Merge remote-tracking branch 'remotes/origin/dev' into 120-portierung-sweep-algorithmen

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/Mat4.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+/**
+ * Minimal column-major 4x4 float matrix helpers, layout-compatible with OpenGL uniform uploads
+ * (element index = column*4 + row).
+ */
+public final class Mat4 {
+
+    private Mat4() {}
+
+    public static float[] identity() {
+        float[] m = new float[16];
+        m[0] = m[5] = m[10] = m[15] = 1f;
+        return m;
+    }
+
+    public static float[] translation(float x, float y, float z) {
+        float[] m = identity();
+        m[12] = x;
+        m[13] = y;
+        m[14] = z;
+        return m;
+    }
+
+    /** Returns a * b (column-major). */
+    public static float[] multiply(float[] a, float[] b) {
+        float[] r = new float[16];
+        for (int col = 0; col < 4; col++) {
+            for (int row = 0; row < 4; row++) {
+                float sum = 0f;
+                for (int k = 0; k < 4; k++) {
+                    sum += a[k * 4 + row] * b[col * 4 + k];
+                }
+                r[col * 4 + row] = sum;
+            }
+        }
+        return r;
+    }
+
+    /** Returns m * (x,y,z,w) as a length-4 array. */
+    public static float[] transform(float[] m, float x, float y, float z, float w) {
+        return new float[] {
+            m[0] * x + m[4] * y + m[8]  * z + m[12] * w,
+            m[1] * x + m[5] * y + m[9]  * z + m[13] * w,
+            m[2] * x + m[6] * y + m[10] * z + m[14] * w,
+            m[3] * x + m[7] * y + m[11] * z + m[15] * w
+        };
+    }
+
+    public static float[] rotationX(float rad) {
+        float c = (float) Math.cos(rad);
+        float s = (float) Math.sin(rad);
+        float[] m = identity();
+        m[5] = c;  m[9]  = -s;
+        m[6] = s;  m[10] = c;
+        return m;
+    }
+
+    public static float[] rotationZ(float rad) {
+        float c = (float) Math.cos(rad);
+        float s = (float) Math.sin(rad);
+        float[] m = identity();
+        m[0] = c;  m[4] = -s;
+        m[1] = s;  m[5] = c;
+        return m;
+    }
+
+    /** Right-handed perspective projection (camera looks down -Z). */
+    public static float[] perspective(float fovyRad, float aspect, float near, float far) {
+        float f = (float) (1.0 / Math.tan(fovyRad / 2.0));
+        float[] m = new float[16];
+        m[0] = f / aspect;
+        m[5] = f;
+        m[10] = (far + near) / (near - far);
+        m[11] = -1f;
+        m[14] = (2f * far * near) / (near - far);
+        return m;
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/MeshAccumulator.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import de.hft.stuttgart.citydoctor2.math.Triangle3d;
+import de.hft.stuttgart.citydoctor2.math.Vector3d;
+
+/**
+ * Builds interleaved-by-attribute vertex arrays from triangles. Vertices are stored per triangle corner
+ * (3 per triangle) so a triangle's vertices occupy a contiguous, predictable range — which lets the
+ * draw index set be built by triangle without dedup bookkeeping.
+ */
+public class MeshAccumulator {
+
+    private final Vector3d center;
+    private final FloatList positions = new FloatList();
+    private final FloatList colors = new FloatList();
+    private final IntList ids = new IntList();
+    private int vertexCount;
+
+    public MeshAccumulator(Vector3d center) {
+        this.center = center;
+    }
+
+    public void addTriangle(Triangle3d t, int id, float r, float g, float b) {
+        addVertex(t.getP1(), id, r, g, b);
+        addVertex(t.getP2(), id, r, g, b);
+        addVertex(t.getP3(), id, r, g, b);
+    }
+
+    private void addVertex(Vector3d p, int id, float r, float g, float b) {
+        positions.add((float) (p.getX() - center.getX()),
+                      (float) (p.getY() - center.getY()),
+                      (float) (p.getZ() - center.getZ()));
+        colors.add(r, g, b);
+        ids.add(id);
+        vertexCount++;
+    }
+
+    public int vertexCount() { return vertexCount; }
+
+    public float[] positions() { return positions.toArray(); }
+
+    public float[] colors() { return colors.toArray(); }
+
+    public int[] ids() { return ids.toArray(); }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/OrbitCamera.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+/**
+ * Orbit camera reproducing the legacy JavaFX interaction model: world is rotated about Z then X, the
+ * camera sits at {@code distance} along -Z (negative distance = farther away) and pans in X/Y.
