<@include gpu/Config.slh@>
<$VERSION_HEADER$>
//  Generated on <$_SCRIBE_DATE$>
//
//  deferred_light_spot.vert
//  vertex shader
//
//  Created by Sam Gateau on 7/8/15.
//  Copyright 2015 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/Inputs.slh@>

<@include gpu/Transform.slh@>

<$declareStandardTransform()$>

<@include graphics/Light.slh@>
<$declareLightBuffer(256)$>

uniform lightIndexBuffer {
    int lightIndex[256];
};
out vec4 _texCoord0;

void main(void) {
    vec4 coneVertex = inPosition;
    int instanceID = lightIndex[gl_InstanceID];
    Light light = getLight(instanceID);
    vec3 lightPos = getLightPosition(light);
    vec4 coneParam = vec4(1.0); // = getLightVolumeGeometry(light);

    if(coneVertex.z >= 0.0) {
        // Evaluate the true position of the spot volume
        vec2 dir =  float(coneVertex.z < 0.5f) * (coneParam.xy
                        +   vec2(coneParam.y, -coneParam.x) * coneParam.z * float(coneVertex.z > 0.0f))
                    +  float(coneVertex.z > 0.5f) * (vec2(1.0, 0.0)
                        +   vec2(0.0, coneParam.z) * float(coneVertex.z < 1.0f));

        coneVertex.xy *= dir.y;
        coneVertex.z = -dir.x;
    } else {
        coneVertex.z = 0.0;
    } 

    coneVertex.xyz *= coneParam.w;

    coneVertex.xyz += lightPos;

    // standard transform
    TransformCamera cam = getTransformCamera();
    <$transformWorldToClipPos(cam, coneVertex, gl_Position)$>;

    vec4 projected = gl_Position / gl_Position.w;
    projected.xy = (projected.xy + 1.0) * 0.5;

#ifdef GPU_TRANSFORM_IS_STEREO
#ifdef GPU_TRANSFORM_STEREO_SPLIT_SCREEN
#else
        if (cam_isStereo()) {
            projected.x = 0.5 * (projected.x + cam_getStereoSide());
        }
#endif
#endif
    _texCoord0 = vec4(projected.xy, 0.0, 1.0) * gl_Position.w;
}