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

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);
+}