Tooltips: Tweak default offset for non-drag and drop tooltips.

docs/CHANGELOG.txt

@@ -41,6 +41,8 @@ Other changes:
 - Clipper: Rework inner logic to allow functioning with a zero-clear constructor.
   This is order to facilitate usage for language bindings (e.g cimgui or dear_binding)
   where user may not be callinga constructor manually. (#5856)
+- Tooltips: Tweak default offset for non-drag and drop tooltips so underlying items
+  isn't covered as much. (Match offset for drag and drop tooltips)
 - Debug Tools: Added 'io.ConfigDebugIniSettings' option to save .ini data with extra
   comments. Currently mainly for inspecting Docking .ini data, but makes saving slower.
 - Backends: OpenGL3: Fixed support for glBindSampler() backup/restore on ES3. (#6375, #6508) [@jsm174]

imgui.cpp

@@ -993,6 +993,9 @@ static const float WINDOWS_HOVER_PADDING                    = 4.0f;     // Exten
 static const float WINDOWS_RESIZE_FROM_EDGES_FEEDBACK_TIMER = 0.04f;    // Reduce visual noise by only highlighting the border after a certain time.
 static const float WINDOWS_MOUSE_WHEEL_SCROLL_LOCK_TIMER    = 0.70f;    // Lock scrolled window (so it doesn't pick child windows that are scrolling through) for a certain time, unless mouse moved.
 
+// Tooltip offset
+static const ImVec2 TOOLTIP_DEFAULT_OFFSET = ImVec2(16, 10);            // Multiplied by g.Style.MouseCursorScale
+
 //-------------------------------------------------------------------------
 // [SECTION] FORWARD DECLARATIONS
 //-------------------------------------------------------------------------
@@ -10050,11 +10053,13 @@ bool ImGui::BeginTooltipEx(ImGuiTooltipFlags tooltip_flags, ImGuiWindowFlags ext
 
     if (g.DragDropWithinSource || g.DragDropWithinTarget)
     {
-        // The default tooltip position is a little offset to give space to see the context menu (it's also clamped within the current viewport/monitor)
+        // Drag and Drop tooltips are positioning differently than other tooltips:
-        // In the context of a dragging tooltip we try to reduce that offset and we enforce following the cursor.
+        // - offset visibility to increase visibility around mouse.
-        // Whatever we do we want to call SetNextWindowPos() to enforce a tooltip position and disable clipping the tooltip without our display area, like regular tooltip do.
+        // - never clamp within outer viewport boundary.
+        // We call SetNextWindowPos() to enforce position and disable clamping.
+        // See FindBestWindowPosForPopup() for positionning logic of other tooltips (not drag and drop ones).
         //ImVec2 tooltip_pos = g.IO.MousePos - g.ActiveIdClickOffset - g.Style.WindowPadding;
-        ImVec2 tooltip_pos = g.IO.MousePos + ImVec2(16 * g.Style.MouseCursorScale, 8 * g.Style.MouseCursorScale);
+        ImVec2 tooltip_pos = g.IO.MousePos + TOOLTIP_DEFAULT_OFFSET * g.Style.MouseCursorScale;
         SetNextWindowPos(tooltip_pos);
         SetNextWindowBgAlpha(g.Style.Colors[ImGuiCol_PopupBg].w * 0.60f);
         //PushStyleVar(ImGuiStyleVar_Alpha, g.Style.Alpha * 0.60f); // This would be nice but e.g ColorButton with checkboard has issue with transparent colors :(
@@ -10625,15 +10630,20 @@ ImVec2 ImGui::FindBestWindowPosForPopup(ImGuiWindow* window)
     }
     if (window->Flags & ImGuiWindowFlags_Tooltip)
     {
-        // Position tooltip (always follows mouse)
+        // Position tooltip (always follows mouse + clamp within outer boundaries)
-        float sc = g.Style.MouseCursorScale;
+        // Note that drag and drop tooltips are NOT using this path: BeginTooltipEx() manually sets their position.
-        ImVec2 ref_pos = NavCalcPreferredRefPos();
+        // In theory we could handle both cases in same location, but requires a bit of shuffling as drag and drop tooltips are calling SetWindowPos() leading to 'window_pos_set_by_api' being set in Begin()
+        IM_ASSERT(g.CurrentWindow == window);
+        const float scale = g.Style.MouseCursorScale;
+        const ImVec2 ref_pos = NavCalcPreferredRefPos();
+        const ImVec2 tooltip_pos = ref_pos + TOOLTIP_DEFAULT_OFFSET * scale;
         ImRect r_avoid;
         if (!g.NavDisableHighlight && g.NavDisableMouseHover && !(g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableSetMousePos))
             r_avoid = ImRect(ref_pos.x - 16, ref_pos.y - 8, ref_pos.x + 16, ref_pos.y + 8);
         else
-            r_avoid = ImRect(ref_pos.x - 16, ref_pos.y - 8, ref_pos.x + 24 * sc, ref_pos.y + 24 * sc); // FIXME: Hard-coded based on mouse cursor shape expectation. Exact dimension not very important.
+            r_avoid = ImRect(ref_pos.x - 16, ref_pos.y - 8, ref_pos.x + 24 * scale, ref_pos.y + 24 * scale); // FIXME: Hard-coded based on mouse cursor shape expectation. Exact dimension not very important.
-        return FindBestWindowPosForPopupEx(ref_pos, window->Size, &window->AutoPosLastDirection, r_outer, r_avoid, ImGuiPopupPositionPolicy_Tooltip);
+        //GetForegroundDrawList()->AddRect(r_avoid.Min, r_avoid.Max, IM_COL32(255, 0, 255, 255));
+        return FindBestWindowPosForPopupEx(tooltip_pos, window->Size, &window->AutoPosLastDirection, r_outer, r_avoid, ImGuiPopupPositionPolicy_Tooltip);
     }
     IM_ASSERT(0);
     return window->Pos;