Working menu. The only thing left is gaming

Makefile

@@ -108,7 +108,7 @@ debug-nox: image.bin
 		-ex "break _start" \
 		-ex "continue"
 
-USERPROGS=./user/false ./user/greet ./user/div0 ./user/shout ./user/badputs ./user/bss ./user/player ./snake/snake
+USERPROGS=./user/false ./user/greet ./user/div0 ./user/shout ./user/badputs ./user/bss ./user/player ./user/getc ./snake/snake
 
 fs.img: ./kernel.bin ./tools/mkfs $(USERPROGS)
 	./tools/mkfs $@ $< $(USERPROGS)

snake/misc_utils.h

@@ -84,3 +84,39 @@ const char* StringBuilder_get_cstr(StringBuilder* self) {
     StringBuilder_putc(self, 0);
     return self->buf;
 }
+
+
+/* We still have beef with keyboard, even in userspace */
+#define KEYCODE_SHIFT 42
+#define KEYCODE_ENTER 28
+#define KEYCODE_BACKSPACE 14
+#define KEYCODE_SPACE 57
+#define KEYCODE_ESCAPE 1
+#define KEYCODE_A 30
+#define KEYCODE_S 31
+#define KEYCODE_D 32
+#define KEYCODE_W 17
+#define KEYCODE_Q 16
+#define KEYCODE_ENTER 28
+#define KEYCODE_LEFT 75
+#define KEYCODE_RIGHT 77
+#define KEYCODE_UP 72
+#define KEYCODE_DOWN 80
+#define KEYCODE_1 2
+#define KEYCODE_2 3
+
+bool is_keycode_for_press_left(uint8_t keycode) {
+    return keycode == KEYCODE_LEFT || keycode == KEYCODE_A;
+}
+
+bool is_keycode_for_press_right(uint8_t keycode) {
+    return keycode == KEYCODE_RIGHT || keycode == KEYCODE_D;
+}
+
+bool is_keycode_for_press_up(uint8_t keycode) {
+    return keycode == KEYCODE_UP || keycode == KEYCODE_W;
+}
+
+bool is_keycode_for_press_down(uint8_t keycode) {
+    return keycode == KEYCODE_DOWN || keycode == KEYCODE_S;
+}

snake/snake.c

@@ -50,7 +50,18 @@ typedef enum {
 #define WALKING_ANIM_TIME_FAST 200
 #define HATCHING_ANIM_TIME_FAST 80
 
+typedef enum {
+    waiting_reason_step,
+    waiting_reason_p1,
+    waiting_reason_p2,
+    waiting_reason_cross,
+    waiting_reason_m2,
+    waiting_reason_m1,
+    waiting_reason_zero_pupa,
+} WaitingReason;
+
 struct Snake {
+    bool is_space_pressed;
     GameScreen game_screen;
     bool have_game;
     /* from 0 to PLAYABLE_MAPS_COUNT - 1 */
@@ -62,7 +73,6 @@ struct Snake {
     uint8_t ghost_apples[WORLD_WIDTH][WORLD_HEIGHT];
     ivec2 snake_head;
     ivec2 snake_pupa;
-    bool is_time_sped_up;
     SnakeDirection cur_snake_direction;
     SnakeDirection new_snake_direction;
     /* If we are about to make a step into a wall, we start dying,
@@ -78,9 +88,14 @@ struct Snake {
     bool is_dead;
     int score;
 
+    /* This stuff regulates game flow and animation progress */
+    WaitingReason waiting_reason;
+    uint32_t waiting_time;
+    bool is_time_sped_up;
 } snake = {1};
 
 void init_snake() {
+    snake.is_space_pressed = false;
     snake.game_screen = game_screen_pause;
     snake.have_game = false;
     snake.selected_map_index = 0;
@@ -104,6 +119,10 @@ void start_snake_game() {
     snake.is_dying = false;
     snake.is_dead = false;
     snake.score = 0;
+
+    snake.waiting_reason = waiting_reason_step;
+    snake.waiting_time = 0;
+    snake.is_time_sped_up = false;
 }
 
