tb_example.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* Ensure feature macros are set before pulling in system headers inside
 * termbox2.h */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#ifndef _XOPEN_SOURCE
#define _XOPEN_SOURCE 700
#endif
#ifndef _DEFAULT_SOURCE
#define _DEFAULT_SOURCE
#endif

/* Include termbox2 header. To compile this example you can either
 *  - link with a system termbox2 library and do: gcc tb_example.c -I.
 * -ltermbox2 -o tb_example
 *  - or build with the header-only implementation by defining TB_IMPL in one
 * TU. (If you use header-only, ensure the environment provides the required
 * feature macros.)
 */
#include "termbox2.h"

static const char *default_path =
	"../b025fe84-7fa2-4ad3-95e6-f3348fc00a1b/frame_images/frame_0001.txt";

int main(int argc, char **argv) {
	const char *path = argc > 1 ? argv[1] : default_path;

	FILE *f = fopen(path, "r");
	if (!f) {
		fprintf(stderr, "failed to open '%s'\n", path);
		return 1;
	}

	if (fseek(f, 0, SEEK_END) != 0) {
		fclose(f);
		return 1;
	}
	long sz = ftell(f);
	if (sz < 0) {
		fclose(f);
		return 1;
	}
	rewind(f);

	char *buf = malloc((size_t)sz + 1);
	if (!buf) {
		fclose(f);
		return 1;
	}
	size_t got = fread(buf, 1, (size_t)sz, f);
	buf[got] = '\0';
	fclose(f);

	/* Split into lines in-place */
	int capacity = 128;
	char **lines = malloc(sizeof(char *) * capacity);
	int nlines = 0;
	/* Use strtok for simplicity */
	char *tok = strtok(buf, "\n");
	while (tok) {
		if (nlines >= capacity) {
			capacity *= 2;
			char **tmp = realloc(lines, sizeof(char *) * capacity);
			if (!tmp)
				break;
			lines = tmp;
		}
		lines[nlines++] = tok;
		tok = strtok(NULL, "\n");
	}

	if (tb_init() != TB_OK) {
		fprintf(stderr, "termbox init failed\n");
		free(buf);
		free(lines);
		return 1;
	}

	tb_clear();
	int w = tb_width();
	int h = tb_height();

	int frame_w = 0;
	for (int i = 0; i < nlines; i++) {
		int l = (int)strlen(lines[i]);
		if (l > frame_w)
			frame_w = l;
	}
	int frame_h = nlines;

	int offset_x = (w - frame_w) / 2;
	if (offset_x < 0)
		offset_x = 0;
	int offset_y = (h - frame_h) / 2;
	if (offset_y < 0)
		offset_y = 0;

	for (int y = 0; y < nlines && (offset_y + y) < h; y++) {
		tb_print(offset_x, offset_y + y, TB_WHITE, TB_DEFAULT, lines[y]);
	}
	tb_present();

	/* Wait for a key press or resize; exit on any key. */
	struct tb_event ev;
	while (tb_poll_event(&ev) == 0) {
		if (ev.type == TB_EVENT_KEY)
			break;
		if (ev.type == TB_EVENT_RESIZE) {
			/* on resize, simple re-render: recompute size and reprint */
			tb_clear();
			w = tb_width();
			h = tb_height();
			offset_x = (w - frame_w) / 2;
			if (offset_x < 0)
				offset_x = 0;
			offset_y = (h - frame_h) / 2;
			if (offset_y < 0)
				offset_y = 0;
			for (int y = 0; y < nlines && (offset_y + y) < h; y++) {
				tb_print(offset_x, offset_y + y, TB_WHITE, TB_DEFAULT,
						 lines[y]);
			}
			tb_present();
		}
	}

	tb_shutdown();
	free(buf);
	free(lines);
	return 0;
}