From 39ed87570bdb2f86969d4be821c94b722dc71179 Mon Sep 17 00:00:00 2001
From: Joe Ludwig <joe@valvesoftware.com>
Date: Wed, 26 Jun 2013 15:22:04 -0700
Subject: First version of the SOurce SDK 2013

---
 mp/src/tier1/sparsematrix.cpp | 141 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 mp/src/tier1/sparsematrix.cpp

(limited to 'mp/src/tier1/sparsematrix.cpp')

diff --git a/mp/src/tier1/sparsematrix.cpp b/mp/src/tier1/sparsematrix.cpp
new file mode 100644
index 00000000..e1a6dcbb
--- /dev/null
+++ b/mp/src/tier1/sparsematrix.cpp
@@ -0,0 +1,141 @@
+//========= Copyright Valve Corporation, All rights reserved. ============//
+//
+//===========================================================================//
+
+#include "tier1/sparsematrix.h"
+
+// memdbgon must be the last include file in a .cpp file!!!
+#include "tier0/memdbgon.h"
+
+
+void CSparseMatrix::AdjustAllRowIndicesAfter( int nStartRow, int nDelta )
+{
+	// now, we need to offset the starting position of all subsequent rows by -1 to compensate for the removal of this element
+	for( int nOtherRow = nStartRow + 1 ; nOtherRow < Height(); nOtherRow++ )
+	{
+		m_rowDescriptors[nOtherRow].m_nDataIndex += nDelta;
+	}
+}
+
+void CSparseMatrix::SetDimensions( int nNumRows, int nNumCols )
+{
+	m_nNumRows = nNumRows;
+	m_nNumCols = nNumCols;
+	m_entries.SetCount( 0 );
+	m_rowDescriptors.SetCount( m_nNumRows );
+	// and set all rows to be empty
+	for( int i = 0; i < m_nNumRows; i++ )
+	{
+		m_rowDescriptors[i].m_nNonZeroCount = 0;
+		m_rowDescriptors[i].m_nDataIndex = 0;
+	}
+	m_nHighestRowAppendedTo = -1;
+
+}
+
+
+void CSparseMatrix::SetElement( int nRow, int nCol, float flValue ) 
+{
+	Assert( nCol < m_nNumCols );
+	int nCount = m_rowDescriptors[nRow].m_nNonZeroCount;
+	bool bValueIsZero = ( flValue == 0.0 );
+	int nFirstEntryIndex = m_rowDescriptors[nRow].m_nDataIndex;
+	if ( nCount )
+	{
+		NonZeroValueDescriptor_t *pValue = &( m_entries[nFirstEntryIndex] );
+		int i;
+		for( i = 0; i < nCount; i++ )
+		{
+			int nIdx = pValue->m_nColumnNumber;
+			if ( nIdx == nCol )								// we found it!
+			{
+				if ( !bValueIsZero )
+				{
+					// we want to overwrite the existing value
+					pValue->m_flValue = flValue;
+				}
+				else
+				{
+					// there is a non-zero element currently at this position. We need to remove it
+					// and we need to remove its storage.
+					m_rowDescriptors[nRow].m_nNonZeroCount--;
+					m_entries.Remove( nFirstEntryIndex + i );
+					// now, we need to offset the starting position of all subsequent rows by -1 to compensate for the removal of this element
+					AdjustAllRowIndicesAfter( nRow, -1 );
+				}
+				return;
+			}
+			if ( nIdx > nCol )
+			{
+				break;
+			}
+			pValue++;
+		}
+		// we did not find an entry for this cell. If we were writing zero, fine - we are
+		// done, otherwise insert
+		if (! bValueIsZero )
+		{
+			m_rowDescriptors[nRow].m_nNonZeroCount++;
+			NonZeroValueDescriptor_t newValue;
+			newValue.m_nColumnNumber = nCol;
+			newValue.m_flValue = flValue;
+			if ( i == nCount )								// need to append
+			{
+				m_entries.InsertAfter( nFirstEntryIndex + nCount - 1, newValue );
+			}
+			else
+			{
+				m_entries.InsertBefore( nFirstEntryIndex + i, newValue );
+			}
+			// now, we need to offset the starting position of all subsequent rows by -1 to compensate for the addition of this element
+			AdjustAllRowIndicesAfter( nRow, +1 );
+		}
+	}
+	else
+	{
+		// row is empty. We may need to insert
+		if ( ! bValueIsZero )
+		{
+			m_rowDescriptors[nRow].m_nNonZeroCount++;
+			NonZeroValueDescriptor_t newValue;
+			newValue.m_nColumnNumber = nCol;
+			newValue.m_flValue = flValue;
+			m_entries.InsertBefore( nFirstEntryIndex, newValue );
+			AdjustAllRowIndicesAfter( nRow, +1 );
+		}
+	}
+}
+
+void CSparseMatrix::FinishedAppending( void )
+{
+	// set all pointers to space for subsequent rows to the right value
+	for( int i = m_nHighestRowAppendedTo + 1 ; i < Height(); i++ )
+	{
+		m_rowDescriptors[i].m_nDataIndex = m_entries.Count();
+	}
+}
+
+void CSparseMatrix::AppendElement( int nRow, int nColumn, float flValue )
+{
+	if ( flValue != 0.0 )
+	{
+		if ( m_nHighestRowAppendedTo != nRow )
+		{
+			Assert( nRow > m_nHighestRowAppendedTo );
+			for( int i = m_nHighestRowAppendedTo + 1; i <= nRow; i++ )
+			{
+				m_rowDescriptors[i].m_nDataIndex = m_entries.Count();
+			}
+		}
+		m_nHighestRowAppendedTo = nRow;
+		m_rowDescriptors[nRow].m_nNonZeroCount++;
+		NonZeroValueDescriptor_t newDesc;
+		newDesc.m_nColumnNumber = nColumn;
+		newDesc.m_flValue = flValue;
+		m_entries.AddToTail( newDesc );
+	}
+}
+	
+	
+
+
-- 
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