Added a screen size parameters to the fragviewer.

tools/fragviewer.cpp

@@ -32,12 +32,14 @@ int main(int argc, char *argv[]) {
   sf::Shader shader;
   sf::RectangleShape rect;
   textures::SpriteTexture sprite_texture;
+  sf::Vector2f u_resolution{720.0, 720.0};
+  sf::Vector2u screen_resolution{720, 720};
 
   textures::init();
 
   dbc::check(sf::Shader::isAvailable(), "You apparently are a time traveler from the 80s who doesn't have shaders.");
 
-  while((opt = getopt(argc, argv, "-hs:f:")) != -1) {
+  while((opt = getopt(argc, argv, "-hs:f:-x:-y:")) != -1) {
     switch(opt) {
       case 's':
         sprite_name = optarg;
@@ -46,13 +48,21 @@ int main(int argc, char *argv[]) {
       case 'f':
         frag_name = optarg;
         break;
+      case 'x':
+        screen_resolution.x = std::atoi(optarg);
+        u_resolution.x = screen_resolution.x;
+        break;
+      case 'y':
+        screen_resolution.y = std::atoi(optarg);
+        u_resolution.y = screen_resolution.y;
+        break;
       case 'h':
         fmt::println(
             "fragviewer is a simple tool to play fragment shaders.\n"
-            "USAGE: fragviewer [-s sprite_name] -f shader.frag");
+            "USAGE: fragviewer [-x size_x -y size_y] [-s sprite_name] -f shader.frag");
         return 0;
       default:
-        fmt::println("USAGE: fragviewer [-s sprite_name] -f shader.frag");
+        fmt::println("USAGE: fragviewer [-x size_x -y size_y] [-s sprite_name] -f shader.frag");
         return -1;
     }
   }
@@ -61,16 +71,13 @@ int main(int argc, char *argv[]) {
 
   dbc::check(frag_name != "", "You must set the -f shader.frag option.");
 
-  sf::Vector2f u_resolution{720.0, 720.0};
-
-  sf::RenderWindow window(sf::VideoMode({720, 720}), "SFML Frag Shader Viewer");
+  sf::RenderWindow window(sf::VideoMode(screen_resolution), "SFML Frag Shader Viewer");
   window.setFramerateLimit(60);
   window.setVerticalSyncEnabled(true);
 
   bool good_shader = shader.loadFromFile(frag_name, sf::Shader::Type::Fragment);
   dbc::check(good_shader, fmt::format("failed to load shader {}", frag_name));
 
-
   if(load_sprite) {
     sprite_texture = textures::get(sprite_name);
     sprite_texture.sprite->setPosition({0,0});