Add SDL TTF rendering example.

Author: HexDecimal

examples/DejaVuSerif.ttf

@@ -0,0 +1,47 @@
+"""Hello world using tcod's SDL API and using Pillow for the TTF rendering."""
+from pathlib import Path
+
+import numpy as np
+import tcod
+import tcod.sdl.render
+import tcod.sdl.video
+from PIL import Image, ImageDraw, ImageFont  # type: ignore  # pip install Pillow
+
+CURRENT_DIR = Path(__file__).parent  # Directory of this script.
+font = ImageFont.truetype(bytes(CURRENT_DIR / "DejaVuSerif.ttf"), size=18)  # Preloaded font file.
+
+
+def render_text(renderer: tcod.sdl.render.Renderer, text: str) -> tcod.sdl.render.Texture:
+    """Render text, upload it to VRAM, then return it as an SDL Texture."""
+    # Use Pillow normally to render the font.  This code is standard.
+    width, height = font.getsize(text)
+    image = Image.new("RGBA", (width, height))
+    draw = ImageDraw.Draw(image)
+    draw.text((0, 0), text, font=font)
+    # Push to VRAM using SDL.
+    texture = renderer.upload_texture(np.asarray(image))
+    texture.blend_mode = tcod.sdl.render.BlendMode.BLEND  # Enable alpha blending by default.
+    return texture
+
+
+def main() -> None:
+    """Show hello world until the window is closed."""
+    # Open an SDL window and renderer.
+    window = tcod.sdl.video.new_window(720, 480, flags=tcod.sdl.video.WindowFlags.RESIZABLE)
+    renderer = tcod.sdl.render.new_renderer(window, target_textures=True)
+    # Render the text once, then reuse the texture.
+    hello_world = render_text(renderer, "Hello World")
+    hello_world.color_mod = (64, 255, 64)  # Set the color when copied.
+
+    while True:
+        renderer.draw_color = (0, 0, 0, 255)
+        renderer.clear()
+        renderer.copy(hello_world, dest=(0, 0, hello_world.width, hello_world.height))
+        renderer.present()
+        for event in tcod.event.get():
+            if isinstance(event, tcod.event.Quit):
+                raise SystemExit()
+
+
+if __name__ == "__main__":
+    main()