+ */
+public class OrbitCamera {
+
+    private static final double INITIAL_AZIMUTH = 180.0;
+    private static final double INITIAL_ELEVATION = -60.0;
+    private static final double INITIAL_DISTANCE = 100.0;
+    private static final double FOVY_RAD = Math.toRadians(30);
+    private static final float NEAR = 0.1f;
+    private static final float FAR = 10000f;
+
+    private double azimuthDeg = INITIAL_AZIMUTH;
+    private double elevationDeg = INITIAL_ELEVATION;
+    private double distance = INITIAL_DISTANCE;
+    private double panX = 0;
+    private double panY = 0;
+    private float aspect = 1.0f;
+
+    public void setAspect(float aspect) {
+        if (aspect > 0) {
+            this.aspect = aspect;
+        }
+    }
+
+    public void orbit(double deltaAzimuthDeg, double deltaElevationDeg) {
+        azimuthDeg += deltaAzimuthDeg;
+        elevationDeg += deltaElevationDeg;
+    }
+
+    public void pan(double dx, double dy) {
+        panX += dx;
+        panY += dy;
+    }
+
+    /** factor > 1 moves farther, < 1 moves closer. */
+    public void zoom(double factor) {
+        distance *= factor;
+    }
+
+    /** Matches legacy MainWindow.zoomOutForBoundingBox distance computation. */
+    public void zoomOutForBoundingBox(double diagonalLength) {
+        double longestSide = diagonalLength * 0.4;
+        distance = longestSide / Math.tan(FOVY_RAD / 2.0);
+        panX = 0;
+        panY = 0;
+    }
+
+    public void reset() {
+        azimuthDeg = INITIAL_AZIMUTH;
+        elevationDeg = INITIAL_ELEVATION;
+        distance = INITIAL_DISTANCE;
+        panX = 0;
+        panY = 0;
+    }
+
+    /** Copies the orbit/zoom/pan state from another camera (but not its aspect ratio). */
+    public void copyOrbitFrom(OrbitCamera other) {
+        this.azimuthDeg = other.azimuthDeg;
+        this.elevationDeg = other.elevationDeg;
+        this.distance = other.distance;
+        this.panX = other.panX;
+        this.panY = other.panY;
+    }
+
+    public double distance() { return distance; }
+
+    /** Current azimuth (rotation about Z) in degrees. */
+    public double azimuthDeg() { return azimuthDeg; }
+
+    /** Current elevation (rotation about X) in degrees. */
+    public double elevationDeg() { return elevationDeg; }
+
+    /** Combined projection * view * model-rotation, column-major, ready for a GL uniform. */
+    public float[] viewProjection() {
+        float[] proj = Mat4.perspective((float) FOVY_RAD, aspect, NEAR, FAR);
+        float[] view = Mat4.translation((float) -panX, (float) -panY, (float) -distance);
+        float[] rot = Mat4.multiply(
+                Mat4.rotationX((float) Math.toRadians(elevationDeg)),
+                Mat4.rotationZ((float) Math.toRadians(azimuthDeg)));
+        return Mat4.multiply(proj, Mat4.multiply(view, rot));
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/PickRegistry.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** Maps picking ids (1-based) to the model objects they represent. */
+public class PickRegistry {
+
+    private final List<Object> targets = new ArrayList<>();
+
+    /** Registers a target and returns its non-zero picking id. */
+    public int register(Object target) {
+        targets.add(target);
+        return targets.size(); // id = index + 1
+    }
+
+    /** Resolves a picking id to its target, or null for background / unknown id. */
+    public Object resolve(int id) {
+        if (id <= 0 || id > targets.size()) {
+            return null;
+        }
+        return targets.get(id - 1);
+    }
+
+    public int size() { return targets.size(); }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/PickingCodec.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+/** Encodes integer ids into RGB bytes for GPU color-picking. Id 0 is reserved for background. */
+public final class PickingCodec {
+
+    private PickingCodec() {}
+
+    public static int red(int id)   { return id & 0xFF; }
+    public static int green(int id) { return (id >> 8) & 0xFF; }
+    public static int blue(int id)  { return (id >> 16) & 0xFF; }
+
+    public static int decode(int r, int g, int b) {
+        return (r & 0xFF) | ((g & 0xFF) << 8) | ((b & 0xFF) << 16);
