obs-studio/plugins/win-capture/funchook.h

#pragma once

#include <stdbool.h>
#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#else
#if defined(_MSC_VER) && !defined(inline)
#define inline __inline
#endif
#endif

enum hook_type {
	HOOKTYPE_FORWARD_OVERWRITE,
	HOOKTYPE_FORWARD_CHAIN,
	HOOKTYPE_REVERSE_CHAIN
};

struct func_hook {
	void                   *call_addr;

	uintptr_t              func_addr;       /* function being hooked to */
	uintptr_t              hook_addr;       /* hook function itself */
	const char             *name;
	enum hook_type         type;
	bool                   is_64bit_jump;
	bool                   hooked;
	bool                   started;
	uint8_t                unhook_data[14];
	uint8_t                rehook_data[14];
};

extern void hook_init(struct func_hook *hook,
		void *func_addr, void *hook_addr, const char *name);
extern void hook_start(struct func_hook *hook);
extern void do_hook(struct func_hook *hook, bool force);
extern void unhook(struct func_hook *hook);

static inline void rehook(struct func_hook *hook)
{
	do_hook(hook, false);
}

static inline void force_rehook(struct func_hook *hook)
{
	do_hook(hook, true);
}

#ifdef __cplusplus
}
#endif