Method build

CodenameOne/src/com/codename1/gpu/GltfLoader.java:185–254

(GraphicsDevice device, Map root, byte[] binChunk)

    }

    private static Mesh build(GraphicsDevice device, Map root, byte[] binChunk) {
        List meshes = (List) root.get("meshes");
        if (meshes == null || meshes.isEmpty()) {
            throw new IllegalArgumentException("glTF has no meshes");
        }
        Map mesh = (Map) meshes.get(0);
        List primitives = (List) mesh.get("primitives");
        if (primitives == null || primitives.isEmpty()) {
            throw new IllegalArgumentException("glTF mesh has no primitives");
        }
        Map primitive = (Map) primitives.get(0);
        // Mode 4 (TRIANGLES) is the default and the only mode this loader builds.
        int mode = primitive.containsKey("mode") ? asInt(primitive.get("mode")) : 4;
        if (mode != 4) {
            throw new IllegalArgumentException("glTF primitive mode " + mode + " is not supported (TRIANGLES only)");
        }
        Map attributes = (Map) primitive.get("attributes");
        if (attributes == null || !attributes.containsKey("POSITION")) {
            throw new IllegalArgumentException("glTF primitive has no POSITION attribute");
        }

        List accessors = (List) root.get("accessors");
        List bufferViews = (List) root.get("bufferViews");
        List buffers = (List) root.get("buffers");

        float[] positions = readFloatAccessor(asInt(attributes.get("POSITION")), 3,
                accessors, bufferViews, buffers, binChunk);
        int vertexCount = positions.length / 3;
        float[] normals = attributes.containsKey("NORMAL")
                ? readFloatAccessor(asInt(attributes.get("NORMAL")), 3, accessors, bufferViews, buffers, binChunk)
                : null;
        float[] texcoords = attributes.containsKey("TEXCOORD_0")
                ? readFloatAccessor(asInt(attributes.get("TEXCOORD_0")), 2, accessors, bufferViews, buffers, binChunk)
                : null;

        int[] indices;
        if (primitive.containsKey("indices")) {
            indices = readIntAccessor(asInt(primitive.get("indices")), accessors, bufferViews, buffers, binChunk);
        } else {
            indices = new int[vertexCount];
            for (int i = 0; i < vertexCount; i++) {
                indices[i] = i;
            }
        }

        if (normals == null) {
            normals = computeFlatNormals(positions, indices);
        }

        float[] interleaved = new float[vertexCount * FLOATS_PER_VERTEX];
        for (int i = 0; i < vertexCount; i++) {
            int o = i * FLOATS_PER_VERTEX;
            interleaved[o] = positions[i * 3];
            interleaved[o + 1] = positions[i * 3 + 1];
            interleaved[o + 2] = positions[i * 3 + 2];
            interleaved[o + 3] = normals[i * 3];
            interleaved[o + 4] = normals[i * 3 + 1];
            interleaved[o + 5] = normals[i * 3 + 2];