std:sdl

Importing

std-sdl.nyx

import "std:sdl" as sdl;

Core Concepts

• Initialize SDL/TTF subsystems first (sdl.init, sdl.ttf_init).
• Create a window, then a renderer for that window.
• Use an event loop (sdl.pollEvent) for user input and window events.
• Render content (shapes, textures) using the renderer.
• Call sdl.renderPresent to show rendered content.
• Load fonts (sdl.ttf_openFont), render text to surfaces (sdl.ttf_renderTextBlended), convert surfaces to textures (sdl.createTextureFromSurface) for display.
• Clean up with sdl.ttf_quit, sdl.quit, and by letting resource handles (window, renderer, font, texture, surface) go out of scope (or assigning nyx_null to them). String arguments to SDL functions (like text for ttf_renderTextBlended) will have their escape sequences (e.g., \\n) processed.

Key Functions (Partial List)

• Initialization/Shutdown: sdl.init(flags), sdl.quit(), sdl.ttf_init(), sdl.ttf_quit()
• Window/Renderer: sdl.createWindow(...), sdl.createRenderer(...)
• Drawing: sdl.setRenderDrawColor(...), sdl.renderClear(...), sdl.renderFillRect(...), sdl.renderCopy(...), sdl.renderPresent(...)
• Text: sdl.ttf_openFont(...), sdl.ttf_renderTextBlended(...), sdl.createTextureFromSurface(...), sdl.queryTexture(...)
• Events/Timing: sdl.pollEvent(), sdl.delay(ms)

Important Constants (Partial List)

Includes init flags (sdl.SDL_INIT_VIDEO), window position/flags (sdl.SDL_WINDOWPOS_CENTERED, sdl.SDL_WINDOW_SHOWN), renderer flags (sdl.SDL_RENDERER_ACCELERATED), event types (sdl.SDL_QUIT, sdl.SDL_KEYDOWN), and key codes (sdl.K_ESCAPE, sdl.K_UP, etc.).

Example Snippet

std-sdl.nyx

// Import necessary standard library modules
import "std:sdl" as sdl; // For graphics, windowing, events, and text rendering
import "std:io" as io;   // For printing error messages to the console

// Define the main function for our SDL test program
func main_sdl_test() = {
  // Window dimensions
  auto WINDOW_WIDTH = 640;
  auto WINDOW_HEIGHT = 480;

  // Initialize SDL video and event subsystems
  if (!sdl.init(sdl.SDL_INIT_VIDEO)) {
      output("SDL Init failed!"); // Print error if SDL initialization fails
      return 1; // Exit the function indicating an error
  }

  // Initialize SDL_ttf library for font rendering
  if (!sdl.ttf_init()) {
      output("SDL_ttf Init failed!"); // Print error if SDL_ttf initialization fails
      sdl.quit(); // Clean up SDL subsystems before exiting
      return 1;   // Exit the function indicating an error
  }

  // Create the main application window
  auto window = sdl.createWindow(
      "Nyx SDL Test",
      sdl.SDL_WINDOWPOS_CENTERED, // Center window horizontally on screen
      sdl.SDL_WINDOWPOS_CENTERED, // Center window vertically on screen
      WINDOW_WIDTH,
      WINDOW_HEIGHT,
      sdl.SDL_WINDOW_SHOWN        // Make the window visible
  );

  // Check if window creation was successful
  if(!window) {
      output("Failed to create window!");
      sdl.ttf_quit(); // Clean up SDL_ttf if window creation fails
      sdl.quit();     // Clean up SDL
      return 1;
  }

  // Create a renderer for the window
  auto renderer = sdl.createRenderer(window, -1, sdl.SDL_RENDERER_ACCELERATED);

  // Check if renderer creation was successful
  if(!renderer) {
      output("Failed to create renderer!");
      sdl.ttf_quit(); // Clean up SDL_ttf
      sdl.quit();     // Clean up SDL
      return 1;
  }

  // Define the path to the font file and load it
  auto FONT_PATH = "examples/snake_game/fonts/Roboto.ttf";
  auto font_size = 24;
  auto font = sdl.ttf_openFont(FONT_PATH, font_size);

  auto running = true; // Flag to keep the main application loop running

  // Main application loop
  for (;running;) {
      // Event handling loop
      for (auto e = sdl.pollEvent(); e; e = sdl.pollEvent()) {
          if (e[0] == sdl.SDL_QUIT) {
              running = false;
          }
      }

      // Rendering phase
      sdl.setRenderDrawColor(renderer, 0, 0, 50, 255); // Dark blue background
      sdl.renderClear(renderer); // Clear the screen

      // Text rendering
      if (font) {
          auto text_surface = sdl.ttf_renderTextBlended(font, "Hello Nyx!", 255, 255, 255, 255); // White text

          if (text_surface) {
              auto text_texture = sdl.createTextureFromSurface(renderer, text_surface);

              if (text_texture) {
                  auto dims = sdl.queryTexture(text_texture);
                  if (dims) {
                      auto text_width = dims[0];
                      auto text_height = dims[1];

                      // Calculate position to center the text
                      auto text_x = (WINDOW_WIDTH / 2) - (text_width / 2);
                      auto text_y = (WINDOW_HEIGHT / 2) - (text_height / 2);

                      // Define the destination rectangle for the text
                      auto text_rect = [text_x, text_y, text_width, text_height];

                      sdl.renderCopy(renderer, text_texture, nyx_null, text_rect);
                  }
              }
          }
      } else {
          output("Font not loaded, cannot render text.");
      }

      // Update the screen
      sdl.renderPresent(renderer);

      // Control frame rate
      sdl.delay(16);
  }

  // Shutdown sequence
  output("Exiting SDL test. Cleaning up resources...");
  if (font) {
      font = nyx_null;
  }
  if (renderer) {
      renderer = nyx_null;
  }
  if (window) {
      window = nyx_null;
  }

  sdl.ttf_quit();
  sdl.quit();

  output("SDL test finished.");
  return 0;
}

// Call the main function
main_sdl_test();