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GLSL problem...

Started by Tree Penguin Nov 22, 2004 at 5:19 PM 3 replies 950+ views

Original Post

103

Nov 22, 2004 at 5:19 PM

I am trying to get basic glsl shaders to work but i get a 'Ongeldige Bewerking' (i think the correct translation is 'Invalid Exception') ogl error after calling glUseProgramObjectARB. As a result the quad i draw is white instead of colored (what my shader should do, it's just not executed). I am not feeling like posting all of the code so if anyone could tell me at what places the cause of the error can be i will post that code. Tnanks a lot. Btw, if you need me to describe my problem better please say so. EDIT: i am able to run my shader with the glsl demo viewer from the 3dlabs website so that can't be the problem.

PinguinDude

Nov 22, 2004 at 5:32 PM

Then it's your code.

Tree Penguin

Author

103

Tree Penguin

Nov 22, 2004 at 5:44 PM

Ah sorry, i checked and the vertex program just isn't compiled in my app, is there something wrong with:

void main(){gl_Position = vect4 (1.0,1.0,1.0,1.0);gl_Color=vec4(0.5,1.0,1.0,1.0);}

?

Have i forgotten anything?

Hmm i guess it's the compiler (maybe it's not there or something).

EDIT: here's the code:

GLhandleARB my_program;GLhandleARB my_vertex_shader;	// Create Shader And Program Objectsmy_program = glCreateProgramObjectARB();my_vertex_shader = glCreateShaderObjectARB(GL_VERTEX_SHADER_ARB);	// Load Shader SourcesglShaderSourceARB(my_vertex_shader, 1, getGLcharARBxx(&my_vertex_shader_source), NULL);	// Compile The ShadersglCompileShaderARB(my_vertex_shader);	int vertCompiled=0;glGetObjectParameterivARB(my_vertex_shader,GL_OBJECT_COMPILE_STATUS_ARB, &vertCompiled);if(!vertCompiled)MessageBox(NULL,"Vp compile failed.","ERROR",NULL);// Attach The Shader Objects To The Program ObjectglAttachObjectARB(my_program, my_vertex_shader);	// Link The Program ObjectglLinkProgramARB(my_program);	// Use The Program Object Instead Of Fixed Function OpenGLglUseProgramObjectARB(my_program);

[Edited by - Tree Penguin on November 22, 2004 6:44:03 PM]

Enigma

188

Enigma

Nov 22, 2004 at 6:10 PM

If you're using windows then make sure you've properly loaded the function pointers for GlSlang functions, since they're only accessible as extensions.

Here's my (quickly hacked) shader loading code from a recent project, it outputs debug information to the console if shader compilation fails:

char* readFile(const char* fileName){	std::ifstream reader(fileName, std::ios::in | std::ios::binary);	reader.seekg(0, std::ios::end);	unsigned int fileLength = reader.tellg();	reader.seekg(0, std::ios::beg);	char* file = new char[fileLength + 1];	file[fileLength] = '\0';	reader.read(file, fileLength);	return file;}GLhandleARB loadShader(const char* shaderSource, GLenum type){	GLhandleARB shader = glCreateShaderObjectARB(type);	char* shaderCode = readFile(shaderSource);	int shaderLength = -1;	glShaderSourceARB(shader, 1, &shaderCode, &shaderLength);	delete[] shaderCode;	glCompileShaderARB(shader);	int objectParameter;	glGetObjectParameterivARB(shader, GL_OBJECT_COMPILE_STATUS_ARB, &objectParameter);	if (!objectParameter)	{		std::cout << "shader error\n";		int infoLogLength;		glGetObjectParameterivARB(shader, GL_OBJECT_INFO_LOG_LENGTH_ARB, &infoLogLength);		char* infoLog = new char[infoLogLength];		glGetInfoLogARB(shader, infoLogLength, 0, infoLog);		std::cout << infoLog << '\n';		delete[] infoLog;		std::exit(-1);	}	return shader;}GLhandleARB buildShaderProgram(std::vector<GLhandleARB> shaders){	GLhandleARB program = glCreateProgramObjectARB();	for (unsigned int index = 0; index < shaders.size(); ++index)	{		glAttachObjectARB(program, shaders[index]);	}	glLinkProgramARB(program);	int objectParameter;	glGetObjectParameterivARB(program, GL_OBJECT_LINK_STATUS_ARB, &objectParameter);	if (!objectParameter)	{		std::cout << "program error\n";		int infoLogLength;		glGetObjectParameterivARB(program, GL_OBJECT_INFO_LOG_LENGTH_ARB, &infoLogLength);		char* infoLog = new char[infoLogLength];		glGetInfoLogARB(program, infoLogLength, 0, infoLog);		std::cout << infoLog << '\n';		delete[] infoLog;		std::exit(-1);	}	return program;}void initShaders(){	std::vector<GLhandleARB> shaders;	shaders.push_back(loadShader("vertexProgram.slang", GL_VERTEX_SHADER_ARB));	shaders.push_back(loadShader("fragmentProgram.slang", GL_FRAGMENT_SHADER_ARB));	shader1 = buildShaderProgram(shaders);	shaders.clear();	shaders.push_back(loadShader("vertexProgram.slang", GL_VERTEX_SHADER_ARB));	shader2 = buildShaderProgram(shaders);	shaders.clear();}

Enigma

Tree Penguin

Author

103

Tree Penguin

Nov 22, 2004 at 6:27 PM

I made a pretty stupid mistake, i passed the shader's filename instead of the shader contents to glShaderSourceARB.

Thanks for your help anyway.

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