/** 
 * @file terrainV.glsl
 *
 * $LicenseInfo:firstyear=2007&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2007, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

uniform mat3 normal_matrix;
uniform mat4 texture_matrix0;
uniform mat4 modelview_projection_matrix;

ATTRIBUTE vec3 position;
ATTRIBUTE vec3 normal;
ATTRIBUTE vec4 diffuse_color;
ATTRIBUTE vec2 texcoord0;
ATTRIBUTE vec2 texcoord1;

VARYING vec3 pos;
VARYING vec3 vary_normal;
VARYING vec4 vary_texcoord0;
VARYING vec4 vary_texcoord1;

uniform vec4 object_plane_s;
uniform vec4 object_plane_t;

vec4 texgen_object(vec4  vpos, vec4 tc, mat4 mat, vec4 tp0, vec4 tp1)
{
    vec4 tcoord;
    
    tcoord.x = dot(vpos, tp0);
    tcoord.y = dot(vpos, tp1);
    tcoord.z = tc.z;
    tcoord.w = tc.w;
    
    tcoord = mat * tcoord; 
    
    return tcoord; 
}

void main()
{
    //transform vertex
    vec4 pre_pos = vec4(position.xyz, 1.0);
    vec4 t_pos = modelview_projection_matrix * pre_pos;

    gl_Position = t_pos;
    pos = t_pos.xyz;

    vary_normal = normalize(normal_matrix * normal);
    
    // Transform and pass tex coords
    vary_texcoord0.xy = texgen_object(vec4(position, 1.0), vec4(texcoord0,0,1), texture_matrix0, object_plane_s, object_plane_t).xy;
    
    vec4 t = vec4(texcoord1,0,1);
    
    vary_texcoord0.zw = t.xy;
    vary_texcoord1.xy = t.xy-vec2(2.0, 0.0);
    vary_texcoord1.zw = t.xy-vec2(1.0, 0.0);
}