From e070b7310493d0a5a32a8745888d236a7c39ed8a Mon Sep 17 00:00:00 2001
From: f4exb <f4exb06@gmail.com>
Date: Tue, 13 Dec 2022 21:46:34 +0100
Subject: [PATCH] FFT filter: removed useless code and some fixes

---
 sdrbase/dsp/fftfilt.cpp | 48 +++++++----------------------------------
 1 file changed, 8 insertions(+), 40 deletions(-)

diff --git a/sdrbase/dsp/fftfilt.cpp b/sdrbase/dsp/fftfilt.cpp
index 8d2391a13..cfc0141d0 100644
--- a/sdrbase/dsp/fftfilt.cpp
+++ b/sdrbase/dsp/fftfilt.cpp
@@ -159,46 +159,6 @@ void fftfilt::create_filter(float f1, float f2, FFTWindow::Function wf)
 	}
 }
 
-void fftfilt::create_filter(const std::vector<std::pair<float, float>>& limits, bool pass)
-{
-	// initialize the filter canvas
-    std::vector<int> canvas(flen, pass ? 0 : 1);
-    fftfilt::cmplx* xfilter = new fftfilt::cmplx[flen];
-
-    for (const auto& fs : limits)
-    {
-        const float& f1 = fs.first + 0.5;
-        const float& w = fs.second > 0.0 ? fs.second : 0.0;
-        const float& f2 = f1 + w;
-
-        for (int i = 0; i < flen; i++)
-        {
-            if (pass) // pass
-            {
-                if ((i >= f1*flen) && (i <= f2*flen)) {
-                    canvas[i] = 1;
-                }
-            }
-            else // reject
-            {
-                if ((i >= f1*flen) && (i <= f2*flen)) {
-                    canvas[i] = 0;
-                }
-            }
-        }
-    }
-
-    for (int i = 0; i < flen; i++) {
-        xfilter[i] = cmplx(canvas[i], 0);
-    }
-
-    // Rearrange
-    std::copy(&xfilter[flen2], &xfilter[flen-1], filter);
-    std::copy(&xfilter[0], &xfilter[flen2-1], &filter[flen2]);
-
-    delete[] xfilter;
-}
-
 void fftfilt::create_filter(const std::vector<std::pair<float, float>>& limits, bool pass, FFTWindow::Function wf)
 {
     std::vector<int> canvasNeg(flen2, pass ? 0 : 1); // initialize the negative frequencies filter canvas
@@ -281,6 +241,10 @@ void fftfilt::create_filter(const std::vector<std::pair<float, float>>& limits,
                 filter[i] -= fsinc(f1, i, flen2);
             }
         }
+
+        if (f2 == 0 && f1 != 0) {
+            filter[flen2 / 2] += 1;
+        }
     }
 
     for (const auto& indexes : indexesNegList)
@@ -297,6 +261,10 @@ void fftfilt::create_filter(const std::vector<std::pair<float, float>>& limits,
                 filterOpp[i] -= fsinc(f1, i, flen2);
             }
         }
+
+        if (f2 == 0 && f1 != 0) {
+            filterOpp[flen2 / 2] += 1;
+        }
     }
 
     FFTWindow fwin;