Jump to content

  • Log In with Google      Sign In   
  • Create Account

FREE SOFTWARE GIVEAWAY

We have 4 x Pro Licences (valued at $59 each) for 2d modular animation software Spriter to give away in this Thursday's GDNet Direct email newsletter.


Read more in this forum topic or make sure you're signed up (from the right-hand sidebar on the homepage) and read Thursday's newsletter to get in the running!


Please help 2 days stuck, simple openGL app doesn't render anything!


Old topic!
Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.

  • You cannot reply to this topic
4 replies to this topic

#1 EddieV223   Members   -  Reputation: 1407

Like
0Likes
Like

Posted 20 February 2013 - 02:54 PM

Here is a link to my vs11 express project.

http://www.filehosting.org/file/details/421749/OpenGLSpaceShip.7z

 

All it does is render the clear color it doesn't render my objects, I have tried loading from my obj loader and also just using vertex and index buffer from a working tutorial, neither work.

 

It is really just 1 Graphics class so it's not complicated code.  For 2 days I struggle with this, since I am new to openGL I don't know what is wrong and have been trying to fix it for days now.  

 

Here is the graphics class.

 

// header

#pragma once

#include "GL\glew.h"
#include "GL\freeglut.h"

#define GLM_FORCE_RADIANS
#include <glm.hpp>
#include <gtc/matrix_transform.hpp>

class Graphics
{
public:
	Graphics();
	~Graphics();

	bool Init(int argc, char* argv[]);

	bool InitWindow(int argc, char* argv[]);

	void StartGlutLoop();

	bool LoadGraphics();
	void UpdateGraphics();
	void RenderGraphics();
	void CleanGraphics();

	int mWindowHandle;

	GLuint mVAO;
	GLuint mVBOCube;
	GLuint mVBOCubeIndices;
	GLuint mCubeIndexCount;

	GLuint mBasicShaderProgram;

	glm::mat4 mView;
	glm::mat4 mProj;
	glm::mat4 mProjView;
	glm::mat4 mCubeWorld;
};

// CPP


#include "Graphics.h"

#include "main.h"

Graphics::Graphics()
	{
	}


Graphics::~Graphics()
	{
	}

bool Graphics::Init(int argc, char* argv[])
	{
	GLenum glewInitResult;
	InitWindow(argc, argv);
	GLenum error = glGetError();
	
	glewExperimental = GL_TRUE;
	glewInitResult = glewInit();
	error = glGetError();
	if ( glewInitResult != GLEW_OK )	
		{
		cout << glewGetErrorString(error) << '\n';
		exit(EXIT_FAILURE);
		return false;
		}
	
	error = glGetError();
	// this triggers 1280 GL_INVALID_ENUM this is before I even set any gl enums manually
	if ( error != GL_NO_ERROR )	
		{
		cout << glewGetErrorString( error );
		exit(-1);
		return false;
		}
	glEnable(GL_DEPTH_TEST);
	glClearColor(0.5f, 0.5f, 0.5f, 0.5f);
	if (LoadGraphics())
		return true;
	else
		{
		return false;
		}
	}

bool Graphics::InitWindow(int argc, char* argv[])
	{
	glutInit(&argc, argv);

	glutInitContextVersion(4, 0);
	glutInitContextFlags(GLUT_FORWARD_COMPATIBLE);
	glutInitContextProfile( GLUT_CORE_PROFILE );

	glutSetOption( GLUT_ACTION_ON_WINDOW_CLOSE, GLUT_ACTION_GLUTMAINLOOP_RETURNS );

	glutInitWindowSize( 800, 600 );
	
	glutInitDisplayMode( GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA );

	mWindowHandle = glutCreateWindow("Hello World!");

	if ( mWindowHandle < 1 )
		{
		exit(EXIT_FAILURE);
		}
	// TODO: add callbacks for freeGLUT
	glutIdleFunc( Update );
	glutDisplayFunc( Render );
	glutCloseFunc( Close );
	
	return true;
	}

bool Graphics::LoadGraphics()
	{
	GLenum error = glGetError();
	if ( error != GL_NO_ERROR )
		{
		cout << glewGetErrorString(error) << '\n';
		exit(-1);
		return false;
		}
	typedef struct
{
    float XYZW[4];
} Vertex2;

