mgba_log.h

#ifndef MGBA_LOG_H
#define MGBA_LOG_H

#include <stdio.h> /* needed for snprintf */

#define MGBA_LOG_ON 0xC0DE
#define MGBA_LOG_OFF 0x0000
#define MGBA_LOG_ON_RESULT 0x1DEA

#define MGBA_LOG_STDOUT ((char*)0x4FFF600)
#define MGBA_LOG_FLAGS (*(volatile unsigned short*)0x4FFF700)
#define MGBA_LOG_CONTROL (*(volatile unsigned short*)0x4FFF780)

#define MGBA_LOG_LEVEL_FATAL 0
#define MGBA_LOG_LEVEL_ERROR 1
#define MGBA_LOG_LEVEL_WARN 2
#define MGBA_LOG_LEVEL_INFO 3
#define MGBA_LOG_LEVEL_DEBUG 4

#define mgba_enable_log() MGBA_LOG_CONTROL = MGBA_LOG_ON
#define mgba_is_log_enabled() MGBA_LOG_CONTROL == MGBA_LOG_ON_RESULT
#define mgba_disable_log() MGBA_LOG_CONTROL = MGBA_LOG_OFF

// NOTE: string output is truncated to 0x100 chars
// this is due to the address range overlapping with
// MGBA_LOG_FLAGS and mgba log buffer size is 0x100
#define mgba_log(level, args...) do { \
    snprintf(MGBA_LOG_STDOUT, 0x100, args); \
    MGBA_LOG_FLAGS = 0x100 | level; \
} while (0)

#define mgba_log_fatal(args...) mgba_log(MGBA_LOG_LEVEL_FATAL, args)
#define mgba_log_error(args...) mgba_log(MGBA_LOG_LEVEL_ERROR, args)
#define mgba_log_warn(args...) mgba_log(MGBA_LOG_LEVEL_WARN, args)
#define mgba_log_info(args...) mgba_log(MGBA_LOG_LEVEL_INFO, args)
#define mgba_log_debug(args...) mgba_log(MGBA_LOG_LEVEL_DEBUG, args)

#endif /* MGBA_LOG_H */