From 98d52b7b26cccae5d3523bbefddbcb8da627e130 Mon Sep 17 00:00:00 2001 From: ocornut Date: Fri, 11 Oct 2024 13:29:13 +0200 Subject: [PATCH] DrawList: AddCallback() added an optional size parameter allowing to copy and store any amount of user data for usage by callbacks: (#6969, #4770, #7665) --- docs/CHANGELOG.txt | 8 ++++++++ docs/TODO.txt | 5 ++--- imgui.h | 23 ++++++++++++++++++----- imgui_draw.cpp | 30 ++++++++++++++++++++++++++++-- 4 files changed, 56 insertions(+), 10 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index 427086625..4fda69c0e 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -60,6 +60,14 @@ Other changes: - IO: added 'void* platform_io.Renderer_RenderState' which is set during the ImGui_ImplXXXX_RenderDrawData() of standard backend to expose selected render state to draw callbacks. (#6969, #5834, #7468, #3590) +- DrawList: AddCallback() added an optional size parameter allowing to copy and + store any amount of user data for usage by callbacks: (#6969, #4770, #7665) + - If userdata_size == 0: we copy/store the 'userdata' argument as-is (existing behavior). + It will be available unmodified in ImDrawCmd::UserCallbackData during render. + - If userdata_size > 0, we copy/store 'userdata_size' bytes pointed to by 'userdata' (new behavior). + We store them in a buffer stored inside the drawlist. ImDrawCmd::UserCallbackData + will point inside that buffer so you have to retrieve data from there. Your callback + may need to use ImDrawCmd::UserCallbackDataSize if you expect dynamically-sized data. - Tables: fixed initial auto-sizing issue with synched-instances. (#8045, #7218) - InputText: fixed an issue with not declaring ownership of Delete/Backspace/Arrow keys, preventing use of external shortcuts not guarded by an ActiveId check. (#8048) [@geertbleyen] diff --git a/docs/TODO.txt b/docs/TODO.txt index ddceb3b3d..e61501d78 100644 --- a/docs/TODO.txt +++ b/docs/TODO.txt @@ -9,8 +9,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i - doc: add a proper documentation system (maybe relying on automation? #435) - doc: checklist app to verify backends/integration of imgui (test inputs, rendering, callback, etc.). - doc/tips: tips of the day: website? applet in imgui_club? - - doc/wiki: work on the wiki https://github.com/ocornut/imgui/wiki - + - window: preserve/restore relative focus ordering (persistent or not), and e.g. of multiple reappearing windows (#2304) -> also see docking reference to same #. - window: calling SetNextWindowSize() every frame with <= 0 doesn't do anything, may be useful to allow (particularly when used for a single axis). (#690) - window: add a way for very transient windows (non-saved, temporary overlay over hundreds of objects) to "clean" up from the global window list. perhaps a lightweight explicit cleanup pass. @@ -44,7 +43,7 @@ It's mostly a bunch of personal notes, probably incomplete. Feel free to query i - drawlist: maintaining bounding box per command would allow to merge draw command when clipping isn't relied on (typical non-scrolling window or non-overflowing column would merge with previous command). (WIP branch) - drawlist: make it easier to toggle AA per primitive, so we can use e.g. non-AA fill + AA borders more naturally - drawlist: non-AA strokes have gaps between points (#593, #288), glitch especially on RenderCheckmark() and ColorPicker4(). - - drawlist: callback: add an extra void* in ImDrawCallback to allow passing render-local data to the callback (would break API). + - drawlist: callback: add an extra void* in ImDrawCallback to expose render state instead of pulling from Renderer_RenderState (would break API). - drawlist: AddRect vs AddLine position confusing (#2441) - drawlist/opt: store rounded corners in texture to use 1 quad