global-type-param2.slang

//DISABLED_TEST(smoke,compute):COMPARE_COMPUTE:

//TEST_INPUT: ubuffer(data=[0], stride=4):out,name outputBuffer
//TEST_INPUT: cbuffer(data=[0.5 0 0 0], stride=4):name existingBuffer
//__disabled__TEST_INPUT: object(type=Impl):name impl
//TEST_INPUT: root_constants(data=[1.0], stride=4):name impl.base
//TEST_INPUT: Texture2D(size=4, content = zero):name tex1
//TEST_INPUT: Texture2D(size=4, content = one):name impl.tex
//TEST_INPUT: Sampler:name sampler
//TEST_INPUT: Sampler:name impl.sampler
//TEST_INPUT: type Impl


/* Testing this scenario: 
The ProgramLayout before specializeIRForEntryPoint() has no global cbuffer
allocated because the program before specialization does not define any
global uniform variables.

However, after specialization, we find ourselves needing a global constant
buffer. The compiler should allocate the next available constant buffer slot
(here c1 because c0 is already used by the explicit cbuffer decl `existingBuffer`)
for the newly generated global constant buffer.
*/

RWStructuredBuffer<float> outputBuffer;

interface IBase
{
    float compute();
}

struct Impl : IBase
{
    float base;  // = 1.0
    Texture2D tex;
    SamplerState sampler;
    float compute()
    {
        return tex.SampleLevel(sampler, float2(0.0), 0.0).x + base;
    }
};

// at binding c0:
cbuffer existingBuffer
{
	float base0; // = 0.5
}
Texture2D tex1;  // = 0.0
SamplerState sampler;

[numthreads(1, 1, 1)]
void computeMain<
    TImpl : IBase>(
    uniform ParameterBlock<TImpl> impl,
    uint3 dispatchThreadID : SV_DispatchThreadID)
{
	uint tid = dispatchThreadID.x;
    float b0 = tex1.SampleLevel(sampler, float2(0.0), 0.0).x + base0; // = 0.5
	float outVal = impl.compute();  // = 2.0
    outVal = b0 / outVal; // = 0.25
	outputBuffer[tid] = outVal;
}