Function TrackDesignDrawPreview

src/openrct2/ride/TrackDesign.cpp:2075–2165

* * rct2: 0x006D1EF0 */

 *  rct2: 0x006D1EF0
 */
void TrackDesignDrawPreview(TrackDesign& td, TrackDesignPreviewBuffer& pixels, bool placeScenery)
{
    StashMap();
    TrackDesignPreviewClearMap();

    if (gLegacyScene == LegacyScene::trackDesignsManager)
    {
        TrackDesignLoadSceneryObjects(td);
    }

    TrackDesignState tds{};

    Ride* ride;
    TrackDesignGameStateData updatedGameStateData = td.gameStateData;
    if (!TrackDesignPlacePreview(tds, td, &ride, updatedGameStateData, placeScenery))
    {
        std::fill(std::begin(pixels), std::end(pixels), PaletteIndex::transparent);
        UnstashMap();
        return;
    }
    td.gameStateData = updatedGameStateData;

    CoordsXYZ centre = { (tds.previewMin.x + tds.previewMax.x) / 2 + 16, (tds.previewMin.y + tds.previewMax.y) / 2 + 16,
                         (tds.previewMin.z + tds.previewMax.z) / 2 };

    int32_t size_x = tds.previewMax.x - tds.previewMin.x;
    int32_t size_y = tds.previewMax.y - tds.previewMin.y;
    int32_t size_z = tds.previewMax.z - tds.previewMin.z;

    // Special case for flat rides - Z-axis info is irrelevant
    // and must be zeroed out lest the preview be off-centre
    if (!GetRideTypeDescriptor(td.trackAndVehicle.rtdIndex).flags.has(RtdFlag::hasTrack))
    {
        centre.z = 0;
        size_z = 0;
    }

    ZoomLevel zoom_level{ 1 };
    if (size_x < size_y)
    {
        size_x = size_y;
    }

    if (size_x > 1000 || size_z > 280)
    {
        zoom_level = ZoomLevel{ 2 };
    }

    if (size_x > 1600 || size_z > 1000)
    {
        zoom_level = ZoomLevel{ 3 };
    }

    size_x = zoom_level.ApplyTo(370);
    size_y = zoom_level.ApplyTo(217);

    Viewport view;
    view.width = 370;