OpenGL exception when glDrawArrays - c++

Question

I am trying to just render a triangle in one file so I can understand how openGL works so I can use that as an example when creating an engine. The program worked correctly before I created the shaders and the VAO stuff. The exception said: "Access violation at memory location: 0x000000" when the glDrawArrays() function was called. My guess is that i messed up the VAO. It could be the shader too. Thanks in advance for your time!
here is my code
#include <GL\glew.h>
#include <GLFW\glfw3.h>
#include <iostream>
#include <string>
#include <fstream>
const std::string FILENAME = "src\\shaders\\basic";
static void error_callback(int error, const char* description);
static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods);
static void resize_callback(GLFWwindow* window, int width, int height);
static std::string LoadShader(const std::string& filename);
static void CheckShaderError(GLuint shader, GLuint flag, bool isProgram, const std::string& errorMessage);
static GLuint CreateShader(const std::string& text, GLenum shaderType);
int main()
{
//Initalize GLFW
if (!glfwInit())
{
//TODO: Failed to initialize GLFW
}
//Create window and store it to a handler
GLFWwindow* window = glfwCreateWindow(1024, 768, "GL Noob Project", NULL, NULL);
if (!window)
{
//TODO: Failed to create window
}
glfwMakeContextCurrent(window); //Set the OpenGL context to our window
glfwSwapInterval(1); //Set the buffer swap interval to 1
//Initialize GLEW
if (glewInit() != GLEW_OK) {
//TODO Failed to initialize glew
}
//Set callbacks
glfwSetErrorCallback(error_callback);
glfwSetKeyCallback(window, key_callback);
glfwSetFramebufferSizeCallback(window, resize_callback);
//Shaders
GLuint program;
GLuint v_shader;
GLuint f_shader;
program = glCreateProgram();
v_shader = CreateShader(LoadShader(FILENAME + ".vs"), GL_VERTEX_SHADER);
f_shader = CreateShader(LoadShader(FILENAME + ".fs"), GL_FRAGMENT_SHADER);
glBindAttribLocation(program, 0, "position");
glAttachShader(program, v_shader);
glAttachShader(program, f_shader);
glLinkProgram(program);
CheckShaderError(program, GL_LINK_STATUS, true, "Shader Error");
glValidateProgram(program);
CheckShaderError(program, GL_VALIDATE_STATUS, true, "Shader Error");
glUseProgram(program);
//CREATE VAO
static const GLfloat data[] = { 0.0, 0.0, 0.0,
0.0, 0.0, 0.0,
0.0, 0.0, 0.0 };
GLuint vao;
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
GLuint vbo;
glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, sizeof(data), GL_FLOAT, GL_FALSE, 0, 0);
while (!glfwWindowShouldClose(window)) //While there is no close flag
{
//DRAW
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glBindVertexArray(vao);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindVertexArray(0);
glfwSwapBuffers(window); //Swap front and back buffer
glfwPollEvents(); //Get events
}
glDetachShader(program, v_shader);
glDeleteShader(v_shader);
glDetachShader(program, f_shader);
glDeleteShader(f_shader);
glDeleteProgram(program);
glfwDestroyWindow(window); //Destroy window
glfwTerminate(); //Terminate GLFW
return 0;
}
//CALLBACK FUNCTIONS
//Error callback
static void error_callback(int error, const char* description) {
std::cerr << "Error: " << description << std::endl;
}
//Key callback
static void key_callback(GLFWwindow* window, int key, int scancode, int action, int mods)
{
if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)
glfwSetWindowShouldClose(window, GLFW_TRUE);
}
static void resize_callback(GLFWwindow* window, int width, int height)
{
glViewport(0, 0, width, height);
}
//SHADER FUNCTIONS
static std::string LoadShader(const std::string& filename) {
std::ifstream file;
file.open(filename.c_str());
std::string output;
std::string line;
if (file.is_open())
{
while (file.good())
{
getline(file, line);
output.append(line + "\n");
}
}
else {
std::cerr << "Unable to load shader from file: "<< filename << std::endl;
}
return output;
}
static void CheckShaderError(GLuint shader, GLuint flag, bool isProgram, const std::string& errorMessage)
{
GLint success = 0;
GLchar error[1024] = { 0 };
if (isProgram)
glGetProgramiv(shader, flag, &success);
else
glGetShaderiv(shader, flag, &success);
if (success == GL_FALSE)
{
if (isProgram)
glGetProgramInfoLog(shader, sizeof(error), NULL, error);
else
glGetShaderInfoLog(shader, sizeof(error), NULL, error);
std::cerr << errorMessage << ": " << error << std::endl;
}
}
static GLuint CreateShader(const std::string& text, GLenum shaderType)
{
GLuint shader = glCreateShader(shaderType);
if (shader == 0) std::cerr << "Error: shader creation failed" << std::endl;
const GLchar* shaderSourceString = text.c_str();
const GLint shaderSourceStringLength = text.length();
glShaderSource(shader, 1, &shaderSourceString, &shaderSourceStringLength);
glCompileShader(shader);
CheckShaderError(shader, GL_COMPILE_STATUS, false, "Error: shader compilation Failed");
return shader;
}
here are the shader files (My guess is that i have propably messed up something here)
Vertex Shader:
#version 330 core
layout(location = 0) in vec3 position;
void main()
{
gl_Position = vec4(position, 1.0);
}
Fragment Shader:
#version 330 core
out vec4 color;
void main() {
color = vec4(1.0, 0.0, 0.0, 1.0);
}