diff --git a/imgui.h b/imgui.h index 8fcd5416..45f3aa7c 100644 --- a/imgui.h +++ b/imgui.h @@ -1874,19 +1874,21 @@ typedef void (*ImDrawCallback)(const ImDrawList* parent_list, const ImDrawCmd* c #define ImDrawCallback_ResetRenderState (ImDrawCallback)(-1) // Typically, 1 command = 1 GPU draw call (unless command is a callback) -// Pre 1.71 back-ends will typically ignore the VtxOffset/IdxOffset fields. When 'io.BackendFlags & ImGuiBackendFlags_RendererHasVtxOffset' -// is enabled, those fields allow us to render meshes larger than 64K vertices while keeping 16-bit indices. +// - VtxOffset/IdxOffset: When 'io.BackendFlags & ImGuiBackendFlags_RendererHasVtxOffset' is enabled, +// those fields allow us to render meshes larger than 64K vertices while keeping 16-bit indices. +// Pre-1.71 back-ends will typically ignore the VtxOffset/IdxOffset fields. +// - The ClipRect/TextureId/VtxOffset fields must be contiguous as we memcmp() them together (this is asserted for). struct ImDrawCmd { - 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[]. ImVec4 ClipRect; // 4*4 // Clipping rectangle (x1, y1, x2, y2). Subtract ImDrawData->DisplayPos to get clipping rectangle in "viewport" coordinates ImTextureID TextureId; // 4-8 // User-provided texture ID. Set by user in ImfontAtlas::SetTexID() for fonts or passed to Image*() functions. Ignore if never using images or multiple fonts atlas. - unsigned int VtxOffset; // 4 // Start offset in vertex buffer. Pre-1.71 or without ImGuiBackendFlags_RendererHasVtxOffset: always 0. With ImGuiBackendFlags_RendererHasVtxOffset: may be >0 to support meshes larger than 64K vertices with 16-bit indices. + unsigned int VtxOffset; // 4 // Start offset in vertex buffer. ImGuiBackendFlags_RendererHasVtxOffset: always 0, otherwise may be >0 to support meshes larger than 64K vertices with 16-bit indices. unsigned int IdxOffset; // 4 // Start offset in index buffer. Always equal to sum of ElemCount drawn so far. + 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. - ImDrawCmd() { ElemCount = 0; TextureId = (ImTextureID)NULL; VtxOffset = IdxOffset = 0; UserCallback = NULL; UserCallbackData = NULL; } + ImDrawCmd() { memset(this, 0, sizeof(*this)); } // Also ensure our padding fields are zeroed }; // Vertex index, default to 16-bit @@ -1977,17 +1979,17 @@ struct ImDrawList // [Internal, used while building lists] const ImDrawListSharedData* _Data; // Pointer to shared draw data (you can use ImGui::GetDrawListSharedData() to get the one from current ImGui context) const char* _OwnerName; // Pointer to owner window's name for debugging - unsigned int _VtxCurrentOffset; // [Internal] Always 0 unless 'Flags & ImDrawListFlags_AllowVtxOffset'. unsigned int _VtxCurrentIdx; // [Internal] Generally == VtxBuffer.Size unless we are past 64K vertices, in which case this gets reset to 0. ImDrawVert* _VtxWritePtr; // [Internal] point within VtxBuffer.Data after each add command (to avoid using the ImVector<> operators too much) ImDrawIdx* _IdxWritePtr; // [Internal] point within IdxBuffer.Data after each add command (to avoid