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/shaders.hpp

@@ -0,0 +1,69 @@
+// 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.
+//
+
+#include "vulkan/vulkan.hpp"
+#include <string>
+#include <vector>
+
+namespace vk
+{
+  namespace su
+  {
+    vk::UniqueShaderModule createShaderModule(vk::UniqueDevice &device, vk::ShaderStageFlagBits shaderStage, std::string const& shaderText);
+
+    bool GLSLtoSPV(const vk::ShaderStageFlagBits shaderType, std::string const& glslShader, std::vector<unsigned int> &spvShader);
+  }
+}
+
+
+const std::string vertexShaderText = R"(
+#version 400
+
+#extension GL_ARB_separate_shader_objects : enable
+#extension GL_ARB_shading_language_420pack : enable
+
+layout (std140, binding = 0) uniform bufferVals
+{
+  mat4 mvp;
+} myBufferVals;
+
+layout (location = 0) in vec4 pos;
+layout (location = 1) in vec4 inColor;
+
+layout (location = 0) out vec4 outColor;
+
+void main()
+{
+  outColor = inColor;
+  gl_Position = myBufferVals.mvp * pos;
+}
+)";
+
+const std::string fragmentShaderText = R"(
+#version 400
+
+#extension GL_ARB_separate_shader_objects : enable
+#extension GL_ARB_shading_language_420pack : enable
+
+layout (location = 0) in vec4 color;
+
+layout (location = 0) out vec4 outColor;
+
+void main()
+{
+  outColor = color;
+}
+)";
+