From d4495446d5330cd9737ab2594cc0fab5b96eca3c Mon Sep 17 00:00:00 2001 From: ocornut Date: Fri, 3 May 2024 18:04:07 +0200 Subject: [PATCH] Windows, Internal: added experimental SkipRefresh mode. (#3515, #4763, #7556, #5116 , #4076, #2749, #2268) currently: ImGui::SetNextWindowRefreshPolicy(ImGuiWindowRefreshFlags_TryToAvoidRefresh); - This is NOT meant to replace frame-wide/app-wide idle mode. - This is another tool: the idea that a given window could avoid refresh and reuse last frame contents. - I think it needs to be backed by a careful and smart design overall (refresh policy, load balancing, making it easy and obvious to user). - It's not there yet, this is currently a toy for experimenting. My other issues with this: - It appears to be very simple, but skipping most of Begin() logic will inevitably lead to tricky/confusing bugs. Let's see how it goes. - I don't like very much that this opens a door to varying inconsistencies - I don't like very much that it can lead us to situation where the lazy refresh gets disabled in bulk due to some reason (e.g. resizing a dock space) and we get sucked in the temptation to update for idle rather than update for dynamism. --- imgui.cpp | 60 ++++++++++++++++++++++++++++++++++++++++++++---- imgui_demo.cpp | 5 ++++ imgui_draw.cpp | 1 + imgui_internal.h | 17 ++++++++++++++ 4 files changed, 79 insertions(+), 4 deletions(-) diff --git a/imgui.cpp b/imgui.cpp index 750c9c923..17c304b48 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -6334,6 +6334,30 @@ void ImGui::UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags } } +// [EXPERIMENTAL] Called by Begin(). NextWindowData is valid at this point. +// This is designed as a toy/test-bed for +void ImGui::UpdateWindowSkipRefresh(ImGuiWindow* window) +{ + ImGuiContext& g = *GImGui; + window->SkipRefresh = false; + if ((g.NextWindowData.Flags & ImGuiNextWindowDataFlags_HasRefreshPolicy) == 0) + return; + if (g.NextWindowData.RefreshFlagsVal & ImGuiWindowRefreshFlags_TryToAvoidRefresh) + { + // FIXME-IDLE: Tests for e.g. mouse clicks or keyboard while focused. + if (window->Appearing) // If currently appearing + return; + if (window->Hidden) // If was hidden (previous frame) + return; + if ((g.NextWindowData.RefreshFlagsVal & ImGuiWindowRefreshFlags_RefreshOnHover) && g.HoveredWindow && window->RootWindow == g.HoveredWindow->RootWindow) + return; + if ((g.NextWindowData.RefreshFlagsVal & ImGuiWindowRefreshFlags_RefreshOnFocus) && g.NavWindow && window->RootWindow == g.NavWindow->RootWindow) + return; + window->DrawList = NULL; + window->SkipRefresh = true; + } +} + // When a modal popup is open, newly created windows that want focus (i.e. are not popups and do not specify ImGuiWindowFlags_NoFocusOnAppearing) // should be positioned behind that modal window, unless the window was created inside the modal begin-stack. // In case of multiple stacked modals newly created window honors begin stack order and does not go below its own modal parent. @@ -6532,11 +6556,14 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags) if (window->Appearing) SetWindowConditionAllowFlags(window, ImGuiCond_Appearing, false); + // [EXPERIMENTAL] Skip Refresh mode + UpdateWindowSkipRefresh(window); + // We intentionally set g.CurrentWindow to NULL to prevent usage until when the viewport is set, then will call SetCurrentWindow() g.CurrentWindow = NULL; // When reusing window again multiple times a frame, just append content (don't need to setup again) - if (first_begin_of_the_frame) + if (first_begin_of_the_frame && !window->SkipRefresh) { // Initialize const bool window_is_child_tooltip = (flags & ImGuiWindowFlags_ChildWindow) && (flags & ImGuiWindowFlags_Tooltip); // FIXME-WIP: Undocumented behavior of Child+Tooltip for