示例#1
0
void DrawRuleMergeSet::apply(const Feature& _feature, const SceneLayer& _layer,
                             StyleContext& _ctx, TileBuilder& _builder) {

    // If no rules matched the feature, return immediately
    if (!match(_feature, _layer, _ctx)) { return; }

    // For each matched rule, find the style to be used and
    // build the feature with the rule's parameters
    for (auto& rule : m_matchedRules) {

        StyleBuilder* style = _builder.getStyleBuilder(rule.getStyleName());
        if (!style) {
            LOGE("Invalid style %s", rule.getStyleName().c_str());
            continue;
        }

        bool visible;
        if (rule.get(StyleParamKey::visible, visible) && !visible) {
            continue;
        }

        bool valid = true;
        for (size_t i = 0; i < StyleParamKeySize; ++i) {

            if (!rule.active[i]) {
                rule.params[i].param = nullptr;
                continue;
            }

            auto*& param = rule.params[i].param;

            // Evaluate JS functions and Stops
            if (param->function >= 0) {

                // Copy param into 'evaluated' and point param to the evaluated StyleParam.
                m_evaluated[i] = *param;
                param = &m_evaluated[i];

                if (!_ctx.evalStyle(param->function, param->key, m_evaluated[i].value)) {
                    if (StyleParam::isRequired(param->key)) {
                        valid = false;
                        break;
                    } else {
                        rule.active[i] = false;
                    }
                }
            } else if (param->stops) {
                m_evaluated[i] = *param;
                param = &m_evaluated[i];

                Stops::eval(*param->stops, param->key, _ctx.getKeywordZoom(),
                            m_evaluated[i].value);
            }
        }

        if (valid) {

            // build outline explicitly with outline style
            const auto& outlineStyleName = rule.findParameter(StyleParamKey::outline_style);
            if (outlineStyleName) {
                auto& styleName = outlineStyleName.value.get<std::string>();
                auto* outlineStyle = _builder.getStyleBuilder(styleName);
                if (!outlineStyle) {
                    LOGE("Invalid style %s", styleName.c_str());
                } else {
                    rule.isOutlineOnly = true;
                    outlineStyle->addFeature(_feature, rule);
                    rule.isOutlineOnly = false;
                }
            }

            // build feature with style
            style->addFeature(_feature, rule);
        }
    }
}