#include "loadshader.h"
int main()
{
glfwInit();
glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3);
glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 3);
glfwOpenWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwOpenWindowHint(GLFW_WINDOW_NO_RESIZE, GL_TRUE);
glfwOpenWindow(800, 600, 0, 0, 0, 0, 0, 0, GLFW_WINDOW);
glfwSetWindowTitle("Crion World Alpha");
glewExperimental = GL_TRUE;
glewInit();
GLuint vertexBuffer;
glGenBuffers( 1, &vertexBuffer );
GLuint vao;
glGenVertexArrays(1, & vao);
glBindVertexArray( vao );
GLuint vbo;
glGenBuffers( 1, &vbo); //generate 1 buffer
float vertices[] = {
0.0f, 0.5f,
0.5f, -0.5f,
-0.5f, -0.5f
};
glBindBuffer( GL_ARRAY_BUFFER, vbo );
glBufferData( GL_ARRAY_BUFFER, sizeof( vertices ), vertices, GL_STATIC_DRAW );
// vertex shader loading
const string vShaderString = loadShaderFile("SimpleVertexShader.vertexshader").c_str();
const GLchar * tempVShader = vShaderString.c_str();
GLuint vertexShader = glCreateShader( GL_VERTEX_SHADER );
glShaderSource(vertexShader, 1, & tempVShader, NULL);
glCompileShader( vertexShader );
std::fstream logs;
logs.open( "logs.txt", ios::in | ios::out | ios::trunc );
char vsbuffer[512];
glGetShaderInfoLog( vertexShader, 512, NULL, vsbuffer );
logs << vsbuffer;
//fragment shader loading
const string fShaderString = loadShaderFile("SimpleFragmentShader.fragmentshader").c_str();
const GLchar * tempFShader = fShaderString.c_str();
GLuint fragmentShader = glCreateShader( GL_FRAGMENT_SHADER );
glShaderSource(fragmentShader, 1, & tempFShader, NULL );
glCompileShader(fragmentShader);
char fsbuffer[512];
glGetShaderInfoLog( fragmentShader, 512, NULL, fsbuffer );
logs << fsbuffer;
if(glGetError() != 0)
{
logs << "sth errors";
cout << "sth wrong" << endl;
}
logs.close();
GLuint shaderProgram = glCreateProgram();
glAttachShader( shaderProgram, vertexShader );
glAttachShader( shaderProgram, fragmentShader);
glBindFragDataLocation( shaderProgram, 0, "outColor" );
glLinkProgram( shaderProgram );
glUseProgram( shaderProgram );
GLint posAttrib = glGetAttribLocation( shaderProgram, "position" );
glEnableVertexAttribArray( posAttrib );
glVertexAttribPointer( posAttrib, 2, GL_FLOAT, GL_FALSE, 0, 0 );
while( glfwGetWindowParam( GLFW_WINDOW ) )
{
glDrawArrays( GL_TRIANGLES, 0, 3);
glfwSwapBuffers();
}
glDeleteProgram( shaderProgram );
glDeleteShader( vertexShader );
glDeleteShader( fragmentShader );
glDeleteBuffers(1, & vbo );
glDeleteVertexArrays(1, &vao );
glfwTerminate();
return 0;
}OpenGL triangle example
Author
I have problem with this code because it doesn't show anything in a window, vertex and fragment shaders are loading successfully but glGetError shows something wrong is here. Please someone help me.
Something is wrong exactly where. When you say something wrong is here, it does not help. Can you be a little bit more clear.
There's missing () after glGetError. As is it's not getting called (what you have there is a comparison of the function's address).
Author
It doesn't change anything. When i turn application on then debug error appears with Invalid allocation size: 4294967295 bytes
Author
SimpleFragmentShader
#version 150
out vec4 outColor;
void main()
{
outColor = vec4( 1.0, 1.0, 1.0, 1.0 );
}SimpleVertexShader
#version 150
in vec2 position;
void main()
{
gl_Position = vec4( position, 0.0, 1.0 );
}and function for loading them
string loadShaderFile(const string fileName)
{
ifstream shaderFile( fileName.c_str());
//find the file size
shaderFile.seekg(0, ios::end);
std::streampos length = shaderFile.tellg();
shaderFile.seekg(0, ios::beg);
//read whole file into a vector
vector<char> buffer(length);
shaderFile.read(&buffer[0], length);
//return the shader string
return string( buffer.begin(), buffer.end());
}I think something is wrong under 53 line but i'm begginer in OpenGL
Check that the functions you're using are returning valid data.
const GLchar * tempVShader = vShaderString.c_str();
Make sure "tempVShader" has a valid string.
char vsbuffer[512];
glGetShaderInfoLog( vertexShader, 512, NULL, vsbuffer );
logs << vsbuffer;
Make sure "vsbuffer" has valid data and is NULL terminated.
const GLchar * tempFShader = fShaderString.c_str();
Check "tempFShader" is valid.
char fsbuffer[512];
glGetShaderInfoLog( fragmentShader, 512, NULL, fsbuffer );
logs << fsbuffer;
Make sure "fsbuffer" has valid data and is NULL terminated.
And to be totally safe, logging should be used as follows, and after the call to glCompileShader()
GLint retParam;
glGetShaderiv(m_openGLID, GL_COMPILE_STATUS, &retParam);
if(retParam != GL_TRUE)
{
GLint errorMsgLen = 0;
glGetShaderiv(m_openGLID, GL_INFO_LOG_LENGTH, &errorMsgLen);
if (errorMsgLen > 0)
{
GLsizei charsWritten = 0;
GLchar *errorMsg = new GLchar[errorMsgLen];
glGetShaderInfoLog(m_openGLID, errorMsgLen, &charsWritten, errorMsg);
/*Do something with errorMsg*/
}
}
Author
I have in console and logs that both shaders loaded successfully and program loaded successfully but still have this same error. Maybe i made something wrong with creating window.
This topic is closed to new replies.
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