From d1e8b698d0e1c26744817490f8ee4f91182dcb9d Mon Sep 17 00:00:00 2001 From: omar Date: Wed, 29 May 2019 15:25:53 +0200 Subject: [PATCH] ImDrawList: Added ImDrawCmd::VtxOffset value to support large meshes (64k+ vertices) using 16-bits indices. To enable the feature, the renderer back-end needs to set 'io.BackendFlags |= ImGuiBackendFlags_HasVtxOffset' and honor the ImDrawCmd::VtxOffset field. Otherwise the value will always be zero. This has the advantage of preserving smaller index buffers and allowing to execute on hardware that do not support 32-bits indices. ImDrawList: Added ImDrawCmd::IdxOffset value, equivalent to summing element count for each draw command. This is provided for convenience and consistency with VtxOffset. (#2591) --- docs/CHANGELOG.txt | 7 +++++++ imconfig.h | 5 ++++- imgui.cpp | 44 ++++++++++++++++++++++++++++++-------------- imgui.h | 27 ++++++++++++++++++--------- imgui_demo.cpp | 2 ++ imgui_draw.cpp | 13 ++++++++++++- 6 files changed, 73 insertions(+), 25 deletions(-) diff --git a/docs/CHANGELOG.txt b/docs/CHANGELOG.txt index acd43c0e..cbd3febf 100644 --- a/docs/CHANGELOG.txt +++ b/docs/CHANGELOG.txt @@ -56,6 +56,13 @@ Other Changes: - Style: Added style.WindowMenuButtonPosition (left/right, defaults to ImGuiDir_Left) to move the collapsing/docking button to the other side of the title bar. - Style: Made window close button cross slightly smaller. +- ImDrawList: Added ImDrawCmd::VtxOffset value to support large meshes (64k+ vertices) using 16-bits indices. + To enable the feature, the renderer back-end needs to set 'io.BackendFlags |= ImGuiBackendFlags_HasVtxOffset' + and honor the ImDrawCmd::VtxOffset field. Otherwise the value will always be zero. + This has the advantage of preserving smaller index buffers and allowing to execute on hardware that do not + support 32-bits indices. Most examples back-ends have been modified to support the VtxOffset field. +- ImDrawList: Added ImDrawCmd::IdxOffset value, equivalent to summing element count for each draw command. + This is provided for convenience and consistency with VtxOffset. - ImFontAtlas: FreeType: Added RasterizerFlags::Monochrome flag to disable font anti-aliasing. (#2545) Combine with RasterizerFlags::MonoHinting for best results. - ImFontGlyphRangesBuilder: Fixed unnecessarily over-sized buffer, which incidentally was also not diff --git a/imconfig.h b/imconfig.h index b496ae91..5476dd66 100644 --- a/imconfig.h +++ b/imconfig.h @@ -62,7 +62,10 @@ operator MyVec4() const { return MyVec4(x,y,z,w); } */ -//---- Use 32-bit vertex indices (default is 16-bit) to allow meshes with more than 64K vertices. Render function needs to support it. +//---- Using 32-bits vertex indices (default is 16-bits) is one way to allow large meshes with more than 64K vertices. +// Your renderer back-end will need to support it (most example renderer back-ends support both 16/32-bits indices). +// Another way to allow large meshes while keeping 16-bits indices is to handle ImDrawCmd::VtxOffset in your renderer. +// Read about ImGuiBackendFlags_HasVtxOffset for details. //#define ImDrawIdx unsigned int //---- Tip: You can add extra functions within the ImGui:: namespace, here or in your own headers files. diff --git a/imgui.cpp b/imgui.cpp index c200f480..2b0cbf4f 100644 --- a/imgui.cpp +++ b/imgui.cpp @@ -3502,7 +3502,13 @@ void ImGui::NewFrame() IM_ASSERT(g.Font->IsLoaded()); g.DrawListSharedData.ClipRectFullscreen = ImVec4(0.0f, 0.0f, g.IO.DisplaySize.x, g.IO.DisplaySize.y); g.DrawListSharedData.CurveTessellationTol = g.Style.CurveTessellationTol; - g.DrawListSharedData.InitialFlags = (g.Style.AntiAliasedLines ? ImDrawListFlags_AntiAliasedLines : 0) | (g.Style.AntiAliasedFill ? ImDrawListFlags_AntiAliasedFill : 0); + g.DrawListSharedData.InitialFlags = ImDrawListFlags_None; + if (g.Style.AntiAliasedLines) + g.DrawListSharedData.InitialFlags |= ImDrawListFlags_AntiAliasedLines; + if (g.Style.AntiAliasedFill) + g.DrawListSharedData.InitialFlags |= ImDrawListFlags_AntiAliasedFill; + if (g.IO.BackendFlags & ImGuiBackendFlags_HasVtxOffset) + g.DrawListSharedData.InitialFlags |= ImDrawListFlags_AllowVtxOffset; g.BackgroundDrawList.Clear(); g.BackgroundDrawList.PushTextureID(g.IO.Fonts->TexID); @@ -3774,19 +3780,28 @@ static void AddDrawListToDrawData(ImVector* out_list, ImDrawList* d return; } - // Draw list sanity check. Detect mismatch between PrimReserve() calls and incrementing _VtxCurrentIdx, _VtxWritePtr etc. May trigger for you if you are using PrimXXX functions incorrectly. + // Draw list sanity check. Detect mismatch between PrimReserve() calls and incrementing _VtxCurrentIdx, _VtxWritePtr etc. + // May trigger for you if you are using PrimXXX functions incorrectly. IM_ASSERT(draw_list->VtxBuffer.Size == 0 || draw_list->_VtxWritePtr == draw_list->VtxBuffer.Data + draw_list->VtxBuffer.Size); IM_ASSERT(draw_list->IdxBuffer.Size == 0 || draw_list->_IdxWritePtr == draw_list->IdxBuffer.Data + draw_list->IdxBuffer.Size); - IM_ASSERT((int)draw_list->_VtxCurrentIdx == draw_list->VtxBuffer.Size); + if (!(draw_list->Flags & ImDrawListFlags_AllowVtxOffset)) + IM_ASSERT((int)draw_list->_VtxCurrentIdx == draw_list->VtxBuffer.Size); // Check that draw_list doesn't use more vertices than indexable (default ImDrawIdx = unsigned short = 2 bytes = 64K vertices per ImDrawList = per window) // If this assert triggers because you are drawing lots of stuff manually: - // A) Make sure you are coarse clipping, because ImDrawList let all your vertices pass. You can use the Metrics window to inspect draw list contents. - // B) If you need/want meshes with more than 64K vertices, uncomment the '#define ImDrawIdx unsigned int' line in imconfig.h to set the index size to 4 bytes. - // You'll need to handle the 4-bytes indices to your renderer. For example, the OpenGL example code detect index size at compile-time by doing: - // glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset); - // Your own engine or render API may use different parameters or function calls to specify index sizes. 2 and 4 bytes indices are generally supported by most API. - // C) If for some reason you cannot use 4 bytes indices or don't want to, a workaround is to call BeginChild()/EndChild() before reaching the 64K limit to split your draw commands in multiple draw lists. + // - First, make sure you are coarse clipping yourself and not trying to draw many things outside visible bounds. + // Be mindful that the ImDrawList API doesn't filter vertices. Use the Metrics window to inspect draw list contents. + // - If you want large meshes with more than 64K vertices, you can either: + // (A) Handle the ImDrawCmd::VtxOffset value in your renderer back-end, and set 'io.BackendFlags |= ImGuiBackendFlags_HasVtxOffset'. + // Most example back-ends already support this from 1.71. Pre-1.71 back-ends won't. + // Some graphics API such as GL ES 1/2 don't have a way to offset the starting vertex so it is not supported for them. + // (B) Or handle 32-bits indices in your renderer back-end, and uncomment '#define ImDrawIdx unsigned int' line in imconfig.h. + // Most example back-ends already support this. For example, the OpenGL example code detect index size at compile-time: + // glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset); + // Your own engine or render API may use different parameters or function calls to specify index sizes. + // 2 and 4 bytes indices are generally