foot/config.h
Daniel Eklöf 299186a654
render: when double-buffering, pre-apply previous frame's damage early
Foot likes it when compositor releases buffer immediately, as that
means we only have to re-render the cells that have changed since the
last frame.

For various reasons, not all compositors do this. In this case, foot
is typically forced to switch between two buffers, i.e. double-buffer.

In this case, each frame starts with copying over the damage from the
previous frame, to the new frame. Then we start rendering the updated
cells.

Bringing over the previous frame's damage can be slow, if the changed
area was large (e.g. when scrolling one or a few lines, or on full
screen updates). It's also done single-threaded. Thus it not only
slows down frame rendering, but pauses everything else (i.e. input
processing). All in all, it reduces performance and increases input
latency.

But we don't have to wait until it's time to render a frame to copy
over the previous frame's damage. We can do that as soon as the
compositor has released the buffer (for the frame _before_ the
previous frame). And we can do this in a thread.

This frees up foot to continue processing input, and reduces frame
rendering time since we can now start rendering the modified cells
immediately, without first doing a large memcpy(3).

In worst case scenarios (or perhaps we should consider them best case
scenarios...), I've seen up to a 10x performance increase in frame
rendering times (this obviously does *not* include the time it takes
to copy over the previous frame's damage, since that doesn't affect
neither input processing nor frame rendering).

Implemented by adding a callback mechanism to the shm abstraction
layer. Use it for the grid buffers, and kick off a thread that copies
the previous frame's damage, and resets the buffers age to 0 (so that
foot understands it can start render to it immediately when it later
needs to render a frame).

Since we have certain way of knowing if a compositor releases buffers
immediately or not, use a bit of heuristics; if we see 10 consecutive
non-immediate releases (that is, we reset the counter as soon as we do
see an immediate release), this new "pre-apply damage" logic is
enabled. It can be force-disabled with tweak.pre-apply-damage=no.

We also need to take care to wait for the thread before resetting the
render's "last_buf" pointer (or we'll SEGFAULT in the thread...).

We must also ensure we wait for the thread to finish before we start
rendering a new frame. Under normal circumstances, the wait time is
always 0, the thread has almost always finished long before we need to
render the next frame. But it _can_ happen.

