Extend set of samples (#296)

+ 12_InitFrameBuffers, 13_InitVertexBuffer, 14_InitPipeline, 15_DrawCube;
+ extend utilities and add utilities on geometries, math, and shaders
+ slightly adjust some other samples

samples/utils/math.hpp

@@ -0,0 +1,26 @@
+// Copyright(c) 2019, NVIDIA CORPORATION. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+#define GLM_FORCE_RADIANS
+#pragma warning(disable:4201)   // disable warning C4201: nonstandard extension used: nameless struct/union; needed to get glm/detail/type_vec?.hpp without warnings
+#include <glm/gtc/matrix_transform.hpp>
+
+namespace vk
+{
+  namespace su
+  {
+    glm::mat4x4 createModelViewProjectionClipMatrix();
+  }
+}