slang-shaders/bezel/Mega_Bezel/shaders/guest/hsm-gaussian_vertical.slang
2022-08-24 22:32:58 -04:00

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#version 450
/*
Gaussian blur - vertical pass, dynamic range, resizable
Copyright (C) 2020 guest(r) - guest.r@gmail.com
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, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
float SIZEV;
float SIGMA_V;
} params;
#pragma parameter SIZEV " Vertical Radius (Num Samples) -- SIZEV" 6.0 1.0 50.0 1.0
#define SIZEV params.SIZEV
#pragma parameter SIGMA_V " Vertical Sigma ( Spread ) -- SIGMA_V" 1.20 0.20 15.0 0.10
#define SIGMA_V params.SIGMA_V
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
} global;
#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;
void main()
{
gl_Position = global.MVP * Position;
vTexCoord = TexCoord;
}
#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
#define COMPAT_TEXTURE(c,d) texture(c,d)
float invsqrsigma = 1.0/(2.0*SIGMA_V*SIGMA_V);
float gaussian(float x)
{
return exp(-x*x*invsqrsigma);
}
void main()
{
vec4 SourceSize1 = vec4(params.SourceSize.x, params.OriginalSize.y, params.SourceSize.z, params.OriginalSize.w);
float f = fract(SourceSize1.y * vTexCoord.y);
f = 0.5 - f;
vec2 tex = floor(SourceSize1.xy * vTexCoord)*SourceSize1.zw + 0.5*SourceSize1.zw;
vec3 color = vec3(0.0);
vec2 dy = vec2(0.0, SourceSize1.w);
float w;
float wsum = 0.0;
vec3 pixel;
float n = -SIZEV;
do
{
pixel = COMPAT_TEXTURE(Source, tex + n*dy).rgb;
w = gaussian(n+f);
color = color + w * pixel;
wsum = wsum + w;
n = n + 1.0;
} while (n <= SIZEV);
color = color / wsum;
FragColor = vec4(color, 1.0);
}