Method RenderText

Source/Graphics/text.cpp:285–381

}

void TextCanvasTexture::RenderText(const char* str, int length, const CanvasTextStyle& style, TextMetrics& metrics, uint32_t mode, uint32_t char_limit) {
    std::vector<uint32_t> utf32_string;

    try {
        utf8::utf8to32(str, str + length, std::back_inserter(utf32_string));
    } catch (const utf8::not_enough_room& ner) {
        LOGE << "Got utf8 exception \"" << ner.what() << "\" this might indicate invalid utf-8 data" << std::endl;
    }

    FontRenderer* font_renderer = FontRenderer::Instance();
    FT_Matrix matrix;
    FTMatrixFromAngle(&matrix, impl_->pen_rotation);
    int orig_pen_x = impl_->pen.x;
    int line_height = font_renderer->GetFontInfo(style.font_face_id, FontRenderer::INFO_HEIGHT);
    int line_start = 0;
    FT_Vector zero_vec = {0};
    ClearTextMetrics(&metrics);
    for (unsigned i = 0; i <= utf32_string.size(); ++i) {
        if (i == utf32_string.size() || utf32_string[i] == '\n') {  // Find line endings to draw entire lines at once
            TextMetrics line_metrics;
            bool need_to_reset = true;
            int next_end_id = 0;

            // Create newlines when the lines are too long.
            // This includes the entire string, not just what we want to show based on
            // char limit
            while (need_to_reset) {
                ClearTextMetrics(&line_metrics);
                need_to_reset = false;
                for (unsigned j = line_start; j < i; ++j) {
                    font_renderer->SetTransform(style.font_face_id, &matrix, &zero_vec);
                    FT_GlyphSlot slot = font_renderer->RenderCharacterBitmap(style.font_face_id, utf32_string[j], FontRenderer::RCB_METRIC);
                    ApplyGlyphSlotToTextMetrics(&line_metrics, slot);

                    if (mode & TMF_AUTO_NEWLINE) {
                        if (line_metrics.advance[0] + impl_->pen.x + slot->metrics.width >= impl_->text_canvas.width() * 64) {
                            for (int k = j; k > 0; k--) {
                                if (utf32_string[k] == ' ') {
                                    j = k;
                                    break;
                                }
                            }
                            need_to_reset = true;
                            next_end_id = j;
                            break;
                        }
                    }
                }

                if (need_to_reset) {
                    i = next_end_id;
                }
            }

            switch (style.alignment) {
                case CanvasTextStyle::RIGHT:
                    if (mode & TMF_DRAW) {
                        impl_->pen.x = impl_->text_canvas.width() * 64 - line_metrics.bounds[1];