<@include gpu/Config.slh@>
<$VERSION_HEADER$>
//  Generated on <$_SCRIBE_DATE$>
//
//  skin_model.vert
//  vertex shader
//
//  Created by Andrzej Kapolka on 10/14/13.
//  Copyright 2013 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
//

<@include gpu/Transform.slh@>
<$declareStandardTransform()$>

const int MAX_TEXCOORDS = 2;
const int MAX_CLUSTERS = 128;
const int INDICES_PER_VERTEX = 4;

uniform mat4 clusterMatrices[MAX_CLUSTERS];
uniform mat4 texcoordMatrices[MAX_TEXCOORDS];

attribute vec4 clusterIndices;
attribute vec4 clusterWeights;

// the interpolated normal
varying vec4 normal;

varying vec3 color;

void main(void) {
    vec4 position = vec4(0.0, 0.0, 0.0, 0.0);
    normal = vec4(0.0, 0.0, 0.0, 0.0);
    for (int i = 0; i < INDICES_PER_VERTEX; i++) {
        mat4 clusterMatrix = clusterMatrices[int(clusterIndices[i])];
        float clusterWeight = clusterWeights[i];
        position += clusterMatrix * gl_Vertex * clusterWeight;
        normal += clusterMatrix * vec4(gl_Normal, 0.0) * clusterWeight;
    }

    // pass along the diffuse color
    color = gl_Color.xyz;

    // and the texture coordinates
    gl_TexCoord[0] = texcoordMatrices[0] * vec4(gl_MultiTexCoord0.xy, 0.0, 1.0);
    
    // standard transform
    TransformCamera cam = getTransformCamera();
    TransformObject obj = getTransformObject();
    <$transformModelToClipPos(cam, obj, position, gl_Position)$>
    <$transformModelToEyeDir(cam, obj, normal.xyz, normal.xyz)$>

    normal = vec4(normalize(normal.xyz), 0.0);
}