 
@@ -205,7 +224,7 @@ void draw_game_world() {
 }
 
 void draw_frame() {
-    clear_frame(0);
+    clear_frame(226);
     draw_game_world();
 
     StringBuilder hud = { 0 };
@@ -213,52 +232,117 @@ void draw_frame() {
         StringBuilder_append_u32(&hud, snake.score);
     } else if (snake.game_screen == game_screen_pause) {
         if (snake.have_game) {
-            StringBuilder_append_cstr(&hud, "PAUSED");
+            StringBuilder_append_cstr(&hud, "PAUSED\n");
         }
-        StringBuilder_append_cstr(&hud, "PRESS 1 FOR NEW GAME");
+        StringBuilder_append_cstr(&hud, "PRESS 1 FOR NEW GAME\n");
         if (snake.have_game) {
-            StringBuilder_append_cstr(&hud, "PRESS 2 TO CONTINUE");
+            StringBuilder_append_cstr(&hud, "PRESS ESC TO CONTINUE\n");
         }
-        StringBuilder_append_cstr(&hud, "PRESS Q TO QUIT");
+        StringBuilder_append_cstr(&hud, "PRESS Q TO QUIT\n");
     } else if (snake.game_screen == game_screen_select_map) {
-        StringBuilder_append_cstr(&hud, "SELECT LEVEL\nCURRENTLY SELECTED:\n");
+        StringBuilder_append_cstr(&hud, "SELECT LEVEL\nCURRENTLY SELECTED\n");
         check(snake.selected_map_index < PLAYABLE_MAPS_COUNT);
         StringBuilder_append_cstr(&hud, map_list.maps[snake.selected_map_index].name);
     } else if (snake.game_screen == game_screen_select_apple_count) {
         StringBuilder_append_cstr(&hud, "SELECT DIFFICULTY\n"
-            "HOW MANY APPLES ON MAP\nCURRENTLY SELECTED:\n");
+            "HOW MANY APPLES ON MAP\nCURRENTLY SELECTED\n");
         StringBuilder_append_u32(&hud, snake.gamemode_apples_count);
     }
     draw_hud(StringBuilder_get_cstr(&hud));
 }
 
