Add Snake game (#829)

* Add snake game
* Applications: Added a classic game https://en.wikipedia.org/wiki/Snake_(video_game_genre)
* Snake Game: Making it impossible to lose button presses
* Use more native press button event
* Snake Game: use low level InputTypePress event instead of InputTypeShort high level unpredictable event

Co-authored-by: LionZXY <nikita@kulikof.ru>
Co-authored-by: あく <alleteam@gmail.com>

1 files changed, 419 insertions, 0 deletions

diff --git a/applications/snake-game/snake-game.c b/applications/snake-game/snake-game.c
new file mode 100644
index 00000000..c1debed2
--- /dev/null
+++ b/applications/snake-game/snake-game.c
@@ -0,0 +1,419 @@
+#include <furi.h>
+#include <gui/gui.h>
+#include <input/input.h>
+#include <stdlib.h>
+
+typedef struct {
+    //    +-----x
+    //    |
+    //    |
+    //    y
+    uint8_t x;
+    uint8_t y;
+} Point;
+
+typedef enum {
+    GameStateLife,
+
+    // https://melmagazine.com/en-us/story/snake-nokia-6110-oral-history-taneli-armanto
+    // Armanto: While testing the early versions of the game, I noticed it was hard
+    // to control the snake upon getting close to and edge but not crashing — especially
+    // in the highest speed levels. I wanted the highest level to be as fast as I could
+    // possibly make the device "run," but on the other hand, I wanted to be friendly
+    // and help the player manage that level. Otherwise it might not be fun to play. So
+    // I implemented a little delay. A few milliseconds of extra time right before
+    // the player crashes, during which she can still change the directions. And if
+    // she does, the game continues.
+    GameStateLastChance,
+
+    GameStateGameOver,
+} GameState;
+
+typedef enum {
+    DirectionUp,
+    DirectionRight,
+    DirectionDown,
+    DirectionLeft,
+} Direction;
+
+#define MAX_SNAKE_LEN 253
+
+typedef struct {
+    Point points[MAX_SNAKE_LEN];
+    uint16_t len;
+    Direction currentMovement;
+    Direction nextMovement; // if backward of currentMovement, ignore
+    Point fruit;
+    GameState state;
+} SnakeState;
+
+typedef enum {
+    EventTypeTick,
+    EventTypeKey,
+} EventType;
+
+typedef struct {
+    EventType type;
+    InputEvent input;
+} SnakeEvent;
+
+static void snake_game_render_callback(Canvas* const canvas, void* ctx) {
+    const SnakeState* snake_state = acquire_mutex((ValueMutex*)ctx, 25);
+    if(snake_state == NULL) {
+        return;
+    }
+
+    // Before the function is called, the state is set with the canvas_reset(canvas)
+
+    // Frame
+    canvas_draw_frame(canvas, 0, 0, 128, 64);
+
+    // Fruit
+    Point f = snake_state->fruit;
+    f.x = f.x * 4 + 1;
+    f.y = f.y * 4 + 1;
+    canvas_draw_rframe(canvas, f.x, f.y, 6, 6, 2);
+
+    // Snake
+    for(uint16_t i = 0; i < snake_state->len; i++) {
+        Point p = snake_state->points[i];
+        p.x = p.x * 4 + 2;
+        p.y = p.y * 4 + 2;
+        canvas_draw_box(canvas, p.x, p.y, 4, 4);
+    }
+
+    // Game Over banner
+    if(snake_state->state == GameStateGameOver) {
+        // Screen is 128x64 px
+        canvas_set_color(canvas, ColorWhite);
+        canvas_draw_box(canvas, 34, 20, 62, 24);
+
+        canvas_set_color(canvas, ColorBlack);
+        canvas_draw_frame(canvas, 34, 20, 62, 24);
+
+        canvas_set_font(canvas, FontPrimary);
+        canvas_draw_str(canvas, 37, 31, "Game Over");
+
+        canvas_set_font(canvas, FontSecondary);
+        char buffer[12];
+        snprintf(buffer, sizeof(buffer), "Score: %u", snake_state->len - 7);
+        canvas_draw_str_aligned(canvas, 64, 41, AlignCenter, AlignBottom, buffer);
+    }
+
+    release_mutex((ValueMutex*)ctx, snake_state);
+}
+
+static void snake_game_input_callback(InputEvent* input_event, osMessageQueueId_t event_queue) {
+    furi_assert(event_queue);
+
+    SnakeEvent event = {.type = EventTypeKey, .input = *input_event};
+    osMessageQueuePut(event_queue, &event, 0, osWaitForever);
+}
+
+static void snake_game_update_timer_callback(osMessageQueueId_t event_queue) {
+    furi_assert(event_queue);
+
+    SnakeEvent event = {.type = EventTypeTick};
+    osMessageQueuePut(event_queue, &event, 0, 0);
+}
+
+static void snake_game_init_game(SnakeState* const snake_state) {
+    Point p[] = {{8, 6}, {7, 6}, {6, 6}, {5, 6}, {4, 6}, {3, 6}, {2, 6}};
+    memcpy(snake_state->points, p, sizeof(p));
+
+    snake_state->len = 7;
+
+    snake_state->currentMovement = DirectionRight;
+
