Add HighlightOverlay dynamic marker buffers

CityDoctorParent/Extensions/CityDoctorGUI/src/main/java/de/hft/stuttgart/citydoctor2/gui/gl/HighlightOverlay.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;
+import java.nio.FloatBuffer;
+import java.nio.IntBuffer;
+
+/**
+ * Dynamic overlay for highlight markers: points for vertices, lines for edges. Positions are in the same
+ * recentred world space as the scene. Colour rides in the color attribute; id attribute is 0.
+ */
+public class HighlightOverlay {
+
+    private int pointVao;
+    private int pointPos;
+    private int pointColor;
+    private int pointId;
+    private int pointCount;
+
+    private int lineVao;
+    private int linePos;
+    private int lineColor;
+    private int lineId;
+    private int lineVertexCount;
+
+    private boolean created;
+
+    public void init(GL3 gl) {
+        int[] v = new int[2];
+        gl.glGenVertexArrays(2, v, 0);
+        pointVao = v[0];
+        lineVao = v[1];
+        int[] b = new int[6];
+        gl.glGenBuffers(6, b, 0);
+        pointPos = b[0]; pointColor = b[1]; pointId = b[2];
+        linePos = b[3]; lineColor = b[4]; lineId = b[5];
+        created = true;
+    }
+
+    /** points: xyz triplets; pointColors: rgb triplets (one per point). */
+    public void setPoints(GL3 gl, float[] points, float[] pointColors) {
+        pointCount = points.length / 3;
+        configure(gl, pointVao, pointPos, points, pointColor, pointColors, pointId, pointCount);
+    }
+
+    /** lines: xyz pairs of endpoints (6 floats per segment); lineColors: rgb per line vertex. */
+    public void setLines(GL3 gl, float[] lines, float[] lineColors) {
+        lineVertexCount = lines.length / 3;
+        configure(gl, lineVao, linePos, lines, lineColor, lineColors, lineId, lineVertexCount);
+    }
+
+    private void configure(GL3 gl, int vao, int posVbo, float[] pos, int colVbo, float[] col,
+                           int idVbo, int vertexCount) {
+        gl.glBindVertexArray(vao);
+        bindFloat(gl, posVbo, pos, 0, 3);
+        bindFloat(gl, colVbo, col, 1, 3);
+        // id attribute all zeros so overlay never matches uSelectedId
+        int[] zeros = new int[vertexCount];
+        gl.glBindBuffer(GL.GL_ARRAY_BUFFER, idVbo);
+        gl.glBufferData(GL.GL_ARRAY_BUFFER, (long) zeros.length * Integer.BYTES, toInt(zeros),
+                GL.GL_DYNAMIC_DRAW);
+        gl.glEnableVertexAttribArray(2);
+        gl.glVertexAttribIPointer(2, 1, GL3.GL_INT, 0, 0L);
+        gl.glBindVertexArray(0);
+    }
+
+    private void bindFloat(GL3 gl, int vbo, float[] data, int loc, int comp) {
+        gl.glBindBuffer(GL.GL_ARRAY_BUFFER, vbo);
+        gl.glBufferData(GL.GL_ARRAY_BUFFER, (long) data.length * Float.BYTES, toFloat(data),
+                GL.GL_DYNAMIC_DRAW);
+        gl.glEnableVertexAttribArray(loc);
+        gl.glVertexAttribPointer(loc, comp, GL.GL_FLOAT, false, 0, 0L);
+    }
+
+    public void draw(GL3 gl, float pointSize) {
+        if (!created) {
+            return;
+        }
+        if (lineVertexCount > 0) {
+            gl.glBindVertexArray(lineVao);
+            gl.glDrawArrays(GL.GL_LINES, 0, lineVertexCount);
+        }
+        if (pointCount > 0) {
+            gl.glPointSize(pointSize);
+            gl.glBindVertexArray(pointVao);
+            gl.glDrawArrays(GL.GL_POINTS, 0, pointCount);
+        }
+        gl.glBindVertexArray(0);
+    }
+
+    public void clear() {
+        pointCount = 0;
+        lineVertexCount = 0;
+    }
+
+    private static FloatBuffer toFloat(float[] d) {
+        FloatBuffer fb = ByteBuffer.allocateDirect(Math.max(1, d.length) * Float.BYTES)
+                .order(ByteOrder.nativeOrder()).asFloatBuffer();
+        fb.put(d).flip();
+        return fb;
+    }
+
+    private static IntBuffer toInt(int[] d) {
+        IntBuffer ib = ByteBuffer.allocateDirect(Math.max(1, d.length) * Integer.BYTES)
+                .order(ByteOrder.nativeOrder()).asIntBuffer();
+        ib.put(d).flip();
+        return ib;
+    }
+}