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////////////////////////////////////////////////////////////
// Headers
////////////////////////////////////////////////////////////
#include <SFML/Window.hpp>
#include <cstdlib>
#define GLAD_GL_IMPLEMENTATION
#include <gl.h>
#ifdef SFML_SYSTEM_IOS
#include <SFML/Main.hpp>
#endif
#include <array>
#include <iostream>
#include <cstdlib>
////////////////////////////////////////////////////////////
/// Entry point of application
///
/// \return Application exit code
///
////////////////////////////////////////////////////////////
int main()
{
// Request a 24-bits depth buffer when creating the window
sf::ContextSettings contextSettings;
contextSettings.depthBits = 24;
// Create the main window
sf::Window window(sf::VideoMode({640, 480}), "SFML window with OpenGL", sf::Style::Default, sf::State::Windowed, contextSettings);
// Make it the active window for OpenGL calls
if (!window.setActive())
{
std::cerr << "Failed to set the window as active" << std::endl;
return EXIT_FAILURE;
}
// Load OpenGL or OpenGL ES entry points using glad
#ifdef SFML_OPENGL_ES
gladLoadGLES1(sf::Context::getFunction);
#else
gladLoadGL(sf::Context::getFunction);
#endif
// Set the color and depth clear values
#ifdef SFML_OPENGL_ES
glClearDepthf(1.f);
#else
glClearDepth(1.f);
#endif
glClearColor(0.f, 0.f, 0.f, 1.f);
// Enable Z-buffer read and write
glEnable(GL_DEPTH_TEST);
glDepthMask(GL_TRUE);
// Disable lighting and texturing
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
// Configure the viewport (the same size as the window)
glViewport(0, 0, static_cast<GLsizei>(window.getSize().x), static_cast<GLsizei>(window.getSize().y));
// Setup a perspective projection
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
const GLfloat ratio = static_cast<float>(window.getSize().x) / static_cast<float>(window.getSize().y);
#ifdef SFML_OPENGL_ES
glFrustumf(-ratio, ratio, -1.f, 1.f, 1.f, 500.f);
#else
glFrustum(-ratio, ratio, -1.f, 1.f, 1.f, 500.f);
#endif
// Define a 3D cube (6 faces made of 2 triangles composed by 3 vertices)
// clang-format off
constexpr std::array<GLfloat, 252> cube =
{
// positions // colors (r, g, b, a)
-50, -50, -50, 0, 0, 1, 1,
-50, 50, -50, 0, 0, 1, 1,
-50, -50, 50, 0, 0, 1, 1,
-50, -50, 50, 0, 0, 1, 1,
-50, 50, -50, 0, 0, 1, 1,
-50, 50, 50, 0, 0, 1, 1,
50, -50, -50, 0, 1, 0, 1,
50, 50, -50, 0, 1, 0, 1,
50, -50, 50, 0, 1, 0, 1,
50, -50, 50, 0, 1, 0, 1,
50, 50, -50, 0, 1, 0, 1,
50, 50, 50, 0, 1, 0, 1,
-50, -50, -50, 1, 0, 0, 1,
50, -50, -50, 1, 0, 0, 1,
-50, -50, 50, 1, 0, 0, 1,
-50, -50, 50, 1, 0, 0, 1,
50, -50, -50, 1, 0, 0, 1,
50, -50, 50, 1, 0, 0, 1,
-50, 50, -50, 0, 1, 1, 1,
50, 50, -50, 0, 1, 1, 1,
-50, 50, 50, 0, 1, 1, 1,
-50, 50, 50, 0, 1, 1, 1,
50, 50, -50, 0, 1, 1, 1,
50, 50, 50, 0, 1, 1, 1,
-50, -50, -50, 1, 0, 1, 1,
50, -50, -50, 1, 0, 1, 1,
-50, 50, -50, 1, 0, 1, 1,
-50, 50, -50, 1, 0, 1, 1,
50, -50, -50, 1, 0, 1, 1,
50, 50, -50, 1, 0, 1, 1,
-50, -50, 50, 1, 1, 0, 1,
50, -50, 50, 1, 1, 0, 1,
-50, 50, 50, 1, 1, 0, 1,
-50, 50, 50, 1, 1, 0, 1,
50, -50, 50, 1, 1, 0, 1,
50, 50, 50, 1, 1, 0, 1,
};
// clang-format on
// Enable position and color vertex components
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_COLOR_ARRAY);
glVertexPointer(3, GL_FLOAT, 7 * sizeof(GLfloat), cube.data());
glColorPointer(4, GL_FLOAT, 7 * sizeof(GLfloat), cube.data() + 3);
// Disable normal and texture coordinates vertex components
glDisableClientState(GL_NORMAL_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
// Create a clock for measuring the time elapsed
const sf::Clock clock;
// Start the game loop
while (window.isOpen())
{
// Process events
while (const std::optional event = window.pollEvent())
{
// Window closed or escape key pressed: exit
if (event->is<sf::Event::Closed>() ||
(event->is<sf::Event::KeyPressed>() &&
event->getIf<sf::Event::KeyPressed>()->code == sf::Keyboard::Key::Escape))
{
window.close();
}
// Resize event: adjust the viewport
if (const auto* resized = event->getIf<sf::Event::Resized>())
{
const auto [width, height] = resized->size;
glViewport(0, 0, static_cast<GLsizei>(width), static_cast<GLsizei>(height));
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
const GLfloat newRatio = static_cast<float>(width) / static_cast<float>(height);
#ifdef SFML_OPENGL_ES
glFrustumf(-newRatio, newRatio, -1.f, 1.f, 1.f, 500.f);
#else
glFrustum(-newRatio, newRatio, -1.f, 1.f, 1.f, 500.f);
#endif
}
}
// Clear the color and depth buffers
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
// Apply some transformations to rotate the cube
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.f, 0.f, -200.f);
glRotatef(clock.getElapsedTime().asSeconds() * 50, 1.f, 0.f, 0.f);
glRotatef(clock.getElapsedTime().asSeconds() * 30, 0.f, 1.f, 0.f);
glRotatef(clock.getElapsedTime().asSeconds() * 90, 0.f, 0.f, 1.f);
// Draw the cube
glDrawArrays(GL_TRIANGLES, 0, 36);
// Finally, display the rendered frame on screen
window.display();
}
return EXIT_SUCCESS;
}
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