+    snake_state->nextMovement = DirectionRight;
+
+    Point f = {18, 6};
+    snake_state->fruit = f;
+
+    snake_state->state = GameStateLife;
+}
+
+static Point snake_game_get_new_fruit(SnakeState const* const snake_state) {
+    // 1 bit for each point on the playing field where the snake can turn
+    // and where the fruit can appear
+    uint16_t buffer[8];
+    memset(buffer, 0, sizeof(buffer));
+    uint8_t empty = 8 * 16;
+
+    for(uint16_t i = 0; i < snake_state->len; i++) {
+        Point p = snake_state->points[i];
+
+        if(p.x % 2 != 0 || p.y % 2 != 0) {
+            continue;
+        }
+        p.x /= 2;
+        p.y /= 2;
+
+        buffer[p.y] |= 1 << p.x;
+        empty--;
+    }
+    // Bit set if snake use that playing field
+
+    uint16_t newFruit = rand() % empty;
+
+    // Skip random number of _empty_ fields
+    for(uint8_t y = 0; y < 8; y++) {
+        for(uint16_t x = 0, mask = 1; x < 16; x += 1, mask <<= 1) {
+            if((buffer[y] & mask) == 0) {
+                if(newFruit == 0) {
+                    Point p = {
+                        .x = x * 2,
+                        .y = y * 2,
+                    };
+                    return p;
+                }
+                newFruit--;
+            }
+        }
+    }
+    // We will never be here
+    Point p = {0, 0};
+    return p;
+}
+
+static bool snake_game_collision_with_frame(Point const next_step) {
+    // if x == 0 && currentMovement == left then x - 1 == 255 ,
+    // so check only x > right border
+    return next_step.x > 30 || next_step.y > 14;
+}
+
+static bool
+    snake_game_collision_with_tail(SnakeState const* const snake_state, Point const next_step) {
+    for(uint16_t i = 0; i < snake_state->len; i++) {
+        Point p = snake_state->points[i];
+        if(p.x == next_step.x && p.y == next_step.y) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+static Direction snake_game_get_turn_snake(SnakeState const* const snake_state) {
+    switch(snake_state->currentMovement) {
+    case DirectionUp:
+        switch(snake_state->nextMovement) {
+        case DirectionRight:
+            return DirectionRight;
+        case DirectionLeft:
+            return DirectionLeft;
+        default:
+            return snake_state->currentMovement;
+        }
+    case DirectionRight:
+        switch(snake_state->nextMovement) {
+        case DirectionUp:
+            return DirectionUp;
+        case DirectionDown:
+            return DirectionDown;
+        default:
+            return snake_state->currentMovement;
+        }
+    case DirectionDown:
+        switch(snake_state->nextMovement) {
+        case DirectionRight:
+            return DirectionRight;
+        case DirectionLeft:
+            return DirectionLeft;
+        default:
+            return snake_state->currentMovement;
+        }
+    default: // case DirectionLeft:
+        switch(snake_state->nextMovement) {
+        case DirectionUp:
+            return DirectionUp;
+        case DirectionDown:
+            return DirectionDown;
+        default:
+            return snake_state->currentMovement;
+        }
+    }
+}
+
+static Point snake_game_get_next_step(SnakeState const* const snake_state) {
+    Point next_step = snake_state->points[0];
+    switch(snake_state->currentMovement) {
+    // +-----x
+    // |
+    // |
+    // y
+    case DirectionUp:
+        next_step.y--;
+        break;
+    case DirectionRight:
+        next_step.x++;
+        break;
+    case DirectionDown:
+        next_step.y++;
+        break;
+    case DirectionLeft:
+        next_step.x--;
+        break;
+    }
+    return next_step;
+}
+
+static void snake_game_move_snake(SnakeState* const snake_state, Point const next_step) {
+    memmove(snake_state->points + 1, snake_state->points, snake_state->len * sizeof(Point));
+    snake_state->points[0] = next_step;
+}
+
+static void snake_game_process_game_step(SnakeState* const snake_state) {
+    if(snake_state->state == GameStateGameOver) {
+        return;
+    }
+
+    bool can_turn = (snake_state->points[0].x % 2 == 0) && (snake_state->points[0].y % 2 == 0);
+    if(can_turn) {
+        snake_state->currentMovement = snake_game_get_turn_snake(snake_state);
+    }
+
+    Point next_step = snake_game_get_next_step(snake_state);
+
+    bool crush = snake_game_collision_with_frame(next_step);
+    if(crush) {
+        if(snake_state->state == GameStateLife) {
+            snake_state->state = GameStateLastChance;
