updated resizer

lib/danbooru_image_resizer/Histogram.cpp

@@ -0,0 +1,48 @@
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "Histogram.h"
+#include "Filter.h"
+#include <algorithm>
+using namespace std;
+
+Histogram::Histogram()
+{
+	memset(m_Histogram, 0, sizeof(m_Histogram));
+}
+
+bool Histogram::Init(int iSourceWidth, int iSourceHeight, int iBPP)
+{
+	assert(iBPP >= 3);
+	m_SourceWidth = iSourceWidth;
+	m_SourceBPP = iBPP;
+
+	return true;
+}
+int Histogram::GetChannels() const
+{
+	return min(m_SourceBPP, 3);
+}
+
+bool Histogram::WriteRow(uint8_t *pNewRow)
+{
+	uint8_t *pInput = pNewRow;
+	int channels = GetChannels();
+	for(int x = 0; x < m_SourceWidth; ++x)
+	{
+		for(int c = 0; c < channels; ++c)
+		{
+			int color = pInput[c];
+			if(m_SourceBPP == 3)
+				color = (color * pInput[3]) / 255;
+			++m_Histogram[c][color];
+		}
+
+		pInput += m_SourceBPP;
+	}
+
+	return true;
+}
+