pinned tooltip (#1345) @@ -7027,12 +7054,17 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags) } else { + // Skip refresh always mark active + if (window->SkipRefresh) + window->Active = true; + // Append SetCurrentWindow(window); SetLastItemDataForWindow(window, window->TitleBarRect()); } - PushClipRect(window->InnerClipRect.Min, window->InnerClipRect.Max, true); + if (!window->SkipRefresh) + PushClipRect(window->InnerClipRect.Min, window->InnerClipRect.Max, true); // Clear 'accessed' flag last thing (After PushClipRect which will set the flag. We want the flag to stay false when the default "Debug" window is unused) window->WriteAccessed = false; @@ -7040,7 +7072,7 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags) g.NextWindowData.ClearFlags(); // Update visibility - if (first_begin_of_the_frame) + if (first_begin_of_the_frame && !window->SkipRefresh) { if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & ImGuiWindowFlags_ChildMenu)) { @@ -7086,6 +7118,11 @@ bool ImGui::Begin(const char* name, bool* p_open, ImGuiWindowFlags flags) skip_items = true; window->SkipItems = skip_items; } + else if (first_begin_of_the_frame) + { + // Skip refresh mode + window->SkipItems = true; + } // [DEBUG] io.ConfigDebugBeginReturnValue override return value to test Begin/End and BeginChild/EndChild behaviors. // (The implicit fallback window is NOT automatically ended allowing it to always be able to receive commands without crashing) @@ -7128,9 +7165,16 @@ void ImGui::End() // Close anything that is open if (window->DC.CurrentColumns) EndColumns(); - PopClipRect(); // Inner window clip rectangle + if (!window->SkipRefresh) + PopClipRect(); // Inner window clip rectangle PopFocusScope(); + if (window->SkipRefresh) + { + IM_ASSERT(window->DrawList == NULL); + window->DrawList = &window->DrawListInst; + } + // Stop logging if (!(window->Flags & ImGuiWindowFlags_ChildWindow)) // FIXME: add more options for scope of logging LogFinish(); @@ -7815,6 +7859,14 @@ void ImGui::SetNextWindowBgAlpha(float alpha) g.NextWindowData.BgAlphaVal = alpha; } +// This is experimental and meant to be a toy for exploring a future/wider range of features. +void ImGui::SetNextWindowRefreshPolicy(ImGuiWindowRefreshFlags flags) +{ + ImGuiContext& g = *GImGui; + g.NextWindowData.Flags |= ImGuiNextWindowDataFlags_HasRefreshPolicy; + g.NextWindowData.RefreshFlagsVal = flags; +} + ImDrawList* ImGui::GetWindowDrawList() { ImGuiWindow* window = GetCurrentWindow(); diff --git a/imgui_demo.cpp b/imgui_demo.cpp index 943f4c4a5..1e261981e 100644 --- a/imgui_demo.cpp +++ b/imgui_demo.cpp @@ -10,6 +10,11 @@ // Read top of imgui.cpp and imgui.h for many details, documentation, comments, links. // Get the latest version at https://github.com/ocornut/imgui +// How to easily locate code? +// - Use the Item Picker to debug break in code by clicking any widgets: https://github.com/ocornut/imgui/wiki/Debug-Tools +// - Browse an online version the demo with code linked to hovered widgets: https://pthom.github.io/imgui_manual_online/manual/imgui_manual.html +// - Find a visible string and search for it in the code! + //--------------------------------------------------- // PLEASE DO NOT REMOVE THIS FILE FROM YOUR PROJECT! //--------------------------------------------------- diff --git a/imgui_draw.cpp b/imgui_draw.cpp index 7861d4e2d..47bdfaa58 100644 --- a/imgui_draw.cpp +++ b/imgui_draw.cpp @@ -385,6 +385,7 @@ void ImDrawListSharedData::SetCircleTessellationMaxError(float max_error) } // Initialize before use in a new frame. We always have a command ready in the buffer. +// In the majority of cases, you would want to call PushClipRect() and PushTextureID() after this. void ImDrawList::_ResetForNewFrame() { // Verify that the ImDrawCmd