#include "Common.hlsl"

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 RayHits rayPayload, SimpleBlocksAttributes attrib)
{
    if (rayPayload.hitCount < 0)
    { // shadow ray
        rayPayload.hitCount = 0;
        // TODO: transparent objects should lead to half shadows
        AcceptHitAndEndSearch();
        return;
    }
    int instanceId = InstanceID();
    int currentTriangle = PrimitiveIndex();
    int textureId = 0;
    int i;
    for (i = 0; currentTriangle >= 0 && polygonSizeBuffer[i] > 0; i++)
    {
        currentTriangle -= polygonSizeBuffer[i];
        textureId = textureIdBuffer[i];
    }
    if (polygonSizeBuffer[i] <= 0)
    {
        // Could not find geometry index, ignore hit
        IgnoreHit();
        return;
    }
    Texture2D<float4> texture = textures[textureId];
    int index = PrimitiveIndex() * 3;

    // Bounds check for vertex indices
    if (indexBuffer[index] < 0 || indexBuffer[index + 1] < 0 || indexBuffer[index + 2] < 0)
    {
        IgnoreHit();
        return;
    }

    VertexData v0 = vertexData[indexBuffer[index]];
    VertexData v1 = vertexData[indexBuffer[index + 1]];
    VertexData v2 = vertexData[indexBuffer[index + 2]];
    float3 normal = v0.normal * (1 - attrib.bary.x - attrib.bary.y) + v1.normal * attrib.bary.x + v2.normal * attrib.bary.y;
    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();
        return;
    }
    SingleHit hit;
    hit.color = color;
    hit.normal = normal;
    hit.distance = RayTCurrent();
    hit.dayLight = 0xFFFFFF;
    hit.dynamicLight = 0xFFFFFF;
    applyHit(rayPayload, hit);
    if (color.w < 1.f)
    {
        IgnoreHit();
        return;
    }
}