sdl2_demo: capture keypresses on screen

ThomasFarstrike · ThomasFarstrike · commit db8c3a956e07 · 2025-05-17T21:34:00.000+02:00
diff --git a/draft_code/sdl2_demo.py b/draft_code/sdl2_demo.py
@@ -1,9 +1,38 @@
 import sdl2
 import sdl2.ext
+import sdl2.sdlttf
+import ctypes
 
+# Initialize SDL2 and TTF
 sdl2.ext.init()
+sdl2.sdlttf.TTF_Init()
+
+# Create window and renderer
 window = sdl2.ext.Window("Test", size=(800, 600))
 window.show()
+renderer = sdl2.ext.Renderer(window)
+
+# Load font
+font = sdl2.sdlttf.TTF_OpenFont(b"/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 24)
+if not font:
+    print("Failed to load font!")
+    exit(1)
+
+# Initialize text variables
+last_key = "No key pressed"
+text_surface = None
+text_texture = None
+
+def render_text(text):
+    global text_surface, text_texture
+    # Clean up previous texture
+    if text_texture:
+        sdl2.SDL_DestroyTexture(text_texture)
+    
+    # Create new surface and texture
+    color = sdl2.SDL_Color(r=255, g=255, b=255)
+    text_surface = sdl2.sdlttf.TTF_RenderText_Solid(font, text.encode('utf-8'), color)
+    text_texture = sdl2.SDL_CreateTextureFromSurface(renderer.sdlrenderer, text_surface)
 
 running = True
 while running:
@@ -12,5 +41,28 @@
         if event.type == sdl2.SDL_QUIT:
             running = False
         elif event.type == sdl2.SDL_KEYDOWN:
-            print(f"Key pressed: {event.key.keysym.sym}")
+            # Update text with pressed key
+            last_key = f"Key pressed: {sdl2.SDL_GetKeyName(event.key.keysym.sym).decode()}"
+            render_text(last_key)
+    
+    # Clear screen
+    renderer.clear()
+    
+    # Render text if available
+    if text_texture:
+        w, h = ctypes.c_int(), ctypes.c_int()
+        sdl2.SDL_QueryTexture(text_texture, None, None, ctypes.byref(w), ctypes.byref(h))
+        dstrect = sdl2.SDL_Rect(x=10, y=10, w=w.value, h=h.value)
+        sdl2.SDL_RenderCopy(renderer.sdlrenderer, text_texture, None, dstrect)
+    
+    # Update display
+    renderer.present()
+
+# Cleanup
+if text_texture:
+    sdl2.SDL_DestroyTexture(text_texture)
+if text_surface:
+    sdl2.SDL_FreeSurface(text_surface)
+sdl2.sdlttf.TTF_CloseFont(font)
+sdl2.sdlttf.TTF_Quit()
 sdl2.ext.quit()
