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author | Romain Forlot <romain.forlot@iot.bzh> | 2017-06-20 10:24:05 +0000 |
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committer | Romain Forlot <romain.forlot@iot.bzh> | 2017-06-20 10:24:05 +0000 |
commit | 32e25cbca210a359b09768537b6f443fe90a3070 (patch) | |
tree | 3309794c15d8a8f8e9c1c08cad072ee1378813ba /libs/bitfield-c/src/canutil/write.c | |
parent | 76c43dec62b2e21cd6446360c00d4fe6b437533f (diff) |
Separation Generator to a dedicated repo
Change-Id: Id94831651c3266861435272a6e36c7884bef2c45
Signed-off-by: Romain Forlot <romain.forlot@iot.bzh>
Diffstat (limited to 'libs/bitfield-c/src/canutil/write.c')
-rw-r--r-- | libs/bitfield-c/src/canutil/write.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/libs/bitfield-c/src/canutil/write.c b/libs/bitfield-c/src/canutil/write.c new file mode 100644 index 00000000..7f3a3e04 --- /dev/null +++ b/libs/bitfield-c/src/canutil/write.c @@ -0,0 +1,48 @@ +#include <canutil/write.h> +#include <bitfield/bitfield.h> +#include <bitfield/8byte.h> + +uint64_t float_to_fixed_point(const float value, const float factor, + const float offset) { + float raw = (value - offset) / factor; + if(raw > 0) { + // round up to avoid losing precision when we cast to an int + // TODO do we need a way to encode an int back to a signal without any + // rounding? + raw += 0.5; + } + return (uint64_t)raw; +} + +uint64_t eightbyte_encode_float(float value, uint8_t bit_offset, uint8_t bit_size, + float factor, float offset) { + uint64_t result = 0; + if(!eightbyte_set_bitfield(float_to_fixed_point(value, factor, offset), + bit_offset, bit_size, &result)) { + // debug("%f will not fit in a %d bit field", value, bit_size); + } + return result; +} + +uint64_t eightbyte_encode_bool(const bool value, const uint8_t bit_offset, + const uint8_t bit_size) { + return eightbyte_encode_float(value, bit_offset, bit_size, 1.0, 0); +} + +bool bitfield_encode_float(const float value, const uint8_t bit_offset, + const uint8_t bit_size, const float factor, const float offset, + uint8_t destination[], const uint8_t destination_length) { + if(!set_bitfield(float_to_fixed_point(value, factor, offset), bit_offset, + bit_size, destination, destination_length)) { + // debug("%f will not fit in a %d bit field", value, bit_size); + return false; + } + return true; +} + +bool bitfield_encode_bool(const bool value, const uint8_t bit_offset, + const uint8_t bit_size, uint8_t destination[], + const uint16_t destination_length) { + return bitfield_encode_float(value, bit_offset, bit_size, 1.0, 0, + destination, destination_length); +} |