problem with glGenVertexArrays

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1 comment, last by proanim 11 years, 5 months ago
I can't get basic triangle tutorial to work i have tried everything and nothing helps not even glewExperimental = GL_TRUE;

here is the code, can someone please help me with this, the program crashes on glGenVertexArrays no matter what

[source lang="cpp"]// preprocessor directives
#define WIN32_LEAN_AND_MEAN
//#define _CRT_SECURE_NO_DEPRECATE
#define DIRECTINPUT_VERSION 0x0800 // direct input version

//#pragma warning(disable : 4995) // #pragma deprecated warning
//#pragma warning(disable : 4996) // deprecated warning
//#pragma warning(disable : 4244) // possible loss of data warning

// included headers
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <string>
#include <vector>
#include <iostream>
#include <fstream>
#include <algorithm>

// opengl headers
#include "GL/glew.h"
#include "GL/freeglut.h"
#include "GL/glfw.h"
#include "GL/glm/glm.hpp"
#include <GL/gl.h>

// input device headers
#include <dinput.h>
#include <xinput.h>

// included libraries
#pragma comment(lib, "glew32.lib")
#pragma comment(lib, "freeglut.lib")
#pragma comment(lib, "glfw.lib")
#pragma comment(lib, "opengl32.lib")

#pragma comment(lib, "dinput8.lib")
#pragma comment(lib, "xinput.lib")

// namespace
using namespace glm;
using namespace std;

// function prototypes
GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path);

// main
int main(int argc, char *argv[])
{
int running = GL_TRUE;
double time;

glewExperimental = GL_TRUE;

// Initialize GLFW
if(!glfwInit())
exit(EXIT_FAILURE);

glfwOpenWindowHint(GLFW_FSAA_SAMPLES, 4);
glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 4);
glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 0);
glfwOpenWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_COMPAT_PROFILE);
glfwOpenWindowHint(GLFW_WINDOW_NO_RESIZE, GL_TRUE);

// position window in the center of the screen
GLFWvidmode DesktopSize;
int width = 800;
int height = 600;

// Open an OpenGL window
if(!glfwOpenWindow(800, 600, 0, 0, 0, 0, 32, 8, GLFW_WINDOW))
{
glfwTerminate();
exit(EXIT_FAILURE);
}

// disable maximize button
HWND windowHandle = GetForegroundWindow();
long Style = GetWindowLong(windowHandle, GWL_STYLE);
Style &amp;= ~WS_MAXIMIZEBOX; //this makes it still work when WS_MAXIMIZEBOX is actually already toggled off
SetWindowLong(windowHandle, GWL_STYLE, Style);

glfwGetDesktopMode(&amp;DesktopSize);
glfwSetWindowPos((DesktopSize.Width - width) / 2, (DesktopSize.Height - height) / 4);

// setup viewport
glViewport(0, 0, width, height);

// setup projection matrix
float znear = 0.1f;
float zfar = 1000.0f;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0.0f, 1.0f, 1.0f, 0.0f, znear, zfar);

// setup aspect ratio according to screen resolution
// and set fov
float fov = 45.0f; // 90 degrees
gluPerspective(fov, width/height, znear, zfar);

// clear the screen to mid gray
glClearColor(0.5f, 0.5f, 0.5f, 0.0f);

// create vertex array object
GLuint VertexArrayID;
glGenVertexArrays(1, &amp;VertexArrayID);
glBindVertexArray(VertexArrayID);

// compile the shader
GLuint programID = LoadShaders("data/shaders/red.vert", "data/shaders/red.frag");

// vertex positions
static const GLfloat g_vertex_buffer_data[] = {
-1.0f, -1.0f, 0.0f,
1.0f, -1.0f, 0.0f,
0.0f, 1.0f, 0.0f,
};

// create vertex buffer
GLuint vertexbuffer;
glGenBuffers(1, &amp;vertexbuffer);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
glBufferData(GL_ARRAY_BUFFER, sizeof(g_vertex_buffer_data), g_vertex_buffer_data, GL_STATIC_DRAW);

// Main loop
while(running)
{
time = glfwGetTime();

// OpenGL rendering goes here
glClear(GL_COLOR_BUFFER_BIT);

// use color shader
glUseProgram(programID);

// Select and setup the projection matrix
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(fov, width/height, znear, zfar);

// Select and setup the modelview matrix
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
gluLookAt(0.0f, 1.0f, 0.0f, // Eye-position
0.0f, 0.0f/*20.0f*/, 0.0f, // View-point
0.0f, 0.0f, 1.0f); // Up-vector

// Draw a rotating triangle


// 1rst attribute buffer : vertices
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, vertexbuffer);
glVertexAttribPointer(
0, // attribute 0. No particular reason for 0, but must match the layout in the shader.
3, // size
GL_FLOAT, // type
GL_FALSE, // normalized?
0, // stride
(void*)0 // array buffer offset
);

