ImageViewer: proper clamp to first/last image top/bottom, change acceleration values

1 files changed, 8 insertions, 7 deletions

diff --git a/src/ImageViewer.cpp b/src/ImageViewer.cpp
index 7b188c8..ff35d06 100644
--- a/src/ImageViewer.cpp
+++ b/src/ImageViewer.cpp
@@ -196,10 +196,10 @@ namespace QuickMedia {
 
     ImageViewerAction ImageViewer::draw() {
         const double frame_delta = frame_timer.restart();
-        const double scroll_speed_key_input = 50.0;
-        const double scroll_speed_mouse_wheel = 600.0;
+        const double scroll_speed_key_input = 200.0;
+        const double scroll_speed_mouse_wheel = 800.0;
         const double scroll_speed_autoscroll = 10.0;
-        const double scroll_deaccel = 0.96;
+        const double scroll_deaccel = 6.0; // higher value = faster stop
 
         if(!window_size_set) {
             auto window_size_i = window->get_size();
@@ -288,7 +288,7 @@ namespace QuickMedia {
             if(scroll_speed < -max_speed)
                 scroll_speed = -max_speed;
 
-            scroll_speed *= scroll_deaccel;
+            scroll_speed *= (1.0 - std::min(1.0, scroll_deaccel * frame_delta));
             if(std::abs(scroll_speed) < 0.01) {
                 scroll_speed = 0.0;
                 scroll = std::round(scroll); /* Better image quality! */
@@ -339,11 +339,12 @@ namespace QuickMedia {
         const double first_image_height = get_page_size(0).y;
         const double last_image_height = get_page_size((int)image_data.size() - 1).y;
 
-        const double top_scroll = -first_image_height * 0.5 + window_size.y * 0.5;
+        const double top_scroll = std::max(0.0, -first_image_height * 0.5 + window_size.y * 0.5);
+        const double bottom_scroll = std::min(window_size.y, window_size.y + last_image_height * 0.5 - window_size.y * 0.5);
         if(scroll > top_scroll) {
             scroll = top_scroll;
-        } else if(scroll + page_offset < window_size.y + last_image_height * 0.5 - window_size.y * 0.5 && page_offset > window_size.y) {
-            scroll = -page_offset + (window_size.y + last_image_height * 0.5 - window_size.y * 0.5);
+        } else if(scroll + page_offset < bottom_scroll && page_offset > window_size.y) {
+            scroll = -page_offset + bottom_scroll;
         }
 
         if(page_closest_to_center != -1) {