OpenGL [CgFX] I ahve a few question about CgFX with OpenGL

This topic is 4166 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

Recommended Posts

**im using CgFX 1.5 beta 2** So far i can load a CgFX get/set parameters etc, but I soon as I load a new CgFX file it all goes wrong. I get errors like during runtime. - invalid param handle - invalid technique - etc. only the last loaded CgFX is working. it is as if it sets parameters, techniques etc from one CgFX with another. Am I forgetting to do something like: cgSetCurrentEffect(myEffect)? see code below how I load and use a CgFX file, every CgFX file is wrapped in a class:

// construct
m_cgContext = cgCreateContext();
cgGLRegisterStates(m_cgContext);
cgGLSetManageTextureParameters(m_cgContext, CG_TRUE);

m_cgTechnique = cgGetFirstTechnique(m_cgEffect);

while (m_cgTechnique && cgValidateTechnique(m_cgTechnique) == CG_FALSE)
{
// get next technique
m_cgTechnique = cgGetNextTechnique(m_cgTechnique);
}

// CgFXShader is the class that wraps a CgFX file and contains all info about technique, params etc

// Render
while (pass)
{
cgSetPassState(pass);

//DrawGeometry
cgResetPassState(pass);

pass = cgGetNextPass(pass);
}


Next question: Do I need to create a new CGcontext for every CgFX file or do I create 1 CGcontext and use it to for all other CgFX files?

Share on other sites
Try 1.5 final and see if you still get those errors. If so let me know! Also more code would help here.

You can use one context for all CgFX effects. The only thing you can't currently do is mix GL and D3D CgFX effects with one context. Each api needs its own context. This is just FYI.

Also you only need to call cgGLRegisterStates once per context. It shouldn't hurt if you called it more than once, but there's no point.

Share on other sites
1.5 final must have been 2day, I often check the nvidia's developers site and yesterday 1.5 final wasnt on yet. Ill try it 1st and post back if it helped or not.

edit:

Share on other sites
The links seem to work for me...

Oh and 1.5 went live around 8pm Central Time yesterday.

Share on other sites
they must have fixed it, a few minutes ago i they didnt work :P

Share on other sites
I didnt work :(

here's more how I do it:

//Initialisation (once)
m_cgContext = cgCreateContext();cgGLRegisterStates(m_cgContext);cgGLSetManageTextureParameters(m_cgContext, CG_TRUE);

class CgFXShaderpublic:	CgFXShader(const char* file, CGcontext cgContext);	CgFXShader();	~CgFXShader();	CGeffect GetEffect()	{ 		return m_cgEffect; 	}	CGtechnique GetTechnique() 	{ 		return m_cgTechnique; 	}	bool LoadCgFXShader(const char* file, CGcontext cgContext);private:	// effect	CGeffect  m_cgEffect;	CGtechnique m_cgTechnique;};

bool CgFXShader::LoadCgFXShader(const char* file, CGcontext cgContext){	// debug print	Console->AddMessage("Loading CgFXShader: %s", file);	bTextureManagement = cgGLGetManageTextureParameters(cgContext);	m_name.append(file);	// load effect from file	m_cgEffect = cgCreateEffectFromFile(cgContext, file, NULL);	if(!m_cgEffect)	{		OutputDebugString(cgGetLastListing( cgContext ));		return false;	}	CGparameter l_cgParameter = cgGetFirstEffectParameter( m_cgEffect );	while (l_cgParameter)	{		ParseParameter(l_cgParameter);		l_cgParameter = cgGetNextParameter( l_cgParameter );	}	// Get valid techique	m_cgTechnique = cgGetFirstTechnique(m_cgEffect);	while (m_cgTechnique && cgValidateTechnique(m_cgTechnique) == CG_FALSE)	{		Console->AddMessage(cgGetTechniqueName(m_cgTechnique));		Console->AddMessage(cgGetLastListing(cgContext));				// get next technique		m_cgTechnique = cgGetNextTechnique(m_cgTechnique);	}	// debug output current technique name	if (m_cgTechnique)	{		Console->AddMessage("- Current Technique: %s", cgGetTechniqueName(m_cgTechnique));		return true;	}	else	{		Console->AddMessage("- ERROR: No Valid Technique");		return false;	}}

Render:

