parameterize max brightness limit

picom.sample.conf

@@ -39,6 +39,8 @@ blur-background-exclude = [
 ];
 # opacity-rule = [ "80:class_g = 'URxvt'" ];
 
+# max-brightness = 0.66
+
 # Fading
 fading = true;
 # fade-delta = 30;

src/backend/backend.c

@@ -251,6 +251,13 @@ void paint_all_new(session_t *ps, struct managed_win *t, bool ignore_damage) {
 			pixman_region32_fini(&reg_shadow);
 		}
 
+		// Set max brightness
+		if (ps->o.max_brightness < 1.0) {
+			ps->backend_data->ops->image_op(
+			    ps->backend_data, IMAGE_OP_MAX_BRIGHTNESS, w->win_image,
+			    NULL, &reg_visible, &ps->o.max_brightness);
+		}
+
 		// Draw window on target
 		if (!w->invert_color && !w->dim && w->frame_opacity == 1 && w->opacity == 1) {
 			ps->backend_data->ops->compose(ps->backend_data, w->win_image,

src/backend/backend.h

@@ -47,6 +47,8 @@ enum image_operations {
 	// effective size. `reg_op` and `reg_visible` is ignored. `arg` is two integers,
 	// width and height, in that order.
 	IMAGE_OP_RESIZE_TILE,
+	// Limit how bright image can be
+	IMAGE_OP_MAX_BRIGHTNESS,
 };
 
 struct gaussian_blur_args {

src/backend/gl/gl_common.c

@@ -361,7 +361,9 @@ static void _gl_compose(backend_t *base, struct gl_image *img, GLuint target,
 		return;
 	}
 
-	GLuint brightness = gl_average_texture_color(base, img);
+	GLuint brightness = 0;
+	if (img->max_brightness < 1.0)
+		brightness = gl_average_texture_color(base, img);
 
 	assert(gd->win_shader.prog);
 	glUseProgram(gd->win_shader.prog);
@@ -381,7 +383,7 @@ static void _gl_compose(backend_t *base, struct gl_image *img, GLuint target,
 		glUniform1i(gd->win_shader.unifm_brightness, 1);
 	}
 	if (gd->win_shader.unifm_max_brightness >= 0) {
-		glUniform1f(gd->win_shader.unifm_max_brightness, 0.5); //TODO: parameterize
+		glUniform1f(gd->win_shader.unifm_max_brightness, (float)img->max_brightness);
 	}
 
 	// log_trace("Draw: %d, %d, %d, %d -> %d, %d (%d, %d) z %d\n",
@@ -1436,6 +1438,9 @@ bool gl_image_op(backend_t *base, enum image_operations op, void *image_data,
 		tex->ewidth = iargs[0];
 		tex->eheight = iargs[1];
 		break;
+	case IMAGE_OP_MAX_BRIGHTNESS:
+		tex->max_brightness = *(double *)arg;
+		break;
 	}
 
 	return true;

src/backend/gl/gl_common.h

@@ -55,6 +55,7 @@ typedef struct gl_image {
 	struct gl_texture *inner;
 	double opacity;
 	double dim;
+	double max_brightness;
 	int ewidth, eheight;
 	bool has_alpha;
 	bool color_inverted;

src/backend/gl/glx.c

@@ -390,6 +390,7 @@ glx_bind_pixmap(backend_t *base, xcb_pixmap_t pixmap, struct xvisual_info fmt, b
 
 	log_trace("Binding pixmap %#010x", pixmap);
 	auto wd = ccalloc(1, struct gl_image);
+	wd->max_brightness = 1;
 	wd->inner = ccalloc(1, struct gl_texture);
 	wd->inner->width = wd->ewidth = r->width;
 	wd->inner->height = wd->eheight = r->height;

src/backend/xrender/xrender.c

@@ -458,6 +458,7 @@ static bool image_op(backend_t *base, enum image_operations op, void *image,
 		img->eheight = iargs[1];
 		break;
 	case IMAGE_OP_APPLY_ALPHA_ALL: assert(false);
+	case IMAGE_OP_MAX_BRIGHTNESS: assert(false);
 	}
 	pixman_region32_fini(&reg);
 	return true;

src/config.c

@@ -549,6 +549,7 @@ char *parse_config(options_t *opt, const char *config_file, bool *shadow_enable,
 	    .inactive_dim_fixed = false,
 	    .invert_color_list = NULL,
 	    .opacity_rules = NULL,
+	    .max_brightness = 1.0,
 
