From 03e46f97ebfb4927cf6ed401b76b3192615800a5 Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Thu, 7 Sep 2023 21:00:22 +0800
Subject: [PATCH] fix fft, display and hw settings

---
 main.cpp | 31 ++++++++++++++-----------------
 1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/main.cpp b/main.cpp
index 01d0dbd..dcf8a85 100644
--- a/main.cpp
+++ b/main.cpp
@@ -24,29 +24,24 @@ static std::atomic<bool> terminate_dsp;
 struct bladerf* bladerf_dev;
 
 static std::mutex waterfall_data_mutex;
-static int waterfall_width = 1600;
-static int waterfall_height = 700;
-static unsigned int waterfall_data[1600*700];
+static int waterfall_width = 1000;
+static int waterfall_height = 2000;
+static unsigned int waterfall_data[1000*2000];
 
 static std::atomic<int> fps;
 
 static void dsp_thread() {
     using namespace std::literals::chrono_literals;
 
-    size_t len = 8192;
+    size_t len = 16384;
     std::vector<std::complex<int16_t>> frames(len);
 
     std::vector<std::complex<float>> frames_f(len);
     pocketfft::shape_t shape{len};
-    pocketfft::stride_t stride(shape.size());
-    size_t tmp=sizeof(float);
-    for (int i=shape.size()-1; i>=0; --i) {
-        stride[i] = tmp;
-        tmp *= shape[i];
-    };
+    pocketfft::stride_t stride(1);
+    stride[0] = 2*sizeof(float);
     pocketfft::shape_t axes;
-    for(size_t i=0; i<shape.size(); ++i)
-        axes.push_back(i);
+    axes.push_back(0);
     std::vector<std::complex<float>> frames_ft(len);
     int iterations = 0;
     auto last_second = std::chrono::steady_clock::now();
@@ -58,12 +53,14 @@ static void dsp_thread() {
         }
         for(size_t i=0;i<len;i++)
             frames_f[i] = frames[i];
-        pocketfft::c2c(shape, stride, stride, axes, true, frames_f.data(), frames_ft.data(), 1.0f);
+        pocketfft::c2c(shape, stride, stride, axes, pocketfft::FORWARD, frames_f.data(), frames_ft.data(), 1.0f);
         {
             std::lock_guard<std::mutex> guard(waterfall_data_mutex);
             std::memmove(&waterfall_data[waterfall_width], &waterfall_data[0], sizeof(int)*waterfall_width*(waterfall_height - 1));
             for(int i=0;i<waterfall_width;i++) {
-                waterfall_data[i] = 0xff000000 | 0x010101*std::min(int(abs(frames_ft[i*len/(2*waterfall_width)])/300.), 255);
+                int j = i*len/waterfall_width;
+                j = (j + len/2) % len; // display negative frequencies first
+                waterfall_data[i] = 0xff000000 | 0x010101*std::min(int(abs(frames_ft[j])/900.), 255);
             }
         }
         iterations++;
@@ -84,7 +81,7 @@ int main(int argc, char* argv[])
     std::atexit(glfwTerminate);
     glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
     glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
-    static GLFWwindow* window = glfwCreateWindow(1900, 720, "fastsa", nullptr, nullptr);
+    static GLFWwindow* window = glfwCreateWindow(1280, 2200, "fastsa", nullptr, nullptr);
     if(window == nullptr) {
         std::cerr << "failed to create GLFW window" << std::endl;
         return 1;
@@ -129,7 +126,7 @@ int main(int argc, char* argv[])
         bladerf_close(bladerf_dev);
     };
     std::atexit(BladeRFClose);
-    if((status = bladerf_set_frequency(bladerf_dev, BLADERF_CHANNEL_RX(0), 1'650'000'000)) != 0) {
+    if((status = bladerf_set_frequency(bladerf_dev, BLADERF_CHANNEL_RX(0), 1'664'000'000)) != 0) {
         std::cerr << "failed to set bladeRF frequency: " << bladerf_strerror(status) << std::endl;
         return 1;
     }
@@ -196,7 +193,7 @@ int main(int argc, char* argv[])
 
         ImGui::BeginTable("fastsa", 2, ImGuiTableFlags_SizingStretchSame | ImGuiTableFlags_Resizable);
         ImGui::TableSetupColumn("", 0, 280.0);
-        ImGui::TableSetupColumn("", 0, 1600.0);
+        ImGui::TableSetupColumn("", 0, 1000.0);
         ImGui::TableNextColumn();
         if(ImGui::Button("Exit"))
             exit = true;