From 1b8e4ee4642b8f324089976659424d3709111843 Mon Sep 17 00:00:00 2001
From: c vw <dl1ycf@darc.de>
Date: Thu, 16 Sep 2021 19:43:21 +0200
Subject: [PATCH] Take care of ZOOM/PAN changes for the waterfall

---
 receiver.h  |  2 ++
 waterfall.c | 57 +++++++++++++++++++++++++++++++++--------------------
 2 files changed, 38 insertions(+), 21 deletions(-)

diff --git a/receiver.h b/receiver.h
index 654cbc0..ce511fd 100644
--- a/receiver.h
+++ b/receiver.h
@@ -149,6 +149,8 @@ typedef struct _receiver {
 
   gint64 waterfall_frequency;
   gint waterfall_sample_rate;
+  gint waterfall_pan;
+  gint waterfall_zoom;
 
   gint mute_radio;
 
diff --git a/waterfall.c b/waterfall.c
index f34c203..67fef0e 100644
--- a/waterfall.c
+++ b/waterfall.c
@@ -125,7 +125,16 @@ void waterfall_update(RECEIVER *rx) {
 
   float *samples;
   long long vfofreq=vfo[rx->id].frequency;  // access only once to be thread-safe
-  int rotate_pixels=0;                      // used to suppress drawing just after rotating
+  int  freq_changed=0;                      // flag whether we have just "rotated"
+  int pan=rx->pan;
+  int zoom=rx->zoom;
+#ifdef CLIENT_SERVER
+  if(radio_is_remote) {
+    pan=0;
+    zoom=1;
+  }
+#endif
+
   if(rx->pixbuf) {
     unsigned char *pixels = gdk_pixbuf_get_pixels (rx->pixbuf);
 
@@ -135,7 +144,12 @@ void waterfall_update(RECEIVER *rx) {
 
     hz_per_pixel=(double)rx->sample_rate/((double)display_width*rx->zoom);
 
-    if(rx->waterfall_frequency!=0 && (rx->sample_rate==rx->waterfall_sample_rate)) {
+    if(rx->waterfall_frequency!=0 && (rx->sample_rate==rx->waterfall_sample_rate) && (rx->zoom == rx->waterfall_zoom)) {
+      //
+      // correct nominal waterfall frequency by change in pan value
+      //
+      rx->waterfall_frequency += (rx->waterfall_pan - pan)*hz_per_pixel;
+      rx->waterfall_pan = pan;
       if(rx->waterfall_frequency!=vfofreq) {
         // scrolled or band change
         long long half=(long long)(rx->sample_rate/2);
@@ -144,9 +158,11 @@ void waterfall_update(RECEIVER *rx) {
 //fprintf(stderr,"waterfall_update: clear waterfall from %lld to %lld\n",rx->waterfall_frequency,vfofreq);
           memset(pixels, 0, display_width*display_height*3);
           rx->waterfall_frequency=vfofreq;
+          rx->waterfall_pan=pan;
+          rx->waterfall_zoom=zoom;
         } else {
           // rotate waterfall
-          rotate_pixels=(int)((double)(rx->waterfall_frequency-vfofreq)/hz_per_pixel);
+          int rotate_pixels=(int)((double)(rx->waterfall_frequency-vfofreq)/hz_per_pixel);
 //fprintf(stderr,"waterfall_update: rotate waterfall from %lld to %lld pixels=%d\n",rx->waterfall_frequency,vfofreq,rotate_pixels);
           if(rotate_pixels<0) {
             memmove(pixels,&pixels[-rotate_pixels*3],((display_width*display_height)+rotate_pixels)*3);
@@ -154,12 +170,14 @@ void waterfall_update(RECEIVER *rx) {
             for(i=0;i<display_height;i++) {
               memset(&pixels[((i*display_width)+(width+rotate_pixels))*3], 0, -rotate_pixels*3);
             }
+            freq_changed=1;
           } else if (rotate_pixels > 0) {
             memmove(&pixels[rotate_pixels*3],pixels,((display_width*display_height)-rotate_pixels)*3);
             //now clear the left hand side
             for(i=0;i<display_height;i++) {
               memset(&pixels[(i*display_width)*3], 0, rotate_pixels*3);
             }
+            freq_changed=1;
           }
           rx->waterfall_frequency -= rotate_pixels*hz_per_pixel;
         }
@@ -167,6 +185,8 @@ void waterfall_update(RECEIVER *rx) {
     } else {
       memset(pixels, 0, display_width*display_height*3);
       rx->waterfall_frequency=vfofreq;
+      rx->waterfall_pan=pan;
+      rx->waterfall_zoom=zoom;
       rx->waterfall_sample_rate=rx->sample_rate;
     }
 
@@ -180,23 +200,17 @@ void waterfall_update(RECEIVER *rx) {
     // stabilized. This will not remove the artifacts in any case but is a big
     // improvement.
     //
-    if (rotate_pixels != 0)  return;
+    if (!freq_changed) {
 
-    memmove(&pixels[rowstride],pixels,(height-1)*rowstride);
+      memmove(&pixels[rowstride],pixels,(height-1)*rowstride);
 
-    float sample;
-    int average=0;
-    unsigned char *p;
-    p=pixels;
-    samples=rx->pixel_samples;
-    int pan=rx->pan;
-#ifdef CLIENT_SERVER
-    if(radio_is_remote) {
-      pan=0;
-    }
-#endif
+      float sample;
+      int average=0;
+      unsigned char *p;
+      p=pixels;
+      samples=rx->pixel_samples;
 
-    for(i=0;i<width;i++) {
+      for(i=0;i<width;i++) {
             if(have_rx_gain) {
               sample=samples[i+pan]+(float)(rx_gain_calibration-adc[rx->adc].gain);
             } else {
@@ -253,12 +267,13 @@ void waterfall_update(RECEIVER *rx) {
                 }
             }
         
-    }
+      }
 
     
-    if(rx->waterfall_automatic) {
-      rx->waterfall_low=average/width;
-      rx->waterfall_high=rx->waterfall_low+50;
+      if(rx->waterfall_automatic) {
+        rx->waterfall_low=average/width;
+        rx->waterfall_high=rx->waterfall_low+50;
+      }
     }
 
     gtk_widget_queue_draw (rx->waterfall);
-- 
2.45.2