filled rectangles

draw_12_rects_and_send.py

@@ -0,0 +1,101 @@
+#!/usr/bin/env python3
+"""
+draw_12_rects_and_send.py
+
+* 800 × 600 framebuffer, 32‑bit ARGB (A,R,G,B each 1 byte)
+* 12 rectangles, aspect ratio width : height = 1 : 12  (tall, upright)
+* rectangles are placed side‑by‑side, centred in the image
+* the complete framebuffer is sent over a TCP connection to
+  a server listening on localhost:12345
+"""
+
+import socket
+import sys
+
+# ----------------------------------------------------------------------
+# Frame‑buffer configuration
+# ----------------------------------------------------------------------
+FB_WIDTH  = 800                # horizontal pixels
+FB_HEIGHT = 600                # vertical   pixels
+BPP       = 4                  # bytes per pixel (A,R,G,B)
+
+# ----------------------------------------------------------------------
+# Geometry of the 12 rectangles
+# ----------------------------------------------------------------------
+# Height of a rectangle must fill the whole image (600 px)
+# width = height / 12  →  600 / 12 = 50 px
+RECT_HEIGHT = FB_HEIGHT // 2
+RECT_WIDTH  = RECT_HEIGHT // 12          # 50
+SPACING = 20
+
+TOTAL_RECT_W = (11 * SPACING) + (RECT_WIDTH * 12)           # 600
+X0_START    = (FB_WIDTH - TOTAL_RECT_W) // 2   # centre the strip
+
+# ----------------------------------------------------------------------
+# Helper – write a pixel into the bytearray (no bounds check for speed)
+# ----------------------------------------------------------------------
+def set_pixel(buf: bytearray, x: int, y: int, color: tuple):
+    """Write an ARGB pixel at (x,y).
+
+    `color` is a 4‑tuple (A,R,G,B) with each component 0‑255.
+    """
+    offset = (y * FB_WIDTH + x) * BPP
+    buf[offset:offset+4] = bytes(color)      # A,R,G,B order
+
+
+# ----------------------------------------------------------------------
+# Build the framebuffer
+# ----------------------------------------------------------------------
+def build_framebuffer() -> bytearray:
+    """Create an ARGB buffer, fill it black and draw the 12 rectangles."""
+    fb = bytearray(FB_WIDTH * FB_HEIGHT * BPP)
+
+    # ------------------------------------------------------------------
+    # 1) background = solid black, fully opaque
+    # ------------------------------------------------------------------
+    bg_color = (255, 0, 0, 0)                 # A,R,G,B
+    # Fill the whole buffer in one go (faster than per‑pixel loop)
+    fb[:] = bg_color * (FB_WIDTH * FB_HEIGHT)
+
+    # ------------------------------------------------------------------
+    # 2) draw the 12 rectangles
+    # ------------------------------------------------------------------
+    for idx in range(12):
+        rect_color = (255, 255, 255, 255)          # opaque
+
+        x_start = X0_START + idx * (RECT_WIDTH + SPACING)
+        x_end   = x_start + RECT_WIDTH            # exclusive
+
+        for y in range(FB_HEIGHT):
+            # slice‑assignment is faster than per‑pixel calls
+            row_offset = (y * FB_WIDTH + x_start) * BPP
+            fb[row_offset:row_offset + RECT_WIDTH * BPP] = rect_color * RECT_WIDTH
+
+    return fb
+
+
+# ----------------------------------------------------------------------
+# Send the buffer to the TCP server
+# ----------------------------------------------------------------------
+def send_framebuffer(buf: bytearray, host: str = "127.0.0.1", port: int = 12345):
+    """Open a TCP socket, connect, and stream the whole framebuffer."""
+    try:
+        with socket.create_connection((host, port), timeout=5) as sock:
+            # Optional: prefix the payload with its length (big‑endian uint32)
+            length_prefix = len(buf).to_bytes(4, byteorder="big")
+            sock.sendall(length_prefix + buf)
+            print(f"Sent {len(buf)} bytes to {host}:{port}")
+    except Exception as exc:
+        print(f"Could not send framebuffer: {exc}", file=sys.stderr)
+
+
+# ----------------------------------------------------------------------
+# Main entry point
+# ----------------------------------------------------------------------
+def main():
+    fb = build_framebuffer()
+    send_framebuffer(fb)
+
+
+if __name__ == "__main__":
+    main()