supported by most graphics API. + // - If for some reason neither of those solutions works for you, a workaround is to call BeginChild()/EndChild() before reaching + // the 64K limit to split your draw commands in multiple draw lists. if (sizeof(ImDrawIdx) == 2) IM_ASSERT(draw_list->_VtxCurrentIdx < (1 << 16) && "Too many vertices in ImDrawList using 16-bit indices. Read comment above"); @@ -9790,9 +9805,10 @@ void ImGui::ShowMetricsWindow(bool* p_open) continue; } ImDrawIdx* idx_buffer = (draw_list->IdxBuffer.Size > 0) ? draw_list->IdxBuffer.Data : NULL; - bool pcmd_node_open = ImGui::TreeNode((void*)(pcmd - draw_list->CmdBuffer.begin()), - "Draw %4d %s vtx, tex 0x%p, clip_rect (%4.0f,%4.0f)-(%4.0f,%4.0f)", - pcmd->ElemCount, draw_list->IdxBuffer.Size > 0 ? "indexed" : "non-indexed", (void*)(intptr_t)pcmd->TextureId, pcmd->ClipRect.x, pcmd->ClipRect.y, pcmd->ClipRect.z, pcmd->ClipRect.w); + char buf[300]; + ImFormatString(buf, IM_ARRAYSIZE(buf), "Draw %4d triangles, tex 0x%p, clip_rect (%4.0f,%4.0f)-(%4.0f,%4.0f)", + pcmd->ElemCount/3, (void*)(intptr_t)pcmd->TextureId, pcmd->ClipRect.x, pcmd->ClipRect.y, pcmd->ClipRect.z, pcmd->ClipRect.w); + bool pcmd_node_open = ImGui::TreeNode((void*)(pcmd - draw_list->CmdBuffer.begin()), "%s", buf); if (show_drawcmd_clip_rects && fg_draw_list && ImGui::IsItemHovered()) { ImRect clip_rect = pcmd->ClipRect; @@ -9806,11 +9822,11 @@ void ImGui::ShowMetricsWindow(bool* p_open) continue; // Display individual triangles/vertices. Hover on to get the corresponding triangle highlighted. + ImGui::Text("ElemCount: %d, ElemCount/3: %d, VtxOffset: +%d, IdxOffset: +%d", pcmd->ElemCount, pcmd->ElemCount/3, pcmd->VtxOffset, pcmd->IdxOffset); ImGuiListClipper clipper(pcmd->ElemCount/3); // Manually coarse clip our print out of individual vertices to save CPU, only items that may be visible. while (clipper.Step()) for (int prim = clipper.DisplayStart, idx_i = elem_offset + clipper.DisplayStart*3; prim < clipper.DisplayEnd; prim++) { - char buf[300]; char *buf_p = buf, *buf_end = buf + IM_ARRAYSIZE(buf); ImVec2 triangles_pos[3]; for (int n = 0; n < 3; n++, idx_i++) @@ -9819,7 +9835,7 @@ void ImGui::ShowMetricsWindow(bool* p_open) ImDrawVert& v = draw_list->VtxBuffer[vtx_i]; triangles_pos[n] = v.pos; buf_p += ImFormatString(buf_p, buf_end - buf_p, "%s %04d: pos (%8.2f,%8.2f), uv (%.6f,%.6f), col %08X\n", - (n == 0) ? "idx" : " ", idx_i, v.pos.x, v.pos.y, v.uv.x, v.uv.y, v.col); + (n == 0) ? "elem" : " ", idx_i, v.pos.x, v.pos.y, v.uv.x, v.uv.y, v.col); } ImGui::Selectable(buf, false); if (fg_draw_list && ImGui::IsItemHovered()) diff --git a/imgui.h b/imgui.h index b3f979bf..4580a181 100644 --- a/imgui.h +++ b/imgui.h @@ -47,7 +47,7 @@ Index of this file: // Version // (Integer encoded as XYYZZ for use in #if preprocessor conditionals. Work in progress versions typically starts at XYY99 then bounce up to XYY00, XYY01 etc. when release tagging happens) #define IMGUI_VERSION "1.71 WIP" -#define IMGUI_VERSION_NUM 17002 +#define IMGUI_VERSION_NUM 17003 #define IMGUI_CHECKVERSION() ImGui::DebugCheckVersionAndDataLayout(IMGUI_VERSION, sizeof(ImGuiIO), sizeof(ImGuiStyle), sizeof(ImVec2), sizeof(ImVec4), sizeof(ImDrawVert), sizeof(ImDrawIdx)) // Define attributes of all API symbols declarations (e.g. for DLL under Windows) @@ -1003,9 +1003,10 @@ enum ImGuiConfigFlags_ enum ImGuiBackendFlags_ { ImGuiBackendFlags_None = 0, - ImGuiBackendFlags_HasGamepad = 1 << 0, // Back-end supports gamepad and currently has one connected. - ImGuiBackendFlags_HasMouseCursors = 1 << 1, // Back-end supports honoring GetMouseCursor() value to change the OS cursor shape. - ImGuiBackendFlags_HasSetMousePos = 1 << 2 // Back-end supports io.WantSetMousePos