// for every cgfxfor(unsigned int i = 0; i < nrCgShaders; ++i){    pCgFXShader = m_vShaders;    CGpass pass = cgGetFirstPass(pCgFXShader->GetTechnique());    while (pass)     {	cgSetPassState(pass);        // for every geometry that uses this cgfx        for(unsigned int x=0; x < nrGemoetry; ++x)            DrawGeometry[x].Render();        cgResetPassState(pass);	pass = cgGetNextPass(pass);    }}

this is the complete source. as i said before as soon as I try to load a new cgfx file the previous becomes invalid. I though that I might be doing sometrhing wront with the params and loaded 2 very simple xgfx file with 0 parameters:

// fixed function fog
technique main {    pass 	{        FogEnable = true;        FogMode = linear;        FogDensity = 5.;        FogStart = 128.0f;        FogEnd = 2048.0f;        FogColor = float4(.72f, .72f, .72f, .72f);    }}

// fixed function lighting
technique main {    pass 	{        LightingEnable = true;        LightEnable[0] = true;        LightPosition[0] = float4(-10, 10, 10, 1);        LightAmbient[0] = float4(.1,.1,.1,.1);        LightDiffuse[0] = float4(1,1,1,1);        LightSpecular[0] = float4(1,1,1,1);        MaterialShininess = 10.f;        MaterialAmbient = float4(1,1,1,1);        MaterialDiffuse = float4(.5, .5, .5, 1);        MaterialSpecular = float4(.5, .5, .5, 1);    }}

btw im using ATI hardware (ATI 9700np)

Share on other sites
Ok I'll look into this in more detail.

I hope this isn't an ATI driver issue. We have been wanting to make Cg more friendly to ATI. As a matter of fact, I have an ATI card that is just for ATI-Cg testing.

Share on other sites
this morning i tried the same build on a pc with an nvidia card and got the same results. and from your replies I got the impression that there was nothing wrong with the code I posted and knew it had to do with something else.

after some debugging i suspected the array in which the cgfx are stored in, for this i used std::vector. I changed it to a static array and it worked perfectly.

// this i how i was using it.

// here's the constructor
{
}

I dont really understand why, but i have a feeling that it has to to with how std::vector pushes values and the memory managent. if im correct in my case CgFXShader(file, m_cgContext) is placed on the stack. std::vector copies it and after that the memory is freed again resulting in invalid pointers etc. but. the desconstructor of CgFXShader doesnt do anything (yet)

{
}

thx for your time and efford and sorry for wasteing your time on this. i know you are very bussy with the cg team.

I also wanna take this oppurtunity to ask if you have any word on when FX Composer 2.0 will be released? :D

Share on other sites
Ah good, I'm glad you found the problem. I was just about to go through your code in more detail. :) I didn't have a chance to this weekend.

As far as FXComposer 2.0, I really don't know when it's supposed to be released. That's a question for the tools group and I'm not sure if they are wanting to say anything just yet. I wouldn't think it would be too much longer though.

