Cycling 74 » Topic: first shader http://cycling74.com/forums/topic/first-shader/feed Wed, 19 Jun 2013 14:58:56 +0000 http://bbpress.org/?v=2.2.4 http://cycling74.com/forums/topic/first-shader/#post-34525 <![CDATA[first shader]]> http://cycling74.com/forums/topic/first-shader/#post-34525 Thu, 08 Nov 2007 17:07:54 +0000 marius.schebella hey,
I just subscribed to the jitter list, trying to test a shader but
something is wrong. I hope it is ok, if I just paste it.
I have to say that this is my first shader, so it could be some very
basic problem with bindings or jitter communication.
anyway, when I try to load the shader I get:
setting GLSL param: GL Error: Invalid operation
thanks for help,
marius.

———

Shader to set alpha related to color thresholds





< ![CDATA[
// VERTEX SHAADER

varying vec2 texcoord;

void main (void)
{
gl_Position = ftransform();
texcoord = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0);
}
]]>

< ![CDATA[
// FRAGMENT SHADER

varying vec2 texcoord;
uniform sampler2DRect image;

uniform vec4 hithresh; // hi and lo threshold
uniform vec4 lothresh;
uniform vec2 pass_other;

void main()
{
vec4 A = texture2DRect(image, texcoord);
A.a = pass_other[0];
if ((A.r >= hithresh.r) || (A.r < = lothresh.r) || (A.g >= hithresh.g)
|| (A.g < = lothresh.g) || (A.b >= hithresh.b) || (A.r < = lothresh.b))
{
A.a = pass_other[1];
}
gl_FragColor = A;

}
]]>


]]> http://cycling74.com/forums/topic/first-shader/#post-116720 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116720 Thu, 08 Nov 2007 18:00:47 +0000 Wesley Smith vec4 A = texture2DRect(image, texcoord);
A.a = pass_other[0];

this should be :

vec4 A = texture2DRect(image, texcoord);
A.a = pass_other.x;

wes

On 11/8/07, marius schebella wrote:
> hey,
> I just subscribed to the jitter list, trying to test a shader but
> something is wrong. I hope it is ok, if I just paste it.
> I have to say that this is my first shader, so it could be some very
> basic problem with bindings or jitter communication.
> anyway, when I try to load the shader I get:
> setting GLSL param: GL Error: Invalid operation
> thanks for help,
> marius.
>
> ———
>
> Shader to set alpha related to color thresholds
> > > > >
>
>
>
>
>
> > < ![CDATA[
> // VERTEX SHAADER
>
> varying vec2 texcoord;
>
> void main (void)
> {
> gl_Position = ftransform();
> texcoord = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0);
> }
> ]]>
> >
> > < ![CDATA[
> // FRAGMENT SHADER
>
> varying vec2 texcoord;
> uniform sampler2DRect image;
>
> uniform vec4 hithresh; // hi and lo threshold
> uniform vec4 lothresh;
> uniform vec2 pass_other;
>
> void main()
> {
> vec4 A = texture2DRect(image, texcoord);
> A.a = pass_other[0];
> if ((A.r >= hithresh.r) || (A.r < = lothresh.r) || (A.g >= hithresh.g)
> || (A.g < = lothresh.g) || (A.b >= hithresh.b) || (A.r < = lothresh.b))
> {
> A.a = pass_other[1];
> }
> gl_FragColor = A;
>
> }
> ]]>
> >
>
>

]]> http://cycling74.com/forums/topic/first-shader/#post-116721 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116721 Thu, 08 Nov 2007 18:21:04 +0000 Andrew Benson your problem is most likely in this line:

Change type to “int” and you will probably be okay.

FWIW, I would recommend ditching all of that conditional stuff (if…)
and replacing with mix() and step() type functions. Support for
conditional statements is pretty unpredictable in GLSL.

Best,
Andrew B.

]]> http://cycling74.com/forums/topic/first-shader/#post-116722 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116722 Thu, 08 Nov 2007 19:19:15 +0000 marius.schebella thank you for the quick reply.
I think I have a problem in my max patch, because
even
void main()
{
vec4 A = texture2DRect(image, texcoord);
A.a = 0.4;
gl_FragColor = A;
}
does not look transparent. (A.r, A.g, A.b all work.)
do I need a special object or argument to turn alphachannel computation
on? sorry if that is a basic question. right now I am only using
jit.qt.movie, jit.gl.slab and jit.gl.videoplane.
thanks,
marius.

