<!
//  MeshDeformer.slh
//  Created by Sam Gateau on 9/20/2018
//  Copyright 2018 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
!>
<@if not MESH_DEFORMER_SLH@>
<@def MESH_DEFORMER_SLH@>
//  MeshDeformer.slh

<@func declareMeshDeformer(USE_NORMAL, USE_TANGENT, USE_SKINNING, USE_DUAL_QUATERNION, USE_BLENDSHAPE)@>

<@if USE_SKINNING@>
<@include Skinning.slh@>
<$declareSkinning($USE_DUAL_QUATERNION$, $USE_NORMAL$, $USE_TANGENT$)$>
<@endif@>

<@if USE_BLENDSHAPE@>
<@include Blendshape.slh@>
<$declareBlendshape($USE_NORMAL$, $USE_TANGENT$)$>
<@endif@>

void evalMeshDeformer(vec4 inPosition, out vec4 outPosition
    <@if USE_NORMAL@>
        , vec3 inNormal, out vec3 outNormal
    <@endif@>
    <@if USE_TANGENT@>
        , vec3 inTangent, out vec3 outTangent
    <@endif@>
    <@if USE_SKINNING@>
        , bool isSkinningEnabled, ivec4 skinClusterIndex, vec4 skinClusterWeight
    <@endif@>
    <@if USE_BLENDSHAPE@>
        , bool isBlendshapeEnabled, int vertexIndex
    <@endif@>
) {

        vec4 _deformedPosition = inPosition;
    <@if USE_NORMAL@>
        vec3 _deformedNormal = inNormal;
    <@endif@>
    <@if USE_TANGENT@>
        vec3 _deformedTangent = inTangent;
    <@endif@>

<@if USE_BLENDSHAPE@>
    if (isBlendshapeEnabled) {
        evalBlendshape(vertexIndex, inPosition, _deformedPosition
    <@if USE_NORMAL@>
                        , inNormal, _deformedNormal
    <@endif@>
    <@if USE_TANGENT@>
                        , inTangent, _deformedTangent
    <@endif@>
        );
    }
<@endif@>

<@if USE_SKINNING@>
    if (isSkinningEnabled) {

        evalSkinning(inSkinClusterIndex, inSkinClusterWeight, _deformedPosition, _deformedPosition
    <@if USE_NORMAL@>
                        , _deformedNormal, _deformedNormal
    <@endif@>
    <@if USE_TANGENT@>
                        , _deformedTangent, _deformedTangent
    <@endif@>
        );
    }
<@endif@>

    outPosition = _deformedPosition;
<@if USE_NORMAL@>
    outNormal = _deformedNormal;
<@endif@>
<@if USE_TANGENT@>
    outTangent = _deformedTangent;
<@endif@>
}

<@endfunc@>

<@func declareMeshDeformerActivation(USE_SKINNING, USE_BLENDSHAPE)@>

const BITFIELD MESH_DEFORMER_BLENDSHAPE_BIT              = 0x00000001;
const BITFIELD MESH_DEFORMER_SKINNING_BIT                = 0x00000002;

<@if USE_BLENDSHAPE@>
bool meshDeformer_doBlendshape(int meshKey) { 
    return ((meshKey & MESH_DEFORMER_BLENDSHAPE_BIT) != 0);
}
<@endif@>

<@if USE_SKINNING@>
bool meshDeformer_doSkinning(int meshKey) { 
    return ((meshKey & MESH_DEFORMER_SKINNING_BIT) != 0);
}
<@endif@>

<@endfunc@>


<@endif@> // if not MESH_DEFORMER_SLH