kicad/3d-viewer/3d_rendering/cpostshader_ssao.cpp

286 lines
12 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2015-2016 Mario Luzeiro <mrluzeiro@ua.pt>
* Copyright (C) 1992-2016 KiCad Developers, see AUTHORS.txt for contributors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* @file cpostshader_ssao.cpp
* @brief Implements a post shader screen space ambient occlusion on software
*/
#include "cpostshader_ssao.h"
#include "../3d_fastmath.h"
CPOSTSHADER_SSAO::CPOSTSHADER_SSAO( const CCAMERA &aCamera ) : CPOSTSHADER( aCamera )
{
}
// There are differente sources for this shader on the web
//https://github.com/scanberg/hbao/blob/master/resources/shaders/ssao_frag.glsl
//http://www.gamedev.net/topic/556187-the-best-ssao-ive-seen/
//http://www.gamedev.net/topic/556187-the-best-ssao-ive-seen/?view=findpost&p=4632208
float CPOSTSHADER_SSAO::aoFF( const SFVEC2I &aShaderPos,
const SFVEC3F &ddiff,
const SFVEC3F &cnorm,
int c1,
int c2 ) const
{
const float shadowGain = 0.5f;
const float aoGain = 1.0f;
const float outGain = 0.80f;
float return_value = 0.0f;
const float rd = glm::length( ddiff );
// This limits the zero of the function (see below)
if( rd < 1.0f )
{
const SFVEC2I vr = aShaderPos + SFVEC2I( c1, c2 );
const float shadow_factor_at_sample = ( 1.0f - GetShadowFactorAt( vr ) ) * shadowGain;
if( rd > FLT_EPSILON )
{
const SFVEC3F vv = glm::normalize( ddiff );
// Calculate an attenuation distance factor, this was get the best
// results by experimentation
// Changing this factor will change how much shadow in relation to the
// distance of the hit it will be in shadow
// http://www.fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIwLjYteCowLjQ1IiwiY29sb3IiOiIjMDAwMDAwIn0seyJ0eXBlIjowLCJlcSI6IiIsImNvbG9yIjoiIzAwMDAwMCJ9LHsidHlwZSI6MTAwMCwid2luZG93IjpbIi0wLjIxNTcyODA1NTg4MzI1ODYiLCIyLjEyNjE0Mzc1MDM0OTM4ODciLCItMC4wOTM1NDA0NzY0MjczNjAzIiwiMS4zNDc2MTE0MDQzMzExOTIyIl0sInNpemUiOls2NDksMzk5XX1d
// zero: 1.0
const float attDistFactor = 0.6f - rd * 0.6f;
// Original:
// http://www.fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIoMS0xL3NxcnQoMS8oeCp4KSsxKSkiLCJjb2xvciI6IiMwMDAwMDAifSx7InR5cGUiOjEwMDAsIndpbmRvdyI6WyItMC42ODY3NDc3NDcxMDg0MTQyIiwiMy44ODcyMjA2MjQ0Mzk3MzM0IiwiLTAuOTA5NTYyNzcyOTMyNDk2IiwiMS45MDUxODY5OTQxNzQwNTczIl19XQ--
// zero: inf
//const float attDistFactor = (1.0f - 1.0f / sqrt( 1.0f / ( rd * rd) + 1.0f) );
//const float attDistFactor = 1.0f;
// Tool for visualize dot product:
// http://www.falstad.com/dotproduct/
// This is a dot product threshold factor.
// it defines after wich angle we consider that the point starts to occlude.