• 9
• 10
• 12
• 10
• 10
• Similar Content

• Good Evening,
I want to make a 2D game which involves displaying some debug information. Especially for collision, enemy sights and so on ...
First of I was thinking about all those shapes which I need will need for debugging purposes: circles, rectangles, lines, polygons.
I am really stucked right now because of the fundamental question:
Where do I store my vertices positions for each line (object)? Currently I am not using a model matrix because I am using orthographic projection and set the final position within the VBO. That means that if I add a new line I would have to expand the "points" array and re-upload (recall glBufferData) it every time. The other method would be to use a model matrix and a fixed vbo for a line but it would be also messy to exactly create a line from (0,0) to (100,20) calculating the rotation and scale to make it fit.
If I proceed with option 1 "updating the array each frame" I was thinking of having 4 draw calls every frame for the lines vao, polygons vao and so on.
In addition to that I am planning to use some sort of ECS based architecture. So the other question would be:
Should I treat those debug objects as entities/components?
For me it would make sense to treat them as entities but that's creates a new issue with the previous array approach because it would have for example a transform and render component. A special render component for debug objects (no texture etc) ... For me the transform component is also just a matrix but how would I then define a line?
Treating them as components would'nt be a good idea in my eyes because then I would always need an entity. Well entity is just an id !? So maybe its a component?
Regards,
LifeArtist
• By QQemka
Hello. I am coding a small thingy in my spare time. All i want to achieve is to load a heightmap (as the lowest possible walking terrain), some static meshes (elements of the environment) and a dynamic character (meaning i can move, collide with heightmap/static meshes and hold a varying item in a hand ). Got a bunch of questions, or rather problems i can't find solution to myself. Nearly all are deal with graphics/gpu, not the coding part. My c++ is on high enough level.
Let's go:
Heightmap - i obviously want it to be textured, size is hardcoded to 256x256 squares. I can't have one huge texture stretched over entire terrain cause every pixel would be enormous. Thats why i decided to use 2 specified textures. First will be a tileset consisting of 16 square tiles (u v range from 0 to 0.25 for first tile and so on) and second a 256x256 buffer with 0-15 value representing index of the tile from tileset for every heigtmap square. Problem is, how do i blend the edges nicely and make some computationally cheap changes so its not obvious there are only 16 tiles? Is it possible to generate such terrain with some existing program?
Collisions - i want to use bounding sphere and aabb. But should i store them for a model or entity instance? Meaning i have 20 same trees spawned using the same tree model, but every entity got its own transformation (position, scale etc). Storing collision component per instance grats faster access + is precalculated and transformed (takes additional memory, but who cares?), so i stick with this, right? What should i do if object is dynamically rotated? The aabb is no longer aligned and calculating per vertex min/max everytime object rotates/scales is pretty expensive, right?
Drawing aabb - problem similar to above (storing aabb data per instance or model). This time in my opinion per model is enough since every instance also does not have own vertex buffer but uses the shared one (so 20 trees share reference to one tree model). So rendering aabb is about taking the model's aabb, transforming with instance matrix and voila. What about aabb vertex buffer (this is more of a cosmetic question, just curious, bumped onto it in time of writing this). Is it better to make it as 8 points and index buffer (12 lines), or only 2 vertices with min/max x/y/z and having the shaders dynamically generate 6 other vertices and draw the box? Or maybe there should be just ONE 1x1x1 cube box template moved/scaled per entity?
What if one model got a diffuse texture and a normal map, and other has only diffuse? Should i pass some bool flag to shader with that info, or just assume that my game supports only diffuse maps without fancy stuff?
There were several more but i forgot/solved them at time of writing
• By RenanRR
Hi All,
I'm reading the tutorials from learnOpengl site (nice site) and I'm having a question on the camera (https://learnopengl.com/Getting-started/Camera).
I always saw the camera being manipulated with the lookat, but in tutorial I saw the camera being changed through the MVP arrays, which do not seem to be camera, but rather the scene that changes:
#version 330 core layout (location = 0) in vec3 aPos; layout (location = 1) in vec2 aTexCoord; out vec2 TexCoord; uniform mat4 model; uniform mat4 view; uniform mat4 projection; void main() { gl_Position = projection * view * model * vec4(aPos, 1.0f); TexCoord = vec2(aTexCoord.x, aTexCoord.y); } then, the matrix manipulated:
..... glm::mat4 projection = glm::perspective(glm::radians(fov), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f); ourShader.setMat4("projection", projection); .... glm::mat4 view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp); ourShader.setMat4("view", view); .... model = glm::rotate(model, glm::radians(angle), glm::vec3(1.0f, 0.3f, 0.5f)); ourShader.setMat4("model", model);
So, some doubts:
- Why use it like that?
- Is it okay to manipulate the camera that way?
-in this way, are not the vertex's positions that changes instead of the camera?
- I need to pass MVP to all shaders of object in my scenes ?

What it seems, is that the camera stands still and the scenery that changes...
it's right?

Thank you

• Sampling a floating point texture where the alpha channel holds 4-bytes of packed data into the float. I don't know how to cast the raw memory to treat it as an integer so I can perform bit-shifting operations.

int rgbValue = int(textureSample.w);//4 bytes of data packed as color
// algorithm might not be correct and endianness might need switching.
vec3 extractedData = vec3(  rgbValue & 0xFF000000,  (rgbValue << 8) & 0xFF000000, (rgbValue << 16) & 0xFF000000);
extractedData /= 255.0f;

• While writing a simple renderer using OpenGL, I faced an issue with the glGetUniformLocation function. For some reason, the location is coming to be -1.
Anyone has any idea .. what should I do?