fields we want to memcmp() are contiguous in memory. diff --git a/imgui_internal.h b/imgui_internal.h index 36abab3f9..27f14baea 100644 --- a/imgui_internal.h +++ b/imgui_internal.h @@ -182,6 +182,7 @@ typedef int ImGuiSeparatorFlags; // -> enum ImGuiSeparatorFlags_ // F typedef int ImGuiTextFlags; // -> enum ImGuiTextFlags_ // Flags: for TextEx() typedef int ImGuiTooltipFlags; // -> enum ImGuiTooltipFlags_ // Flags: for BeginTooltipEx() typedef int ImGuiTypingSelectFlags; // -> enum ImGuiTypingSelectFlags_ // Flags: for GetTypingSelectRequest() +typedef int ImGuiWindowRefreshFlags; // -> enum ImGuiWindowRefreshFlags_ // Flags: for SetNextWindowRefreshPolicy() typedef void (*ImGuiErrorLogCallback)(void* user_data, const char* fmt, ...); @@ -1117,6 +1118,15 @@ struct IMGUI_API ImGuiInputTextState }; +enum ImGuiWindowRefreshFlags_ +{ + ImGuiWindowRefreshFlags_None = 0, + ImGuiWindowRefreshFlags_TryToAvoidRefresh = 1 << 0, // [EXPERIMENTAL] Try to keep existing contents, USER MUST NOT HONOR BEGIN() RETURNING FALSE AND NOT APPEND. + ImGuiWindowRefreshFlags_RefreshOnHover = 1 << 1, // [EXPERIMENTAL] Always refresh on hover + ImGuiWindowRefreshFlags_RefreshOnFocus = 1 << 2, // [EXPERIMENTAL] Always refresh on focus + // Refresh policy/frequency, Load Balancing etc. +}; + enum ImGuiNextWindowDataFlags_ { ImGuiNextWindowDataFlags_None = 0, @@ -1129,6 +1139,7 @@ enum ImGuiNextWindowDataFlags_ ImGuiNextWindowDataFlags_HasBgAlpha = 1 << 6, ImGuiNextWindowDataFlags_HasScroll = 1 << 7, ImGuiNextWindowDataFlags_HasChildFlags = 1 << 8, + ImGuiNextWindowDataFlags_HasRefreshPolicy = 1 << 9, }; // Storage for SetNexWindow** functions @@ -1150,6 +1161,7 @@ struct ImGuiNextWindowData void* SizeCallbackUserData; float BgAlphaVal; // Override background alpha ImVec2 MenuBarOffsetMinVal; // (Always on) This is not exposed publicly, so we don't clear it and it doesn't have a corresponding flag (could we? for consistency?) + ImGuiWindowRefreshFlags RefreshFlagsVal; ImGuiNextWindowData() { memset(this, 0, sizeof(*this)); } inline void ClearFlags() { Flags = ImGuiNextWindowDataFlags_None; } @@ -2534,6 +2546,7 @@ struct IMGUI_API ImGuiWindow bool Collapsed; // Set when collapsing window to become only title-bar bool WantCollapseToggle; bool SkipItems; // Set when items can safely be all clipped (e.g. window not visible or collapsed) + bool SkipRefresh; // [EXPERIMENTAL] Reuse previous frame drawn contents, Begin() returns false. bool Appearing; // Set during the frame where the window is appearing (or re-appearing) bool Hidden; // Do not display (== HiddenFrames*** > 0) bool IsFallbackWindow; // Set on the "Debug##Default" window. @@ -3007,6 +3020,7 @@ namespace ImGui IMGUI_API ImGuiWindow* FindWindowByID(ImGuiID id); IMGUI_API ImGuiWindow* FindWindowByName(const char* name); IMGUI_API void UpdateWindowParentAndRootLinks(ImGuiWindow* window, ImGuiWindowFlags flags, ImGuiWindow* parent_window); + IMGUI_API void UpdateWindowSkipRefresh(ImGuiWindow* window); IMGUI_API ImVec2 CalcWindowNextAutoFitSize(ImGuiWindow* window); IMGUI_API bool IsWindowChildOf(ImGuiWindow* window, ImGuiWindow* potential_parent, bool popup_hierarchy); IMGUI_API bool IsWindowWithinBeginStackOf(ImGuiWindow* window, ImGuiWindow* potential_parent); @@ -3032,6 +3046,9 @@ namespace ImGui IMGUI_API int FindWindowDisplayIndex(ImGuiWindow* window); IMGUI_API ImGuiWindow* FindBottomMostVisibleWindowWithinBeginStack(ImGuiWindow* window); + // Windows: Idle, Refresh Policies [EXPERIMENTAL] + IMGUI_API void SetNextWindowRefreshPolicy(ImGuiWindowRefreshFlags flags); + // Fonts, drawing IMGUI_API void SetCurrentFont(ImFont* font); inline ImFont* GetDefaultFont() { ImGuiContext& g = *GImGui; return g.IO.FontDefault ? g.IO.FontDefault : g.IO.Fonts->Fonts[0]; }