Method GetCharPosition

Source/Engine/Render2D/Font.cpp:408–471

}

Float2 Font::GetCharPosition(const StringView& text, int32 index, const TextLayoutOptions& layout)
{
    // Check if there is no need to do anything
    if (text.IsEmpty())
    {
        Float2 location = layout.Bounds.Location;
        if (layout.VerticalAlignment == TextAlignment::Center)
            location.Y += layout.Bounds.Size.Y * 0.5f - static_cast<float>(_height) * 0.5f;
        else if (layout.VerticalAlignment == TextAlignment::Far)
            location.Y += layout.Bounds.Size.Y - static_cast<float>(_height) * 0.5f;

        if (layout.HorizontalAlignment == TextAlignment::Center)
            location.X += layout.Bounds.Size.X * 0.5f;
        else if (layout.HorizontalAlignment == TextAlignment::Far)
            location.X += layout.Bounds.Size.X;
        return location;
    }

    // Process text
    Array<FontLineCache, InlinedAllocation<8>> lines;
    ProcessText(text, lines, layout);
    ASSERT(lines.HasItems());
    float scale = layout.Scale / FontManager::FontScale;
    float baseLinesDistance = static_cast<float>(_height) * layout.BaseLinesGapScale * scale;

    // Find line with that position
    FontCharacterEntry previous;
    FontCharacterEntry entry;
    for (int32 lineIndex = 0; lineIndex < lines.Count(); lineIndex++)
    {
        const FontLineCache& line = lines[lineIndex];

        // Check if desire position is somewhere inside characters in line range
        if (Math::IsInRange(index, line.FirstCharIndex, line.LastCharIndex))
        {
            Float2 charPos = line.Location;

            // Check all characters in the line
            for (int32 currentIndex = line.FirstCharIndex; currentIndex < index; currentIndex++)
            {
                // Cache current character
                const Char currentChar = text[currentIndex];
                GetCharacter(currentChar, entry);
                const bool isWhitespace = StringUtils::IsWhitespace(currentChar);

                // Apply kerning
                if (!isWhitespace && previous.IsValid)
                {
                    charPos.X += entry.Font->GetKerning(previous.Character, entry.Character);
                }
                previous = entry;

                // Move
                charPos.X += entry.AdvanceX * scale;
            }

            // Upper left corner of the character
            return layout.Bounds.Location + charPos;