converter: Improve bit_position computation

[apps/agl-service-can-low-level.git] / low-can-binding / utils / converter.cpp

diff --git a/low-can-binding/utils/converter.cpp b/low-can-binding/utils/converter.cpp
index 5cfc8f5..c6c2f5e 100644 (file)
--- a/low-can-binding/utils/converter.cpp
+++ b/low-can-binding/utils/converter.cpp
@@ -19,6 +19,7 @@
 #include <sstream>
 #include <net/if.h>
 #include <afb/afb-binding>
+#include <climits>
 
 /**
  * @brief Convert hex data to string
@@ -32,9 +33,8 @@ std::string converter_t::to_hex(const uint8_t data[], const size_t length)
        std::stringstream stream;
        stream << std::hex << std::setfill('0');
        for(int i = 0; i < length; i++)
-       {
-               stream << std::hex << ((int) data[i]);
-       }
+               stream << std::setfill('0') << std::setw(2) << std::hex << ((int) data[i]);
+
        return stream.str();
 }
 
@@ -49,10 +49,40 @@ std::string converter_t::to_hex(const uint8_t data[], const size_t length)
  * @param new_start_bit The first bit of the signal in the frame
  * @param new_end_bit The last bit of the signal in the frame
  */
-void converter_t::signal_to_bits_bytes(uint32_t bit_position, uint32_t bit_size, int &new_start_byte, int &new_end_byte, int &new_start_bit, int &new_end_bit)
+void converter_t::signal_to_bits_bytes(unsigned int bit_position, unsigned int bit_size, int &new_start_byte, int &new_end_byte, uint8_t &new_start_bit, uint8_t &new_end_bit)
 {
        new_start_byte = bit_position >> 3;
-       new_start_bit = bit_position % 8;
+       new_start_bit = bit_position % CHAR_BIT;
        new_end_byte = (bit_position + bit_size - 1) >> 3;
-       new_end_bit = (bit_position + bit_size - 1) % 8;
-}
\ No newline at end of file
+       new_end_bit = (bit_position + bit_size - 1) % CHAR_BIT;
+}
+
+
+/**
+ * @brief      This is to use when you have a big endian CAN frame layout.
+ *             It converts the bit position so it matches with little endiant CAN frame layout.
+ *
+ * @param msg_length   Message length in bytes.
+ * @param bit_position         Original bit position.
+ * @param bit_size     Size of the data.
+ * @return uint32_t    New bit position.
+ */
+uint32_t converter_t::bit_position_swap(unsigned int msg_length, unsigned int bit_position, unsigned int bit_size)
+{
+       return (msg_length * CHAR_BIT) - bit_position - bit_size;
+}
+
+/**
+ * @brief      This allow to get the correct bit_position using the weird Continental.
+ *             bit numbering method where the Frame is read using little endianness
+ *             and bit count using a big endianness
+ *
+ * @param msg_length   Message length in bytes.
+ * @param bit_position Original bit position.
+ * @param bit_size     Size of the data.
+ * @return uint32_t    New bit position.
+ */
+uint32_t converter_t::continental_bit_position_mess(unsigned int msg_length, unsigned int bit_position, unsigned int bit_size)
+{
+       return bit_position + (CHAR_BIT - bit_position % CHAR_BIT) - bit_size;
+}