	Vertex2 vertices[] =
{
    { { 0.0f, 0.0f, 0.0f, 1.0f } },
    // Top
    { { -0.2f, 0.8f, 0.0f, 1.0f } },
    { { 0.2f, 0.8f, 0.0f, 1.0f } },
    { { 0.0f, 0.8f, 0.0f, 1.0f }},
    { { 0.0f, 1.0f, 0.0f, 1.0f }},
    // Bottom
    { { -0.2f, -0.8f, 0.0f, 1.0f } },
    { { 0.2f, -0.8f, 0.0f, 1.0f } },
    { { 0.0f, -0.8f, 0.0f, 1.0f } },
    { { 0.0f, -1.0f, 0.0f, 1.0f } },
    // Left
    { { -0.8f, -0.2f, 0.0f, 1.0f } },
    { { -0.8f, 0.2f, 0.0f, 1.0f } },
    { { -0.8f, 0.0f, 0.0f, 1.0f } },
    { { -1.0f, 0.0f, 0.0f, 1.0f } },
    // Right
    { { 0.8f, -0.2f, 0.0f, 1.0f } },
    { { 0.8f, 0.2f, 0.0f, 1.0f } },
    { { 0.8f, 0.0f, 0.0f, 1.0f }},
    { { 1.0f, 0.0f, 0.0f, 1.0f } }
};

GLubyte indices[] = {
    // Top
    0, 1, 3,
    0, 3, 2,
    3, 1, 4,
    3, 4, 2,
    // Bottom
    0, 5, 7,
    0, 7, 6,
    7, 5, 8,
    7, 8, 6,
    // Left
    0, 9, 11,
    0, 11, 10,
    11, 9, 12,
    11, 12, 10,
    // Right
    0, 13, 15,
    0, 15, 14,
    15, 13, 16,
    15, 16, 14
};


	// create VBO
	OBJLoader loader;
	
	UPMesh upMesh = loader.Load( "c:\\objBox.obj" );

	glGenBuffers(1, &mVBOCube);
	glBindBuffer(GL_ARRAY_BUFFER, mVBOCube);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW );
	//glBufferData(GL_ARRAY_BUFFER, sizeof(Vertex2) * upMesh->mVertices.size(), upMesh->mVertices.data(), GL_STATIC_DRAW );

	glGenBuffers(1, &mVBOCubeIndices);
	glBindBuffer( GL_ELEMENT_ARRAY_BUFFER, mVBOCubeIndices);
	glBufferData( GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW );
	//glBufferData( GL_ELEMENT_ARRAY_BUFFER, sizeof(upMesh->mIndices[0]) * upMesh->mIndices.size(), upMesh->mIndices.data(), GL_STATIC_DRAW );

	
	// create VAO
	glGenVertexArrays(1, &mVAO);
	glBindVertexArray(mVAO);
	error = glGetError();

	if ( error != GL_NO_ERROR )
		{
		cout << glewGetErrorString( error ) << '\n';
		exit(-1);
		return false;
		}
	
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, (void*)0 );
	//glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 0, (void*)(3 * sizeof(GLfloat)) );
	//glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 0, (void*)(5 * sizeof(GLfloat)) );
	error = glGetError();

	if ( error != GL_NO_ERROR )
		{
		cout << glewGetErrorString( error ) << '\n';
		exit(-1);
		return false;
		}
	
	glEnableVertexAttribArray(0);
	//glEnableVertexAttribArray(1);
	//glEnableVertexAttribArray(2);
	

	mCubeIndexCount = upMesh->mIndices.size();

