I want to know why is SFML and GL/glew.h is not working when I try to compile C++ code, I am new to learning OpenGL from this page:
https://github.com/Overv/Open.GL/blob/master/content/code/c2_color_triangle.txt
This is my code / MWE:
// Link statically with GLEW
#define GLEW_STATIC
// Headers
#include <GL/glew.h>
#include <SFML/Window.hpp>
// Shader sources
const GLchar* vertexSource = R"glsl(
#version 150 core
in vec2 position;
in vec3 color;
out vec3 Color;
void main()
{
Color = color;
gl_Position = vec4(position, 0.0, 1.0);
// gl_Position = vec4(position.x, -position.y, 0.0, 1.0); //uncomment to invert the colors of the triangle by altering the fragment shader
}
)glsl";
const GLchar* fragmentSource = R"glsl(
#version 150 core
in vec3 Color;
out vec4 outColor;
void main()
{
outColor = vec4(Color, 1.0);
}
)glsl";
int main()
{
sf::ContextSettings settings;
settings.depthBits = 24;
settings.stencilBits = 8;
settings.majorVersion = 3;
settings.minorVersion = 2;
sf::Window window(sf::VideoMode(800, 600, 32), "OpenGL", sf::Style::Titlebar | sf::Style::Close, settings);
// Initialize GLEW
glewExperimental = GL_TRUE;
glewInit();
// Create Vertex Array Object
GLuint vao;
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
// Create a Vertex Buffer Object and copy the vertex data to it
GLuint vbo;
glGenBuffers(1, &vbo);
GLfloat vertices[] = {
0.0f, 0.5f, 1.0f, 0.0f, 0.0f,
0.5f, -0.5f, 0.0f, 1.0f, 0.0f,
-0.5f, -0.5f, 0.0f, 0.0f, 1.0f
};
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
// Create and compile the vertex shader
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexSource, NULL);
glCompileShader(vertexShader);
// Create and compile the fragment shader
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentSource, NULL);
glCompileShader(fragmentShader);
// Link the vertex and fragment shader into a shader program
GLuint shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glBindFragDataLocation(shaderProgram, 0, "outColor");
glLinkProgram(shaderProgram);
glUseProgram(shaderProgram);
// Specify the layout of the vertex data
GLint posAttrib = glGetAttribLocation(shaderProgram, "position");
glEnableVertexAttribArray(posAttrib);
glVertexAttribPointer(posAttrib, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), 0);
GLint colAttrib = glGetAttribLocation(shaderProgram, "color");
glEnableVertexAttribArray(colAttrib);
glVertexAttribPointer(colAttrib, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (void*)(2 * sizeof(GLfloat)));
bool running = true;
while (running)
{
sf::Event windowEvent;
while (window.pollEvent(windowEvent))
{
switch (windowEvent.type)
{
case sf::Event::Closed:
running = false;
break;
}
}
// Clear the screen to black
glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// Draw a triangle from the 3 vertices
glDrawArrays(GL_TRIANGLES, 0, 3);
// Swap buffers
window.display();
}
glDeleteProgram(shaderProgram);
glDeleteShader(fragmentShader);
glDeleteShader(vertexShader);
glDeleteBuffers(1, &vbo);
glDeleteVertexArrays(1, &vao);
window.close();
return 0;
}
I try this on terminal:
g++ glewcolortriangle.cpp -lGLEW -lGL
The error is undefined reference to 'sf::String::String(char const, std::locale const&)'*
- I am using Linux OS
- I have build and install SFML
How to solve my problem?
