Hey! May be it will be interesting. I started to play in PS1 and got extremely bad graphics, and found that there is no shader/filtering solution
So, I created my using previous shader, I hope it will be useful, you could use some idea or part of code
The problem in emulation of CRT platforms - actually graphics looks more natural on CRT tv cause there is some analog noise. Also, CRT and LCD colors are different, different brighness levels and CRT 0-255 is not equal to LCD 0-255, on LCD black is very black and white is very white. Also, you could use blur + noise to emulate CRT,
Difference from real life
![[Image: sbfg5x1qL1Q.jpg]]()
Window is too bright
![[Image: -WLo4oDgUpQ.jpg]]()
Screenshots comparison
![[Image: 34RnL.png]]()
![[Image: 34RnM.png]]()
You can tune this shader for you purposes. Also, OpenGL2 does not have time variable so you cant create eternal good noise, but you could create noise using pixel coordinates. I added colors after
LITTLE text coordinate color correction and if color on some position changes, noise changes
You could change some values for platform to reduce/increase blur level
gpuPeteOGL2.slf
Code:
//patched by Danila Zabiaka - white black noise
#define white 236.0
#define black 20.0
#define noise 15.0
#define offset -25.0
#define red -0.0
#define green -0.0
#define blue -0.2
#define satoffset 5.0 //5 as start point. sat=satoffset-5.0, 6 means 1.1
float pseudoNoise(vec2 co)
{
return fract(sin(dot(vec2(co.x+0.513,co.y+0.4124) ,vec2(12.9898,78.233))) * 43758.5453);// *fract(sin(dot(vec2(co.x+4.231,co.y+3.143) ,vec2(12.9898,78.233)*2.0)) * 43758.5453); //pseudo random number generator
}
vec3 czm_saturation(vec3 rgb, float adjustment)
{
// Algorithm from Chapter 16 of OpenGL Shading Language
const vec3 W = vec3(0.2125, 0.7154, 0.0721);
vec3 intensity = vec3(dot(rgb, W));
return mix(intensity, rgb, adjustment);
}
uniform sampler2D OGL2Texture;
const vec3 RGBtoY = vec3(0.299, 0.587, 0.114);
const vec3 RGBtoI = vec3(0.596,-0.275,-0.321);
const vec3 RGBtoQ = vec3(0.212,-0.523, 0.311);
const vec3 YIQtoR = vec3(1.0, 0.95568806036115671171, 0.61985809445637075388);
const vec3 YIQtoG = vec3(1.0,-0.27158179694405859326,-0.64687381613840131330);
const vec3 YIQtoB = vec3(1.0,-1.10817732668266195230, 1.70506455991918171490);
void main()
{
vec3 c0, c1;
c0 = (texture2D(OGL2Texture,gl_TexCoord[0].xy).rgb +
(texture2D(OGL2Texture,gl_TexCoord[0].zy).rgb) * 0.25 +
(texture2D(OGL2Texture,gl_TexCoord[0].xw).rgb) * 0.25 +
texture2D(OGL2Texture,gl_TexCoord[1].xy).rgb +
(texture2D(OGL2Texture,gl_TexCoord[1].zy).rgb) * 0.25 +
(texture2D(OGL2Texture,gl_TexCoord[1].xw).rgb) * 0.25 +
texture2D(OGL2Texture,gl_TexCoord[2].xy).rgb +
(texture2D(OGL2Texture,gl_TexCoord[2].zy).rgb) * 0.25 +
(texture2D(OGL2Texture,gl_TexCoord[2].xw).rgb) * 0.25 +
texture2D(OGL2Texture,gl_TexCoord[3].xy).rgb +
(texture2D(OGL2Texture,gl_TexCoord[3].zy).rgb) * 0.25 +
(texture2D(OGL2Texture,gl_TexCoord[3].xw).rgb) * 0.25 ) / 6.0;
c1 = vec3(pow(dot(c0, RGBtoY), 1.2), dot(c0, RGBtoI) * 1.2, dot(c0, RGBtoQ) * 1.2);
gl_FragColor = vec4(dot(c1, YIQtoR), dot(c1, YIQtoG), dot(c1, YIQtoB), 0.0);
gl_FragColor.xyz = czm_saturation(gl_FragColor.xyz, 1.0+(satoffset-5.0)/10.0);
gl_FragColor = gl_FragColor *white/255.0+black/255.0-gl_FragColor*black/255.0 +(pseudoNoise(gl_TexCoord[0].xy))*1.0/255.0;
gl_FragColor = gl_FragColor +(pseudoNoise(vec2(gl_FragColor.x+gl_FragColor.z,gl_FragColor.y+gl_FragColor.z))-0.5)*noise/255.0;
// gl_FragColor = gl_FragColor +(pseudoNoise(vec2(gl_FragColor.x,gl_FragColor.x))-0.5)*noise/255.0;
gl_FragColor.x = gl_FragColor.x*(1.0+red);
gl_FragColor.y=gl_FragColor.y*(1.0+green);
gl_FragColor.z=gl_FragColor.z*(1.0+blue);
}
And gpuPeteOGL2.slv
Code:
uniform vec4 OGL2Param;
#define soffset 0.00031
void main()
{
gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;
gl_TexCoord[0]=gl_MultiTexCoord0.xyxy+vec4(-0.5,-0.5,-1.5,-1.5) * (OGL2Param.xyxy+soffset);
gl_TexCoord[1]=gl_MultiTexCoord0.xyxy+vec4( 0.5,-0.5, 1.5,-1.5) * (OGL2Param.xyxy+soffset);
gl_TexCoord[2]=gl_MultiTexCoord0.xyxy+vec4(-0.5, 0.5,-1.5, 1.5) * (OGL2Param.xyxy+soffset);
gl_TexCoord[3]=gl_MultiTexCoord0.xyxy+vec4( 0.5, 0.5, 1.5, 1.5) * (OGL2Param.xyxy+soffset);
}
^_^
![[Image: cPelVzuvvZw.jpg]]()
![[Image: sbfg5x1qL1Q.jpg]](http://sun9-66.userapi.com/c858036/v858036608/1e5a2b/sbfg5x1qL1Q.jpg)
![[Image: -WLo4oDgUpQ.jpg]](http://sun9-43.userapi.com/c855616/v855616608/2328df/-WLo4oDgUpQ.jpg)
![[Image: 34RnL.png]](http://funkyimg.com/i/34RnL.png)
![[Image: 34RnM.png]](http://funkyimg.com/i/34RnM.png)
![[Image: cPelVzuvvZw.jpg]](http://sun7-8.userapi.com/_o9ln7kFFfhEaOWqSSXsWWiN6yTuViiRe-adMQ/cPelVzuvvZw.jpg)
![[Image: Zwischenablage01.png]](http://i.ibb.co/b2yNzPp/Zwischenablage01.png)
