Tweak comments (#768)

imgui.cpp

@@ -9116,10 +9116,10 @@ bool ImGui::IsRectVisible(const ImVec2& size)
     return window->ClipRect.Overlaps(ImRect(window->DC.CursorPos, window->DC.CursorPos + size));
 }
 
-bool ImGui::IsRectVisible(const ImVec2& a, const ImVec2& b)
+bool ImGui::IsRectVisible(const ImVec2& rect_min, const ImVec2& rect_max)
 {
     ImGuiWindow* window = GetCurrentWindowRead();
-    return window->ClipRect.Overlaps(ImRect(a, b));
+    return window->ClipRect.Overlaps(ImRect(rect_min, rect_max));
 }
 
 // Lock horizontal starting position + capture group bounding box into one "item" (so you can use IsItemHovered() or layout primitives such as SameLine() on whole group, etc.)

imgui.h

@@ -409,8 +409,8 @@ namespace ImGui
     IMGUI_API bool          IsRootWindowFocused();                                              // is current root window focused (root = top-most parent of a child, otherwise self)
     IMGUI_API bool          IsRootWindowOrAnyChildFocused();                                    // is current root window or any of its child (including current window) focused
     IMGUI_API bool          IsRootWindowOrAnyChildHovered();                                    // is current root window or any of its child (including current window) hovered and hoverable (not blocked by a popup)
-    IMGUI_API bool          IsRectVisible(const ImVec2& size);                                  // test if rectangle of given size starting from cursor pos is visible (not clipped). to perform coarse clipping on user's side (as an optimization)
+    IMGUI_API bool          IsRectVisible(const ImVec2& size);                                  // test if rectangle (of given size, starting from cursor position) is visible / not clipped.
-    IMGUI_API bool          IsRectVisible(const ImVec2& a, const ImVec2& b);                    // "
+    IMGUI_API bool          IsRectVisible(const ImVec2& rect_min, const ImVec2& rect_max);      // test if rectangle (in screen space) is visible / not clipped. to perform coarse clipping on user's side.
     IMGUI_API bool          IsPosHoveringAnyWindow(const ImVec2& pos);                          // is given position hovering any active imgui window
     IMGUI_API float         GetTime();
     IMGUI_API int           GetFrameCount();