Closes #2188
2025-10-10 10:23:17 +02:00

469 lines
10 KiB
C

#pragma once
#include <regex.h>
#include <stdbool.h>
#include <stdint.h>
#include <uchar.h>
#include <xkbcommon/xkbcommon.h>
#include <tllist.h>
#include <fcft/fcft.h>
#include "user-notification.h"
#define DEFINE_LIST(type) \
type##_list { \
size_t count; \
type *arr; \
}
/* If px != 0 then px is valid, otherwise pt is valid */
struct pt_or_px {
int16_t px;
float pt;
};
struct font_size_adjustment {
struct pt_or_px pt_or_px;
float percent;
};
enum cursor_style { CURSOR_BLOCK, CURSOR_UNDERLINE, CURSOR_BEAM, CURSOR_HOLLOW };
enum cursor_unfocused_style {
CURSOR_UNFOCUSED_UNCHANGED,
CURSOR_UNFOCUSED_HOLLOW,
CURSOR_UNFOCUSED_NONE
};
enum conf_size_type {CONF_SIZE_PX, CONF_SIZE_CELLS};
struct config_font {
char *pattern;
float pt_size;
int px_size;
};
DEFINE_LIST(struct config_font);
#if 0
struct config_key_modifiers {
bool shift;
bool alt;
bool ctrl;
bool super;
};
#endif
struct argv {
char **args;
};
enum binding_aux_type {
BINDING_AUX_NONE,
BINDING_AUX_PIPE,
BINDING_AUX_TEXT,
BINDING_AUX_REGEX,
};
struct binding_aux {
enum binding_aux_type type;
bool master_copy;
union {
struct argv pipe;
struct {
uint8_t *data;
size_t len;
} text;
char *regex_name;
};
};
enum key_binding_type {
KEY_BINDING,
MOUSE_BINDING,
};
typedef tll(char *) config_modifier_list_t;
struct config_key_binding {
int action; /* One of the various bind_action_* enums from wayland.h */
//struct config_key_modifiers modifiers;
config_modifier_list_t modifiers;
union {
/* Key bindings */
struct {
xkb_keysym_t sym;
} k;
/* Mouse bindings */
struct {
int button;
int count;
} m;
};
struct binding_aux aux;
/* For error messages in collision handling */
const char *path;
int lineno;
};
DEFINE_LIST(struct config_key_binding);
typedef tll(char *) config_override_t;
struct config_spawn_template {
struct argv argv;
};
struct env_var {
char *name;
char *value;
};
typedef tll(struct env_var) env_var_list_t;
struct custom_regex {
char *name;
char *regex;
regex_t preg;
struct config_spawn_template launch;
};
struct color_theme {
uint32_t fg;
uint32_t bg;
uint32_t flash;
uint32_t flash_alpha;
uint32_t table[256];
uint16_t alpha;
uint32_t selection_fg;
uint32_t selection_bg;
uint32_t url;
uint32_t dim[8];
uint32_t sixel[16];
enum {
ALPHA_MODE_DEFAULT,
ALPHA_MODE_MATCHING,
ALPHA_MODE_ALL
} alpha_mode;
struct {
uint32_t text;
uint32_t cursor;
} cursor;
struct {
uint32_t fg;
uint32_t bg;
} jump_label;
struct {
uint32_t fg;
uint32_t bg;
} scrollback_indicator;
struct {
struct {
uint32_t fg;
uint32_t bg;
} no_match;
struct {
uint32_t fg;
uint32_t bg;
} match;
} search_box;
struct {
bool cursor:1;
bool jump_label:1;
bool scrollback_indicator:1;
bool url:1;
bool search_box_no_match:1;
bool search_box_match:1;
uint8_t dim;
} use_custom;
};
enum which_color_theme {
COLOR_THEME1,
COLOR_THEME2,
};
enum shm_bit_depth {
SHM_BITS_AUTO,
SHM_BITS_8,
SHM_BITS_10,
SHM_BITS_16,
};
enum center_when {
CENTER_INVALID,
CENTER_NEVER,
CENTER_FULLSCREEN,
CENTER_MAXIMIZED_AND_FULLSCREEN,
CENTER_ALWAYS,
};
struct config {
char *term;
char *shell;
char *title;
char *app_id;
char32_t *word_delimiters;
bool login_shell;
bool locked_title;
struct {
enum conf_size_type type;
uint32_t width;
uint32_t height;
} size;
unsigned pad_x;
unsigned pad_y;
enum center_when center_when;
bool resize_by_cells;
bool resize_keep_grid;
uint16_t resize_delay_ms;
struct {
float amount;
} dim;
struct {
bool enabled;
bool palette_based;
float amount;
} bold_in_bright;
enum { STARTUP_WINDOWED, STARTUP_MAXIMIZED, STARTUP_FULLSCREEN } startup_mode;
bool dpi_aware;
bool gamma_correct;
bool uppercase_regex_insert;
struct config_font_list fonts[4];
struct font_size_adjustment font_size_adjustment;
/* Custom font metrics (-1 = use real font metrics) */
struct pt_or_px line_height;
struct pt_or_px letter_spacing;
/* Adjusted letter x/y offsets */
struct pt_or_px horizontal_letter_offset;
struct pt_or_px vertical_letter_offset;
bool use_custom_underline_offset;
struct pt_or_px underline_offset;
struct pt_or_px underline_thickness;
struct pt_or_px strikeout_thickness;
bool box_drawings_uses_font_glyphs;
bool can_shape_grapheme;
