bgfx/examples/14-shadowvolumes/vs_shadowvolume_svback.sc

$input a_position

/*
 * Copyright 2013-2014 Dario Manesku. All rights reserved.
 * License: http://www.opensource.org/licenses/BSD-2-Clause
 */

#include "../common/common.sh"

uniform vec4 u_virtualLightPos_extrusionDist;

#define u_virtualLightPos   u_virtualLightPos_extrusionDist.xyz
#define u_extrusionDistance u_virtualLightPos_extrusionDist.w

void main()
{
	vec3 pos = a_position;

	vec3 toLight = pos - u_virtualLightPos;
	pos += normalize(toLight) * u_extrusionDistance;

	gl_Position = mul(u_modelViewProj, vec4(pos, 1.0));
}