Method merge

src/main/java/field/graphics/MeshBuilder.java:858–919

Merges the geometry contained by "source" into this MeshBuilder. This is a relatively fast operation, consider caching sub-geometry inside individual MeshBuilders (and, of course, protecting this merge operation between two bookmarks).

(MeshBuilder source)

        if (target.elements == null && source.target.elements != null)
            throw new IllegalArgumentException(" cannot merge, mismatch in element dimension ");
        if (target.elements != null && source.target.elements == null)
            throw new IllegalArgumentException(" cannot merge, mismatch in element dimension ");
        if (target.elements == null && source.target.elements == null) {
        } else if (target.elements.getDimension() != source.target.elements.getDimension())
            throw new IllegalArgumentException(" cannot merge, mismatch in element dimension ");

        // thread shenanigans
        int sc = source.vertexCursor;
        FloatBuffer vv = source.target.vertex(true).asReadOnlyBuffer();
        vv.clear();
        vv.limit(sc * 3);
        FloatBuffer v = ensureSize(0, 3, vertexCursor + sc);
        v.put(vv);
        if (target.elements==null)
        {}
        else {
            IntBuffer e = ensureElementSize(target.elements.getDimension(), elementCursor + source.elementCursor);
            IntBuffer e2 = source.target.elements(true);
            for (int i = 0; i < source.elementCursor * target.elements.getDimension(); i++)
                e.put(e2.get() + vertexCursor);
        }


        Set<Integer> auxes = new LinkedHashSet<>();
        auxes.addAll(this.target.buffers()
                .keySet());
        auxes.addAll(source.target.buffers()
                .keySet());
        auxes.remove(0);

        for (Integer ii : auxes) {
            ArrayBuffer a = this.target.buffers[ii];
            ArrayBuffer b = source.target.buffers[ii];
            if (a == null && b == null) continue;

            if (a != null && b != null && a.getDimension() != b.getDimension())
                throw new IllegalArgumentException(
                        " dimension mismatch in merge " + a.getDimension() + "!=" + b.getDimension());
            if (b != null) {
                FloatBuffer left = ensureSize(ii, b.getDimension(), vertexCursor + source.vertexCursor);
                FloatBuffer right = b.floats();
                try {
                    right.limit(sc * b.getDimension());
                    left.put(right); // fill with blank ?
                }
                catch(BufferUnderflowException e)
                {
                    e.printStackTrace();
                }
            }
            if (b == null)
                ensureSize(ii, a.getDimension(), vertexCursor + source.vertexCursor); // fill with blank?
        }

        elementCursor += source.elementCursor;
        vertexCursor += source.vertexCursor;

        return this;