81 lines
2.7 KiB
Plaintext
81 lines
2.7 KiB
Plaintext
#include "common.effect"
|
|
|
|
// # Linear Optimization
|
|
// While the normal way is to sample every texel in the pSize, linear optimization
|
|
// takes advantage of the fact that most people, especially after compression,
|
|
// will not be able to tell the difference between a linear approximation and
|
|
// the actual thing.
|
|
//
|
|
// Instead of sampling every texel like this:
|
|
//
|
|
// |Tx|Tx|Tx|Tx|Tx|
|
|
// Tx|-2|-1| 0|+1|+2|
|
|
//
|
|
// Linear optimization will sample like this:
|
|
//
|
|
// |Tx|Tx|Tx|Tx|Tx|
|
|
// Tx| -1 | 0| +1 |
|
|
//
|
|
// This effectively removes half the necessary samples and looks identical when
|
|
// when used with box blur. However there is an edge case when the blur width
|
|
// is not a multiple of two, where two additional samples have to be spent on
|
|
// reading the outer edge:
|
|
//
|
|
// |Tx|Tx|Tx|Tx|Tx|Tx|Tx|
|
|
// Tx|-2| -1 | 0| +1 |+2|
|
|
//
|
|
// or this alternative pattern that uses two less samples:
|
|
//
|
|
// |Tx|Tx|Tx|Tx|Tx|Tx|Tx|
|
|
// Tx| 0 | +1 | +2 |+3|
|
|
//
|
|
// With careful planning this can even be used for other types of Blur, such as
|
|
// Gaussian Blur, which suffers a larger hit - however there are better and
|
|
// faster alternatives than linear sampling with Gaussian Blur, such as
|
|
// Dual Filtering ("Dual Kawase").
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Defines
|
|
//------------------------------------------------------------------------------
|
|
#define MAX_BLUR_SIZE 128u
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Technique: Directional / Area
|
|
//------------------------------------------------------------------------------
|
|
float4 PSBlur1D(VertexInformation vtx) : TARGET {
|
|
// y = yes, s = skip, b = break
|
|
// Size-> | 1| 2| 3| 4| 5| 6| 7|
|
|
// -------+--+--+--+--+--+--+--+
|
|
// n=1 | b| y| y| y| y| y| y|
|
|
// n=2 | |bs| s| s| s| s| s|
|
|
// n=3 | | b| b| y| y| y| y|
|
|
// n=4 | | | |bs| s| s| s|
|
|
// n=5 | | | | b| b| y| y|
|
|
// n=6 | | | | | |bs| s|
|
|
// n=7 | | | | | | b| b|
|
|
// n=8 | | | | | | | |
|
|
|
|
float4 final = pImage.Sample(LinearClampSampler, vtx.uv);
|
|
for (uint n = 1u; (n < uint(pSize)) && (n < MAX_BLUR_SIZE); n += 2u) {
|
|
float2 nstep = (pImageTexel * pStepScale) * (float(n) + 0.5);
|
|
final += pImage.Sample(LinearClampSampler, vtx.uv + nstep) * 2.;
|
|
final += pImage.Sample(LinearClampSampler, vtx.uv - nstep) * 2.;
|
|
}
|
|
|
|
if ((uint(pSize) % 2u) == 1u) {
|
|
float2 nstep = (pImageTexel * pStepScale) * pSize;
|
|
final += pImage.Sample(LinearClampSampler, vtx.uv + nstep);
|
|
final += pImage.Sample(LinearClampSampler, vtx.uv - nstep);
|
|
}
|
|
|
|
final *= pSizeInverseMul;
|
|
return final;
|
|
}
|
|
|
|
technique Draw {
|
|
pass {
|
|
vertex_shader = VSDefault(vtx);
|
|
pixel_shader = PSBlur1D(vtx);
|
|
}
|
|
}
|