Function LayoutText

engine/font/src/text_layout_skribidi.cpp:52–205

}

static bool LayoutText(LayoutContext* ctx,
                        uint32_t* codepoints, uint32_t num_codepoints,
                        TextLayoutSettings* settings,
                         TextLayout* layout)
{
    HFontCollection font_collection = layout->m_FontCollection;

    float line_width = settings->m_Width;
    // Ensure explicit line breaks are honored without forcing word-wrap.
    // When auto line breaking is disabled or width is zero, use a very large width
    // and keep wrap enabled so the layout engine can still split on '\n'.
    if (!settings->m_LineBreak || line_width <= 0.0f)
        line_width = 1000000.0f;
    skb_layout_params_t params = {0};
    params.font_collection    = FontCollectionGetSkribidiPtr(font_collection),
    params.lang               = "en-us",                  // TODO: support setting
    params.origin             = {0, 0},
    params.layout_width       = line_width,
    params.layout_height      = 1000000.0f,
    params.base_direction     = SKB_DIRECTION_AUTO,
    // Always allow wrapping in the layout engine. With a very large width, this
    // does not introduce automatic wraps, but it lets explicit '\n' split lines.
    params.text_wrap          = (uint8_t)SKB_WRAP_WORD,
    params.text_overflow      = SKB_OVERFLOW_NONE,
    params.vertical_trim      = SKB_VERTICAL_TRIM_DEFAULT,
    params.horizontal_align   = SKB_ALIGN_START,          // TODO: support the other way around (ask author for SKB_ALIGN_RIGHT/LEFT ?)
    params.vertical_align     = SKB_ALIGN_START,          // TODO: support the other way around (ask author for SKB_ALIGN_RIGHT/LEFT ?)
    params.baseline_align     = SKB_BASELINE_MIDDLE,
    params.flags              = 0;

    float tracking = settings->m_Tracking * settings->m_Size;
    HFont default_font = FontCollectionGetFont(font_collection, 0);
    float font_scale = FontGetScaleFromSize(default_font, settings->m_Size);
    uint32_t ascent = (uint32_t)FontGetAscent(default_font, 1.0f);
    uint32_t descent = (uint32_t)fabsf(FontGetDescent(default_font, 1.0f));
    float line_height_scaled = (ascent + descent) * font_scale;

    // TODO: Allo setting default as italic etc
    const skb_attribute_t attributes[] = {
        skb_attribute_make_font(SKB_FONT_FAMILY_DEFAULT, settings->m_Size, SKB_WEIGHT_NORMAL, SKB_STYLE_NORMAL, SKB_STRETCH_NORMAL),
        skb_attribute_make_line_height(SKB_LINE_HEIGHT_METRICS_RELATIVE, settings->m_Leading),
        skb_attribute_make_spacing(tracking, 0.0f)
    };

    // TODO: Support rich text

    skb_text_run_utf32_t runs[] = {
        { codepoints, (int32_t)num_codepoints, attributes, DM_ARRAY_SIZE(attributes) },
    };

    skb_layout_t* skblayout = skb_layout_create_from_runs_utf32(ctx->m_Alloc, &params, runs, DM_ARRAY_SIZE(runs));
    ctx->m_Layout = skblayout;

    const int32_t glyphs_count = skb_layout_get_glyphs_count(skblayout);
    const skb_glyph_t* glyphs = skb_layout_get_glyphs(skblayout);
    const skb_glyph_run_t* glyph_runs = skb_layout_get_glyph_runs(skblayout);
    const skb_text_attributes_span_t* attrib_spans = skb_layout_get_attribute_spans(skblayout);
    const skb_layout_line_t* layout_lines = skb_layout_get_lines(skblayout);