diff options
Diffstat (limited to 'src/snake.c')
| -rw-r--r-- | src/snake.c | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/src/snake.c b/src/snake.c new file mode 100644 index 0000000..577c832 --- /dev/null +++ b/src/snake.c @@ -0,0 +1,360 @@ +#include <stdio.h> +#include <stdlib.h> +#include <time.h> +#include <pthread.h> +#include <signal.h> /* handling ctrl-c */ +#include <sys/ioctl.h> /* terminal size */ +#include <string.h> /* argument parsing */ +#include <math.h> /* time calculations */ + +#include "vector.h" +#include "snake.h" +#include "conio.h" +#include "colors.h" +#include "config.h" +#define UNUSED(x) (void)(x) + +/*** GLOBAL VARIABLES ***/ +volatile sig_atomic_t intCtrlC = 0; /* flag for ctrl-c interrupt */ +int score = 0; +int updateInterval = 300000000L; + +vectorp_t obstaclePositions; +vectorp_t snakePositions; +vector_t foodPos; +vector_t lastMoveDir; + +/* unsafe functions like printf cannot be called in async interrupt handler */ +void interrupt_handler(int sig) { + UNUSED(sig); + intCtrlC = 1; +} + +int main(int argc, char **argv) { + /* parsing arguments */ + char *last_flag = NULL; + int was_flag = 0; + for(int i = 1; i < argc; i++) { + if(strcmp("--version", argv[i]) == 0) { + printf("snake3, version 2.0\n"); + printf("Copyright 2023 Kai Stevenson\n"); + printf("Copyright 2023 Preston Pan\n"); + printf("This software was licensed under the MIT license;\n"); + printf("for more information, see the license file.\n"); + return 0; + } + else if(strcmp("--help", argv[i]) == 0) { + fprintf(stderr, "usage: snake3 [--version] [--help] [--size board_size] [--speed speed] [--obstacles obstacles]\n"); + return 1; + } + else if(strcmp("--size", argv[i]) == 0 || strcmp("--speed", argv[i]) == 0 || strcmp("--obstacles", argv[i]) == 0) { + last_flag = argv[i]; + was_flag = 1; + } + else if(was_flag) { + if(strcmp("--size", last_flag) == 0) { + boardSize = atoi(argv[i]); + if(boardSize < 3) { + fprintf(stderr, "%sboard size too small or argument invalid, please try again.%s\n", RED, COLOR_RESET); + return 1; + } + } + else if(strcmp("--speed", last_flag) == 0) { + speed = atoi(argv[i]); + if(speed <= 0) { + fprintf(stderr, "%sspeed level must be greater than zero and integer. Please try again.%s\n", RED, COLOR_RESET); + return 1; + } + else if(speed > 10) { + fprintf(stderr, "%sspeed must not be greater than ten. Please try again.%s\n", RED, COLOR_RESET); + return 1; + } + } + else if(strcmp("--obstacles", last_flag) == 0) { + obstacles = atoi(argv[i]); + if(obstacles < 0) { + fprintf(stderr, "%sobstacle count cannot be negative. Please try again.%s\n", RED, COLOR_RESET); + return 1; + } + } + was_flag = 0; + } + else { + printf("usage: snake3 [--version] [--help]\n"); + return 1; + } + } + /* check argument compatibility */ + if((obstacles * obstacleSize) * 3 > pow(boardSize, 2)) { + fprintf(stderr, "%stoo many obstacles. Please try again.%s\n", RED, COLOR_RESET); + exit(1); + } + /* get terminal size */ + struct winsize win; + ioctl(fileno(stdout), TIOCGWINSZ, &win); + int width = (int)(win.ws_col); + int height = (int)(win.ws_row); + /* multiplied by 2 to account for the fact that the board is twice as wide as high */ + int smallestAxis = width / 2 < height ? width / 2 : height; + boardSize = smallestAxis < boardSize ? smallestAxis : boardSize; + /* hide cursor */ + printf("\033[?25l"); + /* make a new thread handling interrupts */ + signal(SIGINT, interrupt_handler); + /* init values */ + snakePositions = init_vectorp(malloc(5 * sizeof(vector_t)), 5); + snakePositions.vectors[0] = init_vector(5, 5); + snakePositions.vectors[1] = init_vector(5, 4); + snakePositions.vectors[2] = init_vector(5, 3); + snakePositions.vectors[3] = init_vector(4, 3); + snakePositions.vectors[4] = init_vector(3, 3); + foodPos = init_vector(7, 9); + lastMoveDir = init_vector(0, 1); + int