Racing Game in Curses
It's about time for another curses game. This time I made something inspired by the old racing games on 8-bit computers. The goal of the game is just to pass as many other cars as possible without crashing into them.
Here is a screenshot:
I noticed that for instance the rxvt terminal emulator has issues with the colors sometimes, probably due to bugs. There is a command line options to disable the color so just the ASCII symbols are present. There is another option is to disable the ASCII symbols and having only the color "blocks" present.
Here is the code:
#include <stdlib.h>
#include <stdbool.h>
#include <time.h>
#include <unistd.h>
#include <curses.h>
const int SPEED_MAX = 30;
const int SPEED_MIN = 0;
const int HPOS_MAX = 35;
const int HPOS_MIN = -35;
const int ROAD_HEIGHT = 19;
const int HORIZON_HEIGHT = 5;
#define COL_BLACK 1
#define COL_RED 2
#define COL_GREEN 3
#define COL_YELLOW 4
#define COL_BLUE 5
#define COL_MAGENTA 6
#define COL_CYAN 7
#define COL_WHITE 8
#define CARS_MAX 5
typedef struct car_s {
float distance; /* Relative to Player */
int row; /* Calculated */
int speed; /* Constant */
int hpos; /* Constant */
} car_t;
static void draw_road(int curve, int speed, bool draw_blank)
{
static unsigned int ticks = 0;
int row;
int col;
int road_start;
int road_width;
bool divider_toggle;
curve += 36; /* Relative to center. */
divider_toggle = ((ticks * speed) / SPEED_MAX) % 2;
for (row = 0; row < ROAD_HEIGHT; row++) {
road_start = (curve / (float)(ROAD_HEIGHT - 1)) * (ROAD_HEIGHT - 1 - row);
road_width = ((row * 4) + 1);
/* Left side of the road: */
for (col = 0; col < road_start + 3; col++) {
if (has_colors()) {
attron(COLOR_PAIR(COL_GREEN));
}
if (draw_blank) {
mvaddch(5 + row, col, ' ');
} else {
mvaddch(5 + row, col, '#');
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_GREEN));
}
}
/* Lane divider: */
if (row > 1 && (row % 2 == divider_toggle)) {
if (has_colors()) {
attron(COLOR_PAIR(COL_WHITE));
}
if (draw_blank) {
mvaddch(5 + row, road_start + (road_width / 2) + 3, ' ');
} else {
mvaddch(5 + row, road_start + (road_width / 2) + 3, '|');
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_WHITE));
}
}
/* Right side of the road: */
for (col = road_start + road_width + 3; col < 80; col++) {
if (has_colors()) {
attron(COLOR_PAIR(COL_GREEN));
}
if (draw_blank) {
mvaddch(5 + row, col, ' ');
} else {
mvaddch(5 + row, col, '#');
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_GREEN));
}
}
}
ticks++;
}
static void draw_horizon(int curve, int speed, bool draw_blank)
{
int row;
int col;
static float direction = 0.0;
char c;
const char horizon[5][361] = {
"........................................................................................................................................................................................................................................................................................................................................................................",
".............................................***.............................................................................................................................................................MMM........................................................................................................................................................",
"....MMM.....................................*****...................................................MMMMMMMMM.......................................................................MMMM......MMMMMM......MMMMMMMMMM.................MMMM...................................................................MMM.........................................................",
"...MMMMM...MMMMMM....MMMMM...................***..................................................MMMMMMMMMMMMM..........MMMM....................................MMMMMM..........MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM........MMMMMMMMMMMMMM....MMMMMMMMM...............MMMMMM...........................MMMMMMM.......................................................",
"MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM................................................................MMMMMMMMMMMMMMMMM........MMMMMMM........MMMMMMMM............MMMMMMMMMMMMMM.....MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM...MMMMMMMMMMMM...MMMMMMMMMMMM...MMMMMMMMMMMMMMM...........MMMM..MMMMMMM.......................MMMMMM",
};
/* Calculate current direction: */
direction += (((speed / (double)SPEED_MAX) * curve) / 20.0);
if (direction < 0) direction = 360;
if (direction > 360) direction = 0;
/* Sky: */
for (row = 0; row < 5; row++) {
for (col = 0; col < 80; col++) {
c = horizon[row][(col + (int)direction) % 360];
if (has_colors()) {
switch (c) {
case '*':
attron(COLOR_PAIR(COL_YELLOW));
break;
case 'M':
attron(COLOR_PAIR(COL_GREEN));
break;
default:
attron(COLOR_PAIR(COL_RED));
break;
}
}
if (draw_blank) {
mvaddch(row, col, ' ');
} else {
mvaddch(row, col, c);
}
if (has_colors()) {
switch (c) {
case '*':
attroff(COLOR_PAIR(COL_YELLOW));
break;
case 'M':
attroff(COLOR_PAIR(COL_GREEN));
break;
default:
attroff(COLOR_PAIR(COL_RED));
break;
}
}
}
}
}
static void draw_car(int curve, int row, int hpos, bool player, bool draw_blank)
{
int col;
int road_width;
int road_start;
if (row == -1) {
return;
}
/* Compensate for distance: */
road_width = ((row - HORIZON_HEIGHT) * 4);
hpos = ((float)hpos / 80.0) * road_width;
/* Compensate for curve: */
road_start = (curve / (float)(ROAD_HEIGHT - 1)) *
(ROAD_HEIGHT - 1 - (row - HORIZON_HEIGHT));
hpos -= road_start;
/* Size of the car depends on the row where it is drawn: */
if (row > 16) { /* Large */
col = 34 - hpos;
/* Body: */
if (player) {
if (has_colors()) {
attron(COLOR_PAIR(COL_MAGENTA));
}
if (draw_blank) {
mvaddstr(row , col + 1, " ");
mvaddstr(row + 1, col , " ");
mvaddstr(row + 2, col , " ");
} else {
mvaddstr(row , col + 1, "/%%%%%%%%\\");
mvaddstr(row + 1, col , "/%%%%%%%%%%\\");
mvaddstr(row + 2, col , "|%%%%%%%%%%|");
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_MAGENTA));
}
} else {
if (has_colors()) {
attron(COLOR_PAIR(COL_CYAN));
}
if (draw_blank) {
mvaddstr(row , col + 1, " ");
mvaddstr(row + 1, col , " ");
mvaddstr(row + 2, col , " ");
} else {
mvaddstr(row , col + 1, "/########\\");
mvaddstr(row + 1, col , "/##########\\");
mvaddstr(row + 2, col , "|##########|");
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_CYAN));
}
}
/* Tyres: */
if (has_colors()) {
attron(COLOR_PAIR(COL_BLUE));
}
if (draw_blank) {
mvaddch(row + 2, col + 1, ' ');
mvaddch(row + 2, col + 2, ' ');
mvaddch(row + 2, col + 9, ' ');
mvaddch(row + 2, col + 10, ' ');
} else {
mvaddch(row + 2, col + 1, '@');
mvaddch(row + 2, col + 2, '@');
mvaddch(row + 2, col + 9, '@');
mvaddch(row + 2, col + 10, '@');
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_BLUE));
}
} else if (row > 11) { /* Medium */
col = 36 - hpos;
/* Body: */
if (has_colors()) {
attron(COLOR_PAIR(COL_CYAN));
}
if (draw_blank) {
mvaddstr(row , col + 1, " ");
mvaddstr(row + 1, col , " ");
} else {
mvaddstr(row , col + 1, "/####\\");
mvaddstr(row + 1, col , "|######|");
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_CYAN));
}
/* Tyres: */
if (has_colors()) {
attron(COLOR_PAIR(COL_BLUE));
}
if (draw_blank) {
mvaddch(row + 1, col + 1, ' ');
mvaddch(row + 1, col + 6, ' ');
} else {
mvaddch(row + 1, col + 1, '@');
mvaddch(row + 1, col + 6, '@');
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_BLUE));
}
} else if (row > 8) { /* Small */
col = 38 - hpos;
/* Body: */
if (has_colors()) {
attron(COLOR_PAIR(COL_CYAN));
}
if (draw_blank) {
mvaddstr(row, col, " ");
} else {
mvaddstr(row, col, "###");
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_CYAN));
}
} else if (row > 4) { /* Tiny */
col = 39 - hpos;
/* Body: */
if (has_colors()) {
attron(COLOR_PAIR(COL_CYAN));
}
if (draw_blank) {
mvaddch(row, col, ' ');
} else {
mvaddch(row, col, '#');
}
if (has_colors()) {
attroff(COLOR_PAIR(COL_CYAN));
}
}
}
static void car_row_update(car_t *car)
{
if (car->distance > 1500) { car->row = -1; }
else if (car->distance > 1200) { car->row = 6; }
else if (car->distance > 1000) { car->row = 7; }
else if (car->distance > 800) { car->row = 8; }
else if (car->distance > 600) { car->row = 9; }
else if (car->distance > 500) { car->row = 10; }
else if (car->distance > 400) { car->row = 11; }
else if (car->distance > 300) { car->row = 12; }
else if (car->distance > 200) { car->row = 13; }
else if (car->distance > 150) { car->row = 14; }