// if the value is high, it will distart low angles point
const float aDotThreshold = 0.15f;
// This is the normal factor using the normal at the sampled point (of the shader)
// agaisnt the vector from the center to the position at sampled point
const float sampledNormalFactor = glm::dot( GetNormalAt( vr ), -vv );
// http://www.fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIobWF4KHgsMC4zKS0wLjMpLygxLTAuMykiLCJjb2xvciI6IiMwMDAwMDAifSx7InR5cGUiOjEwMDAsIndpbmRvdyI6WyItMC42ODY3NDc3NDcxMDg0MTQyIiwiMy44ODcyMjA2MjQ0Mzk3MzM0IiwiLTAuOTA5NTYyNzcyOTMyNDk2IiwiMS45MDUxODY5OTQxNzQwNTczIl19XQ--
const float sampledNormalFactorWithThreshold = (glm::max( sampledNormalFactor, aDotThreshold ) - aDotThreshold) /
(1.0f - aDotThreshold);
// This is the dot product between the center pixel (the one that is being shaded)
// and the vector from the center to the sampled point
const float localNormalFactor = glm::dot( cnorm, vv );
const float localNormalFactorWithThreshold = (glm::max( localNormalFactor, aDotThreshold ) - aDotThreshold) /
(1.0f - aDotThreshold);
const float aoFactor = (1.0f - sampledNormalFactorWithThreshold) *
localNormalFactorWithThreshold *
aoGain;
return_value = ( ( aoFactor + shadow_factor_at_sample ) * attDistFactor );
// Test / Debug code
//return_value = glm::max( aaFactor, shadow_factor );
//return_value = aaFactor;
//return_value = shadow_factor;
//return_value = glm::clamp( aaFactor, 0.0f, 1.0f );
}
else
{
return_value = shadow_factor_at_sample;
}
}
return return_value * outGain;
}
float CPOSTSHADER_SSAO::giFF( const SFVEC2I &aShaderPos,
const SFVEC3F &ddiff,
const SFVEC3F &cnorm,
int c1,
int c2 ) const
{
if( (ddiff.x > FLT_EPSILON) ||
(ddiff.y > FLT_EPSILON) ||
(ddiff.z > FLT_EPSILON) )
{
const SFVEC3F vv = glm::normalize( ddiff );
const float rd = glm::length( ddiff );
const SFVEC2I vr = aShaderPos + SFVEC2I( c1, c2 );
return glm::clamp( glm::dot( GetNormalAt( vr ), -vv), 0.0f, 1.0f ) *
glm::clamp( glm::dot( cnorm, vv ), 0.0f, 1.0f ) / ( rd * rd + 1.0f );
}
return 0.0f;
}
SFVEC3F CPOSTSHADER_SSAO::Shade( const SFVEC2I &aShaderPos ) const
{
// Test source code
//return SFVEC3F( GetShadowFactorAt( aShaderPos ) );
//return GetColorAt( aShaderPos );
//return SFVEC3F( 1.0f - GetDepthNormalizedAt( aShaderPos ) );
//return SFVEC3F( (1.0f / GetDepthAt( aShaderPos )) * 0.5f );
//return SFVEC3F( 1.0f - GetDepthNormalizedAt( aShaderPos ) +
// (1.0f / GetDepthAt( aShaderPos )) * 0.5f );
#if 1
float cdepth = GetDepthAt( aShaderPos );
if( cdepth > FLT_EPSILON )
{
//const float cNormalizedDepth = GetDepthNormalizedAt( aShaderPos );
//wxASSERT( cNormalizedDepth <= 1.0f );
//wxASSERT( cNormalizedDepth >= 0.0f );
cdepth = (10.0f / (cdepth + 1.0f) );
// read current normal,position and color.
const SFVEC3F n = GetNormalAt( aShaderPos );
const SFVEC3F p = GetPositionAt( aShaderPos );
//const SFVEC3F col = GetColorAt( aShaderPos );
// initialize variables:
float ao = 0.0f;
SFVEC3F gi = SFVEC3F(0.0f);
// This calculated the "window range" of the shader. So it will get
// more or less sparsed samples
const int incx = 2;
const int incy = 2;
//3 rounds of 8 samples each.
for( unsigned int i = 0; i < 3; ++i )
{
static const int mask[3] = { 0x01, 0x03, 0x03 };
const int pw = 0 + (Fast_rand() & mask[i]);
const int ph = 0 + (Fast_rand() & mask[i]);
const int npw = (int)((pw + incx * i) * cdepth ) + (i + 1);
const int nph = (int)((ph + incy * i) * cdepth ) + (i + 1);
const SFVEC3F ddiff = GetPositionAt( aShaderPos + SFVEC2I( npw, nph ) ) - p;
const SFVEC3F ddiff2 = GetPositionAt( aShaderPos + SFVEC2I( npw,-nph ) ) - p;
const SFVEC3F ddiff3 = GetPositionAt( aShaderPos + SFVEC2I(-npw, nph ) ) - p;
const SFVEC3F ddiff4 = GetPositionAt( aShaderPos + SFVEC2I(-npw,-nph ) ) - p;
