LYGIA Shader Library

Dependencies:

• lygia/v1.1.4/space/xyz2equirect.glsl
• lygia/v1.1.4/generative/random.glsl
• lygia/v1.1.4/generative/srandom.glsl
• lygia/v1.1.4/sample.glsl

Use:

sampleEquirect(<sampler2D> texture, <vec3> dir)

Check it on Github

#ifndef FNC_SAMPLEEQUIRECT
#define FNC_SAMPLEEQUIRECT
vec4 sampleEquirect(sampler2D tex, vec3 dir) { 
    vec2 st = xyz2equirect(dir);
    #ifdef SAMPLEEQUIRECT_FLIP_Y
    st.y = 1.0-st.y;
    #endif
    return SAMPLER_FNC(tex, st); 
}

vec4 sampleEquirect(sampler2D tex, vec3 dir, float lod) { 

    #if defined(SAMPLEEQUIRET_ITERATIONS)
    vec4 acc = vec4(0.0);
    vec2 st = xyz2equirect(dir);
    #ifdef SAMPLEEQUIRECT_FLIP_Y
    st.y = 1.0-st.y;
    #endif
    mat2 rot = mat2(cos(GOLDEN_ANGLE), sin(GOLDEN_ANGLE), -sin(GOLDEN_ANGLE), cos(GOLDEN_ANGLE));
    float r = 1.;
    vec2 vangle = vec2(0.0, lod * 0.01);
    for (int i = 0; i < SAMPLEEQUIRET_ITERATIONS; i++) {
        vangle = rot * vangle;
        r++;
        vec4 col = SAMPLER_FNC(tex, st + random( vec3(st, r) ) * vangle );
        acc += col * col;
    }
    return vec4(acc.rgb/acc.a, 1.0); 

    #else
    dir += srandom3( dir ) * 0.01 * lod;
    vec2 st = xyz2equirect(dir);
    #ifdef SAMPLEEQUIRECT_FLIP_Y
    st.y = 1.0-st.y;
    #endif
    return SAMPLER_FNC(tex, st);

    #endif
}

#endif

Dependencies:

• lygia/v1.1.4/space/xyz2equirect.glsl
• lygia/v1.1.4/generative/random.glsl
• lygia/v1.1.4/generative/srandom.glsl
• lygia/v1.1.4/sample.glsl

Use:

sampleEquirect(<sampler2D> texture, <float3> dir)

Check it on Github

#ifndef FNC_SAMPLEEQUIRECT
#define FNC_SAMPLEEQUIRECT
float4 sampleEquirect(sampler2D tex, float3 dir) { 
    float2 st = xyz2equirect(dir);
    #ifdef SAMPLEEQUIRECT_FLIP_Y
    st.y = 1.0-st.y;
    #endif
    return SAMPLER_FNC(tex, st); 
}

float4 sampleEquirect(sampler2D tex, float3 dir, float lod) { 

    #if defined(SAMPLEEQUIRET_ITERATIONS)
    float4 acc = float4(0.0, 0.0, 0.0, 0.0);
    float2 st = xyz2equirect(dir);
    #ifdef SAMPLEEQUIRECT_FLIP_Y
    st.y = 1.0-st.y;
    #endif
    float2x2 rot = float2x2(cos(GOLDEN_ANGLE), sin(GOLDEN_ANGLE), -sin(GOLDEN_ANGLE), cos(GOLDEN_ANGLE));
    float r = 1.;
    float2 vangle = float2(0.0, lod * 0.01);
    for (int i = 0; i < SAMPLEEQUIRET_ITERATIONS; i++) {
        vangle = mul(rot, vangle);
        r++;
        float4 col = SAMPLER_FNC(tex, st + random( float3(st, r) ) * vangle );
        acc += col * col;
    }
    return float4(acc.rgb/acc.a, 1.0); 

    #else
    dir += srandom3( dir ) * 0.01 * lod;
    float2 st = xyz2equirect(dir);
    #ifdef SAMPLEEQUIRECT_FLIP_Y
    st.y = 1.0-st.y;
    #endif
    return SAMPLER_FNC(tex, st);

    #endif
}

#endif