xsnip

commit f8570b7bf7002823d73817c309ef0255cdfed71e
Author: Louis Burda <quent.burda@gmail.com>
Date:   Sat, 11 Sep 2021 02:11:16 +0200

Basic functionality

Diffstat:
A
.gitignore
 | 
3
+++
A
Makefile
 | 
12
++++++++++++
A
main.c
 | 
196
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 211 insertions(+), 0 deletions(-)
diff --git a/.gitignore b/.gitignore
@@ -0,0 +1,3 @@
+.cache
+dsnip
+compile_commands.json
diff --git a/Makefile b/Makefile
@@ -0,0 +1,12 @@
+CFLAGS =
+LDLIBS = -lX11 -lImlib2
+
+.PHONY: all clean
+
+all: dsnip
+
+clean:
+	rm overdraw
+
+dsnip: main.c
+	$(CC) -o $@ $^ $(CFLAGS) $(LDLIBS)
diff --git a/main.c b/main.c
@@ -0,0 +1,196 @@
+/* REF: https://github.com/rDr4g0n/gidoodle */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+
+#include <X11/Xlib.h>
+#include <X11/XKBlib.h>
+#include <X11/keysym.h>
+#include <X11/cursorfont.h>
+
+#include <Imlib2.h>
+
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define MAX(a, b) ((a) >= (b) ? (a) : (b))
+
+const char *filename;
+XWindowAttributes scr;
+Display *display;
+Window root, win;
+int rx, ry, rw, rh;
+GC gc;
+
+void
+die(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+
+	exit(1);
+}
+
+int
+handleopt(char flag, const char *arg)
+{
+	switch (flag) {
+	case 'h':
+		die("USAGE: dsnip [-h] [-f filename]\n");
+	case 'f':
+		if (arg) filename = arg;
+		return 1;
+	default:
+		die("Bad flag: -%c\n", flag);
+	}
+
+	die("Bad argument: -%c %s\n", flag, arg);
+	return 0;
+}
+
+void
+parseargs(int argc, const char **argv)
+{
+	int i;
+
+	filename = "out.png";
+	for (i = 1; i < argc; i++) {
+		if (argv[i][0] == '-' && !argv[i][2])
+			i += handleopt(argv[i][1], argv[i+1]);
+		else
+			die("Bad argument: %s\n", argv[i]);
+	}
+}
+
+void
+update(int x1, int y1, int x2, int y2)
+{
+	rx = MIN(x1, x2);
+	ry = MIN(y1, y2);
+	rw = MAX(1, MAX(x1, x2) - MIN(x1, x2));
+	rh = MAX(1, MAX(y1, y2) - MIN(y1, y2));
+}
+
+void
+init(void)
+{
+	XSetWindowAttributes swa;
+	XGCValues gcvals;
+	Screen *screen;
+
+	display = XOpenDisplay(NULL);
+	screen = XDefaultScreenOfDisplay(display);
+
+	root = DefaultRootWindow(display);
+	XGetWindowAttributes(display, root, &scr);
+
+	swa.override_redirect = 1;
+	win = XCreateWindow(display, root, scr.x, scr.y, scr.width, scr.height,
+		0, CopyFromParent, InputOutput, CopyFromParent,
+		CWOverrideRedirect, &swa);
+	XMapWindow(display, win);
+
+	gcvals = (XGCValues) { 0 };
+	gcvals.foreground = XWhitePixelOfScreen(screen);
+	gcvals.function = GXxor;
+	gc = XCreateGC(display, win, GCFunction | GCForeground, &gcvals);
+}
+
+void
+deinit(void)
+{
+	XDestroyWindow(display, win);
+	XCloseDisplay(display);
+}
+
+void
+saveimg(void)
+{
+	Imlib_Image img;
+
+	imlib_context_set_display(display);
+	imlib_context_set_visual(DefaultVisual(display, 0));
+	imlib_context_set_drawable(win);
+
+	img = imlib_create_image_from_drawable(0, rx, ry, rw, rh, 1);
+
+	imlib_context_set_image(img);
+	imlib_save_image(filename);
+	imlib_free_image();
+}
+
+void
+capture(void)
+{
+	int draw, dirty, done;
+	int px, py, x, y, keysym;
+	Cursor cursor;
+	XEvent ev;
+
+	cursor = XCreateFontCursor(display, XC_left_ptr);
+
+	XGrabPointer(display, root, False,
+		ButtonMotionMask | ButtonPressMask | ButtonReleaseMask,
+		GrabModeAsync, GrabModeAsync, root, cursor, CurrentTime);
+
+	XGrabKeyboard(display, root, False, GrabModeAsync,
+		GrabModeAsync, CurrentTime);
+
+	done = dirty = 0;
+	while (!done) {
+		if (!XPending(display)) continue;
+		XNextEvent(display, &ev);
+		switch (ev.type) {
+		case KeyPress:
+			keysym = XkbKeycodeToKeysym(display, ev.xkey.keycode, 0,
+				ev.xkey.state & ShiftMask ? 1 : 0);
+			if (keysym == XK_Escape) {
+				deinit();
+				exit(0);
+			}
+			break;
+		case MotionNotify:
+			if (draw && dirty) {
+				XDrawRectangle(display, win, gc,
+					rx, ry, rw, rh);
+			}
+
+			x = ev.xmotion.x;
+			y = ev.xmotion.y;
+			update(px, py, x, y);
+
+			if (draw) {
+				XDrawRectangle(display, win, gc,
+					rx, ry, rw, rh);
+				dirty = 1;
+				XFlush(display);
+			}
+			break;
+		case ButtonPress:
+			px = ev.xbutton.x;
+			py = ev.xbutton.y;
+			draw = 1;
+			break;
+		case ButtonRelease:
+			done = 1;
+			break;
+		}
+	}
+}
+
+int
+main(int argc, const char **argv)
+{
+	parseargs(argc, argv);
+
+	init();
+
+	capture();
+
+	saveimg();
+
+	deinit();
+}