Game state now updates based on boat position. Arrows drawn as boat travels course. Currently do not point in correct direction, also the sparkline does not work.

#bug #refactor #implement #story[1118]

src/main/java/seng302/gameServer/messages/Header.java

@@ -0,0 +1,80 @@
+package seng302.gameServer.messages;
+
+import java.nio.ByteBuffer;
+
+public class Header {
+    // From API spec
+    private final int syncByte1 = 0x47;
+    private final int syncByte2 = 0x83;
+
+    private MessageType messageType;
+    private int timeStamp;
+    private int sourceId;
+    private short messageLength;
+    private static final int MESSAGE_LEN = 15;
+    private ByteBuffer buff;
+    private int buffPos;
+
+    /**
+     * Message Header from section 3.2 of the AC35 Streaming
+     * Data spec
+     * @param messageType The type of the message following this header
+     * @param sourceId The message source (as defined in the spec)
+     * @param messageLength The length of the message following this header
+     */
+    public Header(MessageType messageType, int sourceId, Short messageLength){
+        this.messageType = messageType;
+        this.sourceId = sourceId;
+        this.messageLength = messageLength;
+        timeStamp = (int) (System.currentTimeMillis() / 1000L);
+        buff = ByteBuffer.allocate(MESSAGE_LEN);
+        buffPos = 0;
+    }
+
+    private void putInBuffer(byte[] bytes, long val){
+        byte[] tmp = bytes.clone();
+        Message.reverse(tmp);
+
+        buff.put(tmp);
+        buffPos += tmp.length;
+        buff.position(buffPos);
+    }
+
+    /**
+     * Reset the buffer
+     */
+    public void reset(){
+        buffPos = 0;
+        buff.clear();
+        buff.position(buffPos);
+    }
+
+    /**
+     * @return a ByteBuffer containing the message header
+     */
+    public ByteBuffer getByteBuffer(){
+        reset();
+
+        putInBuffer(ByteBuffer.allocate(1).put((byte)syncByte1).array(), syncByte1);
+
+        putInBuffer(ByteBuffer.allocate(1).put((byte)syncByte2).array(), syncByte2);
+
+        putInBuffer(ByteBuffer.allocate(1).put((byte)messageType.getCode()).array(), messageType.getCode());
+
+        putInBuffer(Message.intToByteArray(timeStamp, 6), timeStamp);
+
+        putInBuffer(Message.intToByteArray(sourceId, 4), sourceId);
+
+        putInBuffer(Message.intToByteArray(messageLength, 2), messageLength);
+
+        return buff;
+    }
+
+    /**
+     * Returns the size of this message
+     * @return the size of the message
+     */
+    public static Integer getSize(){
+        return MESSAGE_LEN;
+    }
+}