Method CalcTextSize

ImGUI GLFW Tutorial/imgui/imgui.cpp:4523–4547

Calculate text size. Text can be multi-line. Optionally ignore text after a ## marker. CalcTextSize("") should return ImVec2(0.0f, g.FontSize)

// Calculate text size. Text can be multi-line. Optionally ignore text after a ## marker.
// CalcTextSize("") should return ImVec2(0.0f, g.FontSize)
ImVec2 ImGui::CalcTextSize(const char* text, const char* text_end, bool hide_text_after_double_hash, float wrap_width)
{
    ImGuiContext& g = *GImGui;

    const char* text_display_end;
    if (hide_text_after_double_hash)
        text_display_end = FindRenderedTextEnd(text, text_end);      // Hide anything after a '##' string
    else
        text_display_end = text_end;

    ImFont* font = g.Font;
    const float font_size = g.FontSize;
    if (text == text_display_end)
        return ImVec2(0.0f, font_size);
    ImVec2 text_size = font->CalcTextSizeA(font_size, FLT_MAX, wrap_width, text, text_display_end, NULL);

    // Round
    // FIXME: This has been here since Dec 2015 (7b0bf230) but down the line we want this out.
    // FIXME: Investigate using ceilf or e.g.
    // - https://git.musl-libc.org/cgit/musl/tree/src/math/ceilf.c
    // - https://embarkstudios.github.io/rust-gpu/api/src/libm/math/ceilf.rs.html
    text_size.x = IM_FLOOR(text_size.x + 0.99999f);

    return text_size;
}

// Find window given position, search front-to-back
// FIXME: Note that we have an inconsequential lag here: OuterRectClipped is updated in Begin(), so windows moved programmatically