// Draw the triangle !
glDrawArrays(GL_TRIANGLES, 0, 3); // From index 0 to 3 -> 1 triangle

glDisableVertexAttribArray(0);

// Swap front and back rendering buffers
glfwSwapBuffers();

// use vsync based on refresh rate
//glfwSwapInterval(1);

// Check if ESC key was pressed or window was closed
running = !glfwGetKey(GLFW_KEY_ESC) &amp;&amp; glfwGetWindowParam(GLFW_OPENED);
}

// Close window and terminate GLFW
glfwTerminate();

// clean up vertex buffer object
glDeleteBuffers(1, &amp;vertexbuffer);
glDeleteVertexArrays(1, &amp;VertexArrayID);

// Exit program
exit(EXIT_SUCCESS);

return 0;
}

GLuint LoadShaders(const char * vertex_file_path,const char * fragment_file_path)
{
// Create the shaders
GLuint VertexShaderID = glCreateShader(GL_VERTEX_SHADER);
GLuint FragmentShaderID = glCreateShader(GL_FRAGMENT_SHADER);

// Read the Vertex Shader code from the file
string VertexShaderCode;
ifstream VertexShaderStream(vertex_file_path, ios::in);
if(VertexShaderStream.is_open()){
string Line = "";
while(getline(VertexShaderStream, Line))
VertexShaderCode += "\n" + Line;
VertexShaderStream.close();
}

// Read the Fragment Shader code from the file
string FragmentShaderCode;
ifstream FragmentShaderStream(fragment_file_path, ios::in);
if(FragmentShaderStream.is_open()){
string Line = "";
while(getline(FragmentShaderStream, Line))
FragmentShaderCode += "\n" + Line;
FragmentShaderStream.close();
}

GLint Result = GL_FALSE;
int InfoLogLength;

// Compile Vertex Shader
printf("Compiling shader : %s\n", vertex_file_path);
char const * VertexSourcePointer = VertexShaderCode.c_str();
glShaderSource(VertexShaderID, 1, &amp;VertexSourcePointer , NULL);
glCompileShader(VertexShaderID);

// Check Vertex Shader
glGetShaderiv(VertexShaderID, GL_COMPILE_STATUS, &amp;Result);
glGetShaderiv(VertexShaderID, GL_INFO_LOG_LENGTH, &amp;InfoLogLength);
vector<char> VertexShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(VertexShaderID, InfoLogLength, NULL, &amp;VertexShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &amp;VertexShaderErrorMessage[0]);

// Compile Fragment Shader
printf("Compiling shader : %s\n", fragment_file_path);
char const * FragmentSourcePointer = FragmentShaderCode.c_str();
glShaderSource(FragmentShaderID, 1, &amp;FragmentSourcePointer , NULL);
glCompileShader(FragmentShaderID);

// Check Fragment Shader
glGetShaderiv(FragmentShaderID, GL_COMPILE_STATUS, &amp;Result);
glGetShaderiv(FragmentShaderID, GL_INFO_LOG_LENGTH, &amp;InfoLogLength);
vector<char> FragmentShaderErrorMessage(InfoLogLength);
glGetShaderInfoLog(FragmentShaderID, InfoLogLength, NULL, &amp;FragmentShaderErrorMessage[0]);
fprintf(stdout, "%s\n", &amp;FragmentShaderErrorMessage[0]);

// Link the program
fprintf(stdout, "Linking program\n");
GLuint ProgramID = glCreateProgram();
glAttachShader(ProgramID, VertexShaderID);
glAttachShader(ProgramID, FragmentShaderID);
glLinkProgram(ProgramID);

// Check the program
glGetProgramiv(ProgramID, GL_LINK_STATUS, &amp;Result);
glGetProgramiv(ProgramID, GL_INFO_LOG_LENGTH, &amp;InfoLogLength);
//vector<char> ProgramErrorMessage(max(InfoLogLength, int(1)));
//glGetProgramInfoLog(ProgramID, InfoLogLength, NULL, &amp;ProgramErrorMessage[0]);
//fprintf(stdout, "%s\n", &amp;ProgramErrorMessage[0]);

glDeleteShader(VertexShaderID);
glDeleteShader(FragmentShaderID);

return ProgramID;
}[/source]
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You're not calling glewInit anywhere in your code; this needs to be called after you create the window but befre you do any GL stuff.

You've also got a lot of redundant projection matrix work there, but that's in addition to this problem.

Direct3D has need of instancing, but we do not. We have plenty of glVertexAttrib calls.

Ok that fixed the crash i had, but now i can't get triangle on the screen, i even tried to copy/paste entire main from tutorial to my project and it still doesnt show the triangle. I have absolutely no idea why is this. Can you help? I found tutorial here http://www.opengl-tutorial.org/beginners-tutorials/tutorial-2-the-first-triangle/

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