Cleanup, add scanline mask builder

PortabilityLayer/ScanlineMaskBuilder.cpp

@@ -0,0 +1,66 @@
+#include "ScanlineMaskBuilder.h"
+
+#include <stdlib.h>
+
+namespace PortabilityLayer
+{
+	ScanlineMaskBuilder::ScanlineMaskBuilder()
+		: m_spans(nullptr)
+		, m_numSpans(0)
+		, m_capacity(0)
+		, m_longestSpan(0)
+	{
+	}
+
+	ScanlineMaskBuilder::~ScanlineMaskBuilder()
+	{
+		if (m_spans)
+			realloc(m_spans, 0);
+	}
+
+	bool ScanlineMaskBuilder::AppendSpan(size_t span)
+	{
+		if (span > m_longestSpan)
+			m_longestSpan = span;
+
+		if (m_capacity == 0)
+		{
+			m_capacity = 8;
+			m_spans = static_cast<size_t*>(realloc(nullptr, sizeof(size_t) * m_capacity));
+			if (!m_spans)
+				return false;
+		}
+
+		if (m_numSpans == m_capacity)
+		{
+			if (m_capacity >= (SIZE_MAX / sizeof(size_t) / 2))
+				return false;
+
+			m_capacity *= 2;
+			void *newSpans = realloc(m_spans, sizeof(size_t) * m_capacity);
+			if (!newSpans)
+				return false;
+
+			m_spans = static_cast<size_t*>(newSpans);
+		}
+
+		m_spans[m_numSpans++] = span;
+
+		return true;
+	}
+
+	size_t ScanlineMaskBuilder::GetLongestSpan() const
+	{
+		return m_longestSpan;
+	}
+
+	const size_t *ScanlineMaskBuilder::GetSpans() const
+	{
+		return m_spans;
+	}
+
+	size_t ScanlineMaskBuilder::GetNumSpans() const
+	{
+		return m_numSpans;
+	}
+}