Add corner-radius-rules configuration option

This option accepts a list of patterns and overrides the corner radii of
matching windows

Authored-by: oofsauce <alanpanayotov@gmail.com>
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>

man/picom.1.asciidoc

@@ -103,6 +103,9 @@ OPTIONS
 *--corner-radius* 'VALUE'::
 	Sets the radius of rounded window corners. When > 0, the compositor will round the corners of windows. Does not interact well with *--transparent-clipping*. (defaults to 0).
 
+*--corner-radius-rules* 'RADIUS':'CONDITION'::
+	Specify a list of corner radius rules. Overrides the corner radii of matching windows. This option takes precedence over the *--rounded-corners-exclude* option, and also overrides the default exclusion of fullscreen windows. The condition has the same format as *--opacity-rule*.
+
 *--rounded-corners-exclude* 'CONDITION'::
 	Exclude conditions for rounded corners.
 

src/config.c

@@ -509,32 +509,37 @@ parse_geometry_end:
 }
 
 /**
- * Parse a list of opacity rules.
+ * Parse a list of window rules, prefixed with a number, separated by a ':'
  */
-bool parse_rule_opacity(c2_lptr_t **res, const char *src) {
-	// Find opacity value
+bool parse_numeric_window_rule(c2_lptr_t **res, const char *src, long min, long max) {
+	if (!src) {
+		return false;
+	}
+
+	// Find numeric value
 	char *endptr = NULL;
 	long val = strtol(src, &endptr, 0);
 	if (!endptr || endptr == src) {
-		log_error("No opacity specified: %s", src);
+		log_error("No number specified: %s", src);
 		return false;
 	}
-	if (val > 100 || val < 0) {
-		log_error("Opacity %ld invalid: %s", val, src);
+
+	if (val < min || val > max) {
+		log_error("Number not in range (%ld <= n <= %ld): %s", min, max, src);
 		return false;
 	}
 
 	// Skip over spaces
-	while (*endptr && isspace((unsigned char)*endptr))
+	while (*endptr && isspace((unsigned char)*endptr)) {
 		++endptr;
+	}
 	if (':' != *endptr) {
-		log_error("Opacity terminator not found: %s", src);
+		log_error("Number separator (':') not found: %s", src);
 		return false;
 	}
 	++endptr;
 
 	// Parse pattern
-	// I hope 1-100 is acceptable for (void *)
 	return c2_parse(res, endptr, (void *)val);
 }
 

src/config.h

@@ -228,6 +228,8 @@ typedef struct options {
 	int corner_radius;
 	/// Rounded corners blacklist. A linked list of conditions.
 	c2_lptr_t *rounded_corners_blacklist;
+	/// Rounded corner rules. A linked list of conditions.
+	c2_lptr_t *corner_radius_rules;
 
 	// === Focus related ===
 	/// Whether to try to detect WM windows and mark them as focused.
@@ -266,7 +268,7 @@ bool must_use parse_long(const char *, long *);
 bool must_use parse_int(const char *, int *);
 struct conv **must_use parse_blur_kern_lst(const char *, bool *hasneg, int *count);
 bool must_use parse_geometry(session_t *, const char *, region_t *);
-bool must_use parse_rule_opacity(c2_lptr_t **, const char *);
+bool must_use parse_numeric_window_rule(c2_lptr_t **, const char *, long, long);
 bool must_use parse_rule_window_shader(c2_lptr_t **, const char *, const char *);
 char *must_use locate_auxiliary_file(const char *scope, const char *path,
                                      const char *include_dir);

src/config_libconfig.c

@@ -135,6 +135,32 @@ void parse_cfg_condlst(const config_t *pcfg, c2_lptr_t **pcondlst, const char *n
 	}
 }
 
+/**
+ * Parse a window corner radius rule list in configuration file.
+ */
+static inline void
+parse_cfg_condlst_corner(options_t *opt, const config_t *pcfg, const char *name) {
+	config_setting_t *setting = config_lookup(pcfg, name);
+	if (setting) {
+		// Parse an array of options
+		if (config_setting_is_array(setting)) {
+			int i = config_setting_length(setting);
+			while (i--)
+				if (!parse_numeric_window_rule(
+				        &opt->corner_radius_rules,
+				        config_setting_get_string_elem(setting, i), 0, INT_MAX))
+					exit(1);
+		}
+		// Treat it as a single pattern if it's a string
+		else if (config_setting_type(setting) == CONFIG_TYPE_STRING) {
+			if (!parse_numeric_window_rule(&opt->corner_radius_rules,
+			                               config_setting_get_string(setting),
+			                               0, INT_MAX))
+				exit(1);
+		}
+	}
+}
+
 /**
  * Parse an opacity rule list in configuration file.
  */
@@ -146,15 +172,15 @@ parse_cfg_condlst_opct(options_t *opt, const config_t *pcfg, const char *name) {
 		if (config_setting_is_array(setting)) {
 			int i = config_setting_length(setting);
 			while (i--)
-				if (!parse_rule_opacity(
+				if (!parse_numeric_window_rule(
 				        &opt->opacity_rules,
-				        config_setting_get_string_elem(setting, i)))
+				        config_setting_get_string_elem(setting, i), 0, 100))
 					exit(1);
 		}
 		// Treat it as a single pattern if it's a string
 		else if (config_setting_type(setting) == CONFIG_TYPE_STRING) {
-			if (!parse_rule_opacity(&opt->opacity_rules,
-			                        config_setting_get_string(setting)))
+			if (!parse_numeric_window_rule(
+			        &opt->opacity_rules, config_setting_get_string(setting), 0, 100))
 				exit(1);
 		}
 	}
@@ -334,6 +360,9 @@ char *parse_config_libconfig(options_t *opt, const char *config_file, bool *shad
 	config_lookup_int(&cfg, "corner-radius", &opt->corner_radius);
 	// --rounded-corners-exclude
 	parse_cfg_condlst(&cfg, &opt->rounded_corners_blacklist, "rounded-corners-exclude");
+	// --corner-radius-rules
+	parse_cfg_condlst_corner(opt, &cfg, "corner-radius-rules");
+
 	// -e (frame_opacity)
 	config_lookup_float(&cfg, "frame-opacity", &opt->frame_opacity);
 	// -c (shadow_enable)