per corner (filled and wireframe) to lower the cost of rounding. (#1962) - drawlist/opt: AddRect() axis aligned pixel aligned (no-aa) could use 8 triangles instead of 16 and no normal calculation. diff --git a/imgui.h b/imgui.h index 8cda26dea..d18879ce1 100644 --- a/imgui.h +++ b/imgui.h @@ -29,7 +29,7 @@ // Library Version // (Integer encoded as XYYZZ for use in #if preprocessor conditionals, e.g. '#if IMGUI_VERSION_NUM >= 12345') #define IMGUI_VERSION "1.91.4 WIP" -#define IMGUI_VERSION_NUM 19132 +#define IMGUI_VERSION_NUM 19133 #define IMGUI_HAS_TABLE /* @@ -2953,9 +2953,11 @@ struct ImDrawCmd unsigned int IdxOffset; // 4 // Start offset in index buffer. unsigned int ElemCount; // 4 // Number of indices (multiple of 3) to be rendered as triangles. Vertices are stored in the callee ImDrawList's vtx_buffer[] array, indices in idx_buffer[]. ImDrawCallback UserCallback; // 4-8 // If != NULL, call the function instead of rendering the vertices. clip_rect and texture_id will be set normally. - void* UserCallbackData; // 4-8 // The draw callback code can access this. + void* UserCallbackData; // 4-8 // Callback user data (when UserCallback != NULL). If called AddCallback() with size == 0, this is a copy of the AddCallback() argument. If called AddCallback() with size > 0, this is pointing to a buffer where data is stored. + int UserCallbackDataSize; // 4 // Size of callback user data when using storage, otherwise 0. + int UserCallbackDataOffset;// 4 // [Internal] Offset of callback user data when using storage, otherwise -1. - ImDrawCmd() { memset(this, 0, sizeof(*this)); } // Also ensure our padding fields are zeroed + ImDrawCmd() { memset(this, 0, sizeof(*this)); } // Also ensure our padding fields are zeroed // Since 1.83: returns ImTextureID associated with this draw call. Warning: DO NOT assume this is always same as 'TextureId' (we will change this function for an upcoming feature) inline ImTextureID GetTexID() const { return TextureId; } @@ -3068,6 +3070,7 @@ struct ImDrawList ImDrawListSplitter _Splitter; // [Internal] for channels api (note: prefer using your own persistent instance of ImDrawListSplitter!) ImVector _ClipRectStack; // [Internal] ImVector _TextureIdStack; // [Internal] + ImVector _CallbacksDataBuf; // [Internal] float _FringeScale; // [Internal] anti-alias fringe is scaled by this value, this helps to keep things sharp while zooming at vertex buffer content const char* _OwnerName; // Pointer to owner window's name for debugging @@ -3140,8 +3143,18 @@ struct ImDrawList IMGUI_API void PathBezierQuadraticCurveTo(const ImVec2& p2, const ImVec2& p3, int num_segments = 0); // Quadratic Bezier (3 control points) IMGUI_API void PathRect(const ImVec2& rect_min, const ImVec2& rect_max, float rounding = 0.0f, ImDrawFlags flags = 0); - // Advanced - IMGUI_API void AddCallback(ImDrawCallback callback, void* callback_data); // Your rendering function must check for 'UserCallback' in ImDrawCmd and call the function instead of rendering triangles. + // Advanced: Draw Callbacks + // - May be used to alter render state (change sampler, blending, current shader). May be used to emit custom rendering commands (difficult to do correctly, but possible). + // - Use special ImDrawCallback_ResetRenderState callback to instruct backend to reset its render state to the default. + // - Your rendering loop must check for 'UserCallback' in ImDrawCmd and call the function instead of rendering triangles. All standard backends are honoring this. + // - For some backends, the callback may access selected render-states exposed by the backend in a ImGui_ImplXXXX_RenderState structure pointed to by platform_io.Renderer_RenderState. + // - IMPORTANT: please be mindful of the different level of indirection between