// is enabled, those fields allow us to render meshes larger than 64K vertices while keeping 16-bit indices.
structImDrawCmd
{
unsignedintElemCount;// 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[].
ImVec4ClipRect;// Clipping rectangle (x1, y1, x2, y2). Subtract ImDrawData->DisplayPos to get clipping rectangle in "viewport" coordinates
ImTextureIDTextureId;// 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.
unsignedintVtxOffset;// 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.
unsignedintIdxOffset;// Start offset in index buffer. Always equal to sum of ElemCount drawn so far.
ImDrawCallbackUserCallback;// 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.
unsignedintElemCount;// 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[].
ImVec4ClipRect;// 4*4 // Clipping rectangle (x1, y1, x2, y2). Subtract ImDrawData->DisplayPos to get clipping rectangle in "viewport" coordinates
ImTextureIDTextureId;// 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.
unsignedintVtxOffset;// 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.
unsignedintIdxOffset;// 4 // Start offset in index buffer. Always equal to sum of ElemCount drawn so far.
ImDrawCallbackUserCallback;// 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.
ImVector<ImVec2>_Path;// [Internal] current path building
ImDrawListSplitter_Splitter;// [Internal] for channels api
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)
// - Use to split render into layers. By switching channels to can render out-of-order (e.g. submit FG primitives before BG primitives)
// - Use to minimize draw calls (e.g. if going back-and-forth between multiple clipping rectangles, prefer to append into separate channels then merge at the end)
// - FIXME-OBSOLETE: This API shouldn't have been in ImDrawList in the first place!
// Prefer using your own persistent copy of ImDrawListSplitter as you can stack them.
// Prefer using your own persistent instance of ImDrawListSplitter as you can stack them.
// Using the ImDrawList::ChannelsXXXX you cannot stack a split over another.
ocornut
5 years ago