picom/src/x.h

// SPDX-License-Identifier: MPL-2.0
// Copyright (c) 2018 Yuxuan Shui <yshuiv7@gmail.com>
#pragma once
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <xcb/render.h>
#include <xcb/sync.h>
#include <xcb/xcb.h>
#include <xcb/xcb_renderutil.h>
#include <xcb/xfixes.h>

#include "compiler.h"
#include "kernel.h"
#include "region.h"

typedef struct session session_t;

/// Structure representing Window property value.
typedef struct winprop {
	union {
		void *ptr;
		int8_t *p8;
		int16_t *p16;
		int32_t *p32;
		uint32_t *c32;        // 32bit cardinal
	};
	unsigned long nitems;
	xcb_atom_t type;
	int format;

	xcb_get_property_reply_t *r;
} winprop_t;

struct xvisual_info {
	/// Bit depth of the red component
	int red_size;
	/// Bit depth of the green component
	int green_size;
	/// Bit depth of the blue component
	int blue_size;
	/// Bit depth of the alpha component
	int alpha_size;
	/// The depth of X visual
	int visual_depth;

	xcb_visualid_t visual;
};

#define XCB_AWAIT_VOID(func, c, ...)                                                     \
	({                                                                               \
		bool success = true;                                                     \
		__auto_type e = xcb_request_check(c, func##_checked(c, __VA_ARGS__));    \
		if (e) {                                                                 \
			x_print_error(e->sequence, e->major_code, e->minor_code,         \
			              e->error_code);                                    \
			free(e);                                                         \
			success = false;                                                 \
		}                                                                        \
		success;                                                                 \
	})

#define XCB_AWAIT(func, c, ...)                                                          \
	({                                                                               \
		xcb_generic_error_t *e = NULL;                                           \
		__auto_type r = func##_reply(c, func(c, __VA_ARGS__), &e);               \
		if (e) {                                                                 \
			x_print_error(e->sequence, e->major_code, e->minor_code,         \
			              e->error_code);                                    \
			free(e);                                                         \
		}                                                                        \
		r;                                                                       \
	})

/// Wraps x_new_id. abort the program if x_new_id returns error
static inline uint32_t x_new_id(xcb_connection_t *c) {
	auto ret = xcb_generate_id(c);
	if (ret == (uint32_t)-1) {
		log_fatal("We seems to have run of XIDs. This is either a bug in the X "
		          "server, or a resource leakage in compton. Please open an "
		          "issue about this problem. compton will die.");
		abort();
	}
	return ret;
}

/**
 * Send a request to X server and get the reply to make sure all previous
 * requests are processed, and their replies received
 *
 * xcb_get_input_focus is used here because it is the same request used by
 * libX11
 */
static inline void x_sync(xcb_connection_t *c) {
	free(xcb_get_input_focus_reply(c, xcb_get_input_focus(c), NULL));
}

/**
 * Get a specific attribute of a window.
 *
 * Returns a blank structure if the returned type and format does not
 * match the requested type and format.
 *
 * @param ps current session
 * @param w window
 * @param atom atom of attribute to fetch
 * @param length length to read
 * @param rtype atom of the requested type
 * @param rformat requested format
 * @return a <code>winprop_t</code> structure containing the attribute
 *    and number of items. A blank one on failure.
 */
winprop_t wid_get_prop_adv(const session_t *ps, xcb_window_t w, xcb_atom_t atom,
                           int offset, int length, xcb_atom_t rtype, int rformat);

/**
 * Wrapper of wid_get_prop_adv().
 */
static inline winprop_t wid_get_prop(const session_t *ps, xcb_window_t wid, xcb_atom_t atom,
                                     int length, xcb_atom_t rtype, int rformat) {
	return wid_get_prop_adv(ps, wid, atom, 0L, length, rtype, rformat);
}

/// Discard all X events in queue or in flight. Should only be used when the server is
/// grabbed
static inline void x_discard_events(xcb_connection_t *c) {
	xcb_generic_event_t *e;
	while ((e = xcb_poll_for_event(c))) {
		free(e);
	}
}

/**
 * Get the value of a type-<code>xcb_window_t</code> property of a window.
 *
 * @return the value if successful, 0 otherwise
 */
xcb_window_t wid_get_prop_window(session_t *ps, xcb_window_t wid, xcb_atom_t aprop);

