Voici celui que j'utilise. C'est une version modifiée (comprendre : qui propose un rendu encore plus vintage/tordu/pourri/qui pique) d'un shader dispo sur le GitHub de Libreto.
Code : Tout sélectionner
<?xml version="1.0" encoding="UTF-8"?>
<!--
Shader d'écran arcade qui a des heures de vols.
Version modifiée de :
CRT shader
Copyright (C) 2010-2012 cgwg, Themaister and DOLLS
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.
-->
<shader language="GLSL">
<fragment filter="nearest" scale="1.0"><![CDATA[
uniform sampler2D rubyTexture;
uniform vec2 rubyTextureSize;
uniform vec2 rubyInputSize;
uniform vec2 rubyOutputSize;
#define CRTgamma 6.5
#define display_gamma 2.2
#define TEX2D(c) pow(texture2D(rubyTexture,(c)),vec4(CRTgamma))
void main()
{
vec2 xy = gl_TexCoord[0].st;
float oney = 1.0/rubyTextureSize.y;
float wid = 2.0;
float c1 = exp(-1.0/wid/wid);
float c2 = exp(-4.0/wid/wid);
float c3 = exp(-9.0/wid/wid);
float c4 = exp(-16.0/wid/wid);
float norm = 1.0 / (1.0 + 2.0*(c1+c2+c3+c4));
vec4 sum = vec4(0.0);
sum += TEX2D(xy + vec2(0.0, -4.0 * oney)) * vec4(c4);
sum += TEX2D(xy + vec2(0.0, -3.0 * oney)) * vec4(c3);
sum += TEX2D(xy + vec2(0.0, -2.0 * oney)) * vec4(c2);
sum += TEX2D(xy + vec2(0.0, -1.0 * oney)) * vec4(c1);
sum += TEX2D(xy);
sum += TEX2D(xy + vec2(0.0, +1.0 * oney)) * vec4(c1);
sum += TEX2D(xy + vec2(0.0, +2.0 * oney)) * vec4(c2);
sum += TEX2D(xy + vec2(0.0, +3.0 * oney)) * vec4(c3);
sum += TEX2D(xy + vec2(0.0, +4.0 * oney)) * vec4(c4);
gl_FragColor = pow(sum*vec4(norm),vec4(1.0/display_gamma));
}
]]></fragment>
<fragment filter="nearest" scale="1.0"><![CDATA[
uniform sampler2D rubyTexture;
uniform vec2 rubyTextureSize;
uniform vec2 rubyInputSize;
uniform vec2 rubyOutputSize;
#define display_gamma 1.6
#define TEX2D(c) pow(texture2D(rubyTexture,(c)),vec4(display_gamma))
void main()
{
vec2 xy = gl_TexCoord[0].st;
float onex = 1.0/rubyTextureSize.x;
float wid = 2.0;
float c1 = exp(-1.0/wid/wid);
float c2 = exp(-4.0/wid/wid);
float c3 = exp(-9.0/wid/wid);
float c4 = exp(-16.0/wid/wid);
float norm = 1.0 / (1.0 + 2.0*(c1+c2+c3+c4));
vec4 sum = vec4(0.0);
sum += TEX2D(xy + vec2(-4.0 * onex, 0.0)) * vec4(c4);
sum += TEX2D(xy + vec2(-3.0 * onex, 0.0)) * vec4(c3);
sum += TEX2D(xy + vec2(-2.0 * onex, 0.0)) * vec4(c2);
sum += TEX2D(xy + vec2(-1.0 * onex, 0.0)) * vec4(c1);
sum += TEX2D(xy);
sum += TEX2D(xy + vec2(+1.0 * onex, 0.0)) * vec4(c1);
sum += TEX2D(xy + vec2(+2.0 * onex, 0.0)) * vec4(c2);
sum += TEX2D(xy + vec2(+3.0 * onex, 0.0)) * vec4(c3);
sum += TEX2D(xy + vec2(+4.0 * onex, 0.0)) * vec4(c4);
gl_FragColor = pow(sum*vec4(norm),vec4(1.0/display_gamma));
}
]]></fragment>
<vertex><![CDATA[
varying float CRTgamma;
varying float monitorgamma;
varying vec2 overscan;
varying vec2 aspect;
varying float d;
varying float R;
varying float cornersize;
varying float cornersmooth;
varying vec3 stretch;
varying vec2 sinangle;
varying vec2 cosangle;
uniform vec2 rubyOrigInputSize;
uniform vec2 rubyOrigTextureSize;