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/PickingFramebuffer.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import com.jogamp.opengl.GL;
+import com.jogamp.opengl.GL3;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+
+/** Off-screen framebuffer that stores picking ids as RGBA8; supports single-pixel readback. */
+public class PickingFramebuffer {
+
+    private int fbo;
+    private int colorTex;
+    private int depthRbo;
+    private int width;
+    private int height;
+    private boolean created;
+
+    public void resize(GL3 gl, int w, int h) {
+        if (w <= 0 || h <= 0 || (w == width && h == height && created)) {
+            return;
+        }
+        dispose(gl);
+        width = w;
+        height = h;
+
+        int[] tmp = new int[1];
+        gl.glGenFramebuffers(1, tmp, 0);
+        fbo = tmp[0];
+        gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, fbo);
+
+        gl.glGenTextures(1, tmp, 0);
+        colorTex = tmp[0];
+        gl.glBindTexture(GL.GL_TEXTURE_2D, colorTex);
+        gl.glTexImage2D(GL.GL_TEXTURE_2D, 0, GL.GL_RGBA8, w, h, 0, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, null);
+        gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MIN_FILTER, GL.GL_NEAREST);
+        gl.glTexParameteri(GL.GL_TEXTURE_2D, GL.GL_TEXTURE_MAG_FILTER, GL.GL_NEAREST);
+        gl.glFramebufferTexture2D(GL.GL_FRAMEBUFFER, GL.GL_COLOR_ATTACHMENT0, GL.GL_TEXTURE_2D, colorTex, 0);
+
+        gl.glGenRenderbuffers(1, tmp, 0);
+        depthRbo = tmp[0];
+        gl.glBindRenderbuffer(GL.GL_RENDERBUFFER, depthRbo);
+        gl.glRenderbufferStorage(GL.GL_RENDERBUFFER, GL.GL_DEPTH_COMPONENT16, w, h);
+        gl.glFramebufferRenderbuffer(GL.GL_FRAMEBUFFER, GL.GL_DEPTH_ATTACHMENT, GL.GL_RENDERBUFFER, depthRbo);
+
+        gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, 0);
+        created = true;
+    }
+
+    public void bind(GL3 gl) {
+        gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, fbo);
+        gl.glViewport(0, 0, width, height);
+    }
+
+    /**
+     * Reads the picking id at canvas pixel (x, y) measured from the top-left. GL's origin is bottom-left,
+     * so the row is flipped.
+     */
+    public int readId(GL3 gl, int x, int y) {
+        if (!created || x < 0 || y < 0 || x >= width || y >= height) {
+            return 0;
+        }
+        ByteBuffer buf = ByteBuffer.allocateDirect(4).order(ByteOrder.nativeOrder());
+        gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, fbo);
+        gl.glReadPixels(x, height - 1 - y, 1, 1, GL.GL_RGBA, GL.GL_UNSIGNED_BYTE, buf);
+        gl.glBindFramebuffer(GL.GL_FRAMEBUFFER, 0);
+        int r = buf.get(0) & 0xFF;
+        int g = buf.get(1) & 0xFF;
+        int b = buf.get(2) & 0xFF;
+        return PickingCodec.decode(r, g, b);
+    }
+
+    public void dispose(GL3 gl) {
+        if (created) {
+            gl.glDeleteFramebuffers(1, new int[]{fbo}, 0);
+            gl.glDeleteTextures(1, new int[]{colorTex}, 0);
+            gl.glDeleteRenderbuffers(1, new int[]{depthRbo}, 0);
+            created = false;
+        }
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/SceneBuilder.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import de.hft.stuttgart.citydoctor2.datastructure.BoundarySurfaceType;
+import de.hft.stuttgart.citydoctor2.datastructure.CityDoctorModel;
+import de.hft.stuttgart.citydoctor2.datastructure.CityObject;
+import de.hft.stuttgart.citydoctor2.datastructure.Geometry;
+import de.hft.stuttgart.citydoctor2.datastructure.Lod;
+import de.hft.stuttgart.citydoctor2.datastructure.Polygon;
+import de.hft.stuttgart.citydoctor2.math.Triangle3d;
+import de.hft.stuttgart.citydoctor2.math.Vector3d;
+import de.hft.stuttgart.citydoctor2.tesselation.TesselatedPolygon;
+import de.hft.stuttgart.citydoctor2.utils.visitors.CityObjectCollector;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Stream;
+import javafx.scene.paint.Color;
+
+/**
+ * Builds {@link SceneData} from model polygons: tesselate, bake shade colour, assign picking ids,
+ * accumulate vertices and per-triangle metadata, recentre by the bounding-box centre.
