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// [config]
// expect_result: pass
// glsl_version: 1.10
//
// [end config]
/*
* GStreamer
* Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#extension GL_ARB_texture_rectangle : enable
uniform sampler2DRect tex;
vec3 rgb2hsl (vec3 v)
{
/* TODO: check this algorythm */
float MIN, MAX;
float r, g, b;
float h, l, s;
float delta;
h = 0.0; l = 0.0; s = 0.0;
r = v.r; g = v.g; b = v.b;
MIN = min (r, min (g, b));
MAX = max (r, max (g, b));
delta = MAX - MIN;
l = (MAX + MIN) / 2.0;
if ((MAX - MIN) < 0.0001) { h = 0.0; s = 0.0; }
else {
if (l <= 0.5) s = (MAX - MIN) / (MAX + MIN);
else s = (MAX - MIN) / (2.0 - MAX - MIN);
if (r == MAX) h = (g - b) / delta;
else if (g == MAX) h = 2.0 + (b - r) / delta;
else h = 4.0 + (r - g) / delta;
h *= 60.0;
if (h < 0.0) h += 360.0;
}
return vec3 (h, l, s);
}
void main () {
vec3 HSL, RGB;
vec4 color = texture2DRect (tex, vec2(gl_TexCoord[0].st));
float luma = dot(color.rgb, vec3(0.2125, 0.7154, 0.0721));
HSL = rgb2hsl (color.rgb);
/* move hls discontinuity away from the desired red zone so we can use
* smoothstep.. to try: convert degrees in radiants, divide by 2 and
* smoothstep cosine */
HSL.x += 180.0;
if ((HSL.x) > 360.0) HSL.x -= 360.0;
/* damn, it is extremely hard to get rid of human face reds! */
/* picked hue is slightly shifted towards violet to prevent this but
* still fails.. maybe hsl is not well suited for this */
float a = smoothstep (110.0, 150.0, HSL.x);
float b = smoothstep (170.0, 210.0, HSL.x);
float alpha = a - b;
gl_FragColor = color * alpha + luma * (1.0 - alpha);
}
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