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authorRomain Forlot <romain.forlot@iot.bzh>2017-05-02 17:50:50 +0200
committerRomain Forlot <romain.forlot@iot.bzh>2017-05-02 17:50:50 +0200
commitd170c9faeae2cf29c19f3523714ecdf58be73bed (patch)
tree114b0f8bc52df642567a7450cfbee2dbfce117d8 /CAN-binder/libs/bitfield-c/src/canutil/write.c
parentb6c09cbda2b6b47981d65265184a21223e526d4a (diff)
parenta34745ec93ae0a1d4f1b640dba8fb6702331a8e9 (diff)
Add 'CAN-binder/libs/bitfield-c/' from commit 'a34745ec93ae0a1d4f1b640dba8fb6702331a8e9'
git-subtree-dir: CAN-binder/libs/bitfield-c git-subtree-mainline: b6c09cbda2b6b47981d65265184a21223e526d4a git-subtree-split: a34745ec93ae0a1d4f1b640dba8fb6702331a8e9
Diffstat (limited to 'CAN-binder/libs/bitfield-c/src/canutil/write.c')
-rw-r--r--CAN-binder/libs/bitfield-c/src/canutil/write.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/CAN-binder/libs/bitfield-c/src/canutil/write.c b/CAN-binder/libs/bitfield-c/src/canutil/write.c
new file mode 100644
index 00000000..7f3a3e04
--- /dev/null
+++ b/CAN-binder/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);
+}