NBT: implement write helpers for int8 and int16

src/lib/nbt.cpp

@@ -186,9 +186,26 @@ namespace NBT {
         }
 
         void writeInt8(std::vector<uint8_t>* destination, int8_t data) {
+            destination->push_back((uint8_t) data);
         }
 
+        //FIXME: endian dependent implementation
         void writeInt16(std::vector<uint8_t>* destination, int16_t data) {
+            int16_t* value = new int16_t;
+            uint8_t* valueAsBytes = reinterpret_cast<uint8_t*>(value);
+            *value = data;
+            #ifdef FOSSVG_BIG_ENDIAN
+                destination->push_back(*valueAsBytes);
+                destination->push_back(*(valueAsBytes+1));
+            #else
+                #ifdef FOSSVG_LITTLE_ENDIAN
+                    destination->push_back(*(valueAsBytes+1));
+                    destination->push_back(*valueAsBytes);
+                #else
+                    #error "NBT::helper::writeInt16: An implementation for your endianness is unavailable."
+                #endif
+            #endif
+            delete value;
         }
 
         void writeInt32(std::vector<uint8_t>* destination, int32_t data) {

src/test/nbt_helpers.cpp

@@ -48,6 +48,14 @@ int main(){
 
     std::cout << "Passed readInt8 NBT helper test" << std::endl;
 
+    std::vector<uint8_t>* writeInt8TestResult = new std::vector<uint8_t>();
+    NBT::helper::writeInt8(writeInt8TestResult, (int8_t) 8);
+    std::vector<uint8_t> dereferencedWriteInt8TestResult = *writeInt8TestResult;
+    delete writeInt8TestResult;
+    ASSERT(dereferencedWriteInt8TestResult.back() == (uint8_t) 8);
+
+    std::cout << "Passed writeInt8 NBT helper test" << std::endl;
+
     // int16 ###########################################################
     // read successfully
     currentPosition = 5;
@@ -72,6 +80,14 @@ int main(){
 
     std::cout << "Passed readInt16 NBT helper test" << std::endl;
 
+    std::vector<uint8_t>* writeInt16TestResult = new std::vector<uint8_t>();
+    NBT::helper::writeInt16(writeInt16TestResult, (int16_t) 0xABCD);
+    std::vector<uint8_t> dereferencedWriteInt16TestResult = *writeInt16TestResult;
+    delete writeInt16TestResult;
+    ASSERT(dereferencedWriteInt16TestResult[0] == (uint8_t) 0xAB && dereferencedWriteInt16TestResult[1] == (uint8_t) 0xCD);
+
+    std::cout << "Passed writeInt8 NBT helper test" << std::endl;
+
     // int32 ###########################################################
     // read successfully
     currentPosition = 5;