/*
 * Copyright (C) 2019 Computer Graphics Group, University of Siegen
 * Written by Martin Lambers <martin.lambers@uni-siegen.de>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

uniform sampler2D tex;

smooth in vec2 vtexcoord;

layout(location = 0) out vec4 fcolor;

float linear_to_s(float x)
{
    const float c0 = 0.416666666667; // 1.0 / 2.4;
    return (x <= 0.0031308 ? (x * 12.92) : (1.055 * pow(x, c0) - 0.055));
}

vec3 rgb_to_srgb(vec3 rgb)
{
    return vec3(linear_to_s(rgb.r), linear_to_s(rgb.g), linear_to_s(rgb.b));
}

void main(void)
{
    vec4 val = texture(tex, vtexcoord).rgba;
    fcolor = vec4(rgb_to_srgb(val.rgb), val.a);
}
