Cleanup, add scanline mask builder

PortabilityLayer/ScanlineMask.cpp

@@ -0,0 +1,80 @@
+#include "CoreDefs.h"
+#include "ScanlineMask.h"
+#include "ScanlineMaskBuilder.h"
+
+#include <stdlib.h>
+#include <new>
+
+namespace PortabilityLayer
+{
+	void ScanlineMask::Destroy()
+	{
+		this->~ScanlineMask();
+		free(this);
+	}
+
+	ScanlineMask *ScanlineMask::Create(const ScanlineMaskBuilder &builder)
+	{
+		size_t alignedPrefixSize = sizeof(ScanlineMask) + PL_SYSTEM_MEMORY_ALIGNMENT - 1;
+		alignedPrefixSize -= alignedPrefixSize % PL_SYSTEM_MEMORY_ALIGNMENT;
+
+		const size_t longestSpan = builder.GetLongestSpan();
+		const size_t numSpans = builder.GetNumSpans();
+		const size_t *spans = builder.GetSpans();
+
+		size_t storageSize = numSpans;
+		DataStorage dataStorage = DataStorage_UInt8;
+		if (longestSpan <= 0xff)
+			dataStorage = DataStorage_UInt8;
+		else if (longestSpan <= 0xffff)
+		{
+			storageSize *= 2;
+			dataStorage = DataStorage_UInt16;
+		}
+		else if (longestSpan <= 0xffffffff)
+		{
+			storageSize *= 4;
+			dataStorage = DataStorage_UInt32;
+		}
+		else
+			return nullptr;
+
+		void *storage = malloc(alignedPrefixSize + storageSize);
+		if (!storage)
+			return nullptr;
+
+		void *spanStorage = static_cast<uint8_t*>(storage) + alignedPrefixSize;
+
+		ScanlineMask *mask = new (storage) ScanlineMask(dataStorage, spanStorage, numSpans);
+
+		for (size_t i = 0; i < numSpans; i++)
+		{
+			switch (dataStorage)
+			{
+			case DataStorage_UInt8:
+				static_cast<uint8_t*>(spanStorage)[i] = static_cast<uint8_t>(spans[i]);
+				break;
+			case DataStorage_UInt16:
+				static_cast<uint16_t*>(spanStorage)[i] = static_cast<uint16_t>(spans[i]);
+				break;
+			case DataStorage_UInt32:
+				static_cast<uint32_t*>(spanStorage)[i] = static_cast<uint32_t>(spans[i]);
+				break;
+			}
+		}
+
+		return mask;
+	}
+
+	ScanlineMask::ScanlineMask(DataStorage dataStorage, const void *data, size_t numSpans)
+		: m_dataStorage(dataStorage)
+		, m_data(data)
+		, m_numSpans(numSpans)
+	{
+	}
+
+	ScanlineMask::~ScanlineMask()
+	{
+	}
+}
+