Method Render

KBotExt/imgui/imgui.cpp:5062–5126

Prepare the data for rendering so you can call GetDrawData() (As with anything within the ImGui:: namspace this doesn't touch your GPU or graphics API at all: it is the role of the ImGui_ImplXXXX_RenderDrawData() function provided by the renderer backend)

// (As with anything within the ImGui:: namspace this doesn't touch your GPU or graphics API at all:
// it is the role of the ImGui_ImplXXXX_RenderDrawData() function provided by the renderer backend)
void ImGui::Render()
{
	ImGuiContext& g = *GImGui;
	IM_ASSERT(g.Initialized);

	if (g.FrameCountEnded != g.FrameCount)
		EndFrame();
	if (g.FrameCountRendered == g.FrameCount)
		return;
	g.FrameCountRendered = g.FrameCount;

	g.IO.MetricsRenderWindows = 0;
	CallContextHooks(&g, ImGuiContextHookType_RenderPre);

	// Draw modal/window whitening backgrounds
	RenderDimmedBackgrounds();

	// Add background ImDrawList (for each active viewport)
	for (ImGuiViewportP* viewport : g.Viewports)
	{
		InitViewportDrawData(viewport);
		if (viewport->BgFgDrawLists[0] != NULL)
			AddDrawListToDrawDataEx(&viewport->DrawDataP, viewport->DrawDataBuilder.Layers[0], GetBackgroundDrawList(viewport));
	}

	// Add ImDrawList to render
	ImGuiWindow* windows_to_render_top_most[2];
	windows_to_render_top_most[0] = (g.NavWindowingTarget && !(g.NavWindowingTarget->Flags & ImGuiWindowFlags_NoBringToFrontOnFocus)) ? g.NavWindowingTarget->RootWindow : NULL;
	windows_to_render_top_most[1] = (g.NavWindowingTarget ? g.NavWindowingListWindow : NULL);
	for (ImGuiWindow* window : g.Windows)
	{
		IM_MSVC_WARNING_SUPPRESS(6011); // Static Analysis false positive "warning C6011: Dereferencing NULL pointer 'window'"
		if (IsWindowActiveAndVisible(window) && (window->Flags & ImGuiWindowFlags_ChildWindow) == 0 && window != windows_to_render_top_most[0] && window != windows_to_render_top_most[1])
			AddRootWindowToDrawData(window);
	}
	for (int n = 0; n < IM_ARRAYSIZE(windows_to_render_top_most); n++)
		if (windows_to_render_top_most[n] && IsWindowActiveAndVisible(windows_to_render_top_most[n])) // NavWindowingTarget is always temporarily displayed as the top-most window
			AddRootWindowToDrawData(windows_to_render_top_most[n]);

	// Draw software mouse cursor if requested by io.MouseDrawCursor flag
	if (g.IO.MouseDrawCursor && g.MouseCursor != ImGuiMouseCursor_None)
		RenderMouseCursor(g.IO.MousePos, g.Style.MouseCursorScale, g.MouseCursor, IM_COL32_WHITE, IM_COL32_BLACK, IM_COL32(0, 0, 0, 48));

	// Setup ImDrawData structures for end-user
	g.IO.MetricsRenderVertices = g.IO.MetricsRenderIndices = 0;
	for (ImGuiViewportP* viewport : g.Viewports)
	{
		FlattenDrawDataIntoSingleLayer(&viewport->DrawDataBuilder);

		// Add foreground ImDrawList (for each active viewport)
		if (viewport->BgFgDrawLists[1] != NULL)
			AddDrawListToDrawDataEx(&viewport->DrawDataP, viewport->DrawDataBuilder.Layers[0], GetForegroundDrawList(viewport));

		// We call _PopUnusedDrawCmd() last thing, as RenderDimmedBackgrounds() rely on a valid command being there (especially in docking branch).
		ImDrawData* draw_data = &viewport->DrawDataP;
		IM_ASSERT(draw_data->CmdLists.Size == draw_data->CmdListsCount);
		for (ImDrawList* draw_list : draw_data->CmdLists)
			draw_list->_PopUnusedDrawCmd();