slang-shaders/vhs/shaders/vhs_mpalko/vhs_mpalko_pass0.slang

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#version 450
2019-06-14 03:29:15 +10:00
// based on VHS Compression
// shadertoy by mpalko https://www.shadertoy.com/view/tsfXWj
layout(push_constant) uniform Push
{
vec4 SourceSize;
vec4 OriginalSize;
vec4 OutputSize;
uint FrameCount;
} params;
layout(std140, set = 0, binding = 0) uniform UBO
{
mat4 MVP;
} global;
#include "vhs_mpalko.inc"
#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;
//////////// -- SET UP LUTS HERE -- ////////////
#define iChannel0 Source
//////////////// -- END PASSES AND LUTS -- ////////////////
//////////// -- SET UP SHADERTOY VARIABLES -- ////////////
float iGlobalTime = float(params.FrameCount)*0.025;
float iTime = float(params.FrameCount)*0.025;
vec2 iResolution = params.OutputSize.xy;
#define FragCoord (params.OutputSize.xy * vTexCoord.xy)
int iFrame = int(params.FrameCount);
//////////// -- END SHADERTOY VARIABLES -- ////////////
//////////// -- PASTE SHADERTOY HERE -- ////////////
// Downsample buffer A and convert to YIQ color space
vec3 downsampleVideo(vec2 uv, vec2 pixelSize, ivec2 samples)
{
//return texture(VIDEO_TEXTURE, uv).rgb * rgb2yiq;
vec2 uvStart = uv - pixelSize / 2.0;
vec2 uvEnd = uv + pixelSize;
vec3 result = vec3(0.0, 0.0, 0.0);
for (int i_u = 0; i_u < samples.x; i_u++)
{
float u = lerp(uvStart.x, uvEnd.x, float(i_u) / float(samples.x));
for (int i_v = 0; i_v < samples.y; i_v++)
{
float v = lerp(uvStart.y, uvEnd.y, float(i_v) / float(samples.y));
result += texture(VIDEO_TEXTURE, vec2(u, v)).rgb;
}
}
return (result / float(samples.x * samples.y)) * rgb2yiq;
}
vec3 downsampleVideo(vec2 fragCoord, vec2 downsampledRes)
{
if (fragCoord.x > downsampledRes.x || fragCoord.y > downsampledRes.y)
{
return vec3(0.0);
}
vec2 uv = fragCoord / downsampledRes;
vec2 pixelSize = 1.0 / downsampledRes;
ivec2 samples = ivec2(8, 3);
pixelSize *= 1.0 + blurAmount; // Slight box blur to avoid aliasing
return downsampleVideo(uv, pixelSize, samples);
}
void mainImage(out vec4 fragColor, in vec2 fragCoord)
{
vec2 resLuminance = min(maxResLuminance, vec2(iResolution));
vec2 resChroma = min(maxResChroma, vec2(iResolution));
float luminance = downsampleVideo(fragCoord, resLuminance).r;
vec2 chroma = downsampleVideo(fragCoord, resChroma).gb;
fragColor = vec4(luminance, chroma, 1);
}
//////////// -- END SHADERTOY -- ////////////
void main()
{
mainImage(FragColor, FragCoord.xy);
}