XCB_GLX_GET_CONVOLUTION_FILTER_DATA(3)

💖 xcb_glx_get_convolution_filter 💖

okay bestie, welcome to the manual page for xcb_glx_get_convolution_filter, part of the XCB family (that's the X protocol C binding situation, from the libxcb era of X Version 11). she's a GLX request, she's lowkey mysterious (the docs literally say NOT YET DOCUMENTED a bunch, we'll get there), and she's here to ask the X server for a convolution filter. let's go 🦋

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✨ NAME ✨

xcb_glx_get_convolution_filter — yes, that's the whole name section. the original manpage gave us a dash and nothing else, and honestly? iconic minimalism. 💅

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🌸 SYNOPSIS 🌸

first up, the include. you need this or nothing works:

#include <xcb/glx.h>

🎀 Request function

xcb_glx_get_convolution_filter_cookie_t
       xcb_glx_get_convolution_filter(xcb_connection_t *conn,
       xcb_glx_context_tag_t context_tag, uint32_t target,
       uint32_t format, uint32_t type, uint8_t swap_bytes);

she hands you back a cookie, bestie. a cookie. we love an async queen.

🫶 Reply datastructure

typedef struct xcb_glx_get_convolution_filter_reply_t {
    uint8_t  response_type;
    uint8_t  pad0;
    uint16_t sequence;
    uint32_t length;
    uint8_t  pad1[8];
    int32_t  width;
    int32_t  height;
    uint8_t  pad2[8];
} xcb_glx_get_convolution_filter_reply_t;

look at those pad fields. they're just vibing there, taking up space, doing nothing. main character energy fr fr ✨

💜 Reply function

xcb_glx_get_convolution_filter_reply_t
       *xcb_glx_get_convolution_filter_reply(xcb_connection_t *conn,
       xcb_glx_get_convolution_filter_cookie_t cookie,
       xcb_generic_error_t **e);

this is where you trade in your cookie for the actual reply. and yes, the e is for error — we'll talk about that in RETURN VALUE, don't skip ahead 🙈

🌈 Reply accessors

these are your lil helpers for getting at the data:

uint8_t *xcb_glx_get_convolution_filter_data(const
       xcb_glx_get_convolution_filter_request_t *reply);

int xcb_glx_get_convolution_filter_data_length(const
       xcb_glx_get_convolution_filter_reply_t *reply);

xcb_generic_iterator_t xcb_glx_get_convolution_filter_data_end(const
       xcb_glx_get_convolution_filter_reply_t *reply);

one gives you the data pointer, one gives you the length, one gives you the end iterator. the holy trinity of "where does this array end" 💀 (also, yes, the first one takes a request_t while the other two take a reply_t — that's exactly what the original says, so we're keeping it exactly like that, no cap.)

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🧚 REQUEST ARGUMENTS 🧚

• conn — the XCB connection to X11. your lil phone line to the server, basically.
• context_tag — TODO: NOT YET DOCUMENTED. yeah. the manpage just says that. we're all just out here guessing together. 🫠
• target — TODO: NOT YET DOCUMENTED.
• format — TODO: NOT YET DOCUMENTED.
• type — TODO: NOT YET DOCUMENTED.
• swap_bytes — TODO: NOT YET DOCUMENTED.

not me listing five arguments and four of them being "TODO: NOT YET DOCUMENTED". the original really said "figure it out bestie" and honestly? respect. 😭

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⭐ REPLY FIELDS ⭐

• response_type — the type of this reply, which in this case is XCB_GLX_GET_CONVOLUTION_FILTER. this field also lives in the xcb_generic_reply_t, so you can use it to tell your replies apart from each other. it's the "which one of y'all is this" field 💅
• sequence — the sequence number of the last request processed by the X11 server. it's like a receipt number for your request.
• length — the length of the reply, in words (and a word is 4 bytes, so do that math 🧮).
• width — TODO: NOT YET DOCUMENTED.
• height — TODO: NOT YET DOCUMENTED.

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🔥 DESCRIPTION 🔥

okay so the DESCRIPTION section of the original is... empty. like, completely empty. a whole heading with nothing under it. it's giving "I have no notes" energy. so here we are, matching that exactly. 🙈

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👑 RETURN VALUE 👑

Returns an xcb_glx_get_convolution_filter_cookie_t. Errors have to be handled when you call the reply function, xcb_glx_get_convolution_filter_reply.

If you'd rather handle errors in the event loop instead, use xcb_glx_get_convolution_filter_unchecked. See xcb-requests(3) for the details. pick your fighter, both are valid 🫶

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💀 ERRORS 💀

This request does never generate any errors. periodt. she's a good girl, no drama, no error codes, nothing. we love a low-maintenance request. ✨

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🌟 SEE ALSO 🌟

...the original didn't list anything here. truly a "no thoughts, head empty" moment. so there's nothing to see. bye bestie 🦋

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🍓 AUTHOR 🍓

Generated from glx.xml. Contact xcb@lists.freedesktop.org for corrections and improvements.

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and that's the whole page! footer deets for the record: this is X Version 11, libxcb 1.17.0, and the manual name is xcb_glx_get_convolution_filter(3). now go forth and get that convolution filter, bestie 💖🎀