using size==0 (copying argument) and using size>0 (copying pointed data into a buffer). + // - If userdata_size == 0: we copy/store the 'userdata' argument as-is. It will be available unmodified in ImDrawCmd::UserCallbackData during render. + // - If userdata_size > 0, we copy/store 'userdata_size' bytes pointed to by 'userdata'. We store them in a buffer stored inside the drawlist. ImDrawCmd::UserCallbackData will point inside that buffer so you have to retrieve data from there. Your callback may need to use ImDrawCmd::UserCallbackDataSize if you expect dynamically-sized data. + // - Support for userdata_size > 0 was added in v1.91.4, October 2024. So earlier code always only allowed to copy/store a simple void*. + IMGUI_API void AddCallback(ImDrawCallback callback, void* userdata, size_t userdata_size = 0); + + // Advanced: Miscellaneous IMGUI_API void AddDrawCmd(); // This is useful if you need to forcefully create a new draw call (to allow for dependent rendering / blending). Otherwise primitives are merged into the same draw-call as much as possible IMGUI_API ImDrawList* CloneOutput() const; // Create a clone of the CmdBuffer/IdxBuffer/VtxBuffer. diff --git a/imgui_draw.cpp b/imgui_draw.cpp index b69bc789f..efee2ec9c 100644 --- a/imgui_draw.cpp +++ b/imgui_draw.cpp @@ -414,6 +414,7 @@ void ImDrawList::_ResetForNewFrame() _IdxWritePtr = NULL; _ClipRectStack.resize(0); _TextureIdStack.resize(0); + _CallbacksDataBuf.resize(0); _Path.resize(0); _Splitter.Clear(); CmdBuffer.push_back(ImDrawCmd()); @@ -431,6 +432,7 @@ void ImDrawList::_ClearFreeMemory() _IdxWritePtr = NULL; _ClipRectStack.clear(); _TextureIdStack.clear(); + _CallbacksDataBuf.clear(); _Path.clear(); _Splitter.ClearFreeMemory(); } @@ -470,7 +472,7 @@ void ImDrawList::_PopUnusedDrawCmd() } } -void ImDrawList::AddCallback(ImDrawCallback callback, void* callback_data) +void ImDrawList::AddCallback(ImDrawCallback callback, void* userdata, size_t userdata_size) { IM_ASSERT_PARANOID(CmdBuffer.Size > 0); ImDrawCmd* curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1]; @@ -480,8 +482,26 @@ void ImDrawList::AddCallback(ImDrawCallback callback, void* callback_data) AddDrawCmd(); curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1]; } + curr_cmd->UserCallback = callback; - curr_cmd->UserCallbackData = callback_data; + if (userdata_size == 0) + { + // Store user data directly in command (no indirection) + curr_cmd->UserCallbackData = userdata; + curr_cmd->UserCallbackDataSize = 0; + curr_cmd->UserCallbackDataOffset = -1; + } + else + { + // Copy and store user data in a buffer + IM_ASSERT(userdata != NULL); + IM_ASSERT(userdata_size < (1u << 31)); + curr_cmd->UserCallbackData = NULL; // Will be resolved during Render() + curr_cmd->UserCallbackDataSize = (int)userdata_size; + curr_cmd->UserCallbackDataOffset = _CallbacksDataBuf.Size; + _CallbacksDataBuf.resize(_CallbacksDataBuf.Size + (int)userdata_size); + memcpy(_CallbacksDataBuf.Data + (size_t)curr_cmd->UserCallbackDataOffset, userdata, userdata_size); + } AddDrawCmd(); // Force a new command after us (see comment below) } @@ -2222,6 +2242,12 @@ void ImGui::AddDrawListToDrawDataEx(ImDrawData* draw_data, ImVector if (sizeof(ImDrawIdx) == 2) IM_ASSERT(draw_list->_VtxCurrentIdx < (1 << 16) && "Too many vertices in ImDrawList using 16-bit indices. Read comment above"); + // Resolve callback data pointers + if (draw_list->_CallbacksDataBuf.Size > 0) + for (ImDrawCmd& cmd : draw_list->CmdBuffer) + if (cmd.UserCallback != NULL && cmd.UserCallbackDataOffset != -1 && cmd.UserCallbackDataSize > 0) + cmd.UserCallbackData = draw_list->_CallbacksDataBuf.Data + cmd.UserCallbackDataOffset; + // Add to output list + records state in ImDrawData out_list->push_back(draw_list); draw_data->CmdListsCount++;