Initial commit

lib/constrain.c

@@ -0,0 +1,87 @@
+#include <lua.h>
+#include <string.h>
+#include <stdio.h>
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+#include <X11/extensions/Xfixes.h>
+#include <X11/extensions/XInput2.h>
+#include <X11/extensions/Xrandr.h>
+#include <threads.h>
+
+#define DEBUG
+
+#ifdef DEBUG
+static FILE *log_file = NULL;
+static void dbg(const char *fmt, ...) {
+    va_list args;
+    if (log_file == NULL) {
+        log_file = fopen("/home/mutzi/xdpb.txt", "a+");
+    }
+    va_start(args, fmt);
+    vfprintf(log_file, fmt, args);
+    va_end(args);
+    fflush(log_file);
+}
+#else
+static inline void dbg(const char *fmt, ...) {}
+#endif
+
+static struct {
+    Display *display;
+    Window root_window;
+
+    int have_barriers;
+    PointerBarrier t, b, l, r;
+} globals;
+
+static PointerBarrier mkbar(int x1, int y1, int x2, int y2, int directions) {
+    PointerBarrier pb = XFixesCreatePointerBarrier(globals.display, globals.root_window, x1, y1, x2, y2, directions, 0, NULL);
+    dbg("mkbar(%d, %d, %d, %d, %d) = %lu\n", x1, y1, x2, y2, directions, pb);
+    return pb;
+}
+
+static int toggle_constrain(lua_State *L) {
+    dbg("Toggling constrain\n");
+    if (globals.have_barriers == 0) {
+        lua_getfield(L, -1, "x");
+        lua_getfield(L, -2, "y");
+        lua_getfield(L, -3, "width");
+        lua_getfield(L, -4, "height");
+
+        int x = (int)lua_tointeger(L, -4), y = (int)lua_tointeger(L, -3), w = (int)lua_tointeger(L, -2), h = (int)lua_tointeger(L, -1);
+
+        dbg("Window x: %d y: %d w: %d h: %d\n", x, y, w, h);
+
+        globals.t = mkbar(x - 1, y, x + w + 1, y, BarrierPositiveY);
+        globals.b = mkbar(x - 1, y + h, x + w + 1, y + h, BarrierNegativeY);
+        globals.l = mkbar(x, y - 1, x, y + h + 1, BarrierPositiveX);
+        globals.r = mkbar(x + w, y - 1, x + w, y + h + 1, BarrierNegativeX);
+
+        globals.have_barriers = 1;
+        char msg_format[200];
+        lua_getfield(L, -5, "name");
+        snprintf(msg_format, 200, "Constraining mouse to %s", lua_tostring(L, -1));
+        lua_pushstring(L, msg_format);
+    } else {
+        XFixesDestroyPointerBarrier(globals.display, globals.t);
+        XFixesDestroyPointerBarrier(globals.display, globals.b);
+        XFixesDestroyPointerBarrier(globals.display, globals.l);
+        XFixesDestroyPointerBarrier(globals.display, globals.r);
+
+        globals.have_barriers = 0;
+        lua_pushstring(L, "Released mouse");
+    }
+    XSync(globals.display, 0);
+    return 1;
+}
+
+int luaopen_libconstrain(lua_State *L) {
+    dbg("Constrain opened\n");
+    globals.have_barriers = 0;
+    globals.display = XOpenDisplay(NULL);
+    globals.root_window = XDefaultRootWindow(globals.display);
+    lua_newtable(L);
+    lua_pushcfunction(L, toggle_constrain);
+    lua_setfield(L, -2, "toggle");
+    return 1;
+}