Tables, Dpi: added dummy g.DpiScale storage (to be altered in docking), using to scale tables border hit thickness.

+ Added note about how equivalent resize padding for windows (sourced from WINDOWS_HOVER_PADDING) would need further rework.

imgui.cpp

@@ -3811,6 +3811,7 @@ static void SetCurrentWindow(ImGuiWindow* window)
     ImGuiContext& g = *GImGui;
     g.CurrentWindow = window;
     g.CurrentTable = window && window->DC.CurrentTableIdx != -1 ? g.Tables.GetByIndex(window->DC.CurrentTableIdx) : NULL;
+    g.DpiScale = 1.0f; // FIXME-DPI: WIP this is modified in docking
     if (window)
     {
         g.FontSize = g.DrawListSharedData.FontSize = window->CalcFontSize();
@@ -4477,6 +4478,9 @@ void ImGui::UpdateHoveredWindowAndCaptureFlags()
 {
     ImGuiContext& g = *GImGui;
     ImGuiIO& io = g.IO;
+
+    // FIXME-DPI: This storage was added on 2021/03/31 for test engine, but if we want to multiply WINDOWS_HOVER_PADDING
+    // by DpiScale, we need to make this window-agnostic anyhow, maybe need storing inside ImGuiWindow.
     g.WindowsHoverPadding = ImMax(g.Style.TouchExtraPadding, ImVec2(WINDOWS_HOVER_PADDING, WINDOWS_HOVER_PADDING));
 
     // Find the window hovered by mouse:

imgui_internal.h

@@ -1942,6 +1942,7 @@ struct ImGuiContext
     ImFont*                 Font;                               // (Shortcut) == FontStack.empty() ? IO.Font : FontStack.back()
     float                   FontSize;                           // (Shortcut) == FontBaseSize * g.CurrentWindow->FontWindowScale == window->FontSize(). Text height for current window.
     float                   FontBaseSize;                       // (Shortcut) == IO.FontGlobalScale * Font->Scale * Font->FontSize. Base text height.
+    float                   DpiScale;                           // Current window DpiScale
     ImDrawListSharedData    DrawListSharedData;
     double                  Time;
     int                     FrameCount;
@@ -1967,7 +1968,7 @@ struct ImGuiContext
     ImVector<ImGuiWindowStackData> CurrentWindowStack;
     ImGuiStorage            WindowsById;                        // Map window's ImGuiID to ImGuiWindow*
     int                     WindowsActiveCount;                 // Number of unique windows submitted by frame
-    ImVec2                  WindowsHoverPadding;                // Padding around resizable windows for which hovering on counts as hovering the window == ImMax(style.TouchExtraPadding, WINDOWS_HOVER_PADDING)
+    ImVec2                  WindowsHoverPadding;                // Padding around resizable windows for which hovering on counts as hovering the window == ImMax(style.TouchExtraPadding, WINDOWS_HOVER_PADDING).
     ImGuiID                 DebugBreakInWindow;                 // Set to break in Begin() call.
     ImGuiWindow*            CurrentWindow;                      // Window being drawn into
     ImGuiWindow*            HoveredWindow;                      // Window the mouse is hovering. Will typically catch mouse inputs.
@@ -2268,7 +2269,7 @@ struct ImGuiContext
         Initialized = false;
         FontAtlasOwnedByContext = shared_font_atlas ? false : true;
         Font = NULL;
-        FontSize = FontBaseSize = 0.0f;
+        FontSize = FontBaseSize = DpiScale = 0.0f;
         IO.Fonts = shared_font_atlas ? shared_font_atlas : IM_NEW(ImFontAtlas)();
         Time = 0.0f;
         FrameCount = 0;

