-                         struct eetg_object *object2,
-                         int x, int y, void *arg)
-{
-    (void)x;
-    (void)y;
-    (void)arg;
-
-    if (et_has_type(object1, object2, ET_TYPE_BG)) {
-        return false;
-    }
-
-    return true;
-}
-
 static void
 et_game_reset_history(struct et_game *game)
 {
@@ -1017,9 +1087,7 @@ et_game_init(struct et_game *game, eetg_write_fn write_fn, void *arg)
     et_bag_init(&game->bag);
 
     eetg_world_init(&game->world, write_fn, arg);
-    eetg_world_register_collision_fn(&game->world,
-                                     et_game_handle_collision,
-                                     game);
+    eetg_world_set_collision_fn(&game->world, et_game_handle_collision, game);
 
     eetg_object_init(&game->title, ET_TYPE_TITLE, ET_TITLE_SPRITE);
     eetg_object_set_color(&game->title, EETG_COLOR_BLUE);
diff --git a/src/et/et.h b/src/et/et.h
index dce0e9a..2c2098e 100644
--- a/src/et/et.h
+++ b/src/et/et.h
@@ -54,8 +54,10 @@
 
 /*
  * Take into account the following :
- *  - Square of the longest piece, with 2 characters per cell when horizontal
- *  - newlines
+ *  - the longest piece is 4 squares long
+ *  - tetromino squares are one character high, two characters wide
+ *  - each row ends with a newline
+ *  - all sprites are initially squares
  *  - null terminating character
  */
 #define ET_PIECE_SPRITE_SIZE ((((4 * 2) + 1) * 4) + 1)