/**
 * Get the value of a text property of a window.
 */
bool wid_get_text_prop(session_t *ps, xcb_window_t wid, xcb_atom_t prop, char ***pstrlst,
                       int *pnstr);

const xcb_render_pictforminfo_t *
x_get_pictform_for_visual(xcb_connection_t *, xcb_visualid_t);
int x_get_visual_depth(xcb_connection_t *, xcb_visualid_t);

xcb_render_picture_t
x_create_picture_with_pictfmt_and_pixmap(xcb_connection_t *,
                                         const xcb_render_pictforminfo_t *pictfmt,
                                         xcb_pixmap_t pixmap, uint32_t valuemask,
                                         const xcb_render_create_picture_value_list_t *attr)
    attr_nonnull(1, 2);

xcb_render_picture_t
x_create_picture_with_visual_and_pixmap(xcb_connection_t *, xcb_visualid_t visual,
                                        xcb_pixmap_t pixmap, uint32_t valuemask,
                                        const xcb_render_create_picture_value_list_t *attr)
    attr_nonnull(1);

xcb_render_picture_t
x_create_picture_with_standard_and_pixmap(xcb_connection_t *, xcb_pict_standard_t standard,
                                          xcb_pixmap_t pixmap, uint32_t valuemask,
                                          const xcb_render_create_picture_value_list_t *attr)
    attr_nonnull(1);

/**
 * Create an picture.
 */
xcb_render_picture_t
x_create_picture_with_pictfmt(xcb_connection_t *, xcb_drawable_t, int w, int h,
                              const xcb_render_pictforminfo_t *pictfmt, uint32_t valuemask,
                              const xcb_render_create_picture_value_list_t *attr)
    attr_nonnull(1, 5);

xcb_render_picture_t
x_create_picture_with_visual(xcb_connection_t *, xcb_drawable_t, int w, int h,
                             xcb_visualid_t visual, uint32_t valuemask,
                             const xcb_render_create_picture_value_list_t *attr)
    attr_nonnull(1);

/// Fetch a X region and store it in a pixman region
bool x_fetch_region(xcb_connection_t *, xcb_xfixes_region_t r, region_t *res);

void x_set_picture_clip_region(xcb_connection_t *, xcb_render_picture_t, int16_t clip_x_origin,
                               int16_t clip_y_origin, const region_t *);

void x_clear_picture_clip_region(xcb_connection_t *, xcb_render_picture_t pict);

/**
 * X11 error handler function.
 *
 * XXX consider making this error to string
 */
void x_print_error(unsigned long serial, uint8_t major, uint16_t minor, uint8_t error_code);

xcb_pixmap_t x_create_pixmap(xcb_connection_t *, uint8_t depth, xcb_drawable_t drawable,
                             int width, int height);

bool x_validate_pixmap(xcb_connection_t *, xcb_pixmap_t pxmap);

/**
 * Free a <code>winprop_t</code>.
 *
 * @param pprop pointer to the <code>winprop_t</code> to free.
 */
static inline void free_winprop(winprop_t *pprop) {
	// Empty the whole structure to avoid possible issues
	if (pprop->r)
		free(pprop->r);
	pprop->ptr = NULL;
	pprop->r = NULL;
	pprop->nitems = 0;
}
/// Get the back pixmap of the root window
xcb_pixmap_t x_get_root_back_pixmap(session_t *ps);

/// Return true if the atom refers to a property name that is used for the
/// root window background pixmap
bool x_is_root_back_pixmap_atom(session_t *ps, xcb_atom_t atom);

bool x_fence_sync(xcb_connection_t *, xcb_sync_fence_t);

/**
 * Convert a struct conv to a X picture convolution filter, normalizing the kernel
 * in the process. Allow the caller to specify the element at the center of the kernel,
 * for compatibility with legacy code.
 *
 * @param[in] kernel the convolution kernel
 * @param[in] center the element to put at the center of the matrix
 * @param[inout] ret pointer to an array of `size`, if `size` is too small, more space
 *                   will be allocated, and `*ret` will be updated.
 * @param[inout] size size of the array pointed to by `ret`.
 */
int x_picture_filter_from_conv(const conv *kernel, double center,
                               xcb_render_fixed_t **ret, size_t *size);

/// Generate a search criteria for fbconfig from a X visual.
/// Returns {-1, -1, -1, -1, -1, -1} on failure
struct xvisual_info x_get_visual_info(xcb_connection_t *c, xcb_visualid_t visual);

xcb_visualid_t x_get_visual_for_standard(xcb_connection_t *c, xcb_pict_standard_t std);

xcb_screen_t *x_screen_of_display(xcb_connection_t *c, int screen);