src/options.c

@@ -161,6 +161,7 @@ static const struct picom_option picom_options[] = {
     {"corner-radius"               , required_argument, 333, NULL          , "Sets the radius of rounded window corners. When > 0, the compositor will "
                                                                              "round the corners of windows. (defaults to 0)."},
     {"rounded-corners-exclude"     , required_argument, 334, "COND"        , "Exclude conditions for rounded corners."},
+    {"corner-radius-rules"         , required_argument, 340, "RADIUS:COND" , "Window rules for specific rounded corner radii."},
     {"clip-shadow-above"           , required_argument, 335, NULL          , "Specify a list of conditions of windows to not paint a shadow over, such "
                                                                              "as a dock window."},
     {"window-shader-fg"            , required_argument, 336, "PATH"        , "Specify GLSL fragment shader path for rendering window contents. Does not"
@@ -174,6 +175,7 @@ static const struct picom_option picom_options[] = {
     {"dithered-present"            , no_argument      , 339, NULL          , "Use higher precision during rendering, and apply dither when presenting the "
                                                                              "rendered screen. Reduces banding artifacts, but might cause performance "
                                                                              "degradation. Only works with OpenGL."},
+    // 340 is corner-radius-rules
     {"legacy-backends"             , no_argument      , 733, NULL          , "Use deprecated version of the backends."},
     {"monitor-repaint"             , no_argument      , 800, NULL          , "Highlight the updated area of the screen. For debugging."},
     {"diagnostics"                 , no_argument      , 801, NULL          , "Print diagnostic information"},
@@ -619,7 +621,7 @@ bool get_cfg(options_t *opt, int argc, char *const *argv, bool shadow_enable,
 			break;
 		case 304:
 			// --opacity-rule
-			if (!parse_rule_opacity(&opt->opacity_rules, optarg))
+			if (!parse_numeric_window_rule(&opt->opacity_rules, optarg, 0, 100))
 				exit(1);
 			break;
 		case 305:
@@ -723,6 +725,11 @@ bool get_cfg(options_t *opt, int argc, char *const *argv, bool shadow_enable,
 			// --rounded-corners-exclude
 			condlst_add(&opt->rounded_corners_blacklist, optarg);
 			break;
+		case 340:
+			// --corner-radius-rules
+			if (!parse_numeric_window_rule(&opt->corner_radius_rules, optarg, 0, INT_MAX))
+				exit(1);
+			break;
 		case 335:
 			// --clip-shadow-above
 			condlst_add(&opt->shadow_clip_list, optarg);

src/win.c

@@ -1139,13 +1139,24 @@ static void win_determine_rounded_corners(session_t *ps, struct managed_win *w)
 		return;
 	}
 
-	// Don't round full screen windows & excluded windows
-	if ((w && win_is_fullscreen(ps, w)) ||
-	    c2_match(ps, w, ps->o.rounded_corners_blacklist, NULL)) {
+	void *radius_override = NULL;
+	if (c2_match(ps, w, ps->o.corner_radius_rules, &radius_override)) {
+		log_debug("Matched corner rule! %d", w->corner_radius);
+	}
+
+	// Don't round full screen windows & excluded windows,
+	// unless we find a corner override in corner_radius_rules
+	if (!radius_override && ((w && win_is_fullscreen(ps, w)) ||
+	                         c2_match(ps, w, ps->o.rounded_corners_blacklist, NULL))) {
 		w->corner_radius = 0;
 		log_debug("Not rounding corners for window %#010x", w->base.id);
+	} else {
+		if (radius_override) {
+			w->corner_radius = (int)(long)radius_override;
 		} else {
 			w->corner_radius = ps->o.corner_radius;
+		}
+
 		log_debug("Rounding corners for window %#010x", w->base.id);
 		// Initialize the border color to an invalid value
 		w->border_col[0] = w->border_col[1] = w->border_col[2] =