using the ImVector<> operators too much) ImVector _ClipRectStack; // [Internal] ImVector _TextureIdStack; // [Internal] ImVector _Path; // [Internal] current path building + ImDrawCmd _CmdHeader; // [Internal] Template of active commands. Fields should match those of CmdBuffer.back(). ImDrawListSplitter _Splitter; // [Internal] for channels api (note: prefer using your own persistent instance of ImDrawListSplitter!) // If you want to create ImDrawList instances, pass them ImGui::GetDrawListSharedData() or create and use your own ImDrawListSharedData (so you can use ImDrawList without ImGui) - ImDrawList(const ImDrawListSharedData* shared_data) { _Data = shared_data; Flags = ImDrawListFlags_None; _VtxCurrentOffset = _VtxCurrentIdx = 0; _VtxWritePtr = NULL; _IdxWritePtr = NULL; _OwnerName = NULL; } + ImDrawList(const ImDrawListSharedData* shared_data) { _Data = shared_data; Flags = ImDrawListFlags_None; _VtxCurrentIdx = 0; _VtxWritePtr = NULL; _IdxWritePtr = NULL; _OwnerName = NULL; } ~ImDrawList() { ClearFreeMemory(); } IMGUI_API void PushClipRect(ImVec2 clip_rect_min, ImVec2 clip_rect_max, bool intersect_with_current_clip_rect = false); // Render-level scissoring. This is passed down to your render function but not used for CPU-side coarse clipping. Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling) diff --git a/imgui_draw.cpp b/imgui_draw.cpp index e3455812..43daede2 100644 --- a/imgui_draw.cpp +++ b/imgui_draw.cpp @@ -379,11 +379,17 @@ void ImDrawListSharedData::SetCircleSegmentMaxError(float max_error) // Initialize before use in a new frame. We always have a command ready in the buffer. void ImDrawList::ResetForNewFrame() { + // Verify that the ImDrawCmd fields we want to memcmp() are contiguous in memory. + // (those should be IM_STATIC_ASSERT() in theory but with our pre C++11 setup the whole check doesn't compile with GCC) + IM_ASSERT(IM_OFFSETOF(ImDrawCmd, ClipRect) == 0); + IM_ASSERT(IM_OFFSETOF(ImDrawCmd, TextureId) == sizeof(ImVec4)); + IM_ASSERT(IM_OFFSETOF(ImDrawCmd, VtxOffset) == sizeof(ImVec4) + sizeof(ImTextureID)); + CmdBuffer.resize(0); IdxBuffer.resize(0); VtxBuffer.resize(0); Flags = _Data->InitialFlags; - _VtxCurrentOffset = 0; + memset(&_CmdHeader, 0, sizeof(_CmdHeader)); _VtxCurrentIdx = 0; _VtxWritePtr = NULL; _IdxWritePtr = NULL; @@ -400,7 +406,6 @@ void ImDrawList::ClearFreeMemory() IdxBuffer.clear(); VtxBuffer.clear(); Flags = ImDrawListFlags_None; - _VtxCurrentOffset = 0; _VtxCurrentIdx = 0; _VtxWritePtr = NULL; _IdxWritePtr = NULL; @@ -420,16 +425,12 @@ ImDrawList* ImDrawList::CloneOutput() const return dst; } -// Using macros because C++ is a terrible language, we want guaranteed inline, no code in header, and no overhead in Debug builds -#define GetCurrentClipRect() (_ClipRectStack.Size ? _ClipRectStack.Data[_ClipRectStack.Size-1] : _Data->ClipRectFullscreen) -#define GetCurrentTextureId() (_TextureIdStack.Size ? _TextureIdStack.Data[_TextureIdStack.Size-1] : (ImTextureID)NULL) - void ImDrawList::AddDrawCmd() { ImDrawCmd draw_cmd; - draw_cmd.ClipRect = GetCurrentClipRect(); - draw_cmd.TextureId = GetCurrentTextureId(); - draw_cmd.VtxOffset = _VtxCurrentOffset; + draw_cmd.ClipRect = _CmdHeader.ClipRect; // Same as calling ImDrawCmd_HeaderCopy() + draw_cmd.TextureId = _CmdHeader.TextureId; + draw_cmd.VtxOffset = _CmdHeader.VtxOffset; draw_cmd.IdxOffset = IdxBuffer.Size; IM_ASSERT(draw_cmd.ClipRect.x <= draw_cmd.ClipRect.z && draw_cmd.ClipRect.y <= draw_cmd.ClipRect.w); @@ -450,68 +451,62 @@ void ImDrawList::AddCallback(ImDrawCallback callback, void* callback_data) AddDrawCmd(); // Force a new command after us (see comment below) } +// Compare ClipRect, TextureId and VtxOffset with a single memcmp() +#define ImDrawCmd_HeaderSize (IM_OFFSETOF(ImDrawCmd, VtxOffset) + sizeof(unsigned int)) +#define ImDrawCmd_HeaderCompare(CMD_LHS, CMD_RHS) (memcmp(CMD_LHS, CMD_RHS, ImDrawCmd_HeaderSize)) // Compare ClipRect, TextureId, VtxOffset +#define ImDrawCmd_HeaderCopy(CMD_DST, CMD_SRC) (memcpy(CMD_DST, CMD_SRC, ImDrawCmd_HeaderSize)) // Copy ClipRect, TextureId, VtxOffset + // Our scheme may appears a bit unusual, basically we want the most-common calls AddLine AddRect etc. to not have to perform any check so we always have a command ready in the stack. // The cost of figuring out if a new command has to be added or if we can merge is paid in those Update** functions only. void ImDrawList::UpdateClipRect() { // If current command is used with different settings we need to add a new command - const ImVec4 curr_clip_rect = GetCurrentClipRect(); ImDrawCmd* curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1]; - if ((curr_cmd->ElemCount != 0 && memcmp(&curr_cmd->ClipRect, &curr_clip_rect, sizeof(ImVec4)) != 0) || curr_cmd->UserCallback != NULL) + if ((curr_cmd->ElemCount != 0 && memcmp(&curr_cmd->ClipRect, &_CmdHeader.ClipRect, sizeof(ImVec4)) != 0) || curr_cmd->UserCallback != NULL) { AddDrawCmd(); return; } // Try to merge with previous command if it matches, else use current command - if (curr_cmd->ElemCount == 0 && CmdBuffer.Size > 1) + ImDrawCmd* prev_cmd = curr_cmd - 1; + if (curr_cmd->ElemCount == 0 && CmdBuffer.Size > 1 && ImDrawCmd_HeaderCompare(&_CmdHeader, prev_cmd) == 0 && prev_cmd->UserCallback == NULL) { - ImDrawCmd* prev_cmd = curr_cmd - 1; - if (memcmp(&prev_cmd->ClipRect, &curr_clip_rect, sizeof(ImVec4)) == 0 && prev_cmd->VtxOffset == _VtxCurrentOffset && prev_cmd->TextureId == GetCurrentTextureId() && prev_cmd->UserCallback == NULL) - { - CmdBuffer.pop_back(); - return; - } + CmdBuffer.pop_back(); + return; } - curr_cmd->ClipRect = curr_clip_rect; + curr_cmd->ClipRect = _CmdHeader.ClipRect; } void ImDrawList::UpdateTextureID() { // If current command is used with different settings we need to add a new command - const ImTextureID curr_texture_id = GetCurrentTextureId(); ImDrawCmd* curr_cmd = &CmdBuffer.Data[CmdBuffer.Size - 1]; - if ((curr_cmd->ElemCount != 0 && curr_cmd->TextureId != curr_texture_id) || curr_cmd->UserCallback != NULL) + if ((curr_cmd->ElemCount != 0 && curr_cmd->TextureId != _CmdHeader.TextureId) || curr_cmd->UserCallback != NULL) { AddDrawCmd(); return; } // Try to merge with previous command if it