requests to reposition the OS mouse position (only used if ImGuiConfigFlags_NavEnableSetMousePos is set). + ImGuiBackendFlags_HasGamepad = 1 << 0, // Platform Back-end supports gamepad and currently has one connected. + ImGuiBackendFlags_HasMouseCursors = 1 << 1, // Platform Back-end supports honoring GetMouseCursor() value to change the OS cursor shape. + ImGuiBackendFlags_HasSetMousePos = 1 << 2, // Platform Back-end supports io.WantSetMousePos requests to reposition the OS mouse position (only used if ImGuiConfigFlags_NavEnableSetMousePos is set). + ImGuiBackendFlags_HasVtxOffset = 1 << 3 // Renderer Back-end supports ImDrawCmd::VtxOffset. This enables output of large meshes (64K+ vertices) while still using 16-bits indices. }; // Enumeration for PushStyleColor() / PopStyleColor() @@ -1771,25 +1772,31 @@ struct ImColor // The expected behavior from your rendering function is 'if (cmd.UserCallback != NULL) { cmd.UserCallback(parent_list, cmd); } else { RenderTriangles() }' typedef void (*ImDrawCallback)(const ImDrawList* parent_list, const ImDrawCmd* cmd); -// Special Draw Callback value to request renderer back-end to reset the graphics/render state. +// Special Draw callback value to request renderer back-end to reset the graphics/render state. // The renderer back-end needs to handle this special value, otherwise it will crash trying to call a function at this address. // This is useful for example if you submitted callbacks which you know have altered the render state and you want it to be restored. // It is not done by default because they are many perfectly useful way of altering render state for imgui contents (e.g. changing shader/blending settings before an Image call). #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_HasVtxOffset) +// is enabled, those fields allow us to render meshes larger than 64K vertices while keeping 16-bits indices. struct ImDrawCmd { unsigned int ElemCount; // 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; // Clipping rectangle (x1, y1, x2, y2). Subtract ImDrawData->DisplayPos to get clipping rectangle in "viewport" coordinates ImTextureID TextureId; // 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; // Start offset in vertex buffer. Pre-1.71 or without ImGuiBackendFlags_HasVtxOffset: always 0. With ImGuiBackendFlags_HasVtxOffset: may be >0 to support meshes larger than 64K vertices with 16-bits indices. + unsigned int IdxOffset; // Start offset in index buffer. Always equal to sum of ElemCount drawn so far. ImDrawCallback UserCallback; // If != NULL, call the function instead of rendering the vertices. clip_rect and texture_id will be set normally. void* UserCallbackData; // The draw callback code can access this. - ImDrawCmd() { ElemCount = 0; ClipRect.x = ClipRect.y = ClipRect.z = ClipRect.w = 0.0f; TextureId = (ImTextureID)NULL; UserCallback = NULL; UserCallbackData = NULL; } + ImDrawCmd() { ElemCount = 0; ClipRect.x = ClipRect.y = ClipRect.z = ClipRect.w = 0.0f; TextureId = (ImTextureID)NULL; VtxOffset = IdxOffset = 0; UserCallback = NULL; UserCallbackData = NULL; } }; -// Vertex index (override with '#define ImDrawIdx unsigned int' in imconfig.h) +// Vertex index +// (to allow large meshes with 16-bits indices: set 'io.BackendFlags |= ImGuiBackendFlags_HasVtxOffset' and handle ImDrawCmd::VtxOffset in the renderer back-end) +// (to use 32-bits indices: override with '#define ImDrawIdx unsigned int' in imconfig.h) #ifndef ImDrawIdx typedef unsigned short ImDrawIdx; #endif @@ -1835,7 +1842,8 @@ enum ImDrawListFlags_ { ImDrawListFlags_None = 0, ImDrawListFlags_AntiAliasedLines = 1 << 0, // Lines are anti-aliased (*2 the number of triangles for 1.0f wide line, otherwise *3 the number of