set next block when placing a new block

src/game/game.c

@@ -12,6 +12,11 @@
 #include "tetromino/placing.h"
 
 
+void set_next_shape(GameData* const game_data) {
+    ShapeId id = (rand() % TETROMINO_COUNT) | (rand() % 4 << 3);
+    game_data->next_shape = id;
+}
+
 void game_init(GameData* const game_data) {
     // zero-initialize the game data
     *game_data = (GameData){0};
@@ -20,7 +25,9 @@ void game_init(GameData* const game_data) {
     for (uint8_t i = 0; i < ROWS; i++)
         game_data->row[i] = game_data->row_raw[i];
 
-    game_data->selected = (SelectedShape){TETROMINO_L, 0, 0};
+    set_next_shape(game_data);
+    game_data->selected = (SelectedShape){game_data->next_shape, 0, 0};
+    set_next_shape(game_data);
 
     // set a random seed using the system clock
     srand(time(NULL));

src/game/game.h

@@ -22,7 +22,9 @@ typedef struct {
     Colour* row[ROWS];             // stores how to interpert the raw level data
     Colour row_raw[ROWS][COLUMNS]; // stores the raw level data
     SelectedShape selected;
+    ShapeId next_shape;
 } GameData;
 
+void set_next_shape(GameData* game_data);
 void game_init(GameData* game_data);                        // initializes the game
 void game_update(GameData* game_data, const uint8_t* keys); // updates the game's state

src/game/tetromino/placing.c

@@ -102,6 +102,8 @@ void place_update(GameData* const game_data, const InputData move) {
         if (shape_intersects(game_data->row, selected->id, selected->x, y)) {
             set_shape(game_data->row, selected->id, selected->x, selected->y); // if the shape intersects vertically, write the shape at the current position and return
             clear_rows(game_data->row);                                        // clear the rows that have been completed
+            game_data->selected = (SelectedShape){game_data->next_shape, 0, 0};
+            set_next_shape(game_data);
             return;
         }