Library for drawing ascii shapes and controlling the cursor in the te…

…rminal

with escape characters.

.gitignore

@@ -0,0 +1,3 @@
+*.o
+termdraw
+*.swp

Makefile

@@ -0,0 +1,42 @@
+# termdraw - terminal drawing program
+# Makefile taken from suckless style.
+
+include config.mk
+
+HEADERS = termdraw.h
+SRC = termdraw.c
+OBJ = ${SRC:.c=.o}
+
+all: options termdraw
+
+options:
+	@echo determinant build options:
+	@echo "CFLAGS   = ${CFLAGS}"
+	@echo "LDFLAGS  = ${LDFLAGS}"
+	@echo "CC       = ${CC}"
+	@echo "LD       = ${LD}"
+
+%.o: %.c
+	@echo CC $<
+	@${CC} -c ${CFLAGS} $<
+
+${OBJ}: config.mk
+
+termdraw: ${OBJ}
+	@echo LD $@
+	@${LD} -o $@ ${OBJ} ${LDFLAGS}
+
+clean:
+	@echo cleaning
+	@rm -f determinant ${OBJ} ${PROG_NAME}-${VERSION}.tar.gz
+
+dist: clean
+	@echo creating dist tarball
+	@mkdir -p ${PROG_NAME}-${VERSION}
+	@cp -R Makefile LICENSE README.md config.mk ${SRC} ${HEADERS} ${PROG_NAME}-${VERSION}
+	@tar -cf ${PROG_NAME}-${VERSION}.tar ${PROG_NAME}-${VERSION}
+	@gzip ${PROG_NAME}-${VERSION}.tar
+	@rm -rf ${PROG_NAME}-${VERSION}
+
+.PHONY: all options clean dist
+

config.mk

@@ -0,0 +1,21 @@
+# program version
+VERSION = 0.0.1
+# program name
+PROG_NAME = termdraw
+
+# Customize below to fit your needs.
+
+# paths
+
+# includes and libs
+INCS =
+LIBS = 
+
+# flags
+CPPFLAGS = -DVERSION=\"${VERSION}\"
+CFLAGS = -g -std=c99 -pedantic -Wall -O3 ${INCS} ${CPPFLAGS}
+LDFLAGS = ${LIBS}
+
+# compiler and linker
+CC = gcc
+LD = ${CC}

termdraw.c

@@ -0,0 +1,154 @@
+#include <sys/ioctl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <ctype.h>
+
+#include <termios.h>
+
+struct screen_state_t {
+	int cur_x;
+	int cur_y;
+	int cols;
+	int rows;
+	char *buf;
+};
+
+int
+set_term_environ(void)
+{
+	struct termios old = {0};
+	if (tcgetattr(0, &old) < 0) {
+		perror("tcgetattr()");
+		return -1;
+	}
+	old.c_lflag &= ~ICANON;
+	old.c_lflag &= ~ECHO;
+	old.c_cc[VMIN] = 1;
+	old.c_cc[VTIME] = 0;
+	if (tcsetattr(0, TCSANOW, &old) < 0) {
+		perror("tcsetattr ICANON");
+		return -1;
+	}
+	return 0;
+}
+
+int
+cleanup(void) 
+{
+	struct termios old = {0};
+	if (tcgetattr(0, &old) < 0) {
+		perror("tcsetattr()");
+		return -1;
+	}
+	old.c_lflag |= ICANON;
+	old.c_lflag |= ECHO;
+	if (tcsetattr(0, TCSADRAIN, &old) < 0) {
+		perror ("tcsetattr ~ICANON");
+		return -1;
+	}
+	return 0;
+}
+
+int
+move_cursor(struct screen_state_t *screen, char direction, int n)
+{
+	switch (direction) {
+		case 'u':
+			if (screen->cur_y <= 1) break;
+			printf("\033[%dA", n);
+			screen->cur_y -= n;
+			break;
+		case 'd':
+			if (screen->cur_y >= screen->rows) break;
+			printf("\033[%dB", n);
+			screen->cur_y += n;
+			break;
+		case 'l':
+			if (screen->cur_x <= 1) break;
+			printf("\033[%dD", n);
+			screen->cur_x -= n;
+			break;
+		case 'r':
+			if (screen->cur_x >= screen->cols) break;
+			printf("\033[%dC", n);
+			screen->cur_x += n;
+			break;
+		default:
+			return -1;
+	}
+	fflush(stdout);
+	return 0;
+}
+
+int
+getch()
+{
+	char buf = 0;
+	if (read(0, &buf, 1) < 0) {
+		perror ("read()");
+		return 0;
+	}
+	return buf;
+}
+
+void
+fill_screen(struct screen_state_t *screen, char c)
+{
+	struct winsize w;
+	int i, j;
+	ioctl(STDOUT_FILENO, TIOCGWINSZ, &w);
+
+	printf("\033[0;0H");
+	fflush(stdout);
+
+	for (i = 0; i < screen->rows; i++) {
+		for (j = 0; j < screen->cols; j++) {
+			printf("%c", c);
+		}
+		printf("\n");
+	}
+
+	//printf("\033[%d;%dH", w.ws_row / 2, w.ws_col / 2);
+	printf("\033[%d;%dH", screen->cur_y, screen->cur_x);
+	fflush(stdout);
+}
+
+int main (int argc, char **argv)
+{
+	int c;
+	struct screen_state_t screen;
+	/* Clear the entire screen intially */
+	printf("\033[2J");
+	set_term_environ();
+	screen.cols = 80;
+	screen.rows = 40;
+	screen.cur_x = 40;
+	screen.cur_y = 20;
+	fill_screen(&screen, '0');
+
+	while (1) {
+		c = getch();
+		if (isspace(c))
+			continue;
+		switch (c) {
+			case 'h':
+				move_cursor(&screen, 'l', 1);
+				break;
+			case 'j':
+				move_cursor(&screen, 'd', 1);
+				break;
+			case 'k':
+				move_cursor(&screen, 'u', 1);
+				break;
+			case 'l':
+				move_cursor(&screen, 'r', 1);
+				break;
+			default:
+				break;
+		}
+		fill_screen(&screen, (char)c);
+	}
+
+	cleanup();
+	return 0;
+}