add sfml and sdl examples

examples/sdl2/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMSDLExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+CPMAddPackage("gh:libsdl-org/SDL#release-2.0.16")
+
+# ---- Executable ----
+
+add_executable(CPMSDLExample main.cpp)
+
+target_link_libraries(CPMSDLExample SDL2)

examples/sdl2/main.cpp

@@ -0,0 +1,33 @@
+// adapted from : https://gist.github.com/fschr/92958222e35a823e738bb181fe045274
+
+#include <SDL.h>
+
+#include <iostream>
+
+#define SCREEN_WIDTH 640
+#define SCREEN_HEIGHT 480
+
+int main() {
+  SDL_Window* window = NULL;
+  SDL_Surface* screenSurface = NULL;
+
+  if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+    std::cerr << "Could not initialize SDL2" << SDL_GetError() << std::endl;
+    return 1;
+  }
+  window = SDL_CreateWindow("hello_sdl2", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
+                            SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
+  if (window == NULL) {
+    std::cerr << "Could not create window" << SDL_GetError() << std::endl;
+    return 1;
+  }
+
+  screenSurface = SDL_GetWindowSurface(window);
+  SDL_FillRect(screenSurface, NULL, SDL_MapRGB(screenSurface->format, 0xFF, 0xFF, 0xFF));
+  SDL_UpdateWindowSurface(window);
+  SDL_Delay(2000);
+  SDL_DestroyWindow(window);
+  SDL_Quit();
+
+  return 0;
+}

examples/sfml/CMakeLists.txt

@@ -0,0 +1,14 @@
+cmake_minimum_required(VERSION 3.14 FATAL_ERROR)
+
+project(CPMSFMLExample)
+
+# ---- Dependencies ----
+
+include(../../cmake/CPM.cmake)
+CPMAddPackage("gh:SFML/SFML#2.5.1")
+
+# ---- Executable ----
+
+add_executable(CPMSFMLExample main.cpp)
+target_compile_features(CPMSFMLExample PRIVATE cxx_std_17)
+target_link_libraries(CPMSFMLExample sfml-system sfml-graphics sfml-window sfml-audio)

examples/sfml/main.cpp

@@ -0,0 +1,16 @@
+#include <SFML/Graphics.hpp>
+#include <SFML/Window.hpp>
+
+int main() {
+  sf::RenderWindow win(sf::VideoMode(800, 600), "SFML window");
+
+  while (win.isOpen()) {
+    sf::Event event;
+    while (win.pollEvent(event)) {
+      if (event.type == sf::Event::Closed) win.close();
+    }
+    win.clear(sf::Color::Black);
+    win.display();
+  }
+  return 0;
+}