Make CHelloTriangle in C++ to simplify Utils

The point of CHelloTriangle is to use the C version of NXT, so having
the code C++ is still ok.

examples/CHelloTriangle.cpp

@@ -0,0 +1,107 @@
+// Copyright 2017 The NXT Authors
+//
+// 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 "Utils.h"
+
+nxtDevice device;
+nxtQueue queue;
+nxtPipeline pipeline;
+nxtRenderPass renderpass;
+nxtFramebuffer framebuffer;
+
+void init() {
+    device = CreateCppNXTDevice().Release();
+
+    {
+        nxtQueueBuilder builder = nxtDeviceCreateQueueBuilder(device);
+        queue = nxtQueueBuilderGetResult(builder);
+        nxtQueueBuilderRelease(builder);
+    }
+
+    const char* vs =
+        "#version 450\n"
+        "const vec2 pos[3] = vec2[3](vec2(0.0f, 0.5f), vec2(-0.5f, -0.5f), vec2(0.5f, -0.5f));\n"
+        "void main() {\n"
+        "   gl_Position = vec4(pos[gl_VertexIndex], 0.0, 1.0);\n"
+        "}\n";
+    nxtShaderModule vsModule = CreateShaderModule(nxt::Device(device), nxt::ShaderStage::Vertex, vs).Release();
+
+    const char* fs =
+        "#version 450\n"
+        "out vec4 fragColor;"
+        "void main() {\n"
+        "   fragColor = vec4(1.0, 0.0, 0.0, 1.0);\n"
+        "}\n";
+    nxtShaderModule fsModule = CreateShaderModule(device, nxt::ShaderStage::Fragment, fs).Release();
+
+    {
+        nxtRenderPassBuilder builder = nxtDeviceCreateRenderPassBuilder(device);
+        nxtRenderPassBuilderSetAttachmentCount(builder, 1);
+        nxtRenderPassBuilderAttachmentSetFormat(builder, 0, NXT_TEXTURE_FORMAT_R8_G8_B8_A8_UNORM);
+        nxtRenderPassBuilderSetSubpassCount(builder, 1);
+        nxtRenderPassBuilderSubpassSetColorAttachment(builder, 0, 0, 0);
+        renderpass = nxtRenderPassBuilderGetResult(builder);
+        nxtRenderPassBuilderRelease(builder);
+    }
+    {
+        nxtFramebufferBuilder builder = nxtDeviceCreateFramebufferBuilder(device);
+        nxtFramebufferBuilderSetRenderPass(builder, renderpass);
+        nxtFramebufferBuilderSetDimensions(builder, 640, 480);
+        framebuffer = nxtFramebufferBuilderGetResult(builder);
+        nxtFramebufferBuilderRelease(builder);
+    }
+    {
+        nxtPipelineBuilder builder = nxtDeviceCreatePipelineBuilder(device);
+        nxtPipelineBuilderSetSubpass(builder, renderpass, 0);
+        nxtPipelineBuilderSetStage(builder, NXT_SHADER_STAGE_VERTEX, vsModule, "main");
+        nxtPipelineBuilderSetStage(builder, NXT_SHADER_STAGE_FRAGMENT, fsModule, "main");
+        pipeline = nxtPipelineBuilderGetResult(builder);
+        nxtPipelineBuilderRelease(builder);
+    }
+
+    nxtShaderModuleRelease(vsModule);
+    nxtShaderModuleRelease(fsModule);
+}
+
+void frame() {
+    nxtCommandBuffer commands;
+    {
+        nxtCommandBufferBuilder builder = nxtDeviceCreateCommandBufferBuilder(device);
+        nxtCommandBufferBuilderBeginRenderPass(builder, renderpass, framebuffer);
+        nxtCommandBufferBuilderSetPipeline(builder, pipeline);
+        nxtCommandBufferBuilderDrawArrays(builder, 3, 1, 0, 0);
+        nxtCommandBufferBuilderEndRenderPass(builder);
+        commands = nxtCommandBufferBuilderGetResult(builder);
+        nxtCommandBufferBuilderRelease(builder);
+    }
+
+    nxtQueueSubmit(queue, 1, &commands);
+    nxtCommandBufferRelease(commands);
+
+    DoSwapBuffers();
+}
+
+int main(int argc, const char* argv[]) {
+    if (!InitUtils(argc, argv)) {
+        return 1;
+    }
+    init();
+
+    while (!ShouldQuit()) {
+        frame();
+        USleep(16000);
+    }
+
+    // TODO release stuff
+}