Dege is doing some of this in his dgVoodoo2 Glide-to-Direct3D wrapper I thnk? It would be HLSL and closed-source though.

Well guess what?

I'm attempting it.

Currently the shader is being prototyped in Darkplaces (relies on pixelsize which is a vec2 of 1 / screen width and 1 / screen height)

Any interest in porting it? I know I haven't posted it yet, it's just a shader tucked in a default.glsl from Darkplaces at the moment...

Alright, i've ported it to eFX+SweetFX 😁

Here are the EFX+SweetFX shaders so far, which could use a *lot* of improvement in the 'dither' and 'filter' aspects:

http://leileilol.mancubus.net/shaders/cg/leifx_reduct.h
http://leileilol.mancubus.net/shaders/cg/leifx_filter.h

EDIT: I've updated with a 5-pass method which kills a lot of awful ringing artifacts i've had. But.......

IS ANYONE HERE EVEN REMOTELY INTERESTED IN ANYTHING LIKE THIS?

Well I am, I just don't have much to say since I had a voodoo 2 card and not a early voodoo 1. I don't remember the voodoo 2 having this kind of filtering going on but I do remember it's unique way of dithering translucency.

leileilol wrote:

IS ANYONE HERE EVEN REMOTELY INTERESTED IN ANYTHING LIKE THIS?

3dfx stuff hovers a wee bit outside my personal nostalgia range, but those shots sure do approximate the way I remember it looking... plus I always appreciate a good show of shader trickery; well done. :D

I'm interested. Can't help any, but I'm all up for a good shader.

Thanks for the support, guys. The shaders will be here. Requires the efx + SweetFX bundle found in the recent posts of this thread.

While it's still buggy and highly approximate (no proper dither) i'm very pleased on the way it's turned out so far. Been playing for HOURS at its current stage unable to think of ways to make it better (For the moment).

Maybe I should set sights on the 2x2 filter?

This is quite cool indeed!

Awesome.

You should get someone (vetz?) to do some side-by-side comparisons, filter vs. real Voodoo 😀

I don't have any VGA captures to work with and i'm going by staring at a CRT running a Voodoo2.

Sadly I don't think I can do a shader to replicate the alpha blending artifacts given the limitations of eFX to be pure postprocessing (rather than allowing to alter blending functions)

I'm not claiming this is accurate at all - it still needs dithering overhauled to look like the dither seen in an unfiltered Voodoo capture, and when it comes to HLSL/CG syntax, i'm still a complete idiot.....

I would post about it on Falconfly (for the learnening of the techniques used) - if registrations were open 😒

Bleh. My attempt at porting the shader to DOSBox (to use with kekko's software emulation of Glide, and the Direct3D patch) kinda failed. It needs 5 passes for it to work (including the gamma pass + lines) and I couldn't seem to do that.

1// "LeiFX" shader - Pixel filtering process
2// 
3// 	Copyright (C) 2013 leilei
4// 
5// This program is free software; you can redistribute it and/or modify it
6// under the terms of the GNU General Public License as published by the Free
7// Software Foundation; either version 2 of the License, or (at your option)
8// any later version.
9
10
11#include "shader.code"
12
13float scaling   : SCALING = 2.0;
14
15// The name of this effect
16string name : NAME = "leifxfilter";
17
18// combineTechnique: Final combine steps. Outputs to destination frame buffer
19string combineTechique : COMBINETECHNIQUE = "leifxfilter";
20
21float2 px;
22
23// Source Texture
24texture SourceTexture : SOURCETEXTURE;
25texture LeiFXTexture : SOURCETEXTURE;
26
27// Point Sampler
28sampler SourcePointSampler = sampler_state {
29 Texture   = (SourceTexture);
30 MinFilter = POINT;
31 MagFilter = POINT;
32};  
33
34// for passes
35sampler Peww = sampler_state {
36 Texture   = (LeiFXTexture);
37 MinFilter = POINT;
38 MagFilter = POINT;
39};  
40
41// Vertex Shader Output
42struct VS_OUTPUT_PRODUCT {
43  float4  coord : POSITION;
44  float2  TexCoord   : TEXCOORD0;
45};
46
47
48
49// Vertex shader
50VS_OUTPUT_PRODUCT S_VERTEX (float3 p : POSITION, float2 tc : TEXCOORD0)
51{
52  VS_OUTPUT_PRODUCT OUT = (VS_OUTPUT_PRODUCT)0;
53  OUT.coord = mul(float4(p,1),WorldViewProjection);
54  OUT.TexCoord = tc;
55  return OUT;
56}
57
58
59// Pixel shader
60float4 S_FRAGMENT ( in VS_OUTPUT_PRODUCT VAR ) : COLOR

