cat_frend_help_friend_good/main.c

#include "cat_api.h"
#include <time.h>

void bye(void)
{
	printf("bye!\n");
	exit(0);
}

struct keydowns
{
	char k;
	struct keydowns* next;
};

struct keydowns* first_keydown = NULL;

void add_keydown(char k)
{
	struct keydowns* new = malloc(sizeof(struct keydowns));
	new->k = k;
	new->next = NULL;
	if (first_keydown == NULL) first_keydown = new;
	else
	{
		struct keydowns* head;
		for (head = first_keydown; head->next != NULL; head = head->next)
			if (head->k == k) return;
		head->next = new;
	}
}

void lit_remove_keydown(struct keydowns* entry)
{
	if (first_keydown == entry) first_keydown = entry->next;
	else
	{
		struct keydowns* head;
		for (head = first_keydown; head->next != entry; head = head->next) ;
		head->next = entry->next;
	}
}

void remove_keydown(char k)
{
	struct keydowns* head;
	for (head = first_keydown; head != NULL; head = head->next)
		if (head->k == k) lit_remove_keydown(head);
}

int is_held(char k)
{
	struct keydowns* head;
	for (head = first_keydown; head != NULL; head = head->next)
		if (head->k == k) return 1;
	return 0;
}

static int player_x = 100;
static int player_y = 100;
static float player_vx = 0.0;
static float player_vy = 0.0;
static float player_ax = 0.0;
static float player_ay = 9.81;
static int jump_ticks = 0;

void key_down(char k)
{
	add_keydown(k);
	printf("%c pressed!\n", k);
	switch (k)
	{
		case 'a': player_ax = -2; break;
		case 'd': player_ax = 2; break;
	}
}

void key_up(char k)
{
	remove_keydown(k);
	printf("%c un-pressed\n", k);
	switch (k)
	{
		case 'a': player_ax = 0; break;
		case 'd': player_ax = 0; break;
	}
}

static int mousex = 0;
static int mousey = 0;

void mouse_move(int x, int y)
{
	/* clear old mouse icn */
	mousex = x;
	mousey = y;
	printf("mouse moved! (%d, %d)\n", x, y);
}

void mouse_down(unsigned char button)
{
	printf("mouse button %02x clicked!\n", button);
	/* TODO struct for this too?? that seems like a lot. what if we *don't* use mouse for anything... */
}

void mouse_up(unsigned char button)
{
	printf("mouse button %02x un-clicked!\n", button);
}

void process_input(void)
{
	struct cat_event* e = cat_get_event();
	if (e == NULL) return;
	if (e->type == QUIT) bye();
	else if (e->type == KEYDOWN)	key_down(e->key);
	else if (e->type == KEYUP)	key_up(e->key);
	else if (e->type == MOUSEMOVE)	mouse_move(e->mousex, e->mousey);
	else if (e->type == MOUSEDOWN)	mouse_down(e->mouse_button);
	else if (e->type == MOUSEUP)	mouse_up(e->mouse_button);
}

void erase_entity(/*struct entity*/)
{
	/* get sprite info, etc */
	/* FIXME */
	cat_fill(1, 0, player_x, player_y, 50, 50, 0, 0, 0);
}

void draw_entity(/* struct entity */)
{
	/* get sprite info, etc */
	/* FIXME */
	cat_fill(1, 1, player_x, player_y, 50, 50, 115, 72, 6);
}

void erase_entities(void)
{
	/* TODO more than just player entity */
	erase_entity(/*player*/);
}

void draw_entities(void)
{
	/* TODO more than just player entity */
	draw_entity(/*player*/);
}

static long last_sec = 0;
static long last_nsec = 0;

#define NS_PER_TICK 30000000

/* FIXME this is just temporary */
void in_bounds(void)
{
	if (player_x < 0) player_x = 0;
	if (player_y < 0) player_y = 0;
	if (player_x > screen_width - 50) player_x = screen_width - 50;
	if (player_y > screen_height- 50) player_y = screen_height - 50;
}

void apply_friction(void) /* FIXME */
{
	if (player_vx > 0) player_vx -= 1;
	else if (player_vx < 0) player_vx += 1;
	if (player_vy > 0) player_vy -= 1;
	else if (player_vy < 0) player_vy += 1;
}

void tick(void)
{
	/* run every N milliseconds... nanoseconds? idk */
	struct timespec t;
	clock_gettime(CLOCK_REALTIME, &t);
	if (last_sec == 0) goto yes;
	else if ((t.tv_sec - last_sec) > 0) goto yes;
	else if ((t.tv_nsec - last_nsec) > NS_PER_TICK) goto yes;
	else return;
	/* do a tick */
	yes:	last_sec = t.tv_sec;
		last_nsec = t.tv_nsec;

	/* code to run every tick goes here */
	erase_entities();
	if (is_held(' ')) player_ay = -5;
	else player_ay = 9.81;
	player_vx += player_ax;
	player_vy += player_ay;
	apply_friction(); /* FIXME */
	player_x += (int)player_vx;
	player_y += (int)player_vy;
	in_bounds();
	draw_entities();
}

void game_loop(void)
{
	cat_render();
	process_input();
	tick();
}

int main(int argc, char** argv)
{
	cat_init();
	cat_create_window(1920, 1080);
	cat_play_wav("etc/example.wav");
		/* layer, visibility, x, y, width, height, r, g, b */
	cat_fill(0, 1, 0, 0, screen_width - 1, screen_height - 1, 132, 155, 132);
	while (1) game_loop();
	return 0;
}