Initial commit.

1 files changed, 261 insertions, 0 deletions

diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..338cc3a
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,261 @@
+#define _XOPEN_SOURCE 700
+
+#include <locale.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <termios.h>
+#include <time.h>
+#include <unistd.h>
+#include <wchar.h>
+
+#define ANSI_COL_DROP "\x1b[97m"
+#define ANSI_CUR_HIDE "\e[?25l"
+#define ANSI_CUR_SHOW "\e[?25h"
+#define ANSI_CUR_RESET "\x1b[H"
+#define ANSI_SCRN_CLEAR "\x1b[2J"
+#define ANSI_FONT_RESET "\x1b[0m"
+
+typedef struct matrix_tag {
+	int rows;
+	int cols;
+	wchar_t *code;
+} matrix;
+
+static int mat_index(const matrix *mat, int row, int col) {
+	return mat->cols * row + col;
+}
+
+static int mat_init(matrix *mat, struct winsize *ws) {
+	int i, j;
+
+	static wchar_t code[] = {
+	  'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+	  'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+	  'a', 'b', 'c', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+	  'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
+
+	static int codelen = sizeof(code) / sizeof(code[0]);
+
+	mat->rows = ws->ws_row + 1;
+	mat->cols = ws->ws_col;
+	mat->code = realloc(mat->code, sizeof mat->code[0] * mat->rows * mat->cols);
+	if (mat->code) {
+		for (i = 0; i < mat->rows; i++) {
+			for (j = 0; j < mat->cols; j++)
+				mat->code[mat_index(mat, i, j)] = code[rand() % codelen];
+		}
+		return 1;
+	}
+	return 0;
+}
+
+typedef struct table_tag {
+	int len;   // number of columns
+	int *cols; // column indices
+	int *rows; // row indices ((rows[i], cols[i]) points to a cell in the matrix)
+	int *attr; // cell attributes
+} table;
+
+static void shuffle(int *a, int n) {
+	int i, j, tmp;
+
+	for (i = n - 1; i > 0; i--) {
+		j = rand() % (i + 1);
+		tmp = a[j];
+		a[j] = a[i];
+		a[i] = tmp;
+	}
+}
+
+static int tab_init(table *tab, const matrix *mat) {
+	size_t i;
+
+	tab->len = mat->cols;
+	tab->cols = realloc(tab->cols, sizeof tab->cols[0] * tab->len);
+	tab->rows = realloc(tab->rows, sizeof tab->rows[0] * tab->len);
+	tab->attr = realloc(tab->attr, sizeof tab->attr[0] * tab->len);
+
+	if (tab->cols && tab->rows && tab->attr) {
+		for (i = 0; i < mat->cols; i++) {
+			tab->rows[i] = 0;
+			tab->cols[i] = i;
+			tab->attr[i] = 0;
+		}
+		shuffle(tab->cols, tab->len);
+		return 1;
+	}
+	return 0;
+}
+
+static void tab_free(table *tab) {
+	free(tab->cols);
+	free(tab->rows);
+	free(tab->attr);
+}
+
+static int term_init() {
+	struct termios ta;
+
+	if (tcgetattr(STDIN_FILENO, &ta) == 0) {
+		ta.c_lflag &= ~ECHO;
+		if (tcsetattr(STDIN_FILENO, TCSANOW, &ta) == 0) {
+			wprintf(L"%s", ANSI_CUR_HIDE);
+			wprintf(L"%s", ANSI_CUR_RESET);
+			wprintf(L"%s", ANSI_SCRN_CLEAR);
+			setvbuf(stdout, 0, _IOFBF, 0);
+			return 1;
+		}
+	}
+	return 0;
+}
+
+static void term_reset() {
+	struct termios ta;
+
+	wprintf(L"%s", ANSI_FONT_RESET);
+	wprintf(L"%s", ANSI_CUR_SHOW);
+	wprintf(L"%s", ANSI_SCRN_CLEAR);
+	wprintf(L"%s", ANSI_CUR_RESET);
+