 	    .use_ewmh_active_win = false,
 	    .focus_blacklist = NULL,

src/config.h

@@ -210,6 +210,8 @@ typedef struct options {
 	c2_lptr_t *invert_color_list;
 	/// Rules to change window opacity.
 	c2_lptr_t *opacity_rules;
+	/// Limit window brightness
+	double max_brightness;
 
 	// === Focus related ===
 	/// Whether to try to detect WM windows and mark them as focused.

src/config_libconfig.c

@@ -422,6 +422,13 @@ char *parse_config_libconfig(options_t *opt, const char *config_file, bool *shad
 	}
 	// --use-damage
 	lcfg_lookup_bool(&cfg, "use-damage", &opt->use_damage);
+
+	// --max-brightness
+	if (config_lookup_float(&cfg, "max-brightness", &opt->max_brightness) && opt->use_damage) {
+		log_warn("max-brightness requires use-damage = false. Falling back to 1.0");
+		opt->max_brightness = 1.0;
+	}
+
 	// --glx-use-gpushader4
 	if (config_lookup_bool(&cfg, "glx-use-gpushader4", &ival) && ival) {
 		log_warn("glx-use-gpushader4 is deprecated since v6, please remove it "

src/dbus.c

@@ -1035,6 +1035,8 @@ static bool cdbus_process_opts_get(session_t *ps, DBusMessage *msg) {
 	cdbus_m_opts_get_do(inactive_dim, cdbus_reply_double);
 	cdbus_m_opts_get_do(inactive_dim_fixed, cdbus_reply_bool);
 
+	cdbus_m_opts_get_do(max_brightness, cdbus_reply_double);
+
 	cdbus_m_opts_get_do(use_ewmh_active_win, cdbus_reply_bool);
 	cdbus_m_opts_get_do(detect_transient, cdbus_reply_bool);
 	cdbus_m_opts_get_do(detect_client_leader, cdbus_reply_bool);

src/options.c

@@ -185,6 +185,11 @@ static void usage(const char *argv0, int ret) {
 	    "--inactive-dim-fixed\n"
 	    "  Use fixed inactive dim value.\n"
 	    "\n"
+	    "--max-brightness\n"
+	    "  Dims windows which average brightness is above this threshold.\n"
+	    "  Requires --no-use-damage.\n"
+	    "  Default: 1.0 or no dimming.\n"
+	    "\n"
 	    "--detect-transient\n"
 	    "  Use WM_TRANSIENT_FOR to group windows, and consider windows in\n"
 	    "  the same group focused at the same time.\n"
@@ -410,6 +415,7 @@ static const struct option longopts[] = {
     {"use-damage", no_argument, NULL, 323},
     {"no-use-damage", no_argument, NULL, 324},
     {"no-vsync", no_argument, NULL, 325},
+    {"max-brightness", required_argument, NULL, 326},
     {"experimental-backends", no_argument, NULL, 733},
     {"monitor-repaint", no_argument, NULL, 800},
     {"diagnostics", no_argument, NULL, 801},
@@ -791,6 +797,11 @@ void get_cfg(options_t *opt, int argc, char *const *argv, bool shadow_enable,
 		case 325:
 			opt->vsync = false;
 			break;
+
+		case 326:
+			opt->max_brightness = atof(optarg);
+			break;
+
 		P_CASEBOOL(733, experimental_backends);
 		P_CASEBOOL(800, monitor_repaint);
 		case 801: opt->print_diagnostics = true; break;
@@ -822,6 +833,12 @@ void get_cfg(options_t *opt, int argc, char *const *argv, bool shadow_enable,
 	opt->shadow_opacity = normalize_d(opt->shadow_opacity);
 	opt->refresh_rate = normalize_i_range(opt->refresh_rate, 0, 300);
 
+	opt->max_brightness = normalize_d(opt->max_brightness);
+	if (opt->max_brightness < 1.0 && opt->use_damage) {
+		log_warn("--max-brightness requires --no-use-damage. Falling back to 1.0");
+		opt->max_brightness = 1.0;
+	}
+
 	// Apply default wintype options that are dependent on global options
 	set_default_winopts(opt, winopt_mask, shadow_enable, fading_enable);