Method Begin

ImGUI GLFW Tutorial/imgui/imgui.cpp:2283–2299

Use case A: Begin() called from constructor with items_height<0, then called again from Step() in StepNo 1 Use case B: Begin() called from constructor with items_height>0 FIXME-LEGACY: Ideally we should remove the Begin/End functions but they are part of the legacy API we still support. This is why some of the code in Step() calling Begin() and reassign some fields, spaghetti style.

// Use case B: Begin() called from constructor with items_height>0
// FIXME-LEGACY: Ideally we should remove the Begin/End functions but they are part of the legacy API we still support. This is why some of the code in Step() calling Begin() and reassign some fields, spaghetti style.
void ImGuiListClipper::Begin(int items_count, float items_height)
{
    ImGuiContext& g = *GImGui;
    ImGuiWindow* window = g.CurrentWindow;

    if (ImGuiTable* table = g.CurrentTable)
        if (table->IsInsideRow)
            ImGui::TableEndRow(table);

    StartPosY = window->DC.CursorPos.y;
    ItemsHeight = items_height;
    ItemsCount = items_count;
    ItemsFrozen = 0;
    StepNo = 0;
    DisplayStart = -1;
    DisplayEnd = 0;
}

void ImGuiListClipper::End()
{