else if (car->distance > 100) { car->row = 15; }
else if (car->distance > 75) { car->row = 16; }
else if (car->distance > 50) { car->row = 17; }
else if (car->distance > 25) { car->row = 18; }
else if (car->distance > 10) { car->row = 19; }
else if (car->distance > 0) { car->row = 20; }
else if (car->distance > -10) { car->row = 21; }
else if (car->distance > -25) { car->row = 22; }
else if (car->distance > -50) { car->row = 23; }
else if (car->distance > -75) { car->row = -1; }
else { car->row = -1; }
}
static int curve_ahead(int speed)
{
static int curve_internal = 0;
static float distance = 0;
distance += speed;
if (distance > 100) {
curve_internal += (1 - random() % 3);
if (curve_internal > 30) {
curve_internal = 30;
} else if (curve_internal < -30) {
curve_internal = -30;
}
distance = 0;
}
return curve_internal;
}
static void car_init(car_t *car, bool far_away)
{
for (int i = 0; i < CARS_MAX; i++) {
car->speed = 3 + (random() % 15);
car->hpos = HPOS_MIN + (random() % (HPOS_MAX - HPOS_MIN));
if (far_away) {
car->distance = 1500 + (random() % 2500);
} else {
car->distance = 100 + (random() % 4000);
}
}
}
static bool car_collision(car_t *car, int hpos)
{
if (car->distance > 10) {
return false;
}
if (car->distance < -10) {
return false;
}
if (abs(car->hpos - hpos) > 12) {
return false;
}
return true;
}
static void display_help(const char *progname)
{
fprintf(stdout, "Usage: %s <options>\n", progname);
fprintf(stdout, "Options:\n"
" -h Display this help.\n"
" -c Disable colors.\n"
" -a Disable ASCII symbols.\n");
}
int main(int argc, char *argv[])
{
int c;
bool disable_color = false;
bool disable_ascii = false;
int ch;
int player_speed = 5;
int player_hpos = 25;
int cars_passed = 0;
int curve = 0;
bool quit = false;
car_t cars[CARS_MAX];
srandom(time(NULL));
/* Initialize: */
for (int i = 0; i < CARS_MAX; i++) {
cars[i].distance = 0;
car_init(&cars[i], false);
}
while ((c = getopt(argc, argv, "hca")) != -1) {
switch (c) {
case 'h':
display_help(argv[0]);
return EXIT_SUCCESS;
case 'c':
disable_color = true;
break;
case 'a':
disable_ascii = true;
break;
case '?':
default:
display_help(argv[0]);
return EXIT_FAILURE;
}
}
if (disable_color && disable_ascii) {
fprintf(stdout, "Disabling both color and ASCII makes no sense!\n");
return EXIT_FAILURE;
}
initscr();
noecho();
keypad(stdscr, TRUE);
timeout(0);
if (has_colors()) {
if (! disable_color) {
start_color();
}
init_pair(COL_BLACK, COLOR_WHITE, COLOR_BLACK);
init_pair(COL_RED, COLOR_BLACK, COLOR_RED);
init_pair(COL_GREEN, COLOR_BLACK, COLOR_GREEN);
init_pair(COL_YELLOW, COLOR_BLACK, COLOR_YELLOW);
init_pair(COL_BLUE, COLOR_BLACK, COLOR_BLUE);
init_pair(COL_MAGENTA, COLOR_BLACK, COLOR_MAGENTA);
init_pair(COL_CYAN, COLOR_BLACK, COLOR_CYAN);
init_pair(COL_WHITE, COLOR_BLACK, COLOR_WHITE);
}
while (! quit) {
/* Player input: */
ch = getch();
switch (ch) {
case KEY_LEFT:
case 'a':
if (player_hpos < HPOS_MAX) {
player_hpos++;
}
break;
case KEY_RIGHT:
case 'd':
if (player_hpos > HPOS_MIN) {
player_hpos--;
}
break;
case KEY_UP:
case 'w':
if (player_speed < SPEED_MAX) {
player_speed++;
}
break;
case KEY_DOWN:
case 's':
if (player_speed > SPEED_MIN) {
player_speed--;
}
break;
case 'q':
quit = true;
break;
default:
break;
}
/* Position update of other cars: */
for (int i = 0; i < CARS_MAX; i++) {
cars[i].distance += (cars[i].speed - player_speed);
/* Re-spawn car if it goes out of range: */
if (cars[i].distance > 6000) {
car_init(&cars[i], true);
} else if (cars[i].distance < -100) {
car_init(&cars[i], true);
cars_passed++;
}
car_row_update(&cars[i]);
}
/* Collision check: */
for (int i = 0; i < CARS_MAX; i++) {
if (car_collision(&cars[i], player_hpos)) {
endwin();
fprintf(stdout, "Crashed!\n");
quit = true;
}
}
/* Draw screen: */
erase();
draw_horizon(curve, player_speed, disable_ascii);
draw_road(curve, player_speed, disable_ascii);
for (int i = 0; i < CARS_MAX; i++) {
draw_car(curve, cars[i].row, cars[i].hpos, false, disable_ascii);
}
draw_car(curve, 20, player_hpos, true, disable_ascii); /* The player */
mvprintw(6, 0, "Score: %d", cars_passed);
mvprintw(7, 0, "%dkm/h", player_speed * 10);
refresh();
usleep(20000);
/* Trajectory and road change: */
curve = curve_ahead(player_speed);
}
endwin();
fprintf(stdout, "Final score: %d\n", cars_passed);
return EXIT_SUCCESS;
}