+ * Intended to run on a worker thread.
+ */
+public final class SceneBuilder {
+
+    private SceneBuilder() {}
+
+    public static SceneData fromPolygons(Collection<? extends Polygon> polygons, Color baseColor) {
+        return build(polygons, baseColor, Lod.LOD2.ordinal(), false);
+    }
+
+    /** General entry: caller supplies polygons already chosen, plus their lod/roof attributes. */
+    public static SceneData build(Collection<? extends Polygon> polygons, Color baseColor,
+                                  int lod, boolean roof) {
+        Vector3d center = findCenter(polygons);
+        MeshAccumulator acc = new MeshAccumulator(center);
+        PickRegistry registry = new PickRegistry();
+        List<TriangleMeta> metas = new ArrayList<>();
+        int triangleIndex = 0;
+
+        for (Polygon p : polygons) {
+            Color base = chooseBase(p, baseColor);
+            Color shaded = ShadeColor.shade(p.calculateNormalNormalized(), base);
+            float r = (float) shaded.getRed();
+            float g = (float) shaded.getGreen();
+            float b = (float) shaded.getBlue();
+            int id = registry.register(p);
+
+            TesselatedPolygon tp = p.tesselate();
+            for (Triangle3d t : tp.getTriangles()) {
+                acc.addTriangle(t, id, r, g, b);
+                metas.add(new TriangleMeta(triangleIndex++, p, lod, roof));
+            }
+        }
+
+        double[] centerArr = {center.getX(), center.getY(), center.getZ()};
+        return new SceneData(acc.positions(), acc.colors(), acc.ids(), metas, registry, centerArr);
+    }
+
+    /**
+     * Builds ALL features of the model into a single {@link SceneData} with one shared center,
+     * one {@link PickRegistry} and continuous triangle indices. Filtering by LOD/roof happens later
+     * via the index set, not at build time. Replicates the per-feature base colours of the legacy
+     * {@code TriangulatedGeometry.of(model, filters)}.
+     */
+    public static SceneData fromModel(CityDoctorModel model) {
+        Vector3d center = findCenterOfModel(model);
+        MeshAccumulator acc = new MeshAccumulator(center);
+        PickRegistry registry = new PickRegistry();
+        List<TriangleMeta> metas = new ArrayList<>();
+        int[] triangleIndex = {0};
+
+        appendFeatures(model.getBuildings(), Color.WHITE, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getBridges(), Color.LIGHTSTEELBLUE, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getTunnels(), Color.SLATEGRAY, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getLand(), Color.TAN, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getTransportation(), Color.DIMGRAY, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getVegetation(), Color.LIGHTGREEN, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getWater(), Color.LIGHTSKYBLUE, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getCityFurniture(), Color.BLUEVIOLET, acc, registry, metas, triangleIndex);
+        appendFeatures(model.getOtherCityObjects(), Color.BLACK, acc, registry, metas, triangleIndex);
+
+        double[] centerArr = {center.getX(), center.getY(), center.getZ()};
+        return new SceneData(acc.positions(), acc.colors(), acc.ids(), metas, registry, centerArr);
+    }
+
+    private static void appendFeatures(Stream<? extends CityObject> cos, Color color,
+                                       MeshAccumulator acc, PickRegistry registry,
+                                       List<TriangleMeta> metas, int[] triangleIndex) {
+        CityObjectCollector collector = new CityObjectCollector();
+        cos.forEach(cityObject -> cityObject.accept(collector));
+        for (CityObject co : collector.getCityObjects()) {
+            for (Geometry geom : co.getGeometries()) {
+                int lod = geom.getLod() == null ? Lod.LOD2.ordinal() : geom.getLod().ordinal();
