import bindless;
import ibl_common;
import common_structs;

const static float3 trianglePoints[] = {
    float3(-1.0f, -1.0f, 1.0f),
    float3(3.0f, -1.0f, 1.0f),
    float3(-1.0f, 3.0f, 1.0f),
};

[vk::push_constant]
uniform Block pcb;

struct VS_Output
{
    float4 vertexPosition : SV_Position;
    float3 worldPosition : World_Position;
};

[shader("vertex")]
VS_Output vsmain(
    uint vertexId : SV_VertexID
)
{
    VS_Output stageOutput;
    stageOutput.vertexPosition = float4(trianglePoints[vertexId], 1.0f);

    float4 clipSpace = mul(float4(trianglePoints[vertexId], 1.0f), pcb.camera->invProj);
    float4 worldSpace = mul(clipSpace / clipSpace.wwww, pcb.camera->invView);
    stageOutput.worldPosition = worldSpace.xyz;
    
    return stageOutput;
}

[shader("fragment")]
float4 fsmain(float3 worldPosition: World_Position) : SV_Target0
{
    float3 direction = normalize(worldPosition - pcb.camera->position.xyz);
#ifndef _DEBUG
    float4 color = pcb.lights->environment.Sample(direction);
#else
    float4 color;
    if (pcb.showDiffuse)
    {
        color = pcb.lights->diffuseIrradiance.Sample(direction);
    }
    else if (pcb.showPrefilter)
    {
        color = pcb.lights->prefilter.Sample(direction);
    }
    else
    {
        color = pcb.lights->environment.Sample(direction);
    }
#endif
    return float4(Uncharted2Tonemap(color.rgb), color.a);
}