Added possibility to invert the scroll direction by using negative values for the deltas

Author: Robin Müller

src/configuraion.c

@@ -80,8 +80,8 @@ configuration_t read_config(const char *filename) {
   }
   result.scroll.vert = iniparser_getboolean(ini, "scroll:vertical", false);
   result.scroll.horz = iniparser_getboolean(ini, "scroll:horizontal", false);
-  result.scroll.vert_delta = (uint8_t) iniparser_getint(ini, "scroll:verticaldelta", 79);
-  result.scroll.horz_delta = (uint8_t) iniparser_getint(ini, "scroll:horizontaldelta", 30);
+  result.scroll.vert_delta = (int8_t) iniparser_getint(ini, "scroll:verticaldelta", 79);
+  result.scroll.horz_delta = (int8_t) iniparser_getint(ini, "scroll:horizontaldelta", 30);
   result.vert_threshold_percentage = iniparser_getint(ini, "thresholds:vertical", 15);
   result.horz_threshold_percentage = iniparser_getint(ini, "thresholds:horizontal", 15);
   result.zoom.enabled = iniparser_getboolean(ini, "zoom:enabled", false);

src/configuraion.h

@@ -44,8 +44,8 @@ typedef struct configuration {
   struct scroll_options {
     bool vert;
     bool horz;
-    uint8_t vert_delta;
-    uint8_t horz_delta;
+    int8_t vert_delta;
+    int8_t horz_delta;
   } scroll;
   struct zoom_options {
     bool enabled;

src/gesture_detection.c

@@ -206,7 +206,7 @@ static input_event_array_t *do_scroll(double distance, int32_t delta, int rel_co
   scroll.width += distance;
   // a scroll width of delta means scroll one "scroll-unit" therefore a scroll event
   // can be first triggered if the absolute value of scroll.width exeeded delta
-  if (fabs(scroll.width) > delta) {
+  if (fabs(scroll.width) > fabs(delta)) {
     result = new_input_event_array(2);
     int width = (int)(scroll.width / delta);
     set_rel_event(&result->data[0], rel_code, width);