opc = (int)pow(obstacleSize, 2) * obstacles; + obstaclePositions = init_vectorp(malloc(opc * sizeof(vector_t)), opc); + srand(time(NULL)); + /* place the obstacles */ + /* TODO: make this less recursive */ + int opi = 0; + for(int i = 0; i < obstacles; i++) { + while(1) { + vector_t basePos = init_vector((rand() % (boardSize - (obstacleSize - 1))), (rand() % (boardSize - (obstacleSize - 1)))); + /* if obstacle overlaps snake, try again */ + uint8 overlap = 0; + for(int r = 0; r < obstacleSize; r++) { + for(int c = 0; c < obstacleSize; c++) { + vector_t voxelPos = init_vector(basePos.mx + c, basePos.my + r); + for(int j = 0; j < snakePositions.length; j++) { + if((snakePositions.vectors[j].mx == voxelPos.mx) && (snakePositions.vectors[j].my == voxelPos.my)) { + overlap = 1; + } + } + if(foodPos.mx == voxelPos.mx && foodPos.my == voxelPos.my) { + overlap = 1; + } + } + } + if(overlap) { + continue; + } + for(int r = 0; r < obstacleSize; r++) { + for(int c = 0; c < obstacleSize; c++) { + vector_t voxelPos = init_vector(basePos.mx + c, basePos.my + r); + obstaclePositions.vectors[opi] = voxelPos; + opi++; + } + } + break; + } + } + /* clear the screen so as to prevent artifacting */ + printf("\033[2J"); + /* prepare the pointers which will be used to communicate with the input getting thread */ + volatile int* lastInput = calloc(1, sizeof(int)); + int* cancellationToken = calloc(1, sizeof(int)); + /* and the wrapper struct */ + threadArg_t threadArg; + threadArg.returnV = (void*)lastInput; + threadArg.cancellationToken = cancellationToken; + /* create listener thread */ + pthread_t listenerID; + pthread_create(&listenerID, NULL, get_dir_loop, &threadArg); + /* main game logic loop */ + while(1) { + /* handle ctrl-c interrupt */ + if(intCtrlC) { + goto EXIT; + } + + /* first, draw the current state of the board */ + draw_board(); + /* handle player input; + * wait for the specified interval */ + struct timespec time; + time.tv_sec = 0; + time.tv_nsec = round((float)updateInterval / ((float)speed / 3)); + nanosleep(&time, NULL); + /* read the most recent value emitted by the listener */ + vector_t dir = parse_dir(*(char*)lastInput); + /* if the player inputted a valid direction, use it. otherwise, use his last valid input */ + if((dir.mx != 0 || dir.my != 0) && !(dir.mx == 1 && lastMoveDir.mx == -1) && !(dir.mx == -1 && lastMoveDir.mx == 1) && !(dir.my == 1 && lastMoveDir.my == -1) && !(dir.my == -1 && lastMoveDir.my == 1)) { + lastMoveDir = dir; + } + + uint8 ateFood = 0; + /* check if snake is moving onto food */ + if((snakePositions.vectors[0].mx + lastMoveDir.mx == foodPos.mx) && (snakePositions.vectors[0].my + lastMoveDir.my == foodPos.my)) { + ateFood = 1; + score += 1; + if(updateInterval > 100000000) { + updateInterval -= 10000000; + } + /* move the food */ + while(1) { + uint8 overlap = 0; + foodPos = init_vector(1 + (rand() % (boardSize - 2)), 1 + (rand() % (boardSize - 2))); + /* if food overlaps snake or obstacles, try again */ + for(int i = 0; i < snakePositions.length; i++) { + if((snakePositions.vectors[i].mx == foodPos.mx) && (snakePositions.vectors[i].my == foodPos.my)) { + overlap = 1; + } + } + for(int i = 0; i < obstaclePositions.length; i++) { + if((obstaclePositions.vectors[i].mx == foodPos.mx) && (obstaclePositions.vectors[i].my == foodPos.my)) { + overlap = 1; + } + } + if(!overlap) { + break; + } + } + } + /* move the snake */ + vectorp_t newSnakePositions = move_snake(lastMoveDir, ateFood); + free(snakePositions.vectors); + snakePositions = newSnakePositions; + /* check if snake landed on self */ + for(int i = 1; i < snakePositions.length; i++) { + if(snakePositions.vectors[0].mx == snakePositions.vectors[i].mx && snakePositions.vectors[0].my == snakePositions.vectors[i].my) { + /* game over */ + goto EXIT; + } + } + /* check if snake landed on obstacle */ + for(int i = 0; i < obstaclePositions.length; i++) { + if((snakePositions.vectors[0].mx == obstaclePositions.vectors[i].mx) && (snakePositions.vectors[0].my == obstaclePositions.vectors[i].my)) { + goto EXIT; + } + } + } +EXIT: + /* clear the last getch call from the listener */ + *cancellationToken = 1; + printf("\n%sYou died. Score: %d. Press any key to exit%s\n", RED, score, COLOR_RESET); + printf("\033[?25h"); + pthread_join(listenerID, NULL); + free(cancellationToken); + free((int*)lastInput); + return 0; +} +void* get_dir_loop(void* threadArg) { + while(!