Properly fixed piston non-animation

Fixes #57

source/Chunk.cpp

@@ -1607,6 +1607,61 @@ void cChunk::FastSetBlock(int a_RelX, int a_RelY, int a_RelZ, BLOCKTYPE a_BlockT
 
 
 
+void cChunk::SetServerBlock(int a_RelX, int a_RelY, int a_RelZ, BLOCKTYPE a_BlockType, BLOCKTYPE a_BlockMeta)
+{
+	ASSERT(!((a_RelX < 0) || (a_RelX >= Width) || (a_RelY < 0) || (a_RelY >= Height) || (a_RelZ < 0) || (a_RelZ >= Width)));
+
+	ASSERT(IsValid());
+	
+	const int index = MakeIndexNoCheck(a_RelX, a_RelY, a_RelZ);
+	const BLOCKTYPE OldBlockType = cChunkDef::GetBlock(m_BlockTypes, index);
+	const BLOCKTYPE OldBlockMeta = GetNibble(m_BlockMeta, index);
+	if ((OldBlockType == a_BlockType) && (OldBlockMeta == a_BlockMeta))
+	{
+		return;
+	}
+
+	MarkDirty();
+	
+	m_BlockTypes[index] = a_BlockType;
+
+	SetNibble(m_BlockMeta, index, a_BlockMeta);
+
+	// ONLY recalculate lighting if it's necessary!
+	if(
+		(g_BlockLightValue[OldBlockType ]        != g_BlockLightValue[a_BlockType]) ||
+		(g_BlockSpreadLightFalloff[OldBlockType] != g_BlockSpreadLightFalloff[a_BlockType]) ||
+		(g_BlockTransparent[OldBlockType]        != g_BlockTransparent[a_BlockType])
+	)
+	{
+		m_IsLightValid = false;
+	}
+
+	// Update heightmap, if needed:
+	if (a_RelY >= m_HeightMap[a_RelX + a_RelZ * Width])
+	{
+		if (a_BlockType != E_BLOCK_AIR)
+		{
+			m_HeightMap[a_RelX + a_RelZ * Width] = (unsigned char)a_RelY;
+		}
+		else
+		{
+			for (int y = a_RelY - 1; y > 0; --y)
+			{
+				if (m_BlockTypes[MakeIndexNoCheck(a_RelX, y, a_RelZ)] != E_BLOCK_AIR)
+				{
+					m_HeightMap[a_RelX + a_RelZ * Width] = (unsigned char)y;
+					break;
+				}
+			}  // for y - column in m_BlockData
+		}
+	}
+}
+
+
+
+
+
 void cChunk::SendBlockTo(int a_RelX, int a_RelY, int a_RelZ, cClientHandle * a_Client)
 {
 	// The coords must be valid, because the upper level already does chunk lookup. No need to check them again.