+            return;
+        } else if(snake_state->state == GameStateLastChance) {
+            snake_state->state = GameStateGameOver;
+            return;
+        }
+    } else {
+        if(snake_state->state == GameStateLastChance) {
+            snake_state->state = GameStateLife;
+        }
+    }
+
+    crush = snake_game_collision_with_tail(snake_state, next_step);
+    if(crush) {
+        snake_state->state = GameStateGameOver;
+        return;
+    }
+
+    bool eatFruit = (next_step.x == snake_state->fruit.x) && (next_step.y == snake_state->fruit.y);
+    if(eatFruit) {
+        snake_state->len++;
+        if(snake_state->len >= MAX_SNAKE_LEN) {
+            snake_state->state = GameStateGameOver;
+            return;
+        }
+    }
+
+    snake_game_move_snake(snake_state, next_step);
+
+    if(eatFruit) {
+        snake_state->fruit = snake_game_get_new_fruit(snake_state);
+    }
+}
+
+int32_t snake_game_app(void* p) {
+    srand(DWT->CYCCNT);
+
+    osMessageQueueId_t event_queue = osMessageQueueNew(8, sizeof(SnakeEvent), NULL);
+
+    SnakeState* snake_state = furi_alloc(sizeof(SnakeState));
+    snake_game_init_game(snake_state);
+
+    ValueMutex state_mutex;
+    if(!init_mutex(&state_mutex, snake_state, sizeof(SnakeState))) {
+        furi_log_print(FURI_LOG_ERROR, "cannot create mutex\r\n");
+        free(snake_state);
+        return 255;
+    }
+
+    ViewPort* view_port = view_port_alloc();
+    view_port_draw_callback_set(view_port, snake_game_render_callback, &state_mutex);
+    view_port_input_callback_set(view_port, snake_game_input_callback, event_queue);
+
+    osTimerId_t timer =
+        osTimerNew(snake_game_update_timer_callback, osTimerPeriodic, event_queue, NULL);
+    osTimerStart(timer, osKernelGetTickFreq() / 4);
+
+    // Open GUI and register view_port
+    Gui* gui = furi_record_open("gui");
+    gui_add_view_port(gui, view_port, GuiLayerFullscreen);
+
+    SnakeEvent event;
+    for(bool processing = true; processing;) {
+        osStatus_t event_status = osMessageQueueGet(event_queue, &event, NULL, 100);
+
+        SnakeState* snake_state = (SnakeState*)acquire_mutex_block(&state_mutex);
+
+        if(event_status == osOK) {
+            // press events
+            if(event.type == EventTypeKey) {
+                if(event.input.type == InputTypePress) {
+                    switch(event.input.key) {
+                    case InputKeyUp:
+                        snake_state->nextMovement = DirectionUp;
+                        break;
+                    case InputKeyDown:
+                        snake_state->nextMovement = DirectionDown;
+                        break;
+                    case InputKeyRight:
+                        snake_state->nextMovement = DirectionRight;
+                        break;
+                    case InputKeyLeft:
+                        snake_state->nextMovement = DirectionLeft;
+                        break;
+                    case InputKeyOk:
+                        if(snake_state->state == GameStateGameOver) {
+                            snake_game_init_game(snake_state);
+                        }
+                        break;
+                    case InputKeyBack:
+                        processing = false;
+                        break;
+                    }
+                }
+            } else if(event.type == EventTypeTick) {
+                snake_game_process_game_step(snake_state);
+            }
+        } else {
+            // event timeout
+        }
+
+        view_port_update(view_port);
+        release_mutex(&state_mutex, snake_state);
+    }
+
+    osTimerDelete(timer);
+    view_port_enabled_set(view_port, false);
+    gui_remove_view_port(gui, view_port);
+    furi_record_close("gui");
+    view_port_free(view_port);
+    osMessageQueueDelete(event_queue);
+    delete_mutex(&state_mutex);
+    free(snake_state);
+
+    return 0;
+}
+
+// Screen is 128x64 px
+// (4 + 4) * 16 - 4 + 2 + 2border == 128
+// (4 + 4) * 8 - 4 + 2 + 2border == 64
+// Game field from point{x:  0, y: 0} to point{x: 30, y: 14}.
+// The snake turns only in even cells - intersections.
+// ┌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┐
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// ╎ ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪   ▪ ╎
+// ╎ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ▪ ╎
+// └╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌┘