`nx_x11_pixmap.nx` source

1// nx_x11_pixmap.nx -- bits-up X11 off-screen pixmap drawable.
2//
3// Part of the "Nishi troubleshoots Nishi" self-closing-loop arc.
4// Off-screen pixmaps let us render the SAME drawing code-path to a
5// drawable we can read back via GetImage, then drop to a file the
6// developer (human OR Claude) can open without needing a live X11
7// session.  Replaces "ask the user did you see X?" with "diff
8// /tmp/nishi_render.ppm against the expected golden."
9//
10// X11 Protocol §6 Pixmap.
11//
12// CreatePixmap (opcode 53):
13//   byte 0:  opcode = 53
14//   byte 1:  depth
15//   bytes 2-3:  request_length (4-byte units) = 4
16//   bytes 4-7:  pixmap id (allocated via nx_x11_alloc_id)
17//   bytes 8-11: drawable (typically the window -- gives screen context)
18//   bytes 12-13: width
19//   bytes 14-15: height
20//
21// FreePixmap (opcode 54):
22//   byte 0:  54
23//   byte 1:  unused
24//   bytes 2-3: request_length = 2
25//   bytes 4-7: pixmap id
26//
27// license_tier: ORIGINAL
28// genealogy_id: international-research-sources/x_org/xproto_v11_r0
29// lineage_id:   nishi_x11_pixmap_q10
30
31import "nx_syscalls.nx"
32import "nx_x11_connect.nx"
33import "nx_x11_window.nx"
34
35// Create an off-screen pixmap.  Returns pixmap_id (positive) or
36// 0 - error.  Use `drawable` = a window on the same screen so the
37// server can pick the right visual.
38func nx_x11_create_pixmap(conn: *X11Conn, drawable: i64,
39                          width: i64, height: i64, depth: i64) -> i64 {
40    let pid: i64 = nx_x11_alloc_id(conn)
41    let req: *u8 = sys_mmap(32)
42    var i: i64 = 0
43    while i < 32 { req[i] = 0; i = i + 1 }
44    req[0] = 53
45    req[1] = depth as u8
46    _x11_wr_u16(req, 2, 4)
47    _x11_wr_u32(req, 4, pid)
48    _x11_wr_u32(req, 8, drawable)
49    _x11_wr_u16(req, 12, width)
50    _x11_wr_u16(req, 14, height)
51    if _x11_send(conn, req, 16) < 0 { return 0 - 1 }
52    return pid
53}
54
55// Free a pixmap (release server resources).
56func nx_x11_free_pixmap(conn: *X11Conn, pixmap_id: i64) -> i64 {
57    let req: *u8 = sys_mmap(16)
58    var i: i64 = 0
59    while i < 16 { req[i] = 0; i = i + 1 }
60    req[0] = 54
61    req[1] = 0
62    _x11_wr_u16(req, 2, 2)
63    _x11_wr_u32(req, 4, pixmap_id)
64    return _x11_send(conn, req, 8)
65}
66
67func main() -> i64 {
68    return 0
69}
nx_x11_pixmap.nx source

`nx_x11_pixmap.nx` source
