added resizer

lib/danbooru_image_resizer/RowBuffer.cpp

@@ -0,0 +1,81 @@
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include "RowBuffer.h"
+#include <algorithm>
+using namespace std;
+
+RowBuffer::RowBuffer()
+{
+	m_Rows = NULL;
+	m_StartRow = 0;
+	m_EndRow = 0;
+	m_BPP = 0;
+	m_Height = 0;
+}
+
+RowBuffer::~RowBuffer()
+{
+	for(int i = 0; i < m_Height; ++i)
+		delete [] m_Rows[i];
+
+	delete [] m_Rows;
+}
+
+bool RowBuffer::Init(int Width, int Height, int BPP)
+{
+	m_Width = Width;
+	m_Height = Height;
+	m_BPP = BPP;
+
+	m_Rows = new uint8_t *[Height];
+	if(m_Rows == NULL)
+		return false;
+	memset(m_Rows, 0, sizeof(uint8_t *) * Height);
+
+	return true;
+}
+
+uint8_t *RowBuffer::GetRow(int Row)
+{
+	assert(m_BPP > 0);
+
+	if(m_Rows[Row] == NULL)
+	{
+		m_Rows[Row] = new uint8_t[m_Width*m_BPP];
+		if(m_Rows[Row] == NULL)
+			return NULL;
+		if(m_StartRow == m_EndRow)
+		{
+			m_StartRow = Row;
+			m_EndRow = m_StartRow + 1;
+		}
+	}
+
+	if(int(Row) == m_StartRow+1)
+	{
+		while(m_StartRow != 0 && m_Rows[m_StartRow-1])
+			--m_StartRow;
+	}
+
+	if(int(Row) == m_EndRow)
+	{
+		while(m_EndRow < m_Height && m_Rows[m_EndRow])
+			++m_EndRow;
+	}
+	return m_Rows[Row];
+}
+
+void RowBuffer::DiscardRows(int DiscardRow)
+{
+	assert(m_BPP > 0);
+
+	for(int i = m_StartRow; i < DiscardRow; ++i)
+	{
+		delete [] m_Rows[i];
+		m_Rows[i] = NULL;
+	}
+
+	m_StartRow = max(m_StartRow, DiscardRow);
+	m_EndRow = max(m_EndRow, DiscardRow);
+}