LYGIA Shader Library

dilation (lygia/morphological/dilation)

morphological dilation operation. Based on: https://lettier.github.io/3d-game-shaders-for-beginners/dilation.html https://www.shadertoy.com/view/WsyXWc

Dependencies:

Use:

dilation(<SAMPLER_TYPE> texture, <float2> st, <float2> pixels_scale, <int> passes)

Check it on Github



#ifndef DILATION_TYPE
#define DILATION_TYPE float
#endif

#ifndef DILATION_SAMPLE_FNC
#define DILATION_SAMPLE_FNC(TEX, UV) SAMPLER_FNC(TEX, UV).r
#endif

#ifndef FNC_DILATE
#define FNC_DILATE

DILATION_TYPE dilation(SAMPLER_TYPE tex, vec2 st, vec2 pixel, int radius) {
    float invKR = 1.0 / float(radius);
    DILATION_TYPE acc = DILATION_TYPE(0.0);
    float w = 0.0;
    for(int i = -radius; i <= radius; ++i)
    for(int j = -radius; j <= radius; ++j) {
        vec2 rxy = vec2(ivec2(i, j));
        vec2 kst = rxy * invKR * 2.0;
        vec2 texOffset = st + rxy * pixel;
        float kernel = saturate(1.0 - dot(kst, kst));
        DILATION_TYPE t = DILATION_SAMPLE_FNC(tex, texOffset);
        DILATION_TYPE v = t + kernel;
        if (sum(v) > sum(acc)) {
            acc = v;
            w = kernel;
        }
    }

    return acc - w;
}

#endif

Dependencies:

Use:

dilation(<SAMPLER_TYPE> texture, <float2> st, <float2> pixels_scale, <int> passes)

Check it on Github



#ifndef DILATION_TYPE
#define DILATION_TYPE float
#endif

#ifndef DILATION_SAMPLE_FNC
#define DILATION_SAMPLE_FNC(TEX, UV) SAMPLER_FNC(TEX, UV).x
#endif

#ifndef FNC_DILATE
#define FNC_DILATE

DILATION_TYPE dilation(SAMPLER_TYPE tex,float2 st,float2 pixel, int radius) {

    float invKR = 1.0 / float(radius);
    DILATION_TYPE acc = DILATION_TYPE(0.0);
    float w = 0.0;
    for(int i = -radius; i <= radius; ++i)
    for(int j = -radius; j <= radius; ++j) {
        float2 rxy = float2(float(i), float(j));
        float2 kst = rxy * invKR;
        float2 texOffset = st + rxy * pixel;
        float kernel = saturate(1.0 - dot(kst, kst));
        DILATION_TYPE t = DILATION_SAMPLE_FNC(tex, texOffset);
        DILATION_TYPE v = t + kernel;
        if (sum(v) > sum(acc)) {
            acc = v;
            w = kernel;
        }
    }

    return acc - w;
}

#endif

Licenses

LYGIA is dual-licensed under the Prosperity License and the Patron License for sponsors and contributors.

Sponsors and contributors are automatically added to the Patron License and they can ignore the any non-commercial rule of the Prosperity Licensed software (please take a look to the exception).

It's also possible to get a permanent comercial license hook to a single and specific version of LYGIA.

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