+                for (Polygon p : geom.getPolygons()) {
+                    if (p.isLink()) {
+                        continue;
+                    }
+                    boolean roof = p.getPartOfSurface() != null
+                            && p.getPartOfSurface().getType() == BoundarySurfaceType.ROOF;
+                    appendPolygon(p, color, lod, roof, acc, registry, metas, triangleIndex);
+                }
+            }
+        }
+    }
+
+    private static void appendPolygon(Polygon p, Color baseColor, int lod, boolean roof,
+                                      MeshAccumulator acc, PickRegistry registry,
+                                      List<TriangleMeta> metas, int[] triangleIndex) {
+        Color base = chooseBase(p, baseColor);
+        Color shaded = ShadeColor.shade(p.calculateNormalNormalized(), base);
+        float r = (float) shaded.getRed();
+        float g = (float) shaded.getGreen();
+        float b = (float) shaded.getBlue();
+        int id = registry.register(p);
+
+        TesselatedPolygon tp = p.tesselate();
+        for (Triangle3d t : tp.getTriangles()) {
+            acc.addTriangle(t, id, r, g, b);
+            metas.add(new TriangleMeta(triangleIndex[0]++, p, lod, roof));
+        }
+    }
+
+    private static Vector3d findCenterOfModel(CityDoctorModel model) {
+        double xMin = Double.MAX_VALUE, yMin = Double.MAX_VALUE, zMin = Double.MAX_VALUE;
+        double xMax = -Double.MAX_VALUE, yMax = -Double.MAX_VALUE, zMax = -Double.MAX_VALUE;
+        boolean any = false;
+        for (CityObject co : model.createFeatureStream().toList()) {
+            CityObjectCollector collector = new CityObjectCollector();
+            co.accept(collector);
+            for (CityObject inner : collector.getCityObjects()) {
+                for (Geometry geom : inner.getGeometries()) {
+                    for (Polygon p : geom.getPolygons()) {
+                        if (p.isLink()) {
+                            continue;
+                        }
+                        for (Vector3d v : p.getExteriorRing().getVertices()) {
+                            xMin = Math.min(xMin, v.getX()); xMax = Math.max(xMax, v.getX());
+                            yMin = Math.min(yMin, v.getY()); yMax = Math.max(yMax, v.getY());
+                            zMin = Math.min(zMin, v.getZ()); zMax = Math.max(zMax, v.getZ());
+                            any = true;
+                        }
+                    }
+                }
+            }
+        }
+        if (!any) {
+            return new Vector3d(0, 0, 0);
+        }
+        return new Vector3d((xMax - xMin) / 2 + xMin, (yMax - yMin) / 2 + yMin, (zMax - zMin) / 2 + zMin);
+    }
+
+    private static Color chooseBase(Polygon p, Color fallback) {
+        Color rc = p.getRenderColor();
+        if (rc != null && !rc.equals(Color.WHITE)) {
+            return rc;
+        }
+        return fallback;
+    }
+
+    private static Vector3d findCenter(Collection<? extends Polygon> polygons) {
+        double xMin = Double.MAX_VALUE, yMin = Double.MAX_VALUE, zMin = Double.MAX_VALUE;
+        double xMax = -Double.MAX_VALUE, yMax = -Double.MAX_VALUE, zMax = -Double.MAX_VALUE;
+        for (Polygon p : polygons) {
+            for (Vector3d v : p.getExteriorRing().getVertices()) {
+                xMin = Math.min(xMin, v.getX()); xMax = Math.max(xMax, v.getX());
+                yMin = Math.min(yMin, v.getY()); yMax = Math.max(yMax, v.getY());
+                zMin = Math.min(zMin, v.getZ()); zMax = Math.max(zMax, v.getZ());
+            }
+        }
+        if (xMin > xMax) {
+            return new Vector3d(0, 0, 0);
+        }
+        return new Vector3d((xMax - xMin) / 2 + xMin, (yMax - yMin) / 2 + yMin, (zMax - zMin) / 2 + zMin);