61{
62  	half3 fragcolor = tex2D(Peww, VAR.TexCoord).rgb; // the unmodified pixels
63	half4 meh	= 1;
64	meh.rgb = fragcolor.rgb;
65
66// Sample things.
67
68	float blendy;	// to blend unblended with blend... trying to smooth the jag :(
69	float blenda;	
70
71	float blendfactor;
72
73	float3 pixel1 = tex2D(Peww, VAR.TexCoord + float2(ps.x*0.5, 0))	.rgb;
74	float3 pixel2 = tex2D(Peww, VAR.TexCoord + float2(ps.x*-1.2, 0))	.rgb;
75	float3 pixel3 = tex2D(Peww, VAR.TexCoord + float2(ps.x*-2.2, 0))	.rgb;
76	float3 pixel4 = tex2D(Peww, VAR.TexCoord + float2(ps.x*-3.2, 0))	.rgb;
77	float3 pixel0 = tex2D(Peww, VAR.TexCoord)	.rgb;
78
79
80	float3 pixelblend;
81
82
83	float gary1 = dot(pixel1.rgb,1);
84	float gary2 = dot(pixel2.rgb,1);
85
86	float mean = 1.0;
87	mean = gary1 - gary2;
88
89	if (mean < 0)	mean *= -1;
90	if (mean > 1) mean = 1;	
91	mean = pow(mean, 0.98f);	// Adjust this value if you want to control the blur...
92
93	if (mean > 1) mean = 1;	
94		meh.rgb = fragcolor.rgb;
95	// New less crappy way
96	{
97		// variably BLEND IT ALL TO H*CK!!!!
98		blendy = 1 - mean;
99		blenda = 1 - blendy;
100		pixel0 /= 5;
101		pixel1 /= 5;
102		pixel2 /= 5;
103		pixel3 /= 5;
104		pixel4 /= 5;
105   		pixelblend.rgb = pixel0 + pixel1 + pixel2 + pixel3 + pixel4;
106		meh.rgb = (pixelblend.rgb * blendy) + (meh.rgb * blenda);
107	}
108
109  return meh;
110}
111
112technique leifxfilter
113{
114  pass P0
115  {
116    VertexShader = compile vs_3_0 S_VERTEX();
117    PixelShader  = compile ps_3_0 S_FRAGMENT();
118  }  
119 
120}

Finally got around to putting up a simple site for it.

Who is that character you're using as the test image?

Also if I knew a damn thing about GLSL I wouldn't mind trying to recreate your thing in that, but I'm still trying to learn how to even touch OpenGL 3...

Some original character i've been polishing over the years, learning and refining constantly, and i'm pretty happy where she is now....

Her top keeps shrinking!

If I'm reading this right... You went from using 3 textures and 2286 tris down to just 1 and 1900 tris?

That's a really good model too by the way. For some reason it made me think of OpenArena.

On topic of the filter shader though... the dithering you mean by this right?: http://en.wikipedia.org/wiki/Ordered_dithering

Because for some reason I remember the dither looking a bit different than that. Of course the only game I remember vividly playing on just a plain non SLI VooDoo 2 was Uprising 2: Lead and Destroy.

also who really cares for tops anyways? (awaits a impending smack across the face)

That's because the Voodoo actually has real ordered dither. My dither is just fake with no regards to error at all, it's literally a bunch of lines on lines with a bunch of ifs ands and buts to make some dot pattern. It's functionally closer to nVidia TNT/Geforce dither than it is to the Voodoo dither, and is something I need the most serious help with. If you look really close in my shader captures you'll notice some slight dot pattern that shouldn't be there...

I do know Kekko's glide software renderer has extremely close ordered dither but that's not something I can directly port to a shader language.