KSG-Framework/AnyHit.hlsl

#include "Common.hlsl"

Texture2D<float4> textures[] : register(t0, space1);
SamplerState gSampler : register(s0, space0);

struct VertexData
{
    float2 texcoord;
    float3 normal;
};

StructuredBuffer<int> textureIdBuffer : register(t1, space2);
StructuredBuffer<int> indexBuffer : register(t1, space3);
StructuredBuffer<VertexData> vertexData : register(t1, space4);
StructuredBuffer<int> polygonSizeBuffer : register(t1, space5);

[shader("anyhit")]
void AnyHit(inout HitInfo payload, Attributes attrib)
{
    //payload.colorAndDistance = float4(1, 1, 1, 1.0);
    int instanceId = InstanceID();
    int currentTriangle = PrimitiveIndex();
    int textureId = 0;
    for (int i = 0; currentTriangle >= 0; i++)
    {
        currentTriangle -= polygonSizeBuffer[i];
        textureId = textureIdBuffer[i];
    }
    Texture2D<float4> texture = textures[textureId];
    int index = PrimitiveIndex() * 3;
    VertexData v0 = vertexData[indexBuffer[index]];
    VertexData v1 = vertexData[indexBuffer[index + 1]];
    VertexData v2 = vertexData[indexBuffer[index + 2]];
    float2 texcoord = v0.texcoord * (1 - attrib.bary.x - attrib.bary.y) + v1.texcoord * attrib.bary.x + v2.texcoord * attrib.bary.y;
    float4 color = texture.SampleLevel(gSampler, texcoord, 0);
    if (color.w == 0.f)
    {
        IgnoreHit();
    }
    float distance = RayTCurrent();
    bool found = false;
    for (int i = 0; i < payload.hitCount; i++)
    {
        if (payload.distance[i] > distance)
        {
            found = true;
            float4 tmpColor = payload.color[i];
            payload.color[i] = color;
            float tmpDistance = payload.distance[i];
            payload.distance[i] = distance;
            if (color.w == 1.f)
            {
                payload.hitCount = i + 1;
            }
            else
            {
                for (int j = i + 1; j < payload.hitCount + 1 && j < MAX_TRANSPACENT_HITS; j++)
                {
                    float4 tmpColor2 = payload.color[j];
                    float tmpDistance2 = payload.distance[j];
                    payload.color[j] = tmpColor;
                    payload.distance[j] = tmpDistance;
                    tmpColor = tmpColor2;
                    tmpDistance = tmpDistance2;
                }
            }
            break;
        }
        else
        {
            if (payload.color[i].w == 1.f)
            {
                found = true;
                break;
            }
        }
    }
    if (!found && payload.hitCount < MAX_TRANSPACENT_HITS)
    {
        payload.color[payload.hitCount] = color;
        payload.distance[payload.hitCount] = distance;
        payload.hitCount++;
    }
    if (color.w < 1.f)
    {
        IgnoreHit();
    }
}