LYGIA Shader Library

Dependencies:

• lygia/space/rotate.glsl
• lygia/space/bracketing.glsl
• lygia/sampler.glsl

Use:

sampleBracketing(<SAMPLER_TYPE> texture, <vec2> st, <vec2> direction [, <float> scale] )

Check it on Github

#ifndef SAMPLEBRACKETING_TYPE
#define SAMPLEBRACKETING_TYPE vec4
#endif

#ifndef SAMPLEBRACKETING_SAMPLER_FNC
#define SAMPLEBRACKETING_SAMPLER_FNC(TEX, UV) SAMPLER_FNC(TEX, UV)
#endif

#ifndef FNC_SAMPLEBRACKETING
#define FNC_SAMPLEBRACKETING

SAMPLEBRACKETING_TYPE sampleBracketing(SAMPLER_TYPE tex, vec2 st, vec2 dir, float scale) {
    vec2 vAxis0 = vec2(0.0);
    vec2 vAxis1 = vec2(0.0);
    float blendAlpha = 0.0;

    bracketing(dir, vAxis0, vAxis1, blendAlpha);

    // Compute the function for the two canonical directions
    vec2 uv0 = scale * rotate(st, vAxis0);
    vec2 uv1 = scale * rotate(st, vAxis1);

    // Now sample function/texture
    SAMPLEBRACKETING_TYPE sample0 = SAMPLEBRACKETING_SAMPLER_FNC(tex, uv0);
    SAMPLEBRACKETING_TYPE sample1 = SAMPLEBRACKETING_SAMPLER_FNC(tex, uv1);

    // Blend to get final result, based on how close the vector was to the first snapped angle
    SAMPLEBRACKETING_TYPE result = mix( sample0, sample1, blendAlpha);

#ifdef SAMPLEBRACKETING_REPLACE_DIVERGENCE
    float strength = smoothstep(0.0, 0.2, dot(dir, dir)*6.0);
    result = mix(   SAMPLEBRACKETING_SAMPLER_FNC(tex, scale * rotate(st, -vec2(cos(0.5),sin(0.5)))), 
                    result, 
                    strength);
#endif

    return result;
}

SAMPLEBRACKETING_TYPE sampleBracketing(SAMPLER_TYPE tex, vec2 st, vec2 dir) { return sampleBracketing(tex, st, dir, 1.0); }
#endif

Dependencies:

• lygia/space/rotate.glsl
• lygia/space/braketing.glsl
• lygia/sampler.glsl

Use:

sampleBracketing(<SAMPLER_TYPE> texture, <float2> st, <float2> direction [, <float> scale] )

Check it on Github

#ifndef SAMPLEBRACKETING_TYPE
#define SAMPLEBRACKETING_TYPE float4
#endif

#ifndef SAMPLEBRACKETING_SAMPLER_FNC
#define SAMPLEBRACKETING_SAMPLER_FNC(UV) SAMPLER_FNC(tex, UV)
#endif

#ifndef FNC_SAMPLEBRACKETING
#define FNC_SAMPLEBRACKETING

SAMPLEBRACKETING_TYPE sampleBracketing(SAMPLER_TYPE tex, float2 st, float2 dir, float scale) {
    float2 vAxis0 = float2(0.0, 0.0);
    float2 vAxis1 = float2(0.0, 0.0);
    float blendAlpha = 0.0;

    bracketing(dir, vAxis0, vAxis1, blendAlpha);

    // Compute the function for the two canonical directions
    float2 uv0 = scale * rotate(st, vAxis0);
    float2 uv1 = scale * rotate(st, vAxis1);

    // Now sample function/texture
    SAMPLEBRACKETING_TYPE sample0 = SAMPLEBRACKETING_SAMPLER_FNC(uv0);
    SAMPLEBRACKETING_TYPE sample1 = SAMPLEBRACKETING_SAMPLER_FNC(uv1);

    // Blend to get final result, based on how close the vector was to the first snapped angle
    SAMPLEBRACKETING_TYPE result = lerp( sample0, sample1, blendAlpha);

#ifdef SAMPLEBRACKETING_REPLACE_DIVERGENCE
    float strength = smoothstep(0.0, 0.2, dot(dir, dir)*6.0);
    result = lerp(   SAMPLEBRACKETING_SAMPLER_FNC(scale * rotate(st, -float2(cos(0.5),sin(0.5)))), 
                    result, 
                    strength);
#endif

    return result;
}

SAMPLEBRACKETING_TYPE sampleBracketing(SAMPLER_TYPE tex, float2 st, float2 dir) { return sampleBracketing(tex, st, dir, 1.0); }
#endif