leddisplay/libraries/FastLED/fastled_progmem.h
2018-10-13 22:34:06 +02:00

81 lines
2.3 KiB
C

#ifndef __INC_FL_PROGMEM_H
#define __INC_FL_PROGMEM_H
#include "FastLED.h"
///@file fastled_progmem.h
/// wrapper definitions to allow seamless use of PROGMEM in environmens that have it
FASTLED_NAMESPACE_BEGIN
// Compatibility layer for devices that do or don't
// have "PROGMEM" and the associated pgm_ accessors.
//
// If a platform supports PROGMEM, it should define
// "FASTLED_USE_PROGMEM" as 1, otherwise FastLED will
// fall back to NOT using PROGMEM.
//
// Whether or not pgmspace.h is #included is separately
// controllable by FASTLED_INCLUDE_PGMSPACE, if needed.
// If FASTLED_USE_PROGMEM is 1, we'll map FL_PROGMEM
// and the FL_PGM_* accessors to the Arduino equivalents.
#if FASTLED_USE_PROGMEM == 1
#ifndef FASTLED_INCLUDE_PGMSPACE
#define FASTLED_INCLUDE_PGMSPACE 1
#endif
#if FASTLED_INCLUDE_PGMSPACE == 1
#include <avr/pgmspace.h>
#endif
#define FL_PROGMEM PROGMEM
// Note: only the 'near' memory wrappers are provided.
// If you're using 'far' memory, you already have
// portability issues to work through, but you could
// add more support here if needed.
#define FL_PGM_READ_BYTE_NEAR(x) (pgm_read_byte_near(x))
#define FL_PGM_READ_WORD_NEAR(x) (pgm_read_word_near(x))
#define FL_PGM_READ_DWORD_NEAR(x) (pgm_read_dword_near(x))
// Workaround for http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34734
#if __GNUC__ < 4 || (__GNUC__ == 4 && (__GNUC_MINOR__ < 6))
#ifdef FASTLED_AVR
#ifdef PROGMEM
#undef PROGMEM
#define PROGMEM __attribute__((section(".progmem.data")))
#endif
#endif
#endif
#else
// If FASTLED_USE_PROGMEM is 0 or undefined,
// we'll use regular memory (RAM) access.
//empty PROGMEM simulation
#define FL_PROGMEM
#define FL_PGM_READ_BYTE_NEAR(x) (*((const uint8_t*)(x)))
#define FL_PGM_READ_WORD_NEAR(x) (*((const uint16_t*)(x)))
#define FL_PGM_READ_DWORD_NEAR(x) (*((const uint32_t*)(x)))
#endif
// On some platforms, most notably ARM M0, unaligned access
// to 'PROGMEM' for multibyte values (eg read dword) is
// not allowed and causes a crash. This macro can help
// force 4-byte alignment as needed. The FastLED gradient
// palette code uses 'read dword', and now uses this macro
// to make sure that gradient palettes are 4-byte aligned.
#ifdef FASTLED_ARM
#define FL_ALIGN_PROGMEM __attribute__ ((aligned (4)))
#else
#define FL_ALIGN_PROGMEM
#endif
FASTLED_NAMESPACE_END
#endif