#version 130

uniform sampler2D qt_Texture0;
varying vec2 qt_TexCoord0;
uniform vec2 scale;
uniform float a;
uniform int stretch;

void main(void)
{
    vec4 color = texture2D(qt_Texture0, qt_TexCoord0);

    switch(stretch)
    {
    case 0:
        break;
    case 1:
       color = sqrt(color);
       break;
    case 2:
        color = pow(color, vec4(a));
        break;
    case 3:
        color = log(a*color + 1.0) / log(vec4(a+1));
        break;
    case 4:
    {
        float l = color.r*0.2126f + color.g*0.7152f + color.b*0.7152f;
        color *= asinh(l / a) / asinh(1 / a);
    }
        break;
    }

    color = color*scale.x + scale.y;
    //float color = pow(c, 0.4545);
    gl_FragColor = color;
}