Function initialize

Examples/hello/hello.cpp:78–223

At initialization time, we are going to load and compile our Spire shader code, and then create the D3D11 API objects we need for rendering.

// code, and then create the D3D11 API objects we need for rendering.
//
HRESULT initialize( ID3D11Device* dxDevice )
{
    //
    // First, we will load and compile our Spire source code.
    //

    // The argument here is an optional directory where the Spire compiler
    // can cache files to speed up compilation of many kernels.
    SpireCompilationContext* spireContext = spCreateCompilationContext(NULL);

    // A diagnostic sink is used to collect output messages from the Spire
    // compiler, so that we can easily iterate over them if an operation
    // fails.
    SpireDiagnosticSink* spireSink = spCreateDiagnosticSink(spireContext);

    // Instruct Spire to generate code as HLSL
    spSetCodeGenTarget(spireContext, SPIRE_HLSL);

    // Load a file of Spire source code, which defines our modules
    spLoadModuleLibrary(spireContext, "hello.spire", spireSink);

    // Inspect any error messages that got reported...
    emitSpireDiagnostics(spireSink);

    //
    // Once the source Spire has been loaded, we can assemble the modules
    // there to make one or more shaders. In our case, we really only
    // have one shader that we will use, so this step is kind of redundant.
    //

    // Create a shader, which will initially be empty
    char const* shaderName = "HelloShader";
	SpireShader* spireShader = spCreateShaderFromSource(spireContext, R"(
		template shader HelloShader(module0) targets StandardPipeline
		{
			using module0;
		}
	)");

	SpireModule * helloModule = spFindModule(spireContext, "HelloModule");

    // Compile the constructed shader
    SpireCompilationResult* spireResult = spCompileShader(spireContext, spireShader, &helloModule, 1, nullptr, spireSink);

    // Inspect any error messages that got reported...
    emitSpireDiagnostics(spireSink);

    //
    // Once we've compiled things successfully, we can extract the HLSL kernel
    // code for our shader, and pass it on to the D3D API.
    //

    // TODO(tfoley): The implementation should allow `NULL` for the length
    // output parameter.
    int sourceCodeLength;

    char const* vertexShaderCode = spGetShaderStageSource(spireResult, nullptr, "vs", &sourceCodeLength);
    char const* fragmentShaderCode = spGetShaderStageSource(spireResult, nullptr, "fs", &sourceCodeLength);