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/SceneData.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import java.util.List;
+
+/** Immutable CPU-side result of building the scene; uploaded to the GPU by the GL layer. */
+public class SceneData {
+
+    private final float[] positions;
+    private final float[] colors;
+    private final int[] ids;
+    private final List<TriangleMeta> triangleMetas;
+    private final PickRegistry pickRegistry;
+    private final double[] center;
+
+    public SceneData(float[] positions, float[] colors, int[] ids,
+                     List<TriangleMeta> triangleMetas, PickRegistry pickRegistry, double[] center) {
+        this.positions = positions;
+        this.colors = colors;
+        this.ids = ids;
+        this.triangleMetas = triangleMetas;
+        this.pickRegistry = pickRegistry;
+        this.center = center;
+    }
+
+    public float[] positions() { return positions; }
+    public float[] colors() { return colors; }
+    public int[] ids() { return ids; }
+    public List<TriangleMeta> triangleMetas() { return triangleMetas; }
+    public PickRegistry pickRegistry() { return pickRegistry; }
+    public double[] center() { return center; }
+    public int triangleCount() { return triangleMetas.size(); }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/ShadeColor.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import de.hft.stuttgart.citydoctor2.math.UnitVector3d;
+import de.hft.stuttgart.citydoctor2.math.Vector3d;
+import javafx.scene.paint.Color;
+
+/**
+ * Computes the surface-differentiation shade used by the legacy renderer: brightness derived from the
+ * angle between the polygon normal and a fixed axis. Not physical lighting; only makes adjacent faces
+ * distinguishable. Ported from {@code TriangulatedGeometry.calculateMaterial}.
+ */
+public final class ShadeColor {
+
+    private static final UnitVector3d AXIS = new Vector3d(19, 0.8, 1.5).normalize();
+
+    private ShadeColor() {}
+
+    public static Color shade(Vector3d normal, Color base) {
+        double cos = normal.dot(AXIS);
+        // clamp to acos domain; raw dot can drift slightly outside [-1,1] for near-parallel normals
+        cos = Math.max(-1.0, Math.min(1.0, cos));
+        double brightness = Math.acos(cos) / Math.PI * 0.6 + 0.3; // -> [0.3, 0.9]
+        return base.deriveColor(0, 1.0, brightness, 1.0);
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/ShaderProgram.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import com.jogamp.opengl.GL3;
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.io.UncheckedIOException;
+import java.nio.charset.StandardCharsets;
+import java.util.stream.Collectors;
+
+/** Compiles and links a GLSL program from classpath resources next to this class. */
+public class ShaderProgram {
+
+    private final int program;
+
+    public ShaderProgram(GL3 gl, String vertexResource, String fragmentResource) {
+        this(gl, vertexResource, null, fragmentResource);
+    }
+
+    /** Builds a program with an optional geometry stage ({@code geometryResource} may be null). */
+    public ShaderProgram(GL3 gl, String vertexResource, String geometryResource, String fragmentResource) {
+        int vs = compile(gl, GL3.GL_VERTEX_SHADER, read(vertexResource));
+        int gs = geometryResource != null ? compile(gl, GL3.GL_GEOMETRY_SHADER, read(geometryResource)) : 0;
+        int fs = compile(gl, GL3.GL_FRAGMENT_SHADER, read(fragmentResource));
+        program = gl.glCreateProgram();
+        gl.glAttachShader(program, vs);
+        if (gs != 0) {
+            gl.glAttachShader(program, gs);
+        }
+        gl.glAttachShader(program, fs);
+        gl.glLinkProgram(program);
+        checkLink(gl, program);
+        gl.glDeleteShader(vs);
+        if (gs != 0) {
+            gl.glDeleteShader(gs);
+        }
+        gl.glDeleteShader(fs);
+    }
+
+    public void use(GL3 gl) { gl.glUseProgram(program); }
