ImGuiFullscreen: Allow smooth scrolling

dep/imgui/imgui.vcxproj

@@ -5,8 +5,8 @@
     <ClInclude Include="include\imconfig.h" />
     <ClInclude Include="include\imgui.h" />
     <ClInclude Include="include\imgui_freetype.h" />
+    <ClInclude Include="include\imgui_internal.h" />
     <ClInclude Include="include\imgui_stdlib.h" />
-    <ClInclude Include="src\imgui_internal.h" />
     <ClInclude Include="src\imstb_rectpack.h" />
     <ClInclude Include="src\imstb_textedit.h" />
     <ClInclude Include="src\imstb_truetype.h" />

dep/imgui/imgui.vcxproj.filters

@@ -3,12 +3,12 @@
   <ItemGroup>
     <ClInclude Include="include\imconfig.h" />
     <ClInclude Include="include\imgui.h" />
-    <ClInclude Include="src\imgui_internal.h" />
     <ClInclude Include="src\imstb_rectpack.h" />
     <ClInclude Include="src\imstb_textedit.h" />
     <ClInclude Include="src\imstb_truetype.h" />
     <ClInclude Include="include\imgui_stdlib.h" />
     <ClInclude Include="include\imgui_freetype.h" />
+    <ClInclude Include="include\imgui_internal.h" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="src\imgui_widgets.cpp" />

dep/imgui/include/imgui.h

@@ -1717,6 +1717,7 @@ enum ImGuiStyleVar_
     ImGuiStyleVar_SeparatorTextBorderSize,  // float     SeparatorTextBorderSize
     ImGuiStyleVar_SeparatorTextAlign,       // ImVec2    SeparatorTextAlign
     ImGuiStyleVar_SeparatorTextPadding,     // ImVec2    SeparatorTextPadding
+    ImGuiStyleVar_ScrollSmooth,             // float     ScrollSmooth
     ImGuiStyleVar_COUNT
 };
 
@@ -2180,6 +2181,8 @@ struct ImGuiStyle
     ImGuiHoveredFlags HoverFlagsForTooltipMouse;// Default flags when using IsItemHovered(ImGuiHoveredFlags_ForTooltip) or BeginItemTooltip()/SetItemTooltip() while using mouse.
     ImGuiHoveredFlags HoverFlagsForTooltipNav;  // Default flags when using IsItemHovered(ImGuiHoveredFlags_ForTooltip) or BeginItemTooltip()/SetItemTooltip() while using keyboard/gamepad.
 
+    float             ScrollSmooth;             // Smooth scrolling amount: 1.0f no smoothing. Anything above 1.0f will make the scroll delta more smooth.
+
     IMGUI_API ImGuiStyle();
     IMGUI_API void ScaleAllSizes(float scale_factor);
 };

dep/imgui/include/imgui_internal.h

@@ -2618,7 +2618,8 @@ struct IMGUI_API ImGuiWindow
     ImGuiID                 MoveId;                             // == window->GetID("#MOVE")
     ImGuiID                 ChildId;                            // ID of corresponding item in parent window (for navigation to return from child window to parent window)
     ImGuiID                 PopupId;                            // ID in the popup stack when this window is used as a popup/menu (because we use generic Name/ID for recycling)
-    ImVec2                  Scroll;
+    ImVec2                  Scroll;                             // Current Visible Scroll position
+    ImVec2                  ScrollExpected;                     // Current Expected Scroll position
     ImVec2                  ScrollMax;
     ImVec2                  ScrollTarget;                       // target scroll position. stored as cursor position with scrolling canceled out, so the highest point is always 0.0f. (FLT_MAX for no change)
     ImVec2                  ScrollTargetCenterRatio;            // 0.0f = scroll so that target position is at top, 0.5f = scroll so that target position is centered

dep/imgui/src/imgui.cpp

@@ -1303,6 +1303,7 @@ ImGuiStyle::ImGuiStyle()
     HoverDelayNormal            = 0.40f;            // Delay for IsItemHovered(ImGuiHoveredFlags_DelayNormal). "
     HoverFlagsForTooltipMouse   = ImGuiHoveredFlags_Stationary | ImGuiHoveredFlags_DelayShort | ImGuiHoveredFlags_AllowWhenDisabled;    // Default flags when using IsItemHovered(ImGuiHoveredFlags_ForTooltip) or BeginItemTooltip()/SetItemTooltip() while using mouse.
     HoverFlagsForTooltipNav     = ImGuiHoveredFlags_NoSharedDelay | ImGuiHoveredFlags_DelayNormal | ImGuiHoveredFlags_AllowWhenDisabled;  // Default flags when using IsItemHovered(ImGuiHoveredFlags_ForTooltip) or BeginItemTooltip()/SetItemTooltip() while using keyboard/gamepad.
+    ScrollSmooth = 1.0f;                            // Disabled by default. It's just immediate jump from ScrollExpected to the visual Scroll.
 