uniform vec2 rubyOutputSize;
uniform vec2 rubyInputSize;
varying vec2 texCoord;
varying vec2 one;
varying float mod_factor;
varying vec2 ilfac;
#define FIX(c) max(abs(c), 1e-5);
float intersect(vec2 xy)
{
float A = dot(xy,xy)+d*d;
float B = 2.0*(R*(dot(xy,sinangle)-d*cosangle.x*cosangle.y)-d*d);
float C = d*d + 2.0*R*d*cosangle.x*cosangle.y;
return (-B-sqrt(B*B-4.0*A*C))/(2.0*A);
}
vec2 bkwtrans(vec2 xy)
{
float c = intersect(xy);
vec2 point = vec2(c)*xy;
point -= vec2(-R)*sinangle;
point /= vec2(R);
vec2 tang = sinangle/cosangle;
vec2 poc = point/cosangle;
float A = dot(tang,tang)+1.0;
float B = -2.0*dot(poc,tang);
float C = dot(poc,poc)-1.0;
float a = (-B+sqrt(B*B-4.0*A*C))/(2.0*A);
vec2 uv = (point-a*sinangle)/cosangle;
float r = R*acos(a);
return uv*r/sin(r/R);
}
vec2 fwtrans(vec2 uv)
{
float r = FIX(sqrt(dot(uv,uv)));
uv *= sin(r/R)/r;
float x = 1.0-cos(r/R);
float D = d/R + x*cosangle.x*cosangle.y+dot(uv,sinangle);
return d*(uv*cosangle-x*sinangle)/D;
}
vec3 maxscale()
{
vec2 c = bkwtrans(-R * sinangle / (1.0 + R/d*cosangle.x*cosangle.y));
vec2 a = vec2(0.5,0.5)*aspect;
vec2 lo = vec2(fwtrans(vec2(-a.x,c.y)).x,
fwtrans(vec2(c.x,-a.y)).y)/aspect;
vec2 hi = vec2(fwtrans(vec2(+a.x,c.y)).x,
fwtrans(vec2(c.x,+a.y)).y)/aspect;
return vec3((hi+lo)*aspect*0.5,max(hi.x-lo.x,hi.y-lo.y));
}
void main()
{
// START of parameters
// gamma of simulated CRT
CRTgamma = 2.0;
// gamma of display monitor (typically 2.2 is correct)
monitorgamma = 2.0;
// overscan (e.g. 1.02 for 2% overscan)
overscan = vec2(1.00,1.00);
// aspect ratio
aspect = vec2(1.0, 0.75);
// lengths are measured in units of (approximately) the width of the monitor
// simulated distance from viewer to monitor
d = 3.5;
// radius of curvature
R = 2.2;
// tilt angle in radians
// (behavior might be a bit wrong if both components are nonzero)
const vec2 angle = vec2(0.0,-0.0);
// size of curved corners
cornersize = 0.015;
// border smoothness parameter
// decrease if borders are too aliased
cornersmooth = 100.0;
// END of parameters
// Do the standard vertex processing.
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
// Precalculate a bunch of useful values we'll need in the fragment
// shader.
sinangle = sin(angle);
cosangle = cos(angle);
stretch = maxscale();
// Texture coords.
texCoord = gl_MultiTexCoord0.xy;
ilfac = vec2(1.0,floor(rubyInputSize.y/200.0));
// The size of one texel, in texture-coordinates.
one = ilfac / rubyOrigTextureSize;
// Resulting X pixel-coordinate of the pixel we're drawing.
mod_factor = texCoord.x * rubyOrigTextureSize.x * rubyOutputSize.x / rubyOrigInputSize.x;
}
]]></vertex>
<fragment filter="linear" outscale="1.0"><![CDATA[
uniform int rubyFrameCount;
// Comment the next line to disable interpolation in linear gamma (and gain speed).
//#define LINEAR_PROCESSING
// Enable screen curvature.
#define CURVATURE
// Enable 3x oversampling of the beam profile
#define OVERSAMPLE
// Use the older, purely gaussian beam profile
//#define USEGAUSSIAN
// Macros.
#define FIX(c) max(abs(c), 1e-5);
#define PI 3.141592653589
#ifdef LINEAR_PROCESSING
# define TEX2D(c) pow(texture2D(rubyOrigTexture, (c)), vec4(CRTgamma))
#else
# define TEX2D(c) texture2D(rubyOrigTexture, (c))
#endif
uniform sampler2D rubyOrigTexture;
uniform vec2 rubyOrigInputSize;
uniform vec2 rubyOrigTextureSize;
uniform sampler2D rubyTexture;
uniform vec2 rubyInputSize;
uniform vec2 rubyTextureSize;
varying vec2 texCoord;
varying vec2 one;
varying float mod_factor;
varying vec2 ilfac;
varying float CRTgamma;
varying float monitorgamma;
varying vec2 overscan;
varying vec2 aspect;
varying float d;
varying float R;
varying float cornersize;
varying float cornersmooth;
varying vec3 stretch;
varying vec2 sinangle;
varying vec2 cosangle;
float intersect(vec2 xy)
{
float A = dot(xy,xy)+d*d;
float B = 2.0*(R*(dot(xy,sinangle)-d*cosangle.x*cosangle.y)-d*d);
float C = d*d + 2.0*R*d*cosangle.x*cosangle.y;
return (-B-sqrt(B*B-4.0*A*C))/(2.0*A);
}
vec2 bkwtrans(vec2 xy)
{
float c = intersect(xy);
vec2 point = vec2(c)*xy;
point -= vec2(-R)*sinangle;
point /= vec2(R);
vec2 tang = sinangle/cosangle;
vec2 poc = point/cosangle;
float A = dot(tang,tang)+1.0;
float B = -2.0*dot(poc,tang);
float C = dot(poc,poc)-1.0;
float a = (-B+sqrt(B*B-4.0*A*C))/(2.0*A);
vec2 uv = (point-a*sinangle)/cosangle;
float r = FIX(R*acos(a));
return uv*r/sin(r/R);
}
vec2 transform(vec2 coord)
{
coord *= rubyOrigTextureSize / rubyOrigInputSize;
coord = vec2(1.0,1.0)*(coord-vec2(0.5))*aspect*stretch.z+stretch.xy;
return (bkwtrans(coord)/overscan/aspect+vec2(0.5)) * rubyOrigInputSize / rubyOrigTextureSize;
}
float corner(vec2 coord)
{
coord *= rubyOrigTextureSize / rubyOrigInputSize;
coord = (coord - vec2(0.5)) * overscan + vec2(0.5);
coord = min(coord, vec2(1.0)-coord) * aspect;
vec2 cdist = vec2(cornersize);
coord = (cdist - min(coord,cdist));
float dist = sqrt(dot(coord,coord));
return clamp((cdist.x-dist)*cornersmooth,0.0, 1.0);
}
// Calculate the influence of a scanline on the current pixel.
//
// 'distance' is the distance in texture coordinates from the current
// pixel to the scanline in question.
// 'color' is the colour of the scanline at the horizontal location of
// the current pixel.
vec4 scanlineWeights(float distance, vec4 color)
{
// "wid" controls the width of the scanline beam, for each RGB channel
// The "weights" lines basically specify the formula that gives
// you the profile of the beam, i.e. the intensity as
// a function of distance from the vertical center of the
// scanline. In this case, it is gaussian if width=2, and
// becomes nongaussian for larger widths. Ideally this should
// be normalized so that the integral across the beam is
// independent of its width. That is, for a narrower beam
// "weights" should have a higher peak at the center of the
// scanline than for a wider beam.
#ifdef USEGAUSSIAN
vec4 wid = 0.3 + 0.1 * pow(color, vec4(3.0));
vec4 weights = vec4(distance / wid);
return 0.4 * exp(-weights * weights) / wid;
#else
vec4 wid = 2.0 + 2.0 * pow(color, vec4(4.0));
vec4 weights = vec4(distance / 0.3);
return 1.4 * exp(-pow(weights * inversesqrt(0.5 * wid), wid)) / (0.6 + 0.2 * wid);
#endif
}
void main()
{
// Here's a helpful diagram to keep in mind while trying to
// understand the code:
//
// | | | | |
// -------------------------------
// | | | | |
// | 01 | 11 | 21 | 31 | <-- current scanline
// | | @ | | |
// -------------------------------
// | | | | |
// | 02 | 12 | 22 | 32 | <-- next scanline
// | | | | |
// -------------------------------
// | | | | |
//
// Each character-cell represents a pixel on the output
// surface, "@" represents the current pixel (always somewhere
// in the bottom half of the current scan-line, or the top-half
// of the next scanline). The grid of lines represents the
// edges of the texels of the underlying texture.
