Add keybind lookup code

Also centralise NEXT_INSN macro, into its own header at least for now.

1 files changed, 70 insertions, 0 deletions

diff --git a/src/bind.c b/src/bind.c
new file mode 100644
index 0000000..62cdec3
--- /dev/null
+++ b/src/bind.c
@@ -0,0 +1,70 @@
+/*
+ * Copyright © 2022 Michael Smith <mikesmiffy128@gmail.com>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED “AS IS” AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdbool.h>
+
+#include "con_.h"
+#include "dbg.h"
+#include "errmsg.h"
+#include "hook.h"
+#include "intdefs.h"
+#include "mem.h"
+#include "x86.h"
+#include "x86util.h"
+
+struct keyinfo {
+	char *binding;
+	uchar keyuptgt : 3;
+	uchar pressed : 1;
+};
+static struct keyinfo *keyinfo; // engine keybinds list (s_pKeyInfo[])
+
+const char *bind_get(int keycode) { return keyinfo[keycode].binding; }
+
+static bool find_keyinfo(con_cmdcb klbc_cb) {
+#ifdef _WIN32
+	for (uchar *p = (uchar *)klbc_cb; p - (uchar *)klbc_cb < 32;) {
+		// key_listboundkeys command, in its loop through each possible index,
+		// does a mov from that index into a register, something like:
+		// mov <reg>, dword ptr [<reg> * 8 + s_pKeyInfo]
+		if (p[0] == X86_MOVRMW && (p[1] & 0xC7) == 4 /* SIB + imm32 */ &&
+				(p[2] & 0xC7) == 0xC5 /* [immediate + reg * 8] */) {
+			keyinfo = mem_loadptr(p + 3);
+			return true;
+		}
+		NEXT_INSN(p, "load from key binding list");
+	}
+#else
+#warning TODO(linux): check whether linux is equivalent!
+#endif
+	return false;
+}
+
+bool bind_init(void) {
+	struct con_cmd *cmd_key_listboundkeys = con_findcmd("key_listboundkeys");
+	if (!cmd_key_listboundkeys) {
+		errmsg_errorx("couldn't find key_listboundkeys command");
+		return false;
+	}
+	con_cmdcb cb = con_getcmdcb(cmd_key_listboundkeys);
+	if (!find_keyinfo(cb)) {
+		errmsg_warnx("couldn't find key binding list");
+		return false;
+	}
+	return true;
+}
+
+// vi: sw=4 ts=4 noet tw=80 cc=80