Add settings and scrollbar configuration

Author: Swagtoy

builtin/settingtypes.txt

@@ -703,6 +703,14 @@ gui_scaling (GUI scaling) float 1.0 0.5 20
 #    Enables smooth scrolling.
 smooth_scrolling (Smooth scrolling) bool true
 
+#    Enables elastic smooth scrolling.
+elastic_smooth_scrolling (Elastic smooth scrolling) bool true
+
+#    Enables precise scrolling.
+#    Helpful for most modern trackpads that have pixel-perfect scroll precision. (and even some mice)
+#    Keep this disabled if your trackpad is scrolling too slowly.
+precision_scrolling (Precision scrolling) bool false
+
 #    Enables animation of inventory items.
 inventory_items_animations (Inventory items animations) bool false
 

src/defaultsettings.cpp

@@ -295,6 +295,8 @@ void set_default_settings()
 	settings->setDefault("gui_scaling_filter", "false");
 	settings->setDefault("gui_scaling_filter_txr2img", "true");
 	settings->setDefault("smooth_scrolling", "true");
+	settings->setDefault("elastic_smooth_scrolling", "true");
+	settings->setDefault("precision_scrolling", "false");
 	settings->setDefault("desynchronize_mapblock_texture_animation", "false");
 	settings->setDefault("hud_hotbar_max_width", "1.0");
 	settings->setDefault("enable_local_map_saving", "false");

src/gui/guiScrollBar.cpp

@@ -263,15 +263,17 @@ void GUIScrollBar::setPosRaw(const s32 &pos)
 		thumb_size = (s32)std::fmin(S32_MAX,
 				thumb_area / (f32(page_size) / f32(thumb_area + border_size * 2)));
 
+    bool is_elastic = g_settings->getBool("elastic_smooth_scrolling");
+    int elastic_amount = is_elastic ? 20 : 0;
 	thumb_size = core::s32_clamp(thumb_size, thumb_min, thumb_area);
-	scroll_pos = core::s32_clamp(pos, min_pos-20, max_pos+20);
+	scroll_pos = core::s32_clamp(pos, min_pos-elastic_amount, max_pos+elastic_amount);
 	//scroll_pos = pos;
 
 	if (!is_dragging)
 	{
         // TODO support deltatime
         if (scroll_pos < 0) {
-            target_pos = (target_pos * 0.9);
+            target_pos = is_elastic ? (target_pos * 0.9) : min_pos;
         }
         else if (scroll_pos > max_pos) {
             target_pos += (target_pos - max_pos) * -0.3;
@@ -306,12 +308,13 @@ void GUIScrollBar::setPosAndSend(const s32 &pos)
 
 void GUIScrollBar::setPosInterpolated(const s32 &pos)
 {
+    bool is_elastic = g_settings->getBool("elastic_smooth_scrolling");
 	if (!g_settings->getBool("smooth_scrolling")) {
 		setPosAndSend(pos);
 		return;
 	}
 
-	target_pos = pos;
+	target_pos = is_elastic ? pos : core::s32_clamp(pos, min_pos, max_pos);
 	interpolatePos();
 }