+
+    public int uniform(GL3 gl, String name) { return gl.glGetUniformLocation(program, name); }
+
+    public void dispose(GL3 gl) { gl.glDeleteProgram(program); }
+
+    private static int compile(GL3 gl, int type, String src) {
+        int shader = gl.glCreateShader(type);
+        gl.glShaderSource(shader, 1, new String[]{src}, new int[]{src.length()}, 0);
+        gl.glCompileShader(shader);
+        int[] status = new int[1];
+        gl.glGetShaderiv(shader, GL3.GL_COMPILE_STATUS, status, 0);
+        if (status[0] == 0) {
+            throw new IllegalStateException("Shader compile failed: " + infoLog(gl, shader, true));
+        }
+        return shader;
+    }
+
+    private static void checkLink(GL3 gl, int program) {
+        int[] status = new int[1];
+        gl.glGetProgramiv(program, GL3.GL_LINK_STATUS, status, 0);
+        if (status[0] == 0) {
+            throw new IllegalStateException("Program link failed: " + infoLog(gl, program, false));
+        }
+    }
+
+    private static String infoLog(GL3 gl, int handle, boolean shader) {
+        int[] len = new int[1];
+        if (shader) {
+            gl.glGetShaderiv(handle, GL3.GL_INFO_LOG_LENGTH, len, 0);
+        } else {
+            gl.glGetProgramiv(handle, GL3.GL_INFO_LOG_LENGTH, len, 0);
+        }
+        byte[] log = new byte[Math.max(1, len[0])];
+        if (shader) {
+            gl.glGetShaderInfoLog(handle, log.length, new int[1], 0, log, 0);
+        } else {
+            gl.glGetProgramInfoLog(handle, log.length, new int[1], 0, log, 0);
+        }
+        return new String(log, StandardCharsets.UTF_8);
+    }
+
+    private static String read(String resource) {
+        try (InputStream in = ShaderProgram.class.getResourceAsStream(resource)) {
+            if (in == null) {
+                throw new IllegalStateException("Shader resource not found: " + resource);
+            }
+            try (BufferedReader r = new BufferedReader(new InputStreamReader(in, StandardCharsets.UTF_8))) {
+                return r.lines().collect(Collectors.joining("\n"));
+            }
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/TriangleMeta.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import de.hft.stuttgart.citydoctor2.datastructure.Polygon;
+
+/**
+ * Metadata for one triangle in the global buffer.
+ * @param triangleIndex index of this triangle (vertices are 3*triangleIndex .. +2)
+ * @param polygon       source polygon (for picking/highlight resolution); may be null in tests
+ * @param lod           LOD ordinal (Lod.ordinal()) of the owning geometry
+ * @param roof          true if the triangle belongs to a ROOF boundary surface
+ */
+public record TriangleMeta(int triangleIndex, Polygon polygon, int lod, boolean roof) {}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/pick.frag

+#version 330 core
+flat in int vId;
+out vec4 fragColor;
+void main() {
+    int id = vId;
+    float r = float( id        & 0xFF) / 255.0;
+    float g = float((id >> 8)  & 0xFF) / 255.0;
+    float b = float((id >> 16) & 0xFF) / 255.0;
+    fragColor = vec4(r, g, b, 1.0);
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/pick.vert

+#version 330 core
+layout(location = 0) in vec3 aPos;
+layout(location = 2) in int  aId;
+uniform mat4 uMVP;
+flat out int vId;
+void main() {
+    gl_Position = uMVP * vec4(aPos, 1.0);
+    vId = aId;
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/point.frag

+#version 330 core
+in vec2 vQuad;
+in vec3 vColor;
+out vec4 fragColor;
+
+void main() {
+    float r2 = dot(vQuad, vQuad);
+    if (r2 > 1.0) {
+        discard; // outside the sphere's silhouette
+    }
+    fragColor = vec4(vColor, 1.0);
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/point.geom

+#version 330 core
+layout(points) in;
+layout(triangle_strip, max_vertices = 4) out;
+
