I'm following
this tutorial in order to learn Modern OpenGL. My code is basically a re-formatted copy of the
fist example, the only difference is I use SFML instead of GLFW, so OpenGL bits should be fine. Here's the code in question:
#include <GL/glew.h>
#include <SFML/Window.hpp>
#include <SFML/OpenGL.hpp>
#include <iostream>
#include <fstream>
// Shaders
const GLchar* vertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 position;\n"
"void main()\n"
"{\n"
"gl_Position = vec4(position.x, position.y, position.z, 1.0);\n"
"}\0";
const GLchar* fragmentShaderSource = "#version 330 core\n"
"out vec4 color;\n"
"void main()\n"
"{\n"
"color = vec4(1.0f, 0.5f, 0.2f, 1.0f);\n"
"}\n\0";
// objects
GLuint shaderProgram;
GLuint VBO, VAO;
void initialize() {
// Build and compile our shader program
// Vertex shader
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &vertexShaderSource, NULL);
glCompileShader(vertexShader);
// Check for compile time errors
GLint success;
GLchar infoLog[512];
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(vertexShader, 512, NULL, infoLog);
std::cerr << "ERROR::SHADER::VERTEX::COMPILATION_FAILED\n" << infoLog << std::endl;
}
// Fragment shader
GLuint fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &fragmentShaderSource, NULL);
glCompileShader(fragmentShader);
// Check for compile time errors
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &success);
if (!success) {
glGetShaderInfoLog(fragmentShader, 512, NULL, infoLog);
std::cerr << "ERROR::SHADER::FRAGMENT::COMPILATION_FAILED\n" << infoLog << std::endl;
}
// Link shaders
shaderProgram = glCreateProgram();
glAttachShader(shaderProgram, vertexShader);
glAttachShader(shaderProgram, fragmentShader);
glLinkProgram(shaderProgram);
// Check for linking errors
glGetProgramiv(shaderProgram, GL_LINK_STATUS, &success);
if (!success) {
glGetProgramInfoLog(shaderProgram, 512, NULL, infoLog);
std::cerr << "ERROR::SHADER::PROGRAM::LINKING_FAILED\n" << infoLog << std::endl;
}
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
// Set up vertex data (and buffer(s)) and attribute pointers
GLfloat vertices[] = {
-0.5f, -0.5f, 0.0f, // Left
0.5f, -0.5f, 0.0f, // Right
0.0f, 0.5f, 0.0f // Top
};
glGenVertexArrays(1, &VAO);
glGenBuffers(1, &VBO);
// Bind the Vertex Array Object first, then bind and set vertex buffer(s) and attribute pointer(s).
glBindVertexArray(VAO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(0);
glBindBuffer(GL_ARRAY_BUFFER, 0); // Note that this is allowed, the call to glVertexAttribPointer registered VBO as the currently bound vertex buffer object so afterwards we can safely unbind
glBindVertexArray(0); // Unbind VAO (it's always a good thing to unbind any buffer/array to prevent strange bugs)
}
void draw() {
// Render
// Clear the colorbuffer
glClearColor(0.2f, 0.3f, 0.3f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// Draw our first triangle
glUseProgram(shaderProgram);
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 3);
glBindVertexArray(0);
}
void release() {
// Properly de-allocate all resources once they've outlived their purpose
glDeleteVertexArrays(1, &VAO);
glDeleteBuffers(1, &VBO);
}
int main() {
sf::ContextSettings settings;
settings.depthBits = 24;
settings.stencilBits = 8;
settings.antialiasingLevel = 4;
settings.majorVersion = 4;
settings.minorVersion = 0;
sf::Window window(sf::VideoMode(800, 600), "OpenGL", sf::Style::Default, settings);
window.setVerticalSyncEnabled(true);
// Order is important...! Call this after creating a window
glewExperimental = GL_TRUE;
glewInit();
GLuint vertexShader = glCreateShader(GL_VERTEX_SHADER);
initialize();
bool running = true;
while (running) {
sf::Event event;
while (window.pollEvent(event)) {
if (event.type == sf::Event::Closed) {
release();
running = false;
} else if (event.type == sf::Event::Resized) {
glViewport(0, 0, event.size.width, event.size.height);
}
}
draw();
window.display();
}
return 0;
}
I compile it using MinGW under Windos 7 with following:
g++ test.cpp -o test -DGLEW_STATIC -I C:\Users\user\Documents\Mariusz\Testy\SFML_OpenGL\GLEW\include -L C:\Users\user\Documents\Mariusz\Testy\SFML_OpenGL\GLEW\lib -DSFML_STATIC -I C:\Users\user\Documents\Tests\SFML_OpenGL\SFML-2.1\include -L C:\Users\user\Documents\Tests\SFML_OpenGL\SFML-2.1\lib -lsfml-graphics-s -lsfml-window-s -lsfml-system-s -o test -lopengl32 -mwindows -static-libgcc -static-libstdc++ -gThis comiles and give following result:
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The questions is: why my Vertexes can't be colored? No matter what I try I cannot change them from white. What I am doing wrong?
