Add new blur_method dual_kawase

src/backend/backend.h

@@ -65,6 +65,11 @@ struct kernel_blur_args {
 	int kernel_count;
 };
 
+struct dual_kawase_blur_args {
+	int size;
+	int strength;
+};
+
 struct backend_operations {
 	// ===========    Initialization    ===========
 

src/backend/gl/gl_common.c

@@ -990,6 +990,12 @@ void *gl_create_blur_context(backend_t *base, enum blur_method method, void *arg
 		return ctx;
 	}
 
+	if (method == BLUR_METHOD_DUAL_KAWASE) {
+		log_warn("Blur method 'dual_kawase' is not yet implemented.");
+		ctx->method = BLUR_METHOD_NONE;
+		return ctx;
+	}
+
 	int nkernels;
 	ctx->method = BLUR_METHOD_KERNEL;
 	if (method == BLUR_METHOD_KERNEL) {

src/backend/xrender/xrender.c

@@ -505,6 +505,12 @@ void *create_blur_context(backend_t *base attr_unused, enum blur_method method,
 		ret->method = BLUR_METHOD_NONE;
 		return ret;
 	}
+	if (method == BLUR_METHOD_DUAL_KAWASE) {
+		log_warn("Blur method 'dual_kawase' is not compatible with the 'xrender' "
+		         "backend.");
+		ret->method = BLUR_METHOD_NONE;
+		return ret;
+	}
 
 	ret->method = BLUR_METHOD_KERNEL;
 	struct conv **kernels;

src/config.c

@@ -88,6 +88,8 @@ enum blur_method parse_blur_method(const char *src) {
 		return BLUR_METHOD_BOX;
 	} else if (strcmp(src, "gaussian") == 0) {
 		return BLUR_METHOD_GAUSSIAN;
+	} else if (strcmp(src, "dual_kawase") == 0) {
+		return BLUR_METHOD_DUAL_KAWASE;
 	} else if (strcmp(src, "none") == 0) {
 		return BLUR_METHOD_NONE;
 	}
@@ -542,6 +544,7 @@ char *parse_config(options_t *opt, const char *config_file, bool *shadow_enable,
 	    .blur_method = BLUR_METHOD_NONE,
 	    .blur_radius = 3,
 	    .blur_deviation = 0.84089642,
+	    .blur_strength = 5,
 	    .blur_background_frame = false,
 	    .blur_background_fixed = false,
 	    .blur_background_blacklist = NULL,

src/config.h

@@ -60,6 +60,7 @@ enum blur_method {
 	BLUR_METHOD_KERNEL,
 	BLUR_METHOD_BOX,
 	BLUR_METHOD_GAUSSIAN,
+	BLUR_METHOD_DUAL_KAWASE,
 	BLUR_METHOD_INVALID,
 };
 
@@ -189,6 +190,8 @@ typedef struct options {
 	int blur_radius;
 	// Standard deviation for the gaussian blur
 	double blur_deviation;
+	// Strength of the dual_kawase blur
+	int blur_strength;
 	/// Whether to blur background when the window frame is not opaque.
 	/// Implies blur_background.
 	bool blur_background_frame;

src/config_libconfig.c

@@ -522,6 +522,8 @@ char *parse_config_libconfig(options_t *opt, const char *config_file, bool *shad
 	config_lookup_int(&cfg, "blur-size", &opt->blur_radius);
 	// --blur-deviation
 	config_lookup_float(&cfg, "blur-deviation", &opt->blur_deviation);
+	// --blur-strength
+	config_lookup_int(&cfg, "blur-strength", &opt->blur_strength);
 	// --blur-background
 	if (config_lookup_bool(&cfg, "blur-background", &ival) && ival) {
 		if (opt->blur_method == BLUR_METHOD_NONE) {
@@ -635,6 +637,7 @@ char *parse_config_libconfig(options_t *opt, const char *config_file, bool *shad
 		}
 
 		config_setting_lookup_float(blur_cfg, "deviation", &opt->blur_deviation);
+		config_setting_lookup_int(blur_cfg, "strength", &opt->blur_strength);
 	}
 
 	// Wintype settings

src/options.c

@@ -212,6 +212,9 @@ static void usage(const char *argv0, int ret) {
 	    "--blur-deviation\n"
 	    "  The standard deviation for the 'gaussian' blur method.\n"
 	    "\n"
+	    "--blur-strength\n"
+	    "  The strength level of the 'dual_kawase' blur method.\n"
+	    "\n"
 	    "--blur-background\n"
 	    "  Blur background of semi-transparent / ARGB windows. Bad in\n"
 	    "  performance. The switch name may change without prior\n"
@@ -437,6 +440,7 @@ static const struct option longopts[] = {
     {"blur-method", required_argument, NULL, 328},
     {"blur-size", required_argument, NULL, 329},
     {"blur-deviation", required_argument, NULL, 330},
+    {"blur-strength", required_argument, NULL, 331},
     {"experimental-backends", no_argument, NULL, 733},
     {"monitor-repaint", no_argument, NULL, 800},
     {"diagnostics", no_argument, NULL, 801},
@@ -841,6 +845,10 @@ bool get_cfg(options_t *opt, int argc, char *const *argv, bool shadow_enable,
 			// --blur-deviation
 			opt->blur_deviation = atof(optarg);
 			break;
+		case 331:
+			// --blur-strength
+			opt->blur_strength = atoi(optarg);
+			break;
 
 		P_CASEBOOL(733, experimental_backends);
 		P_CASEBOOL(800, monitor_repaint);
@@ -930,6 +938,20 @@ bool get_cfg(options_t *opt, int argc, char *const *argv, bool shadow_enable,
 		CHECK(opt->blur_kernel_count);
 	}
 
+	// Sanitize parameters for dual-filter kawase blur
+	if (opt->blur_method == BLUR_METHOD_DUAL_KAWASE) {
+		if (opt->blur_strength < 0 && opt->blur_radius > 500) {
+			log_warn("Blur radius >500 not supported by dual_kawase method, "
+			         "capping to 500.");
+			opt->blur_radius = 500;
+		}
+		if (opt->blur_strength > 20) {
+			log_warn("Blur strength >20 not supported by dual_kawase method, "
+			         "capping to 20.");
+			opt->blur_strength = 20;
+		}
+	}
+
 	if (opt->resize_damage < 0) {
 		log_warn("Negative --resize-damage will not work correctly.");
 	}

src/picom.c

@@ -704,6 +704,7 @@ static bool initialize_blur(session_t *ps) {
 	struct kernel_blur_args kargs;
 	struct gaussian_blur_args gargs;
 	struct box_blur_args bargs;
+	struct dual_kawase_blur_args dkargs;
 
 	void *args = NULL;
 	switch (ps->o.blur_method) {
@@ -721,6 +722,11 @@ static bool initialize_blur(session_t *ps) {
 		gargs.deviation = ps->o.blur_deviation;
 		args = (void *)&gargs;
 		break;
+	case BLUR_METHOD_DUAL_KAWASE:
+		dkargs.size = ps->o.blur_radius;
+		dkargs.strength = ps->o.blur_strength;
+		args = (void *)&dkargs;
+		break;
 	default: return true;
 	}