struct {
enum {
OSC52_DISABLED,
OSC52_COPY_ENABLED,
OSC52_PASTE_ENABLED,
OSC52_ENABLED,
} osc52;
} security;
struct {
bool urgent;
bool notify;
bool flash;
bool system_bell;
struct config_spawn_template command;
bool command_focused;
} bell;
struct {
uint32_t lines;
struct {
enum {
SCROLLBACK_INDICATOR_POSITION_NONE,
SCROLLBACK_INDICATOR_POSITION_FIXED,
SCROLLBACK_INDICATOR_POSITION_RELATIVE
} position;
enum {
SCROLLBACK_INDICATOR_FORMAT_PERCENTAGE,
SCROLLBACK_INDICATOR_FORMAT_LINENO,
SCROLLBACK_INDICATOR_FORMAT_TEXT,
} format;
char32_t *text;
} indicator;
float multiplier;
} scrollback;
struct {
char32_t *label_letters;
struct config_spawn_template launch;
enum {
OSC8_UNDERLINE_URL_MODE,
OSC8_UNDERLINE_ALWAYS,
} osc8_underline;
char *regex;
regex_t preg;
} url;
tll(struct custom_regex) custom_regexes;
struct color_theme colors;
struct color_theme colors2;
enum which_color_theme initial_color_theme;
struct {
enum cursor_style style;
enum cursor_unfocused_style unfocused_style;
struct {
bool enabled;
uint32_t rate_ms;
} blink;
struct pt_or_px beam_thickness;
struct pt_or_px underline_thickness;
} cursor;
struct {
bool hide_when_typing;
bool alternate_scroll_mode;
//struct config_key_modifiers selection_override_modifiers;
config_modifier_list_t selection_override_modifiers;
} mouse;
struct {
/* Bindings for "normal" mode */
struct config_key_binding_list key;
struct config_key_binding_list mouse;
/*
* Special modes
*/
/* While searching (not - action to *start* a search is in the
* 'key' bindings above */
struct config_key_binding_list search;
/* While showing URL jump labels */
struct config_key_binding_list url;
} bindings;
struct {
enum { CONF_CSD_PREFER_NONE, CONF_CSD_PREFER_SERVER, CONF_CSD_PREFER_CLIENT } preferred;
uint16_t title_height;
uint16_t border_width;
uint16_t border_width_visible;
uint16_t button_width;
bool hide_when_maximized;
bool double_click_to_maximize;
struct {
bool title_set:1;
bool buttons_set:1;
bool minimize_set:1;
bool maximize_set:1;
bool close_set:1;
bool border_set:1;
uint32_t title;
uint32_t buttons;
uint32_t minimize;
uint32_t maximize;
uint32_t quit; /* 'close' collides with #define in epoll-shim */
uint32_t border;
} color;
struct config_font_list font;
} csd;
uint16_t render_worker_count;
char *server_socket_path;
bool presentation_timings;
bool hold_at_exit;
enum {
SELECTION_TARGET_NONE,
SELECTION_TARGET_PRIMARY,
SELECTION_TARGET_CLIPBOARD,
SELECTION_TARGET_BOTH
} selection_target;
struct {
struct config_spawn_template command;
struct config_spawn_template command_action_arg;
struct config_spawn_template close;
bool inhibit_when_focused;
} desktop_notifications;
env_var_list_t env_vars;
char *utmp_helper_path;
struct {
enum fcft_scaling_filter fcft_filter;
bool overflowing_glyphs;
bool grapheme_shaping;
enum {
GRAPHEME_WIDTH_WCSWIDTH,
GRAPHEME_WIDTH_DOUBLE,
GRAPHEME_WIDTH_MAX,
} grapheme_width_method;
enum {
RENDER_TIMER_NONE,
RENDER_TIMER_OSD,
RENDER_TIMER_LOG,
RENDER_TIMER_BOTH
} render_timer;
bool damage_whole_window;
uint32_t delayed_render_lower_ns;
uint32_t delayed_render_upper_ns;
off_t max_shm_pool_size;
float box_drawing_base_thickness;
bool box_drawing_solid_shades;
bool font_monospace_warn;
bool sixel;
enum shm_bit_depth surface_bit_depth;
uint32_t min_stride_alignment;
bool preapply_damage;
} tweak;
struct {
uint32_t long_press_delay;
} touch;
user_notifications_t notifications;
};
bool config_override_apply(struct config *conf, config_override_t *overrides,
bool errors_are_fatal);
bool config_load(
struct config *conf, const char *path,
user_notifications_t *initial_user_notifications,
config_override_t *overrides, bool errors_are_fatal,
bool as_server);
void config_free(struct config *conf);
struct config *config_clone(const struct config *old);
bool config_font_parse(const char *pattern, struct config_font *font);
void config_font_list_destroy(struct config_font_list *font_list);
#if 0
struct seat;
xkb_mod_mask_t
conf_modifiers_to_mask(
const struct seat *seat, const struct config_key_modifiers *modifiers);
#endif
bool check_if_font_is_monospaced(
const char *pattern, user_notifications_t *notifications);