Function NewFrameSanityChecks

lib/imgui/imgui.cpp:3557–3584

}

static void NewFrameSanityChecks()
{
    ImGuiContext& g = *GImGui;

    // Check user data
    // (We pass an error message in the assert expression to make it visible to programmers who are not using a debugger, as most assert handlers display their argument)
    IM_ASSERT(g.Initialized);
    IM_ASSERT((g.IO.DeltaTime > 0.0f || g.FrameCount == 0)              && "Need a positive DeltaTime!");
    IM_ASSERT((g.FrameCount == 0 || g.FrameCountEnded == g.FrameCount)  && "Forgot to call Render() or EndFrame() at the end of the previous frame?");
    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value!");
    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8() ?");
    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not built. Did you call io.Fonts->GetTexDataAsRGBA32() / GetTexDataAsAlpha8() ?");
    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting!");
    IM_ASSERT(g.Style.CircleSegmentMaxError > 0.0f                      && "Invalid style setting!");
    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)!");
    IM_ASSERT(g.Style.WindowMinSize.x >= 1.0f && g.Style.WindowMinSize.y >= 1.0f && "Invalid style setting.");
    IM_ASSERT(g.Style.WindowMenuButtonPosition == ImGuiDir_None || g.Style.WindowMenuButtonPosition == ImGuiDir_Left || g.Style.WindowMenuButtonPosition == ImGuiDir_Right);
    for (int n = 0; n < ImGuiKey_COUNT; n++)
        IM_ASSERT(g.IO.KeyMap[n] >= -1 && g.IO.KeyMap[n] < IM_ARRAYSIZE(g.IO.KeysDown) && "io.KeyMap[] contains an out of bound value (need to be 0..512, or -1 for unmapped key)");

    // Perform simple check: required key mapping (we intentionally do NOT check all keys to not pressure user into setting up everything, but Space is required and was only recently added in 1.60 WIP)
    if (g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard)
        IM_ASSERT(g.IO.KeyMap[ImGuiKey_Space] != -1 && "ImGuiKey_Space is not mapped, required for keyboard navigation.");

    // Perform simple check: the beta io.ConfigWindowsResizeFromEdges option requires back-end to honor mouse cursor changes and set the ImGuiBackendFlags_HasMouseCursors flag accordingly.
    if (g.IO.ConfigWindowsResizeFromEdges && !(g.IO.BackendFlags & ImGuiBackendFlags_HasMouseCursors))
        g.IO.ConfigWindowsResizeFromEdges = false;
}

void ImGui::NewFrame()
{