*(int*)((threadArg_t*)threadArg)->cancellationToken) { + *(char*)((threadArg_t*)threadArg)->returnV = getch(); + } + return NULL; +} +/* parses WASD or HJKL, returns the necessary deltas to move within a 2d array */ +vector_t parse_dir(char cDir) { + if(cDir == 'w' || cDir == 'k') { + return init_vector(0, -1); + } + else if(cDir == 'd' || cDir == 'l') { + return init_vector(1, 0); + } + else if(cDir == 's' || cDir == 'j') { + return init_vector(0, 1); + } + else if(cDir == 'a' || cDir == 'h') { + return init_vector(-1, 0); + } + else { + return init_vector(0, 0); + } +} +vectorp_t move_snake(vector_t dir, int lengthen) { + int newLength = snakePositions.length + (lengthen ? 1 : 0); + vector_t* newSnakePositions = malloc((newLength * sizeof(vector_t))); + /* wrap around edges */ + int nhx = snakePositions.vectors[0].mx + dir.mx; + nhx = nhx < 0 ? boardSize - 1 : nhx >= boardSize ? 0 : nhx; + int nhy = snakePositions.vectors[0].my + dir.my; + nhy = nhy < 0 ? boardSize - 1 : nhy >= boardSize ? 0 : nhy; + newSnakePositions[0] = init_vector(nhx, nhy); + for(int i = 1; i < newLength; i++) { + newSnakePositions[i] = snakePositions.vectors[i - 1]; + } + return init_vectorp(newSnakePositions, newLength); +} +void draw_board() { + /* move the cursor to the top left corner of the screen */ + printf("\033[0;0H"); + /* iterate through and write the board */ + for(int r = 0; r < boardSize; r++) { + for(int c = 0; c < boardSize; c++) { + /* determine the contents of the board position */ + int type = 0; + /* 0=horizontal, 1=vertical, 2=diagonal slant right, 3=diagonal slant left */ + int tailOrientation = 0; + for(int i = 0; i < snakePositions.length; i++) { + if(snakePositions.vectors[i].mx == c && snakePositions.vectors[i].my == r) { + if(i > 0) { + type = 2; + /* get the delta to the connecting tail */ + int dx; + int dy; + if(i < snakePositions.length - 1) { + dx = snakePositions.vectors[i - 1].mx - snakePositions.vectors[i + 1].mx; + dy = snakePositions.vectors[i - 1].my - snakePositions.vectors[i + 1].my; + } + else { + dx = snakePositions.vectors[i - 1].mx - c; + dy = snakePositions.vectors[i - 1].my - r; + } + if(dy == 0) { + tailOrientation = 0; + } + else if(dx == 0) { + tailOrientation = 1; + } + else if((dx == 1 && dy == 1) || (dx == -1 && dy == -1)) { + tailOrientation = 3; + } + else if((dx == -1 && dy == 1) || (dx == 1 && dy == -1)) { + tailOrientation = 2; + } + } + else { + type = 1; + } + break; + } + } + if(foodPos.mx == c && foodPos.my == r) { + type = 3; + } + for(int i = 0; i < obstaclePositions.length; i++) { + if(obstaclePositions.vectors[i].mx == c && obstaclePositions.vectors[i].my == r) { + type = 4; + break; + } + } + /* append the appropriate value */ + if(type == 0) { + /* empty square */ + printf("` "); + } + else if(type == 1) { + /* snake head */ + printf("%s@ %s", GRN, COLOR_RESET); + } + else if(type == 2) { + /* snake body */ + char bodyChar = tailOrientation == 0 ? '-' + : tailOrientation == 1 ? '|' + : tailOrientation == 2 ? '/' + : tailOrientation == 3 ? '\\' + : '*'; + printf("%s%c %s", GRN, bodyChar, COLOR_RESET); + } + else if(type == 3) { + /* food */ + printf("%sF %s", MAG, COLOR_RESET); + } + else if(type == 4) { + /* obstacle */ + printf("%s# %s", RED, COLOR_RESET); + } + } + printf("\n"); + } +} |