triangles) - ImDrawListFlags_AntiAliasedFill = 1 << 1 // Filled shapes have anti-aliased edges (*2 the number of vertices) + ImDrawListFlags_AntiAliasedFill = 1 << 1, // Filled shapes have anti-aliased edges (*2 the number of vertices) + ImDrawListFlags_AllowVtxOffset = 1 << 2 // Can emit 'VtxOffset > 0' to allow large meshes. Set when 'io.BackendFlags & ImGuiBackendFlags_HasVtxOffset' is enabled. }; // Draw command list @@ -1855,7 +1863,8 @@ 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 _VtxCurrentIdx; // [Internal] == VtxBuffer.Size + 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] diff --git a/imgui_demo.cpp b/imgui_demo.cpp index 78327e74..82aa7431 100644 --- a/imgui_demo.cpp +++ b/imgui_demo.cpp @@ -350,6 +350,7 @@ void ImGui::ShowDemoWindow(bool* p_open) ImGui::CheckboxFlags("io.BackendFlags: HasGamepad", (unsigned int *)&backend_flags, ImGuiBackendFlags_HasGamepad); ImGui::CheckboxFlags("io.BackendFlags: HasMouseCursors", (unsigned int *)&backend_flags, ImGuiBackendFlags_HasMouseCursors); ImGui::CheckboxFlags("io.BackendFlags: HasSetMousePos", (unsigned int *)&backend_flags, ImGuiBackendFlags_HasSetMousePos); + ImGui::CheckboxFlags("io.BackendFlags: HasVtxOffset", (unsigned int *)&backend_flags, ImGuiBackendFlags_HasVtxOffset); ImGui::TreePop(); ImGui::Separator(); } @@ -2862,6 +2863,7 @@ void ImGui::ShowAboutWindow(bool* p_open) if (io.BackendFlags & ImGuiBackendFlags_HasGamepad) ImGui::Text(" HasGamepad"); if (io.BackendFlags & ImGuiBackendFlags_HasMouseCursors) ImGui::Text(" HasMouseCursors"); if (io.BackendFlags & ImGuiBackendFlags_HasSetMousePos) ImGui::Text(" HasSetMousePos"); + if (io.BackendFlags & ImGuiBackendFlags_HasVtxOffset) ImGui::Text(" HasVtxOffset"); ImGui::Separator(); ImGui::Text("io.Fonts: %d fonts, Flags: 0x%08X, TexSize: %d,%d", io.Fonts->Fonts.Size, io.Fonts->Flags, io.Fonts->TexWidth, io.Fonts->TexHeight); ImGui::Text("io.DisplaySize: %.2f,%.2f", io.DisplaySize.x, io.DisplaySize.y); diff --git a/imgui_draw.cpp b/imgui_draw.cpp index 09e4473e..442c0e18 100644 --- a/imgui_draw.cpp +++ b/imgui_draw.cpp @@ -364,6 +364,7 @@ void ImDrawList::Clear() IdxBuffer.resize(0); VtxBuffer.resize(0); Flags = _Data->InitialFlags; + _VtxCurrentOffset = 0; _VtxCurrentIdx = 0; _VtxWritePtr = NULL; _IdxWritePtr = NULL; @@ -416,6 +417,8 @@ void ImDrawList::AddDrawCmd() ImDrawCmd draw_cmd; draw_cmd.ClipRect = GetCurrentClipRect(); draw_cmd.TextureId = GetCurrentTextureId(); + draw_cmd.VtxOffset = _VtxCurrentOffset; + draw_cmd.IdxOffset = IdxBuffer.Size; IM_ASSERT(draw_cmd.ClipRect.x <= draw_cmd.ClipRect.z && draw_cmd.ClipRect.y <= draw_cmd.ClipRect.w); CmdBuffer.push_back(draw_cmd); @@ -604,6 +607,14 @@ void ImDrawList::ChannelsSetCurrent(int idx) // NB: this can be called with negative count for removing primitives (as long as the result does not underflow) void ImDrawList::PrimReserve(int idx_count, int vtx_count) { + // Large mesh support (when enabled) + if (sizeof(ImDrawIdx) == 2 && (_VtxCurrentIdx + vtx_count >= (1 << 16)) && (Flags & ImDrawListFlags_AllowVtxOffset)) + { + _VtxCurrentOffset = VtxBuffer.Size; + _VtxCurrentIdx = 0; + AddDrawCmd(); + } + ImDrawCmd& draw_cmd = CmdBuffer.Data[CmdBuffer.Size-1]; draw_cmd.ElemCount += idx_count; @@ -2950,7 +2961,7 @@ void ImFont::RenderText(ImDrawList* draw_list, float size, ImVec2 pos, ImU32 col draw_list->CmdBuffer[draw_list->CmdBuffer.Size-1].ElemCount -= (idx_expected_size - draw_list->IdxBuffer.Size); draw_list->_VtxWritePtr = vtx_write; draw_list->_IdxWritePtr = idx_write; - draw_list->_VtxCurrentIdx = (unsigned int)draw_list->VtxBuffer.Size; + draw_list->_VtxCurrentIdx = vtx_current_idx; } //-----------------------------------------------------------------------------