This shader is enabled when the player in my game is dead

blur_grayscale_variable.frag

// Copyright © 2024 MGDS Studio. All rights reserved.

/** Used to create a visual effect when the player in my game is dead.
*   Values must be passed: 
            shaderProgram.setUniformf( "time", deltaTime );
            shaderProgram.setUniformf( "u_imageSize", new Vector2(textureRegion.getWidth(), textureRegion.getHeight()) );
*/


#ifdef GL_FRAGMENT_PRECISION_HIGH
precision highp float;
#else
precision mediump float;
#endif

/* For grayscale */
const float START_RELATIVE_SHIFTING = 1.0;
const float END_RELATIVE_SHIFTING = 0.20;
const float TIME_TO_CHANGE_COLOR = 3.0;	//sec

/** For blur */
varying vec4 v_color;
varying vec2 v_texCoords;
uniform sampler2D u_texture;
uniform vec2 u_imageSize;
//uniform int u_blurRadius;
const float TIME_TO_CHANGE_BLUR = 6.0;	//sec
const float MIN_BLUR_RADIUS = 1.0;
const float MAX_BLUR_RADIUS = 8.0;

/** For both */
uniform float time;

void applyBlurFilter(){
    vec4 color = texture2D(u_texture, v_texCoords);
    vec2 pixelToTextureCoords = 1.0 / u_imageSize;
    vec4 averageColor = vec4(0.0, 0.0, 0.0, 0.0);
    float relativeEllapsedTime = time/TIME_TO_CHANGE_BLUR;
    if (relativeEllapsedTime > 1.0) relativeEllapsedTime = 1.0;
    int u_blurRadius = int(MIN_BLUR_RADIUS) + int(relativeEllapsedTime*(MAX_BLUR_RADIUS-MIN_BLUR_RADIUS));
    for (int dx = -u_blurRadius; dx <= u_blurRadius; dx++)
    {
        for (int dy = -u_blurRadius; dy <= u_blurRadius; dy++)
        {
            vec2 point = v_texCoords + vec2(dx,dy) * pixelToTextureCoords;
            averageColor += texture2D(u_texture, point);
        }
    }

    averageColor /= pow(2.0 * u_blurRadius + 1.0, 2.0);
    gl_FragColor = v_color * averageColor;
}

void applyGrayscaleFilter(){
    float relativeColorShifting = END_RELATIVE_SHIFTING+(1.0-time/TIME_TO_CHANGE_COLOR)*(START_RELATIVE_SHIFTING-END_RELATIVE_SHIFTING);
    if (relativeColorShifting<END_RELATIVE_SHIFTING) relativeColorShifting = END_RELATIVE_SHIFTING;
    float average = (gl_FragColor.r + gl_FragColor.g + gl_FragColor.b) / 3.0;
    float red = average + (gl_FragColor.r-average)*relativeColorShifting;
    float green = average + (gl_FragColor.g-average)*relativeColorShifting;
    float blue = average + (gl_FragColor.b-average)*relativeColorShifting;
    gl_FragColor.rgb = vec3(red,green, blue);
}

void main()
{
    applyBlurFilter();
    applyGrayscaleFilter();
}