test: ipa: libipa: Add histogram tests

Add some basic tests for the histogram class.

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

test/ipa/libipa/histogram.cpp

@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Ideas on Board Oy
+ *
+ * Histogram tests
+ */
+
+#include "../src/ipa/libipa/histogram.h"
+
+#include <cmath>
+#include <iostream>
+#include <map>
+#include <stdint.h>
+
+#include "test.h"
+
+using namespace std;
+using namespace libcamera;
+using namespace ipa;
+
+#define ASSERT_EQ(a, b)                                 \
+	if (!((a) == (b))) {                            \
+		std::cout << #a " != " #b << std::endl; \
+		return TestFail;                        \
+	}
+
+class HistogramTest : public Test
+{
+protected:
+	int run()
+	{
+		auto hist = Histogram({ { 50, 50 } });
+
+		ASSERT_EQ(hist.bins(), 2);
+		ASSERT_EQ(hist.total(), 100);
+
+		ASSERT_EQ(hist.cumulativeFrequency(1.0), 50);
+		ASSERT_EQ(hist.cumulativeFrequency(1.5), 75);
+		ASSERT_EQ(hist.cumulativeFrequency(2.0), 100);
+
+		ASSERT_EQ(hist.quantile(0.0), 0.0);
+		ASSERT_EQ(hist.quantile(1.0), 2.0);
+		ASSERT_EQ(hist.quantile(0.5), 1.0);
+
+		ASSERT_EQ(hist.interQuantileMean(0.0, 1.0), 1.0);
+		ASSERT_EQ(hist.interQuantileMean(0.0, 0.5), 0.5);
+		ASSERT_EQ(hist.interQuantileMean(0.5, 1.0), 1.5);
+
+		return TestPass;
+	}
+};
+
+TEST_REGISTER(HistogramTest)

test/ipa/libipa/meson.build

@@ -2,6 +2,7 @@
 
 libipa_test = [
     {'name': 'fixedpoint', 'sources': ['fixedpoint.cpp']},
+    {'name': 'histogram', 'sources': ['histogram.cpp']},
     {'name': 'interpolator', 'sources': ['interpolator.cpp']},
 ]