+	if (tcgetattr(STDIN_FILENO, &ta) == 0) {
+		ta.c_lflag |= ECHO;
+		if (tcsetattr(STDIN_FILENO, TCSANOW, &ta) != 0)
+			perror("term_reset()");
+	}
+	setvbuf(stdout, 0, _IOLBF, 0);
+}
+
+static void term_size(struct winsize *ws) {
+	ioctl(STDOUT_FILENO, TIOCGWINSZ, ws);
+}
+
+static void term_clear_cell(int row, int col) {
+	wprintf(L"\x1b[%d;%dH ", row, col);
+}
+
+static void term_reset_cell(const matrix *mat, int row, int col) {
+	wprintf(L"\x1b[%d;%dH\x1b[39m%lc", row, col,
+	        mat->code[mat_index(mat, row, col)]);
+}
+
+static void term_print(const matrix *mat, int row, int col) {
+	wprintf(L"\x1b[%d;%dH%s%lc", row, col, ANSI_COL_DROP,
+	        mat->code[mat_index(mat, row, col)]);
+}
+
+static void term_glitch(int row, int col) {
+	static wchar_t code[] = {
+	  0x0413, // Г
+	  0x0418, // И
+	  0x042F, // Я
+	  0x2200, // ∀
+	  0x04D9, // ә
+	  0x0500, // Ԁ
+	  0x2203, // ∃
+	  0x2132, // Ⅎ
+	  0x0245, // Ʌ
+	  0x037B, // ͻ
+	  0x03FD, // Ͻ
+	  0x041F, // П
+	  0x04D4, // Ӕ
+	  0x0424, // Ф
+	};
+
+	static int codelen = sizeof(code) / sizeof(code[0]);
+
+	wprintf(L"\x1b[%d;%dH\x1b[39m%lc", row, col, code[rand() % codelen]);
+}
+
+static volatile int run;
+
+static void handle_signal(int sa) {
+	switch (sa) {
+	case SIGINT:
+	case SIGQUIT:
+	case SIGTERM:
+		run = 0;
+		break;
+	}
+}
+
+int main(int argc, char *argv[]) {
+	matrix mat;
+	table tab;
+	struct winsize ws;
+	struct timespec ts;
+	struct sigaction sa;
+	int i, cols, blank, delay, tmp;
+
+	setlocale(LC_CTYPE, "");
+
+	sa.sa_handler = handle_signal;
+	sigaction(SIGINT, &sa, 0);
+	sigaction(SIGQUIT, &sa, 0);
+	sigaction(SIGTERM, &sa, 0);
+
+	srand(time(0));
+
+	if (!term_init())
+		return 1;
+
+	term_size(&ws);
+	mat = (matrix){0};
+	if (!mat_init(&mat, &ws)) {
+		term_reset();
+		return 1;
+	}
+
+	tab = (table){0};
+	if (!tab_init(&tab, &mat)) {
+		term_reset();
+		return 1;
+	}
+
+	delay = 75;
+	ts.tv_sec = delay / 1000;
+	ts.tv_nsec = (delay % 1000) * 1000000;
+
+	run = cols = 1;
+	blank = tab.cols[tab.len - 1];
+	while (run) {
+		for (i = 0; run && i < cols; i++) {
+			if (tab.rows[i] == mat.rows) {
+				tab.rows[i] = 0;
+				term_reset_cell(&mat, mat.rows - 1, tab.cols[i]);
+			}
+			if (tab.attr[i] == 0) {
+				// hard-coding to 5 (row[i] - rand() % rows[i] glitches on empty rows)
+				if (tab.rows[i] > 5 && rand() % 6 == 0)
+					term_glitch(tab.rows[i] - 5, tab.cols[i]);
+				if (tab.rows[i] > 0)
+					term_reset_cell(&mat, tab.rows[i] - 1, tab.cols[i]);
+				term_print(&mat, tab.rows[i], tab.cols[i]);
+				if (tab.rows[i] == mat.rows - 1)
+					tab.attr[i] = 1;
+				tab.rows[i]++;
+			} else {
+				term_clear_cell(tab.rows[i], tab.cols[i]);
+				if (tab.rows[i] == mat.rows - 1) {
+					tab.rows[i] = 0;
+					tab.attr[i] = 0;
+					tmp = blank;
+					blank = tab.cols[i];
+					tab.cols[i] = tmp;
+				} else
+					tab.rows[i]++;
+			}
+		}
+		if (cols < tab.len * 0.6)
+			tab.rows[cols++] = 0;
+		fflush(stdout);
+		nanosleep(&ts, &ts);
+	}
+
+	term_reset();
+	tab_free(&tab);
+	free(mat.code);
+	return 0;
+}