	mView = glm::lookAt( glm::vec3(0.f,0.f,10.f), glm::vec3(0.f,0.f,0.f), glm::vec3(0.f, 1.0f, 0.f));
	mProj = glm::perspective( 3.14f / 2.0f, 800.f / 600.f, 0.1f, 1000.f );
	mProjView = mProj * mView;

	mCubeWorld = glm::mat4(1.0f);

	error = glGetError();

	if ( error != GL_NO_ERROR )
		{
		cout << glewGetErrorString( error ) << '\n';
		exit(-1);
		return false;
		}

	ifstream ifs;
	ifs.open( "..\\Resources\\basicShader.vertex", ios::in );
	if ( !ifs.good() )
		{
		cout << "ifs open failed.\n";
		exit(-1);
		return false;
		}
	string buffer;
	string errorBuffer;
	errorBuffer.reserve(2048);
	string shaderCode;
	while ( getline(ifs, buffer ) )
		{
		shaderCode += buffer += '\n';
		}
	char const * pSource = shaderCode.c_str();	
	GLuint vertShader = glCreateShader(GL_VERTEX_SHADER);
	glShaderSource( vertShader, 1, &pSource, NULL );
	glCompileShader(vertShader);
	glGetShaderInfoLog( vertShader, 2047, NULL, &errorBuffer[0] );
	ifs.close();
	
	error = glGetError();
	ifs.open( "..\\Resources\\basicShader.fragment", ios::in );
	if ( !ifs.good() )
		{
		exit(-1);
		return false;
		}

	shaderCode.clear();
	while ( getline( ifs, buffer ) )
		{
		shaderCode += buffer += '\n';
		}
	pSource = shaderCode.c_str();
	GLuint fragShader = glCreateShader(GL_FRAGMENT_SHADER);
	glShaderSource( fragShader, 1, &pSource, NULL );
	glCompileShader( fragShader );
	glGetShaderInfoLog( fragShader, 2047, NULL, &errorBuffer[0] );
	mBasicShaderProgram = glCreateProgram();
	glAttachShader(mBasicShaderProgram, vertShader);
	glAttachShader(mBasicShaderProgram, fragShader);
	glLinkProgram( mBasicShaderProgram );
	glGetProgramInfoLog( mBasicShaderProgram, 2047, NULL, &errorBuffer[0] );
	glUseProgram( mBasicShaderProgram );

	error = glGetError();

	if ( error != GL_NO_ERROR )
		{
		cout << glewGetErrorString(error) << '\n';
		exit(-1);
		return false;
		}

	return true;
	}

void Graphics::UpdateGraphics()
	{
	glutPostRedisplay();
	}

void Graphics::RenderGraphics()
	{
	static float color = 0.0;
	static float dir = 1.0;
	color += (.0001f * dir);
	if ( 1.0f < color )
		{
		color = 0.999f;
		dir *= -1.0f;
		}
	if ( color < 0.0f )
		{
		color = 0.0001f;
		dir *= -1.0f;
		}
	glClearColor( color, color, color, 0.0);
	glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	glPolygonMode( GL_FRONT_AND_BACK, GL_FILL );

	glm::mat4 mvp = mProjView * mCubeWorld;

	GLint location = glGetUniformLocation(mBasicShaderProgram, "world");

	glProgramUniformMatrix4fv( mBasicShaderProgram, location, 1, GL_FALSE, &mvp[0][0] );

	glDrawElements( GL_TRIANGLES, mCubeIndexCount, GL_UNSIGNED_INT, (void*)0);

	glutSwapBuffers();
	glutPostRedisplay();

	GLenum error = glGetError();
	if ( error != GL_NO_ERROR )
		{
		cout << glewGetErrorString(error) << '\n';
		exit(-1);
		return;
		}
	}

void Graphics::CleanGraphics()
	{
	glDisableVertexAttribArray(mVAO);
	glDisableVertexAttribArray(0);

	glBindVertexArray(0);
	glDeleteVertexArrays(1, &mVAO);

	glBindBuffer( GL_ARRAY_BUFFER, 0 );

	glDeleteBuffers(1, &mVBOCube);

	GLenum error = glGetError();
	if ( error != GL_NO_ERROR )
		{
		exit(-1);
		}
	}

void Graphics::StartGlutLoop()
	{
	glutMainLoop();
	}

Edited by EddieV223, 20 February 2013 - 03:08 PM.