Wesley Smith wrote:
> vec4 A = texture2DRect(image, texcoord);
> A.a = pass_other[0];
>
> this should be :
>
> vec4 A = texture2DRect(image, texcoord);
> A.a = pass_other.x;
>
> wes
>
> On 11/8/07, marius schebella wrote:
>> hey,
>> I just subscribed to the jitter list, trying to test a shader but
>> something is wrong. I hope it is ok, if I just paste it.
>> I have to say that this is my first shader, so it could be some very
>> basic problem with bindings or jitter communication.
>> anyway, when I try to load the shader I get:
>> setting GLSL param: GL Error: Invalid operation
>> thanks for help,
>> marius.
>>
>> ———
>>
>> Shader to set alpha related to color thresholds
>> >> >> >> >>
>>
>>
>>
>>
>>
>> >> < ![CDATA[
>> // VERTEX SHAADER
>>
>> varying vec2 texcoord;
>>
>> void main (void)
>> {
>> gl_Position = ftransform();
>> texcoord = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0);
>> }
>> ]]>
>> >>
>> >> < ![CDATA[
>> // FRAGMENT SHADER
>>
>> varying vec2 texcoord;
>> uniform sampler2DRect image;
>>
>> uniform vec4 hithresh; // hi and lo threshold
>> uniform vec4 lothresh;
>> uniform vec2 pass_other;
>>
>> void main()
>> {
>> vec4 A = texture2DRect(image, texcoord);
>> A.a = pass_other[0];
>> if ((A.r >= hithresh.r) || (A.r < = lothresh.r) || (A.g >= hithresh.g)
>> || (A.g < = lothresh.g) || (A.b >= hithresh.b) || (A.r < = lothresh.b))
>> {
>> A.a = pass_other[1];
>> }
>> gl_FragColor = A;
>>
>> }
>> ]]>
>> >>
>>
>>
>

]]> http://cycling74.com/forums/topic/first-shader/#post-116723 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116723 Thu, 08 Nov 2007 19:24:08 +0000 marius.schebella hello andrew,
thanks, that solved one of the problems
I read that glsl is not optimized for conditional stuff, but I have to
learn more glsl commands to see what could replace them.
the thing is, I only want a comparison of 3 of the 4 channels. yes, I
would like to boost efficiency by using glsl internal commands.
marius.

andrew benson wrote:
> your problem is most likely in this line:
>
> >
> Change type to “int” and you will probably be okay.
>
> FWIW, I would recommend ditching all of that conditional stuff (if…)
> and replacing with mix() and step() type functions. Support for
> conditional statements is pretty unpredictable in GLSL.
>
> Best,
> Andrew B.
>

]]> http://cycling74.com/forums/topic/first-shader/#post-116724 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116724 Thu, 08 Nov 2007 19:30:17 +0000 vade make sure your output geometry has blend_enable 1 ;

sosomething like jit.gl.videoplane context @blend_enable 1

:)

On Nov 8, 2007, at 2:19 PM, marius schebella wrote:

> thank you for the quick reply.
> I think I have a problem in my max patch, because
> even
> void main()
> {
> vec4 A = texture2DRect(image, texcoord);
> A.a = 0.4;
> gl_FragColor = A;
> }
> does not look transparent. (A.r, A.g, A.b all work.)
> do I need a special object or argument to turn alphachannel
> computation on? sorry if that is a basic question. right now I am
> only using jit.qt.movie, jit.gl.slab and jit.gl.videoplane.
> thanks,
> marius.
>
> Wesley Smith wrote:
>> vec4 A = texture2DRect(image, texcoord);
>> A.a = pass_other[0];
>> this should be :
>> vec4 A = texture2DRect(image, texcoord);
>> A.a = pass_other.x;
>> wes
>> On 11/8/07, marius schebella wrote:
>>> hey,
>>> I just subscribed to the jitter list, trying to test a shader but
>>> something is wrong. I hope it is ok, if I just paste it.
>>> I have to say that this is my first shader, so it could be some very
>>> basic problem with bindings or jitter communication.
>>> anyway, when I try to load the shader I get:
>>> setting GLSL param: GL Error: Invalid operation
>>> thanks for help,
>>> marius.
>>>
>>> ———
>>>
>>> Shader to set alpha related to color
>>> thresholds
>>> >>> >>>
>>>
>>>
>>>
>>>
>>>
>>> >>> < ![CDATA[
>>> // VERTEX SHAADER
>>>
>>> varying vec2 texcoord;
>>>
>>> void main (void)
>>> {
>>> gl_Position = ftransform();
>>> texcoord = vec2(gl_TextureMatrix[0] * gl_MultiTexCoord0);
>>> }
>>> ]]>
>>> >>>
>>> >>> < ![CDATA[
>>> // FRAGMENT SHADER
>>>
>>> varying vec2 texcoord;
>>> uniform sampler2DRect image;
>>>
>>> uniform vec4 hithresh; // hi and lo threshold
>>> uniform vec4 lothresh;
>>> uniform vec2 pass_other;
>>>
>>> void main()
>>> {
>>> vec4 A = texture2DRect(image, texcoord);
>>> A.a = pass_other[0];
>>> if ((A.r >= hithresh.r) || (A.r < = lothresh.r) || (A.g >=
>>> hithresh.g)
>>> || (A.g < = lothresh.g) || (A.b >= hithresh.b) ||
>>> (A.r < = lothresh.b))
>>> {
>>> A.a = pass_other[1];
>>> }
>>> gl_FragColor = A;
>>>
>>> }
>>> ]]>
>>> >>>
>>>
>>>
>

