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

#pragma anki technique ForwardLegacy vert pixel

#include <AnKi/Shaders/ForwardShadingCommon.hlsl>
#include <AnKi/Shaders/Functions.hlsl>

#pragma anki struct AnKiLocalConstants
#pragma anki member Vec3 m_fogColor
#pragma anki member F32 m_fogAlphaScale
#pragma anki member F32 m_fogDistanceOfMaxThikness
#pragma anki struct_end

struct VertIn
{
	U32 m_svVertexId : SV_VERTEXID;
};

struct VertOut
{
	Vec4 m_svPosition : SV_POSITION;
	F32 m_zVSpace : ZVSPACE;
	nointerpolation U32 m_constantsOffset : CONSTANTS_OFFSET;
};

#if ANKI_VERTEX_SHADER
VertOut main(VertIn input)
{
	VertOut output;

	const GpuScenePerDraw perDraw = getGpuScenePerDraw();
	const GpuSceneMeshLod mesh = g_meshLods[perDraw.m_meshLodIndex];
	const Mat3x4 worldTransform = g_transforms[perDraw.m_worldTransformsIndex];
	const UnpackedMeshVertex vertex = loadVertex(mesh, input.m_svVertexId, false);

	const Vec3 worldPos = mul(worldTransform, Vec4(vertex.m_position, 1.0));
	output.m_svPosition = mul(g_globalConstants.m_viewProjectionMatrix, Vec4(worldPos, 1.0));

	const Vec3 viewPos = mul(g_globalConstants.m_viewTransform, Vec4(worldPos, 1.0));
	output.m_zVSpace = viewPos.z;

	output.m_constantsOffset = perDraw.m_constantsOffset;

	return output;
}
#endif // ANKI_VERTEX_SHADER

#if ANKI_PIXEL_SHADER
PixelOut main(VertOut input)
{
	PixelOut output = (PixelOut)0;
	const AnKiLocalConstants localConstants = loadAnKiLocalConstants(g_gpuScene, input.m_constantsOffset);

	fog(localConstants.m_fogColor, localConstants.m_fogAlphaScale, localConstants.m_fogDistanceOfMaxThikness, input.m_svPosition, input.m_zVSpace,
		output);

	return output;
}
#endif // ANKI_PIXEL_SHADER