Merge a7c4fc410a into dev

CHANGELOG.md

@@ -10,6 +10,7 @@
 ### Bugfixes
 - fix(draw_triangle): fix polygon/triangle drawing when the order of points is counter-clockwise
 - fix(btnmatrix): fix setting the same map with modified pointers
+- fix(arc) fix and improve arc dragging
 
 ## v7.7.1 (04.11.2020)
 ### Bugfixes

src/lv_widgets/lv_arc.c

@@ -85,6 +85,7 @@ lv_obj_t * lv_arc_create(lv_obj_t * par, const lv_obj_t * copy)
     ext->arc_angle_end   = 270;
     ext->type = LV_ARC_TYPE_NORMAL;
     ext->cur_value = -1;
+    ext->min_close = 1;
     ext->min_value = 0;
     ext->max_value = 100;
     ext->dragging = false;
@@ -751,6 +752,9 @@ static lv_res_t lv_arc_signal(lv_obj_t * arc, lv_signal_t sign, void * param)
         /*It must be in "dragging" mode to turn the arc*/
         if(ext->dragging == false) return res;
 
+        /*No angle can be determined if exactly the middle of the arc is being pressed*/
+        if(p.x == 0 && p.y == 0) return res;
+
         /*Calculate the angle of the pressed point*/
         int16_t angle;
         int16_t bg_end = ext->bg_angle_end;
@@ -758,13 +762,30 @@ static lv_res_t lv_arc_signal(lv_obj_t * arc, lv_signal_t sign, void * param)
             bg_end = ext->bg_angle_end + 360;
         }
 
-        angle = 360 - _lv_atan2(p.x, p.y) + 90; /*Some transformation is required*/
+
+        angle = _lv_atan2(p.y, p.x);
         angle -= ext->rotation_angle;
-        if(angle < ext->bg_angle_start) angle = ext->bg_angle_start;
-        if(angle > bg_end) angle = bg_end;
+        angle -= ext->bg_angle_start;   /*Make the angle relative to the start angle*/
+        if(angle < 0) angle += 360;
+
+        int16_t deg_range = bg_end - ext->bg_angle_start;
+
+        int16_t last_angle_rel = ext->last_angle - ext->bg_angle_start;
+        int16_t delta_angle = angle - last_angle_rel;
+
+        /* Do not allow big jumps.
+         * It's mainly to avoid jumping to the opposite end if the "dead" range between min. an max. is crossed.
+         * Check which and was closer on the last valid press (ext->min_close) and prefer that end */
+        if(LV_MATH_ABS(delta_angle) > 180) {
+            if(ext->min_close) angle = 0;
+            else angle = deg_range;
+        } else {
+            if(angle < deg_range / 2) ext->min_close = 1;
+            else ext->min_close = 0;
+        }
 
         /*Calculate the slew rate limited angle based on change rate (degrees/sec)*/
-        int16_t delta_angle = angle - ext->last_angle;
+        delta_angle = angle - last_angle_rel;
         uint32_t delta_tick = lv_tick_elaps(ext->last_tick);
         int16_t delta_angle_max = (ext->chg_rate * delta_tick) / 1000;
 
@@ -775,13 +796,15 @@ static lv_res_t lv_arc_signal(lv_obj_t * arc, lv_signal_t sign, void * param)
             delta_angle = -delta_angle_max;
         }
 
-        angle = ext->last_angle + delta_angle; /*Apply the limited angle change*/
+        angle = last_angle_rel + delta_angle; /*Apply the limited angle change*/
 
         /*Rounding for symmetry*/
         int32_t round = ((bg_end - ext->bg_angle_start) * 8) / (ext->max_value - ext->min_value);
         round = (round + 4) >> 4;
         angle += round;
 
+        angle += ext->bg_angle_start;   /*Make the angle absolute again*/
+
         /*Set the new value*/
         int16_t old_value = ext->cur_value;
         int16_t new_value = _lv_map(angle, ext->bg_angle_start, bg_end, ext->min_value, ext->max_value);

src/lv_widgets/lv_arc.h

@@ -51,6 +51,7 @@ typedef struct {
     uint16_t dragging    : 1;
     uint16_t type        : 2;
     uint16_t adjustable  : 1;
+    uint16_t min_close   : 1;  /*1: the last pressed angle was closer to minimum end*/
     uint16_t chg_rate; /*Drag angle rate of change of the arc (degrees/sec)*/
     uint32_t last_tick; /*Last dragging event timestamp of the arc*/
     int16_t last_angle; /*Last dragging angle of the arc*/