FPGA: Fixes and simplifications to spot_finder core + SNR threshold test

tests/FPGAIntegrationTest.cpp

@@ -1181,4 +1181,52 @@ TEST_CASE("HLS_C_Simulation_internal_packet_generator_spot_finder_count_threshol
     REQUIRE (spot_finder_result.strong_pixel[0] == (1<<0));
     REQUIRE (spot_finder_result.strong_pixel[(123*1024 + 578) / 8] == (1<<2)); // 578 % 8 == 2
     REQUIRE (spot_finder_result.strong_pixel[(121*1024 + 800) / 8] == (1<<0)); // 800 % 8 == 0
+}
+
+TEST_CASE("HLS_C_Simulation_internal_packet_generator_spot_finder_snr_threshold", "[FPGA][Full]") {
+    const uint16_t nmodules = 4;
+
+    DiffractionExperiment x((DetectorGeometry(nmodules)));
+
+    x.Mode(DetectorMode::Raw);
+    x.UseInternalPacketGenerator(true).ImagesPerTrigger(1).PedestalG0Frames(0);
+
+    HLSSimulatedDevice test(0, 64);
+
+    std::vector<uint16_t> frame(RAW_MODULE_SIZE);
+    for (int i = 0; i < RAW_MODULE_SIZE; i++) {
+        frame[i] = ((i / RAW_MODULE_COLS) + (i % RAW_MODULE_COLS)) % 2;
+    }
+    // Mean = 0.5
+    // Std. dev. = 0.5
+    // Threshold = 10 * std. dev. - 6 is minimum count
+
+    frame [             0] = 8;
+    frame [123*1024 + 578] = 5;
+    frame [121*1024 + 800] = 4;
+    frame [ 89*1024 + 300] = 7;
+    frame [300*1024 +   0] = 3;
+
+    test.SetInternalGeneratorFrame(frame);
+
+    test.SetSpotFinderParameters(0, 10);
+
+    REQUIRE_NOTHROW(test.StartAction(x));
+    REQUIRE_NOTHROW(test.WaitForActionComplete());
+
+    REQUIRE(test.OutputStream().size() == 1);
+
+    JFJochProtoBuf::AcquisitionDeviceStatistics device_statistics;
+    REQUIRE_NOTHROW(test.SaveStatistics(x, device_statistics));
+    REQUIRE(device_statistics.bytes_received() == 128 * nmodules * JUNGFRAU_PACKET_SIZE_BYTES);
+
+    auto imageBuf = test.GetDeviceOutput(0, 0)->pixels;
+    REQUIRE(memcmp(imageBuf, frame.data(), RAW_MODULE_SIZE * sizeof(uint16_t)) == 0);
+
+    auto spot_finder_result = test.GetDeviceOutput(0, 0)->spot_finding_result;
+    REQUIRE (spot_finder_result.strong_pixel_count == 2);
+    REQUIRE (spot_finder_result.snr_threshold == 10 * 4);
+    REQUIRE (spot_finder_result.count_threshold == 0);
+    REQUIRE (spot_finder_result.strong_pixel[0] == (1<<0));
+    REQUIRE (spot_finder_result.strong_pixel[(89*1024 + 300) / 8] == (1<<4));  // 300 % 8 == 4
 }