obs-StreamFX/data/effects/blur/gaussian.effect
2023-04-05 18:51:03 +02:00

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#include "common.effect"
//------------------------------------------------------------------------------
// Uniforms
//------------------------------------------------------------------------------
// This shader requires that pSize is the number of samples, not the size of the
// kernel. That way oversampling can be performed, which is much more accurate than
//------------------------------------------------------------------------------
// Defines
//------------------------------------------------------------------------------
#define MAX_SAMPLES 128u
//------------------------------------------------------------------------------
// Technique: Directional / Area
//------------------------------------------------------------------------------
float4 PSBlur1D(VertexInformation vtx) : TARGET {
float2 uvstep = pImageTexel * pStepScale;
float weights = 0;
// Move to texel center.
vtx.uv.xy += pImageTexel.xy / 2.;
// Calculate the actual Gaussian Blur
// 1. Sample the center immediately.
float kernel = kernelAt(0u);
weights += kernel;
float4 final = pImage.Sample(LinearClampSampler, vtx.uv) * kernel;
// 2. Then sample both + and - coordinates in one go to reduce code iterations.
for (uint step = 1u; (step < uint(pSize)) && (step < MAX_SAMPLES); step++) {
float2 offset = uvstep * float2(step, step);
kernel = kernelAt(step);
weights += kernel * 2.;
final += pImage.Sample(LinearClampSampler, vtx.uv + offset) * kernel;
final += pImage.Sample(LinearClampSampler, vtx.uv - offset) * kernel;
}
// 3. Ensure we always have a total of 1.0, even if the kernel is bad.
final /= weights;
return final;
}
technique Draw {
pass {
vertex_shader = VSDefault(vtx);
pixel_shader = PSBlur1D(vtx);
}
}
//------------------------------------------------------------------------------
// Technique: Rotate
//------------------------------------------------------------------------------
float4 PSRotate(VertexInformation vtx) : TARGET {
float angstep = pAngle * pStepScale.x;
float weights = 0.;
// Move to texel center.
vtx.uv.xy += pImageTexel.xy / 2.;
// Calculate the actual Gaussian Blur
// 1. Sample the center immediately.
float kernel = kernelAt(0u);
weights += kernel;
float4 final = pImage.Sample(LinearClampSampler, vtx.uv) * kernel;
// 2. Then sample both + and - coordinates in one go to reduce code iterations.
for (uint step = 1u; (step < uint(pSize)) && (step < MAX_SAMPLES); step++) {
float offset = angstep * step;
kernel = kernelAt(step);
weights += kernel * 2.;
final += pImage.Sample(LinearClampSampler, rotateAround(vtx.uv, pCenter, offset)) * kernel;
final += pImage.Sample(LinearClampSampler, rotateAround(vtx.uv, pCenter, -offset)) * kernel;
}
// 3. Ensure we always have a total of 1.0, even if the kernel is bad.
final /= weights;
return final;
}
technique Rotate {
pass {
vertex_shader = VSDefault(vtx);
pixel_shader = PSRotate(vtx);
}
}
//------------------------------------------------------------------------------
// Technique: Zoom
//------------------------------------------------------------------------------
float4 PSZoom(VertexInformation vtx) : TARGET {
float2 dir = normalize(vtx.uv - pCenter) * pStepScale * pImageTexel;
float dist = distance(vtx.uv, pCenter);
float weights = 0.;
// Move to texel center.
vtx.uv.xy += pImageTexel.xy / 2.;
// Calculate the actual Gaussian Blur
// 1. Sample the center immediately.
float kernel = kernelAt(0u);
weights += kernel;
float4 final = pImage.Sample(LinearClampSampler, vtx.uv) * kernel;
// 2. Then sample both + and - coordinates in one go to reduce code iterations.
for (uint step = 1u; (step < uint(pSize)) && (step < MAX_SAMPLES); step++) {
float2 offset = dir * step * dist;
kernel = kernelAt(step);
weights += kernel * 2.;
final += pImage.Sample(LinearClampSampler, vtx.uv + offset) * kernel;
final += pImage.Sample(LinearClampSampler, vtx.uv - offset) * kernel;
}
// 3. Ensure we always have a total of 1.0, even if the kernel is bad.
final /= weights;
return final;
}
technique Zoom {
pass {
vertex_shader = VSDefault(vtx);
pixel_shader = PSZoom(vtx);
}
}