-void wait_until(uint32_t deadline_ms) {
-    while ((int32_t)(time_ms() - deadline_ms) < 0) {
-        syscall(SYS_halt, 0);
+/* Called when game_screen is game_screen_gaming */
+void handle_gaming_keycode(uint8_t keycode) {
+    if (keycode == KEYCODE_ESCAPE) {
+        snake.game_screen = game_screen_pause;
     }
+    if (!snake.is_dying) {
+        if (is_keycode_for_press_left(keycode) &&
+            snake.cur_snake_direction != snake_direction_right) {
+            snake.new_snake_direction = snake_direction_left;
+        } else if (is_keycode_for_press_right(keycode) &&
+            snake.cur_snake_direction != snake_direction_left) {
+            snake.new_snake_direction = snake_direction_right;
+        } else if (is_keycode_for_press_up(keycode) &&
+            snake.cur_snake_direction != snake_direction_bottom) {
+            snake.new_snake_direction = snake_direction_top;
+        } else if (is_keycode_for_press_down(keycode) &&
+            snake.cur_snake_direction != snake_direction_top) {
+            snake.new_snake_direction = snake_direction_bottom;
+        }
+    }
+}
+
+/* return 1 if we are quitting */
+int handle_incoming_keycode_after_halt(uint8_t keycode) {
+    if (keycode == KEYCODE_SPACE) {
+        snake.is_space_pressed = true;
+    } else if (keycode == (KEYCODE_SPACE | 0x80)) {
+        snake.is_space_pressed = false;
+    }
+    if (keycode == KEYCODE_Q && snake.game_screen != game_screen_gaming) {
+        return 1;
+    }
+    if (snake.game_screen == game_screen_gaming) {
+        handle_gaming_keycode(keycode);
+    } else if (snake.game_screen == game_screen_pause) {
+        if (keycode == KEYCODE_1) {
+            snake.game_screen = game_screen_select_map;
+        } else if (keycode == KEYCODE_ESCAPE && snake.have_game) {
+            snake.game_screen = game_screen_gaming;
+        }
+    } else if (snake.game_screen == game_screen_select_map) {
+        if (keycode == KEYCODE_ESCAPE) {
+            snake.game_screen = game_screen_pause;
+        } else if (is_keycode_for_press_left(keycode)) {
+            snake.selected_map_index--;
+            if (snake.selected_map_index < 0)
+                snake.selected_map_index = PLAYABLE_MAPS_COUNT - 1;
+        } else if (is_keycode_for_press_right(keycode)) {
+            snake.selected_map_index++;
+            if (snake.selected_map_index >= PLAYABLE_MAPS_COUNT)
+                snake.selected_map_index = 0;
+        } else if (keycode == KEYCODE_ENTER) {
+            snake.game_screen = game_screen_select_apple_count;
+        }
+    } else if (snake.game_screen == game_screen_select_apple_count) {
+        if (keycode == KEYCODE_ESCAPE) {
+            snake.game_screen = game_screen_select_map;
+        } else if (is_keycode_for_press_left(keycode)) {
+            if (snake.gamemode_apples_count > 1)
+                snake.gamemode_apples_count--;
+        } else if (is_keycode_for_press_right(keycode)) {
+            if (snake.gamemode_apples_count < SNAKE_GAMEMODE_MAX_APPLES)
+                snake.gamemode_apples_count++;
+        } else if (keycode == KEYCODE_ENTER) {
+            start_snake_game();
+        }
+    }
+    return 0;
 }
 
 int main(void) {
     init_snake();
     syscall(SYS_switch_to_graphics, 0);
 
-    snake.selected_map_index = 5;
-    start_snake_game();
-
-    uint32_t next_frame_ms = time_ms();
     while (1) {
-        // while (true) {
-        //     int ch = syscall(SYS_getc, 0);
-        //     if (ch < 0)
-        //         break;
-        //     uint8_t keycode = (uint8_t)ch;
-        //
-        // }
+        /* Returned from halt, we can enjoy keyboard input and animation progress*/
+        for (int ch;(ch = syscall(SYS_getc, 0)) >= 0;) {
+            int ret = handle_incoming_keycode_after_halt((uint8_t)ch);
+            if (ret == 1)
+                goto quit;
+        }
+        /* As an additional benefit, we can check if is_space_pressed here */
+        if (snake.is_space_pressed) {
+            snake.is_time_sped_up = true;
+        }
+        /* snake.is_time_sped_up will be relevant when checking animation end */
         draw_frame();
 
         syscall(SYS_swap_frame, (uintptr_t)frame);
-
-        next_frame_ms += 500;
-        wait_until(next_frame_ms);
     }
+    quit:
+    syscall(SYS_switch_to_text, 0);
+    syscall(SYS_puts, (uintptr_t)"Quit from game\n");
+    return 0;
 }

user/getc.c

@@ -0,0 +1,18 @@
+#include "../snake/misc_utils.h"
+#include "../syscall.h"
+#include <stdint.h>
+
+int main(void) {
+    while (1) {
+        int keycode = syscall(SYS_getc, 0);
+        if (keycode == -1) {
+            syscall(SYS_halt, 0);
+            continue;
+        }
+
+        StringBuilder sb = {0};
+        StringBuilder_append_u32(&sb, (uint32_t)keycode);
+        StringBuilder_putc(&sb, '\n');
+        syscall(SYS_puts, (uintptr_t)StringBuilder_get_cstr(&sb));
+    }
+}