imgui_tables.cpp

@@ -1256,7 +1256,7 @@ void ImGui::TableUpdateBorders(ImGuiTable* table)
     // really problematic (whereas the actual visual will be displayed in EndTable() and using the current frame height).
     // Actual columns highlight/render will be performed in EndTable() and not be affected.
     ImGuiTableInstanceData* table_instance = TableGetInstanceData(table, table->InstanceCurrent);
-    const float hit_half_width = TABLE_RESIZE_SEPARATOR_HALF_THICKNESS;
+    const float hit_half_width = ImTrunc(TABLE_RESIZE_SEPARATOR_HALF_THICKNESS * g.DpiScale);
     const float hit_y1 = (table->FreezeRowsCount >= 1 ? table->OuterRect.Min.y : table->WorkRect.Min.y) + table->AngledHeadersHeight;
     const float hit_y2_body = ImMax(table->OuterRect.Max.y, hit_y1 + table_instance->LastOuterHeight - table->AngledHeadersHeight);
     const float hit_y2_head = hit_y1 + table_instance->LastTopHeadersRowHeight;
@@ -1433,7 +1433,7 @@ void    ImGui::EndTable()
     if (table->ResizedColumn != -1 && table->InstanceCurrent == table->InstanceInteracted)
     {
         ImGuiTableColumn* column = &table->Columns[table->ResizedColumn];
-        const float new_x2 = (g.IO.MousePos.x - g.ActiveIdClickOffset.x + TABLE_RESIZE_SEPARATOR_HALF_THICKNESS);
+        const float new_x2 = (g.IO.MousePos.x - g.ActiveIdClickOffset.x + ImTrunc(TABLE_RESIZE_SEPARATOR_HALF_THICKNESS * g.DpiScale));
         const float new_width = ImTrunc(new_x2 - column->MinX - table->CellSpacingX1 - table->CellPaddingX * 2.0f);
         table->ResizedColumnNextWidth = new_width;
     }
@@ -4041,7 +4041,7 @@ float ImGui::GetColumnNormFromOffset(const ImGuiOldColumns* columns, float offse
     return offset / (columns->OffMaxX - columns->OffMinX);
 }
 
-static const float COLUMNS_HIT_RECT_HALF_WIDTH = 4.0f;
+static const float COLUMNS_HIT_RECT_HALF_THICKNESS = 4.0f;
 
 static float GetDraggedColumnOffset(ImGuiOldColumns* columns, int column_index)
 {
@@ -4052,7 +4052,7 @@ static float GetDraggedColumnOffset(ImGuiOldColumns* columns, int column_index)
     IM_ASSERT(column_index > 0); // We are not supposed to drag column 0.
     IM_ASSERT(g.ActiveId == columns->ID + ImGuiID(column_index));
 
-    float x = g.IO.MousePos.x - g.ActiveIdClickOffset.x + COLUMNS_HIT_RECT_HALF_WIDTH - window->Pos.x;
+    float x = g.IO.MousePos.x - g.ActiveIdClickOffset.x + ImTrunc(COLUMNS_HIT_RECT_HALF_THICKNESS * g.DpiScale) - window->Pos.x;
     x = ImMax(x, ImGui::GetColumnOffset(column_index - 1) + g.Style.ColumnsMinSpacing);
     if ((columns->Flags & ImGuiOldColumnFlags_NoPreserveWidths))
         x = ImMin(x, ImGui::GetColumnOffset(column_index + 1) - g.Style.ColumnsMinSpacing);
@@ -4367,7 +4367,7 @@ void ImGui::EndColumns()
             ImGuiOldColumnData* column = &columns->Columns[n];
             float x = window->Pos.x + GetColumnOffset(n);
             const ImGuiID column_id = columns->ID + ImGuiID(n);
-            const float column_hit_hw = COLUMNS_HIT_RECT_HALF_WIDTH;
+            const float column_hit_hw = ImTrunc(COLUMNS_HIT_RECT_HALF_THICKNESS * g.DpiScale);
             const ImRect column_hit_rect(ImVec2(x - column_hit_hw, y1), ImVec2(x + column_hit_hw, y2));
             if (!ItemAdd(column_hit_rect, column_id, NULL, ImGuiItemFlags_NoNav))
                 continue;