receive image data

src/viewer.py

@@ -1,10 +1,51 @@
 import socket
+import struct
 
 sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 sock.connect(("127.0.0.1", 64999))
 
 recv_limit = 1024
+filename = "image.ppm"
 
-received = sock.recv(recv_limit)
-print(received)
+ppm_data = b""
+
+# TODO: write to file while still receivinig data, for more speed!
+# receive data from server
+while True:
+    data = sock.recv(recv_limit)
+    if not data:
+        break
+
+    ppm_data += data
+
+# .ppm format:
+# P3
+# WIDTH HEIGHT
+# MAXIMUM_COLOR_VALUE
+# PIXEL_DATA
+
+# read the image data and write it into a file
+with open(filename, "w") as file:
+
+    # read image dimensions from first 8 bytes (2 ints)
+    dimensions = struct.unpack("!ii", ppm_data[0:8]);
+    width = dimensions[0]
+    height = dimensions[1]
+    maximum_value = 255
+
+    # write file header
+    file.write("P3\n")
+    file.write(f"{width} {height}\n")
+    file.write(f"{maximum_value}\n")
+
+    # a pixel is 3 bytes, so we should expect the data 
+    # block to be 3 * length long
+    length = dimensions[0] * dimensions[1]
+    data = ppm_data[8:]
+
+    for i in range(0, len(data), 3):
+        line = f"{data[i]} {data[i+1]} {data[i+2]}\n"
+        file.write(line)
+
+print("done!")