// Texture coordinates of the texel containing the active pixel.
#ifdef CURVATURE
vec2 xy = transform(texCoord);
#else
vec2 xy = texCoord;
#endif
float cval = corner(xy);
vec2 xy2 = ((xy*rubyOrigTextureSize/rubyOrigInputSize-vec2(0.5))*vec2(1.0,1.0)+vec2(0.5))*rubyInputSize/rubyTextureSize;
// Of all the pixels that are mapped onto the texel we are
// currently rendering, which pixel are we currently rendering?
vec2 ilvec = vec2(0.0,ilfac.y > 1.5 ? mod(float(rubyFrameCount),2.0) : 0.0);
vec2 ratio_scale = (xy * rubyTextureSize - vec2(0.5) + ilvec)/ilfac;
// vec2 ratio_scale = xy * rubyOrigTextureSize - vec2(0.5);
#ifdef OVERSAMPLE
float filter = fwidth(ratio_scale.y);
#endif
vec2 uv_ratio = fract(ratio_scale);
// Snap to the center of the underlying texel.
xy = (floor(ratio_scale)*ilfac + vec2(0.5) - ilvec) / rubyTextureSize;
// xy = (floor(ratio_scale) + vec2(0.5)) / rubyOrigTextureSize;
// Calculate Lanczos scaling coefficients describing the effect
// of various neighbour texels in a scanline on the current
// pixel.
vec4 coeffs = PI * vec4(1.0 + uv_ratio.x, uv_ratio.x, 1.0 - uv_ratio.x, 2.0 - uv_ratio.x);
// Prevent division by zero.
coeffs = FIX(coeffs);
// Lanczos2 kernel.
coeffs = 2.0 * sin(coeffs) * sin(coeffs / 2.0) / (coeffs * coeffs);
// Normalize.
coeffs /= dot(coeffs, vec4(1.0));
// Calculate the effective colour of the current and next
// scanlines at the horizontal location of the current pixel,
// using the Lanczos coefficients above.
vec4 col = clamp(mat4(
TEX2D(xy + vec2(-one.x, 0.0)),
TEX2D(xy),
TEX2D(xy + vec2(one.x, 0.0)),
TEX2D(xy + vec2(2.0 * one.x, 0.0))) * coeffs,
0.0, 1.0);
vec4 col2 = clamp(mat4(
TEX2D(xy + vec2(-one.x, one.y)),
TEX2D(xy + vec2(0.0, one.y)),
TEX2D(xy + one),
TEX2D(xy + vec2(2.0 * one.x, one.y))) * coeffs,
0.0, 1.0);
#ifndef LINEAR_PROCESSING
col = pow(col , vec4(CRTgamma));
col2 = pow(col2, vec4(CRTgamma));
#endif
// Calculate the influence of the current and next scanlines on
// the current pixel.
vec4 weights = scanlineWeights(uv_ratio.y, col);
vec4 weights2 = scanlineWeights(1.0 - uv_ratio.y, col2);
#ifdef OVERSAMPLE
uv_ratio.y =uv_ratio.y+1.0/3.0*filter;
weights = (weights+scanlineWeights(uv_ratio.y, col))/3.0;
weights2=(weights2+scanlineWeights(abs(1.0-uv_ratio.y), col2))/3.0;
uv_ratio.y =uv_ratio.y-2.0/3.0*filter;
weights=weights+scanlineWeights(abs(uv_ratio.y), col)/3.0;
weights2=weights2+scanlineWeights(abs(1.0-uv_ratio.y), col2)/3.0;
#endif
vec3 mul_res = (col * weights + col2 * weights2).rgb;
mul_res += pow(texture2D(rubyTexture, xy2).rgb, vec3(monitorgamma))*0.1;
mul_res *= vec3(cval);
// dot-mask emulation:
// Output pixels are alternately tinted green and magenta.
vec3 dotMaskWeights = mix(
vec3(1.0, 0.7, 1.0),
vec3(0.7, 1.0, 0.7),
floor(mod(mod_factor, 2.0))
);
mul_res *= dotMaskWeights;
// Convert the image gamma for display on our output device.
mul_res = pow(mul_res, vec3(1.0 / monitorgamma));
// Color the texel.
gl_FragColor = vec4(mul_res, 1.0);
}
]]></fragment>
</shader>
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