If this post or signature was helpful and/or constructive please give rep.

 

// C++ Video tutorials

http://www.youtube.com/watch?v=Wo60USYV9Ik

 

// Easy to learn 2D Game Library c++

SFML2.1 Download http://www.sfml-dev.org/download.php

SFML2.1 Tutorials http://www.sfml-dev.org/tutorials/2.1/

 

// SFML 2 book

http://www.amazon.com/gp/product/1849696845/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=1849696845&linkCode=as2&tag=gamer2creator-20

 


Sponsor:

#2 Cornstalks   Crossbones+   -  Reputation: 6991

Like
0Likes
Like

Posted 20 February 2013 - 03:00 PM

It is really just 1 Graphics class so it's not complicated code.  For 2 days I struggle with this, since I am new to openGL I don't know what is wrong and have been trying to fix it for days now.

I don't know what's wrong either, because you haven't described any kind of problem. I see code, but I don't even know what kind of problem to look for.

 

You may not be able to know the cause of a problem, but we need to at least know what the problem is in order to help you find the cause of it.


[ I was ninja'd 71 times before I stopped counting a long time ago ] [ f.k.a. MikeTacular ] [ My Blog ] [ SWFer: Gaplessly looped MP3s in your Flash games ]

#3 Nercury   Crossbones+   -  Reputation: 796

Like
0Likes
Like

Posted 20 February 2013 - 03:04 PM

To find a problem, you should comment out most of the code and start from basics.

 

Get empty window to show up, draw something on it.

Enable perspective code.

Replace test drawing with your cube.

Add shaders.

And so on.

 

Not only you will find the error, but this way you will learn OpenGL easier. And you would ask much more specific questions :)


Edited by Nercury, 20 February 2013 - 03:05 PM.


#4 EddieV223   Members   -  Reputation: 1407

Like
0Likes
Like

Posted 20 February 2013 - 03:24 PM

It is really just 1 Graphics class so it's not complicated code.  For 2 days I struggle with this, since I am new to openGL I don't know what is wrong and have been trying to fix it for days now.

I don't know what's wrong either, because you haven't described any kind of problem. I see code, but I don't even know what kind of problem to look for.

 

You may not be able to know the cause of a problem, but we need to at least know what the problem is in order to help you find the cause of it.

added some explaination.


If this post or signature was helpful and/or constructive please give rep.

 

// C++ Video tutorials

http://www.youtube.com/watch?v=Wo60USYV9Ik

 

// Easy to learn 2D Game Library c++

SFML2.1 Download http://www.sfml-dev.org/download.php

SFML2.1 Tutorials http://www.sfml-dev.org/tutorials/2.1/

 

// SFML 2 book

http://www.amazon.com/gp/product/1849696845/ref=as_li_ss_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=1849696845&linkCode=as2&tag=gamer2creator-20

 


#5 __SKYe   Members   -  Reputation: 1102

Like
0Likes
Like

Posted 20 February 2013 - 04:43 PM

// this triggers 1280 GL_INVALID_ENUM this is before I even set any gl enums manually
	if ( error != GL_NO_ERROR )	
		{
		cout << glewGetErrorString( error );
		exit(-1);
		return false;
		}

 

This GL_INVALID_ENUM may be because you have a call to glGetError() before calling glewInit().

 

And, as was said, it's hard to know why it doesn't work.

Have you tried rendering a single triangle only, instead of more complicated objects?

Try disables back face culling, perhaps the vertices are being specified in the wrong winding.

 

Also, don't know if it's relevant but .obj files store vertices in 1 based indices (eg. indices start at 1 and not 0).






Old topic!
Guest, the last post of this topic is over 60 days old and at this point you may not reply in this topic. If you wish to continue this conversation start a new topic.



PARTNERS