     // Default theme
     ImGui::StyleColorsDark(this);
@@ -3297,6 +3298,7 @@ static const ImGuiDataVarInfo GStyleVarInfo[] =
     { ImGuiDataType_Float, 1, (ImU32)offsetof(ImGuiStyle, SeparatorTextBorderSize)},    // ImGuiStyleVar_SeparatorTextBorderSize
     { ImGuiDataType_Float, 2, (ImU32)offsetof(ImGuiStyle, SeparatorTextAlign) },        // ImGuiStyleVar_SeparatorTextAlign
     { ImGuiDataType_Float, 2, (ImU32)offsetof(ImGuiStyle, SeparatorTextPadding) },      // ImGuiStyleVar_SeparatorTextPadding
+    { ImGuiDataType_Float, 1, (ImU32)offsetof(ImGuiStyle, ScrollSmooth) },              // ImGuiStyleVar_ScrollSmooth
 };
 
 const ImGuiDataVarInfo* ImGui::GetStyleVarInfo(ImGuiStyleVar idx)
@@ -3926,6 +3928,7 @@ ImGuiWindow::ImGuiWindow(ImGuiContext* ctx, const char* name) : DrawListInst(NUL
     IDStack.push_back(ID);
     MoveId = GetID("#MOVE");
     ScrollTarget = ImVec2(FLT_MAX, FLT_MAX);
+    ScrollExpected = ImVec2(0, 0);
     ScrollTargetCenterRatio = ImVec2(0.5f, 0.5f);
     AutoFitFramesX = AutoFitFramesY = -1;
     AutoPosLastDirection = ImGuiDir_None;
@@ -9524,7 +9527,7 @@ void ImGui::UpdateMouseWheel()
                 LockWheelingWindow(window, wheel.x);
                 float max_step = window->InnerRect.GetWidth() * 0.67f;
                 float scroll_step = ImTrunc(ImMin(2 * window->CalcFontSize(), max_step));
-                SetScrollX(window, window->Scroll.x - wheel.x * scroll_step);
+                SetScrollX(window, window->ScrollExpected.x - wheel.x * scroll_step);
                 g.WheelingWindowScrolledFrame = g.FrameCount;
             }
             if (do_scroll[ImGuiAxis_Y])
@@ -9532,7 +9535,7 @@ void ImGui::UpdateMouseWheel()
                 LockWheelingWindow(window, wheel.y);
                 float max_step = window->InnerRect.GetHeight() * 0.67f;
                 float scroll_step = ImTrunc(ImMin(5 * window->CalcFontSize(), max_step));
-                SetScrollY(window, window->Scroll.y - wheel.y * scroll_step);
+                SetScrollY(window, window->ScrollExpected.y - wheel.y * scroll_step);
                 g.WheelingWindowScrolledFrame = g.FrameCount;
             }
         }
@@ -10761,11 +10764,46 @@ static ImVec2 CalcNextScrollFromScrollTargetAndClamp(ImGuiWindow* window)
                 float snap_max = window->ScrollMax[axis] + window->SizeFull[axis] - decoration_size[axis];
                 scroll_target = CalcScrollEdgeSnap(scroll_target, snap_min, snap_max, window->ScrollTargetEdgeSnapDist[axis], center_ratio);
             }
-            scroll[axis] = scroll_target - center_ratio * (window->SizeFull[axis] - decoration_size[axis]);
+            window->ScrollExpected[axis] = scroll_target - center_ratio * (window->SizeFull[axis] - decoration_size[axis]);
         }
-        scroll[axis] = IM_ROUND(ImMax(scroll[axis], 0.0f));
+
+        // Based on https://github.com/ocornut/imgui/pull/7348
+        // TODO: Make it not dependent on frame rate, easiest way would be to multiply by delta_time / (1/60).
+        // Smooth scroll.
+        // Instead use "Scroll" value in the window, all setters that sets the scroll absolutely now points to
+        // "ScrollExpected" Here, we take from ScrollTarget (from some functions like ScrollHere + mouse wheel) to set
+        // the ScrollExpected value Also, Scroll var in window is processed to meet ScrollExpected Value
+        //
+        // The formula is pretty simple to generate a smooth scrolling that can be tweaked just by one float value.
+        //
+        // The Float is "ImGuiStyleVar_ScrollSmooth". Can be set on the style or via PushStyleVar.
+        // A Value of 1.0f is just inmediate (transported from ScrollExpected to Scroll).
+        // A Value higher of 1.0f will make the scrolling smoother.
+        //
+        // The ScrollExpected is also clamped (as previously the "Scroll" value) from 0 to sScrollMax
+        //
+        // The approach is frame bounded and not time bounded.
+        // It should be prefereable use a time bounded approach but this is pretty simple so we don't need to add extra
+        // vars to save a scrolling "start" time to have a delta / deal with posible increments during the scrolling
+        // itself (restar timer) Anyway it should not be complicated to add but this approach is small, simple, can be
+        // user or not and works pretty well
+        //
+        window->ScrollExpected[axis] = IM_ROUND(ImMax(window->ScrollExpected[axis], 0.0f));
         if (!window->Collapsed && !window->SkipItems)
-            scroll[axis] = ImMin(scroll[axis], window->ScrollMax[axis]);
+            window->ScrollExpected[axis] = ImMin(window->ScrollExpected[axis], window->ScrollMax[axis]);
+        ImGuiContext& g = *GImGui;
+        ImGuiStyle& style = g.Style;
+        if (scroll[axis] != window->ScrollExpected[axis])
+        {
+            const float multiplier = GImGui->IO.DeltaTime / (1.0f / 60.0f);
+            const float diff = window->ScrollExpected[axis] - scroll[axis];
+            if (diff > 0)
+                scroll[axis] += ImMin(diff, (diff / (style.ScrollSmooth * multiplier)));
+            else
+                scroll[axis] -= ImMin(-diff, (-diff / (style.ScrollSmooth * multiplier)));
+
+            scroll[axis] = window->Appearing ? window->ScrollExpected[axis] : scroll[axis];
+        }
     }
     return scroll;
 }
@@ -10858,13 +10896,13 @@ ImVec2 ImGui::ScrollToRectEx(ImGuiWindow* window, const ImRect& item_rect, ImGui
 float ImGui::GetScrollX()
 {
     ImGuiWindow* window = GImGui->CurrentWindow;
-    return window->Scroll.x;
+    return window->ScrollExpected.x;
 }
 
