An attempt at getting image data back

spider-cam/libcamera/test/ipa/rkisp1/meson.build

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: CC0-1.0
+
+rkisp1_ipa_test = [
+    {'name': 'rkisp1-utils', 'sources': ['rkisp1-utils.cpp']},
+]
+
+foreach test : rkisp1_ipa_test
+    exe = executable(test['name'], test['sources'], libcamera_generated_ipa_headers,
+                     dependencies : [libcamera_private, libipa_dep],
+                     link_with : [test_libraries],
+                     include_directories : [test_includes_internal,
+                                            '../../../src/ipa/rkisp1/'])
+
+    test(test['name'], exe, suite : 'ipa')
+endforeach

spider-cam/libcamera/test/ipa/rkisp1/rkisp1-utils.cpp

@@ -0,0 +1,108 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2024, Paul Elder <paul.elder@ideasonboard.com>
+ *
+ * Miscellaneous utility tests
+ */
+
+#include <cmath>
+#include <iostream>
+#include <map>
+#include <stdint.h>
+
+#include "../src/ipa/rkisp1/utils.h"
+
+#include "test.h"
+
+using namespace std;
+using namespace libcamera;
+using namespace ipa::rkisp1;
+
+class RkISP1UtilsTest : public Test
+{
+protected:
+	/* R for real, I for integer */
+	template<unsigned int IntPrec, unsigned int FracPrec, typename I, typename R>
+	int testFixedToFloat(I input, R expected)
+	{
+		R out = utils::fixedToFloatingPoint<IntPrec, FracPrec, R>(input);
+		R prec = 1.0 / (1 << FracPrec);
+		if (std::abs(out - expected) > prec) {
+			cerr << "Reverse conversion expected " << input
+			     << " to convert to " << expected
+			     << ", got " << out << std::endl;
+			return TestFail;
+		}
+
+		return TestPass;
+	}
+
+	template<unsigned int IntPrec, unsigned int FracPrec, typename T>
+	int testSingleFixedPoint(double input, T expected)
+	{
+		T ret = utils::floatingToFixedPoint<IntPrec, FracPrec, T>(input);
+		if (ret != expected) {
+			cerr << "Expected " << input << " to convert to "
+			     << expected << ", got " << ret << std::endl;
+			return TestFail;
+		}
+
+		/*
+		 * The precision check is fairly arbitrary but is based on what
+		 * the rkisp1 is capable of in the crosstalk module.
+		 */
+		double f = utils::fixedToFloatingPoint<IntPrec, FracPrec, double>(ret);
+		if (std::abs(f - input) > 0.005) {
+			cerr << "Reverse conversion expected " << ret
+			     << " to convert to " << input
+			     << ", got " << f << std::endl;
+			return TestFail;
+		}
+
+		return TestPass;
+	}
+
+	int testFixedPoint()
+	{
+		/*
+		 * The second 7.992 test is to test that unused bits don't
+		 * affect the result.
+		 */
+		std::map<double, uint16_t> testCases = {
+			{ 7.992, 0x3ff },
+			{   0.2, 0x01a },
+			{  -0.2, 0x7e6 },
+			{  -0.8, 0x79a },
+			{  -0.4, 0x7cd },
+			{  -1.4, 0x74d },
+			{    -8, 0x400 },
+			{     0, 0 },
+		};
+
+		int ret;
+		for (const auto &testCase : testCases) {
+			ret = testSingleFixedPoint<4, 7, uint16_t>(testCase.first,
+								   testCase.second);
+			if (ret != TestPass)
+				return ret;
+		}
+
+		/* Special case with a superfluous one in the unused bits */
+		ret = testFixedToFloat<4, 7, uint16_t, double>(0xbff, 7.992);
+		if (ret != TestPass)
+			return ret;
+
+		return TestPass;
+	}
+
+	int run()
+	{
+		/* fixed point conversion test */
+		if (testFixedPoint() != TestPass)
+			return TestFail;
+
+		return TestPass;
+	}
+};
+
+TEST_REGISTER(RkISP1UtilsTest)