// Copyright (C) 2009-present, Panagiotis Christopoulos Charitos and contributors.
// All rights reserved.
// Code licensed under the BSD License.
// http://www.anki3d.org/LICENSE

#include <AnKi/Shaders/RtShadows.hlsl>
#include <AnKi/Shaders/Include/GpuSceneTypes.h>

#pragma anki technique comp

StructuredBuffer<GpuSceneRenderable> g_renderables : register(t0);
ByteAddressBuffer g_gpuScene : register(t1);

StructuredBuffer<U32> g_visibleRenderableIndices : register(t2); // 1st element is the count

StructuredBuffer<U32> g_shaderHandles : register(t3);

RWStructuredBuffer<U32> g_sbtBuffer : register(u0);

ANKI_FAST_CONSTANTS(RtShadowsSbtBuildConstants, g_consts)

#define NUMTHREADS 64

[numthreads(NUMTHREADS, 1, 1)] void main(U32 svDispatchThreadId : SV_DISPATCHTHREADID)
{
	const U32 renderableCount = g_visibleRenderableIndices[0];
	if(svDispatchThreadId >= renderableCount)
	{
		return;
	}

	const GpuSceneRenderable renderable = g_renderables[g_visibleRenderableIndices[svDispatchThreadId + 1]];

	U32 sbtDwordOffset = g_consts.m_sbtRecordDwordSize * 2; // Skip raygen and miss shaders which are first
	sbtDwordOffset += g_consts.m_sbtRecordDwordSize * svDispatchThreadId;

	// Copy the handle
	for(U32 i = 0; i < g_consts.m_shaderHandleDwordSize; ++i)
	{
		g_sbtBuffer[sbtDwordOffset] = g_shaderHandles[renderable.m_rtShadowsShaderHandleIndex * g_consts.m_shaderHandleDwordSize + i];
		++sbtDwordOffset;
	}

	// Copy the GpuScenePerDraw
	g_sbtBuffer[sbtDwordOffset++] = renderable.m_worldTransformsIndex;
	g_sbtBuffer[sbtDwordOffset++] = renderable.m_constantsOffset;
	g_sbtBuffer[sbtDwordOffset++] = renderable.m_meshLodsIndex;
	g_sbtBuffer[sbtDwordOffset] = 0;
}