glsl330

gistfile1.txt

#version 330

in vec2 fragTexCoord;
in vec4 fragColor;

uniform sampler2D texture0;
uniform vec4 colDiffuse;

out vec4 finalColor;

// CRT effect controls (set from src/crt.c)
uniform float curvature;
uniform float chromaticAberrationPixels;
uniform float chromaticAberrationCurve;
uniform float contrast;
uniform float brightness;
uniform float scanlineStrength;
uniform float scanlineSpacing;
uniform float vignetteStrength;
uniform vec2 aspectScale;
uniform vec2 texelSize;
uniform vec3 tiltShiftParams; // focus start, strength, blur radius in pixels
uniform vec3 colorGradeParams; // purple tint, glow threshold, glow strength

void main()
{
    vec2 centered = fragTexCoord*2.0 - 1.0;
    vec2 aspectCentered = centered*aspectScale;
    float radius = dot(aspectCentered, aspectCentered);
    vec2 warped = centered*(1.0 + radius*curvature);
    vec2 uv = warped*0.5 + 0.5;

    if (max(abs(warped.x), abs(warped.y)) > 1.0)
    {
        finalColor = vec4(0.0);
        return;
    }

    vec2 halfTexel = texelSize*0.5;
    vec2 minimumUv = halfTexel;
    vec2 maximumUv = vec2(1.0) - halfTexel;
    float radialLength = sqrt(radius);
    vec2 radialDirection = aspectCentered/max(radialLength, 0.0001);
    float edgeAmount = pow(clamp(radius*0.5, 0.0, 1.0), chromaticAberrationCurve);
    vec2 aberrationOffset = radialDirection*chromaticAberrationPixels*edgeAmount*texelSize;
    vec2 centerUv = clamp(uv, minimumUv, maximumUv);
    vec3 centerColor = texture(texture0, centerUv).rgb;
    vec3 aberratedColor = vec3(
        texture(texture0, clamp(uv + aberrationOffset, minimumUv, maximumUv)).r,
        centerColor.g,
        texture(texture0, clamp(uv - aberrationOffset, minimumUv, maximumUv)).b
    );

    vec2 blurOffset = vec2(0.0, texelSize.y*tiltShiftParams.z);
    vec3 softColor = centerColor*0.5;
    softColor += texture(texture0, clamp(uv + blurOffset, minimumUv, maximumUv)).rgb*0.25;
    softColor += texture(texture0, clamp(uv - blurOffset, minimumUv, maximumUv)).rgb*0.25;

    float defocus = smoothstep(tiltShiftParams.x, 1.0, abs(centered.y));
    vec3 color = mix(aberratedColor, softColor, defocus*tiltShiftParams.y);
    vec3 glow = max(softColor - vec3(colorGradeParams.y), vec3(0.0));
    color += glow*colorGradeParams.z;

    vec3 lumaWeights = vec3(0.2126, 0.7152, 0.0722);
    vec3 violetColor = color*vec3(1.18, 0.82, 1.28);
    float originalLuma = dot(color, lumaWeights);
    float violetLuma = max(dot(violetColor, lumaWeights), 0.0001);
    float shadowAmount = 1.0 - clamp(originalLuma*2.0, 0.0, 1.0);
    violetColor *= originalLuma/violetLuma;
    violetColor += vec3(0.035, 0.0, 0.06)*shadowAmount;
    color = mix(color, violetColor, colorGradeParams.x);

    // mod() keeps the sin() argument small so mediump gl_FragCoord (GLES) stays precise
    float phase = mod(gl_FragCoord.y, scanlineSpacing)*6.28318531/scanlineSpacing;
    float scanline = 1.0 - scanlineStrength*(0.5 - 0.5*sin(phase));
    float vignetteEdge = smoothstep(0.25, 1.0, clamp(radius*0.5, 0.0, 1.0));
    float vignette = 1.0 - vignetteStrength*vignetteEdge;

    color = clamp(((color - 0.5)*contrast + 0.5)*brightness, 0.0, 1.0);
    color *= scanline*vignette;
    finalColor = vec4(color, 1.0)*colDiffuse*fragColor;
}