]]> http://cycling74.com/forums/topic/first-shader/#post-116725 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116725 Thu, 08 Nov 2007 19:40:19 +0000 Wesley Smith jit.gl.videoplane @blend_enable 1?
wes

On 11/8/07, marius schebella wrote:
> hello andrew,
> thanks, that solved one of the problems
> I read that glsl is not optimized for conditional stuff, but I have to
> learn more glsl commands to see what could replace them.
> the thing is, I only want a comparison of 3 of the 4 channels. yes, I
> would like to boost efficiency by using glsl internal commands.
> marius.
>
> andrew benson wrote:
> > your problem is most likely in this line:
> >
> > > >
> > Change type to “int” and you will probably be okay.
> >
> > FWIW, I would recommend ditching all of that conditional stuff (if…)
> > and replacing with mix() and step() type functions. Support for
> > conditional statements is pretty unpredictable in GLSL.
> >
> > Best,
> > Andrew B.
> >
>
>

]]> http://cycling74.com/forums/topic/first-shader/#post-116726 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116726 Thu, 08 Nov 2007 19:57:13 +0000 Rob Ramirez oooh anton beat me to it.

btw, marius, does the gem list know you’re over here in segmented patch cord land?

#P window setfont “Sans Serif” 9.;
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#P flonum 235 268 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P newex 438 315 76 196617 prepend param;
#P newex 438 292 102 196617 pak pass_other 0. 0.;
#P newex 324 315 76 196617 prepend param;
#P newex 324 292 113 196617 pak lothresh 0. 0. 0. 0.;
#P newex 210 315 76 196617 prepend param;
#P newex 210 292 113 196617 pak hithresh 0. 0. 0. 0.;
#P message 145 317 63 196617 flush_cache;
#P newex 231 183 138 196617 jit.gl.texture m @name tex1;
#P newex 262 374 32 196617 print;
#P message 76 317 67 196617 getparamlist;
#P user jit.fpsgui 132 121 60 196617 0;
#P newex 78 95 66 196617 t b b erase b;
#P flonum 306 108 35 9 0 0 0 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P message 306 128 42 196617 rate $1;
#P message 366 108 28 196617 read;
#P flonum 265 108 35 9 0.5 0 1 3 0 0 0 221 221 221 222 222 222 0 0 0;
#P toggle 231 108 15 0;
#P newex 231 128 44 196617 metro 2;
#P newex 231 161 103 196617 jit.qt.movie 320 240;
#B color 5;
#P toggle 78 49 15 0;
#P newex 78 70 50 196617 qmetro 5;
#P newex 228 214 303 196617 jit.gl.videoplane m @texture tex1 @automatic 0 @blend_enable 1;
#P newex 78 239 69 196617 jit.window m;
#P newex 78 213 146 196617 jit.gl.render m @shader shady;
#P newex 76 351 217 196617 jit.gl.shader m @name shady @file marius.jxs;
#P fasten 24 0 0 0 443 341 81 341;
#P fasten 22 0 0 0 329 341 81 341;
#P fasten 20 0 0 0 215 341 81 341;
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#P connect 5 0 4 0;
#P connect 4 0 13 0;
#P connect 13 0 1 0;
#P connect 13 2 1 0;
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#P hidden connect 35 0 25 0;
#P connect 25 0 19 1;
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#P connect 34 0 23 2;
#P window clipboard copycount 37;

]]> http://cycling74.com/forums/topic/first-shader/#post-116727 <![CDATA[Re: first shader]]> http://cycling74.com/forums/topic/first-shader/#post-116727 Sat, 10 Nov 2007 18:08:41 +0000 marius.schebella ok,
thanks to josh, rob, vade, wes and andrew, I posted the unspectular
result at http://www.parasitaere-kapazitaeten.net/max_msp/pix_alpha (in
case someone wants to check).
I outsourced the vert and frag programs to extra files and replaced my
original comparators with glsl native
if all(greaterThanEqual(A.rgb,lothresh.rgb)…

Robert Ramirez wrote:

> btw, marius, does the gem list know you’re over here in segmented patch cord land?

naaahh! all these open source freaks are totally ignorant and
insensitive to the beauties of segmented patchcord land…

m.

]]>