+in vec3 vColorG[];
+
+uniform vec2 uViewport;   // framebuffer size in pixels
+uniform float uPointSize; // sphere diameter in pixels
+
+out vec2 vQuad;           // billboard-local coords in [-1, 1]
+out vec3 vColor;
+
+void main() {
+    vec4 c = gl_in[0].gl_Position;
+    if (c.w <= 0.0) {
+        return; // behind the camera
+    }
+    // half-extent in clip space for a constant on-screen pixel size
+    vec2 h = vec2(uPointSize / uViewport.x, uPointSize / uViewport.y) * c.w;
+    vColor = vColorG[0];
+
+    gl_Position = c + vec4(-h.x, -h.y, 0.0, 0.0); vQuad = vec2(-1.0, -1.0); EmitVertex();
+    gl_Position = c + vec4( h.x, -h.y, 0.0, 0.0); vQuad = vec2( 1.0, -1.0); EmitVertex();
+    gl_Position = c + vec4(-h.x,  h.y, 0.0, 0.0); vQuad = vec2(-1.0,  1.0); EmitVertex();
+    gl_Position = c + vec4( h.x,  h.y, 0.0, 0.0); vQuad = vec2( 1.0,  1.0); EmitVertex();
+    EndPrimitive();
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/point.vert

+#version 330 core
+layout(location = 0) in vec3 aPos;
+layout(location = 1) in vec3 aColor;
+uniform mat4 uMVP;
+out vec3 vColorG;
+void main() {
+    gl_Position = uMVP * vec4(aPos, 1.0);
+    vColorG = aColor;
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/scene.frag

+#version 330 core
+in vec3 vColor;
+out vec4 fragColor;
+void main() {
+    fragColor = vec4(vColor, 1.0);
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/main/resources/de/hft/stuttgart/citydoctor2/gui/gl/scene.vert

+#version 330 core
+layout(location = 0) in vec3 aPos;
+layout(location = 1) in vec3 aColor;
+uniform mat4 uMVP;
+out vec3 vColor;
+void main() {
+    gl_Position = uMVP * vec4(aPos, 1.0);
+    vColor = aColor;
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/test/java/de/hft/stuttgart/citydoctor2/gui/gl/FloatListTest.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import org.junit.Test;
+
+public class FloatListTest {
+
+    @Test
+    public void growsBeyondInitialCapacityAndPreservesOrder() {
+        FloatList list = new FloatList(2);
+        for (int i = 0; i < 10; i++) {
+            list.add(i);
+        }
+        assertEquals(10, list.size());
+        float[] expected = {0,1,2,3,4,5,6,7,8,9};
+        assertArrayEquals(expected, list.toArray(), 0.0f);
+    }
+
+    @Test
+    public void addThreeAddsAllInOrder() {
+        FloatList list = new FloatList(1);
+        list.add(1f, 2f, 3f);
+        assertArrayEquals(new float[]{1,2,3}, list.toArray(), 0.0f);
+    }
+
+    @Test
+    public void clearResetsSizeAndArray() {
+        FloatList list = new FloatList(4);
+        list.add(1f, 2f, 3f);
+        list.add(4f);
+        list.clear();
+        assertEquals(0, list.size());
+        assertEquals(0, list.toArray().length);
+    }
+}

CityDoctorParent/Extensions/CityDoctorGUI/src/test/java/de/hft/stuttgart/citydoctor2/gui/gl/IndexSetBuilderTest.java

+package de.hft.stuttgart.citydoctor2.gui.gl;
+
+import static org.junit.Assert.assertArrayEquals;
+import java.util.Arrays;
+import java.util.List;
+import java.util.function.Predicate;
+import org.junit.Test;
+
+public class IndexSetBuilderTest {
+
+    @Test
+    public void includesOnlyTrianglesMatchingThePredicate() {
+        List<TriangleMeta> metas = Arrays.asList(
+                new TriangleMeta(0, null, 1, false),
+                new TriangleMeta(1, null, 2, false),
+                new TriangleMeta(2, null, 1, false));
+        Predicate<TriangleMeta> onlyGroup1 = m -> m.lod() == 1;
+        int[] indices = IndexSetBuilder.build(metas, onlyGroup1);
+        assertArrayEquals(new int[]{0, 1, 2, 6, 7, 8}, indices);
+    }
+
+    @Test
+    public void emptyWhenNothingMatches() {
+        List<TriangleMeta> metas = Arrays.asList(new TriangleMeta(0, null, 1, false));
+        int[] indices = IndexSetBuilder.build(metas, m -> false);
+        assertArrayEquals(new int[]{}, indices);
+    }
+}