const SFVEC3F ddiff5 = GetPositionAt( aShaderPos + SFVEC2I( pw, nph ) ) - p;
const SFVEC3F ddiff6 = GetPositionAt( aShaderPos + SFVEC2I( pw,-nph ) ) - p;
const SFVEC3F ddiff7 = GetPositionAt( aShaderPos + SFVEC2I( npw, ph ) ) - p;
const SFVEC3F ddiff8 = GetPositionAt( aShaderPos + SFVEC2I(-npw, ph ) ) - p;
ao+= aoFF( aShaderPos, ddiff , n, npw, nph );
ao+= aoFF( aShaderPos, ddiff2, n, npw,-nph );
ao+= aoFF( aShaderPos, ddiff3, n, -npw, nph );
ao+= aoFF( aShaderPos, ddiff4, n, -npw,-nph );
ao+= aoFF( aShaderPos, ddiff5, n, pw, nph );
ao+= aoFF( aShaderPos, ddiff6, n, pw,-nph );
ao+= aoFF( aShaderPos, ddiff7, n, npw, ph );
ao+= aoFF( aShaderPos, ddiff8, n, -npw, ph );
gi+= giFF( aShaderPos, ddiff , n, npw, nph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( npw, nph ) ) );
gi+= giFF( aShaderPos, ddiff2, n, npw, -nph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( npw,-nph ) ) );
gi+= giFF( aShaderPos, ddiff3, n,-npw, nph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( -npw, nph ) ) );
gi+= giFF( aShaderPos, ddiff4, n,-npw, -nph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( -npw,-nph ) ) );
gi+= giFF( aShaderPos, ddiff5, n, pw, nph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( pw, nph ) ) );
gi+= giFF( aShaderPos, ddiff6, n, pw,-nph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( pw,-nph ) ) );
gi+= giFF( aShaderPos, ddiff7, n, npw, ph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( npw, ph ) ) );
gi+= giFF( aShaderPos, ddiff8, n,-npw, ph) *
giColorCurve( GetColorAt( aShaderPos + SFVEC2I( -npw, ph ) ) );
}
ao = (ao / 24.0f) + 0.0f; // Apply a bias for the ambient oclusion
gi = (gi * 5.0f / 24.0f); // Apply a bias for the global illumination
//return SFVEC3F(ao);
return SFVEC3F(ao) - gi;
// Test source code
//return SFVEC3F( col );
//return SFVEC3F( col - SFVEC3F(ao) + gi * 5.0f );
//return SFVEC3F( SFVEC3F(1.0f) - SFVEC3F(ao) + gi * 5.0f );
//return SFVEC3F(cdepth);
//return SFVEC3F(cNormalizedDepth);
//return 1.0f - SFVEC3F(ao);
//return SFVEC3F(ao);
}
else
return SFVEC3F(0.0f);
#endif
}
SFVEC3F CPOSTSHADER_SSAO::ApplyShadeColor( const SFVEC2I &aShaderPos, const SFVEC3F &aInputColor, const SFVEC3F &aShadeColor ) const
{
// This is the final stage of the shader and make the last calculation how to apply the shader
const SFVEC3F shadedColor = aInputColor - ( -aShadeColor * (aShadeColor * SFVEC3F(0.1f) - SFVEC3F(1.0f) ) );
return shadedColor;
}
SFVEC3F CPOSTSHADER_SSAO::giColorCurve( const SFVEC3F &aColor ) const
{
const SFVEC3F vec1 = SFVEC3F(1.0f);
// http://fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIxLjAtKDEvKHgqMS4wKzEuMCkpK3gqMC4xIiwiY29sb3IiOiIjMDAwMDAwIn0seyJ0eXBlIjoxMDAwLCJ3aW5kb3ciOlsiLTAuMDYyMTg0NjE1Mzg0NjE1NTA1IiwiMS4xNDI5ODQ2MTUzODQ2MTQ2IiwiLTAuMTI3MDk5OTk5OTk5OTk5NzciLCIxLjEzMjYiXX1d
//return vec1 - ( vec1 / (aColor + vec1) ) + aColor * SFVEC3F(0.10f);
// http://fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIxLjAtKDEuMC8oeCoyLjArMS4wKSkreCowLjEiLCJjb2xvciI6IiMwMDAwMDAifSx7InR5cGUiOjEwMDAsIndpbmRvdyI6WyItMC4wNjIxODQ2MTUzODQ2MTU1MDUiLCIxLjE0Mjk4NDYxNTM4NDYxNDYiLCItMC4xMjcwOTk5OTk5OTk5OTk3NyIsIjEuMTMyNiJdfV0-
//return vec1 - ( vec1 / (aColor * SFVEC3F(2.0f) + vec1) ) + aColor * SFVEC3F(0.10f);
// This option actually apply a gama since we are using linear color space
// and the result shader will be applied after convert back to sRGB
// http://fooplot.com/#W3sidHlwZSI6MCwiZXEiOiIxLjAtKDEuMC8oeCo5LjArMS4wKSkreCowLjEiLCJjb2xvciI6IiMwMDAwMDAifSx7InR5cGUiOjEwMDAsIndpbmRvdyI6WyItMC4wNjIxODQ2MTUzODQ2MTU1MDUiLCIxLjE0Mjk4NDYxNTM4NDYxNDYiLCItMC4xMjcwOTk5OTk5OTk5OTk3NyIsIjEuMTMyNiJdfV0-
return vec1 - ( vec1 / (aColor * SFVEC3F(9.0f) + vec1) ) + aColor * SFVEC3F(0.10f);
// return aColor;
}