 float ImGui::GetScrollY()
 {
     ImGuiWindow* window = GImGui->CurrentWindow;
-    return window->Scroll.y;
+    return window->ScrollExpected.y;
 }
 
 float ImGui::GetScrollMaxX()

dep/imgui/src/imgui_widgets.cpp

@@ -933,9 +933,9 @@ void ImGui::Scrollbar(ImGuiAxis axis)
     }
     float size_visible = window->InnerRect.Max[axis] - window->InnerRect.Min[axis];
     float size_contents = window->ContentSize[axis] + window->WindowPadding[axis] * 2.0f;
-    ImS64 scroll = (ImS64)window->Scroll[axis];
+    ImS64 scroll = (ImS64)window->ScrollExpected[axis];
     ScrollbarEx(bb, id, axis, &scroll, (ImS64)size_visible, (ImS64)size_contents, rounding_corners);
-    window->Scroll[axis] = (float)scroll;
+    window->ScrollExpected[axis] = (float)scroll;
 }
 
 // Vertical/Horizontal scrollbar

src/core/fullscreen_ui.cpp

@@ -571,6 +571,7 @@ bool FullscreenUI::Initialize()
     return false;
 
   ImGuiFullscreen::SetTheme(Host::GetBaseBoolSettingValue("Main", "UseLightFullscreenUITheme", false));
+  ImGuiFullscreen::SetSmoothScrolling(Host::GetBaseBoolSettingValue("Main", "FullscreenUISmoothScrolling", true));
   ImGuiFullscreen::UpdateLayoutScale();
 
   if (!ImGuiManager::AddFullscreenFontsIfMissing() || !ImGuiFullscreen::Initialize("images/placeholder.png") ||
@@ -3114,6 +3115,13 @@ void FullscreenUI::DrawInterfaceSettingsPage()
     ImGuiFullscreen::SetTheme(bsi->GetBoolValue("Main", "UseLightFullscreenUITheme", false));
   }
 