matches, else use current command - if (curr_cmd->ElemCount == 0 && CmdBuffer.Size > 1) + ImDrawCmd* prev_cmd = curr_cmd - 1; + if (curr_cmd->ElemCount == 0 && CmdBuffer.Size > 1 && ImDrawCmd_HeaderCompare(&_CmdHeader, prev_cmd) == 0 && prev_cmd->UserCallback == NULL) { - ImDrawCmd* prev_cmd = curr_cmd - 1; - if (prev_cmd->TextureId == curr_texture_id && memcmp(&prev_cmd->ClipRect, &GetCurrentClipRect(), sizeof(ImVec4)) == 0 && prev_cmd->VtxOffset == _VtxCurrentOffset && prev_cmd->UserCallback == NULL) - { - CmdBuffer.pop_back(); - return; - } + CmdBuffer.pop_back(); + return; } - curr_cmd->TextureId = curr_texture_id; + curr_cmd->TextureId = _CmdHeader.TextureId; } -#undef GetCurrentClipRect -#undef GetCurrentTextureId - // Render-level scissoring. This is passed down to your render function but not used for CPU-side coarse clipping. Prefer using higher-level ImGui::PushClipRect() to affect logic (hit-testing and widget culling) void ImDrawList::PushClipRect(ImVec2 cr_min, ImVec2 cr_max, bool intersect_with_current_clip_rect) { ImVec4 cr(cr_min.x, cr_min.y, cr_max.x, cr_max.y); - if (intersect_with_current_clip_rect && _ClipRectStack.Size) + if (intersect_with_current_clip_rect) { - ImVec4 current = _ClipRectStack.Data[_ClipRectStack.Size-1]; + ImVec4 current = _CmdHeader.ClipRect; if (cr.x < current.x) cr.x = current.x; if (cr.y < current.y) cr.y = current.y; if (cr.z > current.z) cr.z = current.z; @@ -521,6 +516,7 @@ void ImDrawList::PushClipRect(ImVec2 cr_min, ImVec2 cr_max, bool intersect_with_ cr.w = ImMax(cr.y, cr.w); _ClipRectStack.push_back(cr); + _CmdHeader.ClipRect = cr; UpdateClipRect(); } @@ -531,21 +527,22 @@ void ImDrawList::PushClipRectFullScreen() void ImDrawList::PopClipRect() { - IM_ASSERT(_ClipRectStack.Size > 0); _ClipRectStack.pop_back(); + _CmdHeader.ClipRect = (_ClipRectStack.Size == 0) ? _Data->ClipRectFullscreen : _ClipRectStack.Data[_ClipRectStack.Size - 1]; UpdateClipRect(); } void ImDrawList::PushTextureID(ImTextureID texture_id) { _TextureIdStack.push_back(texture_id); + _CmdHeader.TextureId = texture_id; UpdateTextureID(); } void ImDrawList::PopTextureID() { - IM_ASSERT(_TextureIdStack.Size > 0); _TextureIdStack.pop_back(); + _CmdHeader.TextureId = (_TextureIdStack.Size == 0) ? (ImTextureID)NULL : _TextureIdStack.Data[_TextureIdStack.Size - 1]; UpdateTextureID(); } @@ -558,7 +555,7 @@ void ImDrawList::PrimReserve(int idx_count, int vtx_count) IM_ASSERT_PARANOID(idx_count >= 0 && vtx_count >= 0); if (sizeof(ImDrawIdx) == 2 && (_VtxCurrentIdx + vtx_count >= (1 << 16)) && (Flags & ImDrawListFlags_AllowVtxOffset)) { - _VtxCurrentOffset = VtxBuffer.Size; + _CmdHeader.VtxOffset = VtxBuffer.Size; _VtxCurrentIdx = 0; AddDrawCmd(); } @@ -1235,9 +1232,9 @@ void ImDrawList::AddText(const ImFont* font, float font_size, const ImVec2& pos, if (font_size == 0.0f) font_size = _Data->FontSize; - IM_ASSERT(font->ContainerAtlas->TexID == _TextureIdStack.back()); // Use high-level ImGui::PushFont() or low-level ImDrawList::PushTextureId() to change font. + IM_ASSERT(font->ContainerAtlas->TexID == _CmdHeader.TextureId); // Use