LYGIA Shader Library

Dependencies:

• lygia/math/gaussian.glsl
• lygia/sample/clamp2edge.glsl

Use:

gaussianBlur1D(<SAMPLER_TYPE> texture, <vec2> st, <vec2> pixel_direction , const int kernelSize)

Check it on Github

#ifndef GAUSSIANBLUR1D_TYPE
#ifdef GAUSSIANBLUR_TYPE
#define GAUSSIANBLUR1D_TYPE GAUSSIANBLUR_TYPE
#else
#define GAUSSIANBLUR1D_TYPE vec4
#endif
#endif

#ifndef GAUSSIANBLUR1D_SAMPLER_FNC
#ifdef GAUSSIANBLUR_SAMPLER_FNC
#define GAUSSIANBLUR1D_SAMPLER_FNC(TEX, UV) GAUSSIANBLUR_SAMPLER_FNC(TEX, UV)
#else
#define GAUSSIANBLUR1D_SAMPLER_FNC(TEX, UV) sampleClamp2edge(TEX, UV)
#endif
#endif

#ifndef FNC_GAUSSIANBLUR1D
#define FNC_GAUSSIANBLUR1D

#ifdef PLATFORM_WEBGL

GAUSSIANBLUR1D_TYPE gaussianBlur1D(in SAMPLER_TYPE tex,in vec2 st,in vec2 offset,const int kernelSize){
    GAUSSIANBLUR1D_TYPE accumColor = GAUSSIANBLUR1D_TYPE(0.0);

    float kernelSizef = float(kernelSize);
    float accumWeight = 0.0;
    const float k = 0.39894228;// 1 / sqrt(2*PI)
    for (int i = 0; i < 16; i++) {
        if( i >= kernelSize)
            break;
        float x = -0.5 * (float(kernelSize) - 1.0)+float(i);
        float weight = (k/float(kernelSize)) * gaussian(x, kernelSizef);
        GAUSSIANBLUR1D_TYPE tex = GAUSSIANBLUR1D_SAMPLER_FNC(tex, st + x * offset);
        accumColor += weight * tex;
        accumWeight += weight;
    }
    return accumColor/accumWeight;
}

#else

GAUSSIANBLUR1D_TYPE gaussianBlur1D(in SAMPLER_TYPE tex,in vec2 st,in vec2 offset,const int kernelSize){
    GAUSSIANBLUR1D_TYPE accumColor=GAUSSIANBLUR1D_TYPE(0.);

    float kernelSizef = float(kernelSize);

    float accumWeight = 0.0;
    const float k = 0.39894228;// 1 / sqrt(2*PI)
    for (int i = 0; i < kernelSize; i++) {
        float x = -0.5 * ( kernelSizef -1.0) + float(i);
        float weight = (k / kernelSizef) * gaussian(x, kernelSizef);
        GAUSSIANBLUR1D_TYPE tex = GAUSSIANBLUR1D_SAMPLER_FNC(tex, st + x * offset);
        accumColor += weight * tex;
        accumWeight += weight;
    }
    return accumColor/accumWeight;
}
#endif

#endif

Dependencies:

• lygia/sample.glsl

Use:

gaussianBlur1D(<SAMPLER_TYPE> texture, <float2> st, <float2> pixel_direction , const int kernelSize)

Check it on Github

#ifndef GAUSSIANBLUR1D_TYPE
#ifdef GAUSSIANBLUR_TYPE
#define GAUSSIANBLUR1D_TYPE GAUSSIANBLUR_TYPE
#else
#define GAUSSIANBLUR1D_TYPE float4
#endif
#endif

#ifndef GAUSSIANBLUR1D_SAMPLER_FNC
#ifdef GAUSSIANBLUR_SAMPLER_FNC
#define GAUSSIANBLUR1D_SAMPLER_FNC(TEX, UV) GAUSSIANBLUR_SAMPLER_FNC(TEX, UV)
#else
#define GAUSSIANBLUR1D_SAMPLER_FNC(TEX, UV) SAMPLER_FNC(TEX, UV)
#endif
#endif

#ifndef FNC_GAUSSIANBLUR1D
#define FNC_GAUSSIANBLUR1D

GAUSSIANBLUR1D_TYPE gaussianBlur1D(in SAMPLER_TYPE tex,in float2 st,in float2 offset,const int kernelSize){
    GAUSSIANBLUR1D_TYPE accumColor = float4(0.0, 0.0, 0.0, 0.0);

    float accumWeight = 0.0;
    const float k = 0.39894228;// 1 / sqrt(2*PI)
    float kernelSize2 = float(kernelSize)*float(kernelSize);
    for(int i = 0; i < 16; i++){
        if( i >= kernelSize)
            break;
        float x = -0.5 * (float(kernelSize) - 1.0)+float(i);
        float weight = (k/float(kernelSize)) * exp(-(x*x)/(2.0*kernelSize2));
        accumColor += weight * GAUSSIANBLUR1D_SAMPLER_FNC(tex, st + x * offset);
        accumWeight += weight;
    }
    return accumColor/accumWeight;
}

#endif