+  if (DrawToggleSetting(bsi, FSUI_ICONSTR(ICON_FA_LIST, "Smooth Scrolling"),
+                        FSUI_CSTR("Enables smooth scrolling of menus in Big Picture UI."), "Main",
+                        "FullscreenUISmoothScrolling", true))
+  {
+    ImGuiFullscreen::SetSmoothScrolling(bsi->GetBoolValue("Main", "FullscreenUISmoothScrolling", false));
+  }
+
   {
     // Have to do this the annoying way, because it's host-derived.
     const auto language_list = Host::GetAvailableLanguageList();
@@ -7386,6 +7394,7 @@ TRANSLATE_NOOP("FullscreenUI", "Enables alignment and bus exceptions. Not needed
 TRANSLATE_NOOP("FullscreenUI", "Enables an additional 6MB of RAM to obtain a total of 2+6 = 8MB, usually present on dev consoles.");
 TRANSLATE_NOOP("FullscreenUI", "Enables an additional three controller slots on each port. Not supported in all games.");
 TRANSLATE_NOOP("FullscreenUI", "Enables more precise frame pacing at the cost of battery life.");
+TRANSLATE_NOOP("FullscreenUI", "Enables smooth scrolling of menus in Big Picture UI.");
 TRANSLATE_NOOP("FullscreenUI", "Enables the older, less accurate MDEC decoding routines. May be required for old replacement backgrounds to match/load.");
 TRANSLATE_NOOP("FullscreenUI", "Enables the replacement of background textures in supported games.");
 TRANSLATE_NOOP("FullscreenUI", "Encore Mode");
@@ -7709,6 +7718,7 @@ TRANSLATE_NOOP("FullscreenUI", "Simulates the system ahead of time and rolls bac
 TRANSLATE_NOOP("FullscreenUI", "Skip Duplicate Frame Display");
 TRANSLATE_NOOP("FullscreenUI", "Skips the presentation/display of frames that are not unique. Can result in worse frame pacing.");
 TRANSLATE_NOOP("FullscreenUI", "Slow Boot");
+TRANSLATE_NOOP("FullscreenUI", "Smooth Scrolling");
 TRANSLATE_NOOP("FullscreenUI", "Smooths out blockyness between colour transitions in 24-bit content, usually FMVs.");
 TRANSLATE_NOOP("FullscreenUI", "Smooths out the blockiness of magnified textures on 2D objects.");
 TRANSLATE_NOOP("FullscreenUI", "Smooths out the blockiness of magnified textures on 3D objects.");

src/util/imgui_fullscreen.cpp

@@ -41,6 +41,7 @@ namespace ImGuiFullscreen {
 using MessageDialogCallbackVariant = std::variant<InfoMessageDialogCallback, ConfirmMessageDialogCallback>;
 
 static constexpr float MENU_BACKGROUND_ANIMATION_TIME = 0.5f;
+static constexpr float SMOOTH_SCROLLING_SPEED = 3.5f;
 
 static std::optional<RGBA8Image> LoadTextureImage(std::string_view path);
 static std::shared_ptr<GPUTexture> UploadTexture(std::string_view path, const RGBA8Image& image);
@@ -90,6 +91,7 @@ static u32 s_menu_button_index = 0;
 static u32 s_close_button_state = 0;
 static FocusResetType s_focus_reset_queued = FocusResetType::None;
 static bool s_light_theme = false;
+static bool s_smooth_scrolling = false;
 
 static LRUCache<std::string, std::shared_ptr<GPUTexture>> s_texture_cache(128, true);
 static std::shared_ptr<GPUTexture> s_placeholder_texture;
@@ -275,6 +277,11 @@ void ImGuiFullscreen::Shutdown()
   s_message_dialog_callback = {};
 }
 
+void ImGuiFullscreen::SetSmoothScrolling(bool enabled)
+{
+  s_smooth_scrolling = enabled;
+}
+
 const std::shared_ptr<GPUTexture>& ImGuiFullscreen::GetPlaceholderTexture()
 {
   return s_placeholder_texture;
@@ -763,6 +770,7 @@ bool ImGuiFullscreen::BeginFullscreenWindow(const ImVec2& position, const ImVec2
   ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, LayoutScale(padding));
   ImGui::PushStyleVar(ImGuiStyleVar_WindowBorderSize, 0.0f);
   ImGui::PushStyleVar(ImGuiStyleVar_WindowRounding, LayoutScale(rounding));
+  ImGui::PushStyleVar(ImGuiStyleVar_ScrollSmooth, s_smooth_scrolling ? SMOOTH_SCROLLING_SPEED : 1.0f);
 
   return ImGui::Begin(name, nullptr,
                       ImGuiWindowFlags_NoTitleBar | ImGuiWindowFlags_NoCollapse | ImGuiWindowFlags_NoResize |
@@ -772,7 +780,7 @@ bool ImGuiFullscreen::BeginFullscreenWindow(const ImVec2& position, const ImVec2
 void ImGuiFullscreen::EndFullscreenWindow()
 {
   ImGui::End();
-  ImGui::PopStyleVar(3);
+  ImGui::PopStyleVar(4);
   ImGui::PopStyleColor();
 }
 

src/util/imgui_fullscreen.h

@@ -120,6 +120,7 @@ ImRect CenterImage(const ImRect& fit_rect, const ImVec2& image_size);
 bool Initialize(const char* placeholder_image_path);
 
 void SetTheme(bool light);
+void SetSmoothScrolling(bool enabled);
 void SetFonts(ImFont* medium_font, ImFont* large_font);
 bool UpdateLayoutScale();