More compact marker drag functions

nanovna.h

@@ -437,6 +437,9 @@ extern uint16_t graph_bottom;
 
 #define GRID_X_TEXT       (AREA_WIDTH_NORMAL - 7*5)
 
+// Marker start drag distance (can be bigger for various display resolution)
+#define MARKER_PICKUP_DISTANCE 20
+
 // Smith/polar chart
 //#define P_CENTER_X (CELLOFFSETX + WIDTH/2)
 //#define P_CENTER_Y (HEIGHT/2)
@@ -697,7 +700,7 @@ void draw_cal_status(void);
 
 //void markmap_all_markers(void);
 
-void marker_position(int m, int t, int *x, int *y);
+int distance_to_index(int8_t t, uint16_t idx, int16_t x, int16_t y);
 int search_nearest_index(int x, int y, int t);
 
 int marker_search_max(void);

plot.c

@@ -1369,29 +1369,23 @@ markmap_all_markers(void)
   markmap_upperarea();
 }
 
-void
-marker_position(int m, int t, int *x, int *y)
+int
+distance_to_index(int8_t t, uint16_t idx, int16_t x, int16_t y)
 {
-  index_t index = trace_index[t][markers[m].index];
-  *x = CELL_X(index);
-  *y = CELL_Y(index);
+  index_t *index = trace_index[t];
+  x-= CELL_X(index[idx]);
+  y-= CELL_Y(index[idx]);
+  return x*x + y*y;
 }
 
 int
 search_nearest_index(int x, int y, int t)
 {
-  index_t *index = trace_index[t];
   int min_i = -1;
-  int min_d = 1000;
+  int min_d = MARKER_PICKUP_DISTANCE * MARKER_PICKUP_DISTANCE;
   int i;
   for (i = 0; i < sweep_points; i++) {
-    int16_t dx = x - CELL_X(index[i]);
-    int16_t dy = y - CELL_Y(index[i]);
-    if (dx < 0) dx = -dx;
-    if (dy < 0) dy = -dy;
-    if (dx > 20 || dy > 20)
-      continue;
-    int d = dx*dx + dy*dy;
+    int d = distance_to_index(t, i, x , y);
     if (d < min_d) {
       min_d = d;
       min_i = i;

ui.c

@@ -2777,36 +2777,41 @@ touch_pickup_marker(void)
   touch_x -= OFFSETX;
   touch_y -= OFFSETY;
 
-  for (m = 0; m < MARKERS_MAX; m++) {
-    if (!markers[m].enabled)
+  int i = MARKER_INVALID, mt;
+  int min_dist = MARKER_PICKUP_DISTANCE * MARKER_PICKUP_DISTANCE;
+  // Search closest marker to touch position
+  for (t = 0; t < TRACES_MAX; t++) {
+    if (!trace[t].enabled)
       continue;
-
-    for (t = 0; t < TRACES_MAX; t++) {
-      int x, y;
-      if (!trace[t].enabled)
+    for (m = 0; m < MARKERS_MAX; m++) {
+      if (!markers[m].enabled)
         continue;
-
-      marker_position(m, t, &x, &y);
-      x -= touch_x;
-      y -= touch_y;
-      if ((x * x + y * y) < 20 * 20) {
-        if (active_marker != m) {
-          previous_marker = active_marker;
-          active_marker = m;
-          redraw_marker(active_marker);
-        }
-        // select trace
-        uistat.current_trace = t;
-        select_lever_mode(LM_MARKER);
-        markers[m].mtype &= ~M_TRACKING;    // Disable tracking when dragging marker
-        // drag marker until release
-        drag_marker(t, m);
-        return TRUE;
+      // Get distance to marker from touch point
+      int dist = distance_to_index(t, markers[m].index, touch_x, touch_y);
+      if (dist < min_dist) {
+        min_dist = dist;
+        i  = m;
+        mt = t;
       }
     }
   }
-
-  return FALSE;
+  // Marker not found
+  if (i == MARKER_INVALID)
+    return FALSE;
+  // Marker found, set as active and start drag it
+  if (active_marker != i) {
+    previous_marker = active_marker;
+    active_marker = i;
+  }
+  // Disable tracking
+  markers[i].mtype &= ~M_TRACKING;    // Disable tracking when dragging marker
+  // Leveler mode = marker move
+  select_lever_mode(LM_MARKER);
+  // select trace
+  uistat.current_trace = mt;
+  // drag marker until release
+  drag_marker(mt, i);
+  return TRUE;
 }
 
 static int touch_quick_menu(void)