Method initialize

src/gui/SpectrumWidget.cpp:8343–8420

}

void SpectrumWidget::initialize(QRhiCommandBuffer* cb)
{
    if (m_rhiInitialized) return;

    QRhi* r = rhi();
    if (!r) {
        qWarning() << "SpectrumWidget: QRhi initialization failed — no GPU backend";
        return;
    }

    qDebug() << "SpectrumWidget: QRhi initialized, backend:" << r->backendName();

    // Upload quad vertex data for both pipelines
    auto* batch = r->nextResourceUpdateBatch();

    initWaterfallPipeline();
    initOverlayPipeline();
    initSpectrumPipeline();
    initDssMeshPipeline();

    // Upload VBO data
    batch->uploadStaticBuffer(m_wfVbo, kQuadData);
    batch->uploadStaticBuffer(m_ovVbo, kQuadData);

    // 3DSS mesh: build the static perspective grid once (geometry never changes —
    // height comes from the ring-buffered texture sampled per-vertex).
    if (m_dssMeshReady) {
        const int cols = m_dss.cols();
        const int rows = m_dss.rows();
        QVector<float> fill;
        QVector<float> line;
        fill.reserve(rows * dssFillVerticesPerRow() * 3);
        line.reserve(rows * dssLineVerticesPerRow() * 3);
        for (int rr = rows - 1; rr >= 0; --rr) {
            const float v = static_cast<float>(rr) / rows;   // 0 front .. ~1 back
            for (int cc = 0; cc + 1 < cols; ++cc) {
                const float u0 = static_cast<float>(cc) / (cols - 1);
                const float u1 = static_cast<float>(cc + 1) / (cols - 1);
                appendDssVertex(fill, u0, v, 0.0f);   // ridge
                appendDssVertex(fill, u0, v, 1.0f);   // floor
                appendDssVertex(fill, u1, v, 0.0f);   // next ridge
                appendDssVertex(fill, u1, v, 0.0f);
                appendDssVertex(fill, u0, v, 1.0f);
                appendDssVertex(fill, u1, v, 1.0f);   // next floor
                appendDssVertex(line, u0, v, -1.0f);
                appendDssVertex(line, u1, v, -1.0f);
            }
        }
        batch->uploadStaticBuffer(m_dssMeshVbo, fill.constData());
        batch->uploadStaticBuffer(m_dssMeshLineVbo, line.constData());
        // The palette LUT is baked from the live floor/range on the first 3D
        // frame (renderGpuFrame) before the surface is drawn — no init upload.
    }

    // Initial full waterfall texture upload (convert RGB32→RGBA8)
    if (!m_waterfall.isNull()) {
        QImage rgba = m_waterfall.convertToFormat(QImage::Format_RGBA8888);
        QRhiTextureSubresourceUploadDescription desc(rgba);