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/**
* @file normgenF.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
* $/LicenseInfo$
*/
/*[EXTRA_CODE_HERE]*/
// generate a normal map using an approximation of the old emboss bump map "brightness/darkness" technique
// srcMap is a source color image, output should be a normal
out vec4 frag_color;
uniform sampler2D srcMap;
in vec2 vary_texcoord0;
uniform float stepX;
uniform float stepY;
uniform float norm_scale;
uniform int bump_code;
#define BE_BRIGHTNESS 1
#define BE_DARKNESS 2
// get luminance or inverse luminance depending on bump_code
float getBumpValue(vec2 texcoord)
{
vec3 c = texture(srcMap, texcoord).rgb;
vec3 WEIGHT = vec3(0.2995, 0.5875, 0.1145);
float l = dot(c, WEIGHT);
if (bump_code == BE_DARKNESS)
{
l = 1.0 - l;
}
return l;
}
void main()
{
float c = getBumpValue(vary_texcoord0);
float scaler = 512.0;
vec3 right = vec3(norm_scale, 0, (getBumpValue(vary_texcoord0+vec2(stepX, 0))-c)*scaler);
vec3 left = vec3(-norm_scale, 0, (getBumpValue(vary_texcoord0-vec2(stepX, 0))-c)*scaler);
vec3 up = vec3(0, -norm_scale, (getBumpValue(vary_texcoord0-vec2(0, stepY))-c)*scaler);
vec3 down = vec3(0, norm_scale, (getBumpValue(vary_texcoord0+vec2(0, stepY))-c)*scaler);
vec3 norm = cross(right, down) + cross(down, left) + cross(left,up) + cross(up, right);
norm = normalize(norm);
norm *= 0.5;
norm += 0.5;
frag_color = vec4(norm, c);
}
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