high-level ImGui::PushFont() or low-level ImDrawList::PushTextureId() to change font. - ImVec4 clip_rect = _ClipRectStack.back(); + ImVec4 clip_rect = _CmdHeader.ClipRect; if (cpu_fine_clip_rect) { clip_rect.x = ImMax(clip_rect.x, cpu_fine_clip_rect->x); @@ -1258,7 +1255,7 @@ void ImDrawList::AddImage(ImTextureID user_texture_id, const ImVec2& p_min, cons if ((col & IM_COL32_A_MASK) == 0) return; - const bool push_texture_id = _TextureIdStack.empty() || user_texture_id != _TextureIdStack.back(); + const bool push_texture_id = user_texture_id != _CmdHeader.TextureId; if (push_texture_id) PushTextureID(user_texture_id); @@ -1274,7 +1271,7 @@ void ImDrawList::AddImageQuad(ImTextureID user_texture_id, const ImVec2& p1, con if ((col & IM_COL32_A_MASK) == 0) return; - const bool push_texture_id = _TextureIdStack.empty() || user_texture_id != _TextureIdStack.back(); + const bool push_texture_id = user_texture_id != _CmdHeader.TextureId; if (push_texture_id) PushTextureID(user_texture_id); @@ -1357,19 +1354,12 @@ void ImDrawListSplitter::Split(ImDrawList* draw_list, int channels_count) if (_Channels[i]._CmdBuffer.Size == 0) { ImDrawCmd draw_cmd; - draw_cmd.ClipRect = draw_list->_ClipRectStack.back(); - draw_cmd.TextureId = draw_list->_TextureIdStack.back(); - draw_cmd.VtxOffset = draw_list->_VtxCurrentOffset; + ImDrawCmd_HeaderCopy(&draw_cmd, &draw_list->_CmdHeader); // Copy ClipRect, TextureId, VtxOffset _Channels[i]._CmdBuffer.push_back(draw_cmd); } } } -static inline bool CanMergeDrawCommands(ImDrawCmd* a, ImDrawCmd* b) -{ - return memcmp(&a->ClipRect, &b->ClipRect, sizeof(a->ClipRect)) == 0 && a->TextureId == b->TextureId && a->VtxOffset == b->VtxOffset && !a->UserCallback && !b->UserCallback; -} - void ImDrawListSplitter::Merge(ImDrawList* draw_list) { // Note that we never use or rely on channels.Size because it is merely a buffer that we never shrink back to 0 to keep all sub-buffers ready for use. @@ -1390,12 +1380,16 @@ void ImDrawListSplitter::Merge(ImDrawList* draw_list) ImDrawChannel& ch = _Channels[i]; if (ch._CmdBuffer.Size > 0 && ch._CmdBuffer.back().ElemCount == 0) ch._CmdBuffer.pop_back(); - if (ch._CmdBuffer.Size > 0 && last_cmd != NULL && CanMergeDrawCommands(last_cmd, &ch._CmdBuffer[0])) + if (ch._CmdBuffer.Size > 0 && last_cmd != NULL) { - // Merge previous channel last draw command with current channel first draw command if matching. - last_cmd->ElemCount += ch._CmdBuffer[0].ElemCount; - idx_offset += ch._CmdBuffer[0].ElemCount; - ch._CmdBuffer.erase(ch._CmdBuffer.Data); // FIXME-OPT: Improve for multiple merges. + ImDrawCmd* next_cmd = &ch._CmdBuffer[0]; + if (ImDrawCmd_HeaderCompare(last_cmd, next_cmd) == 0 && last_cmd->UserCallback == NULL && next_cmd->UserCallback == NULL) + { + // Merge previous channel last draw command with current channel first draw command if matching. + last_cmd->ElemCount += next_cmd->ElemCount; + idx_offset += next_cmd->ElemCount; + ch._CmdBuffer.erase(ch._CmdBuffer.Data); // FIXME-OPT: Improve for multiple merges. + } } if (ch._CmdBuffer.Size > 0) last_cmd = &ch._CmdBuffer.back();