Merge pull request #247 from Jauler/dim_bright_windows

Brightness clamping

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

@@ -183,6 +183,165 @@ static void gl_free_prog_main(gl_win_shader_t *pprogram) {
 	}
 }
 
+/*
+ * @brief Implements recursive part of gl_average_texture_color.
+ *
+ * @note In order to reduce number of textures which needs to be
+ * allocated and deleted during this recursive render
+ * we reuse the same two textures for render source and
+ * destination simply by alterating between them.
+ * Unfortunately on first iteration source_texture might
+ * be read-only. In this case we will select auxilary_texture as
+ * destination_texture in order not to touch that read-only source
+ * texture in following render iteration.
+ * Otherwise we simply will switch source and destination textures
+ * between each other on each render iteration.
+ */
+static GLuint _gl_average_texture_color(backend_t *base, GLuint source_texture,
+                                        GLuint destination_texture, GLuint auxilary_texture,
+                                        GLuint fbo, int width, int height) {
+	const int max_width = 1;
+	const int max_height = 1;
+	const int from_width = next_power_of_two(width);
+	const int from_height = next_power_of_two(height);
+	const int to_width = from_width > max_width ? from_width / 2 : from_width;
+	const int to_height = from_height > max_height ? from_height / 2 : from_height;
+
+	// Prepare coordinates
+	GLint coord[] = {
+		// top left
+		0, 0,                // vertex coord
+		0, 0,                // texture coord
+
+		// top right
+		to_width, 0,         // vertex coord
+		1, 0,                // texture coord
+
+		// bottom right
+		to_width, to_height, // vertex coord
+		1, 1,                // texture coord
+
+		// bottom left
+		0, to_height,        // vertex coord
+		0, 1,                // texture coord
+	};
+	glBufferSubData(GL_ARRAY_BUFFER, 0, (long)sizeof(*coord) * 16, coord);
+
+	// Prepare framebuffer for new render iteration
+	glBindTexture(GL_TEXTURE_2D, destination_texture);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, to_width, to_height, 0, GL_RGB, GL_UNSIGNED_BYTE, NULL);
+	glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, destination_texture, 0);
+
+	// Bind source texture as downscaling shader uniform input
+	glBindTexture(GL_TEXTURE_2D, source_texture);
+
+	// Render into framebuffer
+	glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, NULL);
+
+	// Have we downscaled enough?
+	GLuint result;
+	if (to_width > max_width || to_height > max_height) {
+		GLuint new_source_texture = destination_texture;
+		GLuint new_destination_texture = auxilary_texture != 0 ? auxilary_texture : source_texture;
+		result = _gl_average_texture_color(base, new_source_texture,
+		                                    new_destination_texture, 0,
+		                                    fbo, to_width, to_height);
+	} else {
+		result = destination_texture;
+	}
+
+	return result;
+}
+
+/*
+ * @brief Builds a 1x1 texture which has color corresponding to the average of all
+ * pixels of img by recursively rendering into texture of quorter the size (half
+ * width and half height).
+ * Returned texture must be deleted by the caller (use glDeleteTextures).
+ */
+static GLuint gl_average_texture_color(backend_t *base, struct gl_image *img) {
+
+	struct gl_data *gd = (void *)base;
+
+	// Prepare textures which will be used for destination and source of rendering
+	// during downscaling.
+	GLuint textures[2] = {0};
+	const int texture_count = sizeof(textures)/sizeof(textures[0]);
+	glGenTextures(texture_count, textures);
+	glActiveTexture(GL_TEXTURE0);
+	for (int i = 0; i < texture_count; i++) {
+		glBindTexture(GL_TEXTURE_2D, textures[i]);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_BORDER);
+		glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_BORDER);
+		glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_BORDER_COLOR, (GLint []){0, 0, 0, 0});
+	}
+
+	// Prepare framebuffer used for rendering and bind it
+	GLuint fbo;
+	glGenFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
+	glDrawBuffer(GL_COLOR_ATTACHMENT0);
+
+	// Enable shaders
+	glUseProgram(gd->brightness_shader.prog);
+
+	// Prepare vertex attributes
+	GLuint vao;
+	glGenVertexArrays(1, &vao);
+	glBindVertexArray(vao);
+	GLuint bo[2];
+	glGenBuffers(2, bo);
+	glBindBuffer(GL_ARRAY_BUFFER, bo[0]);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, bo[1]);
+	glEnableVertexAttribArray(vert_coord_loc);
+	glEnableVertexAttribArray(vert_in_texcoord_loc);
+	glVertexAttribPointer(vert_coord_loc, 2, GL_INT, GL_FALSE,
+	                      sizeof(GLint) * 4, NULL);
+	glVertexAttribPointer(vert_in_texcoord_loc, 2, GL_INT, GL_FALSE,
+	                      sizeof(GLint) * 4, (void *)(sizeof(GLint) * 2));
+
+	// Allocate buffers for render input
+	GLint coord[16] = {0};
+	GLuint indices[] = {0, 1, 2, 2, 3, 0};
+	glBufferData(GL_ARRAY_BUFFER, (long)sizeof(*coord) * 16, coord, GL_DYNAMIC_DRAW);
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, (long)sizeof(*indices) * 6, indices, GL_STATIC_DRAW);
+
+	// Do actual recursive render to 1x1 texture
+	GLuint result_texture = _gl_average_texture_color(base, img->inner->texture,
+	                                                   textures[0], textures[1],
+	                                                   fbo, img->inner->width,
+	                                                   img->inner->height);
+
+	// Cleanup vertex attributes
+	glDisableVertexAttribArray(vert_coord_loc);
+	glDisableVertexAttribArray(vert_in_texcoord_loc);
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+	glDeleteBuffers(2, bo);
+	glBindVertexArray(0);
+	glDeleteVertexArrays(1, &vao);
+
+	// Cleanup shaders
+	glUseProgram(0);
+
+	// Cleanup framebuffers
+	glDeleteFramebuffers(1, &fbo);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+	glDrawBuffer(GL_BACK);
+
+	// Cleanup render textures
+	glBindTexture(GL_TEXTURE_2D, 0);
+	for (int i = 0; i < texture_count; i++) {
+		if (result_texture != textures[i])
+			glDeleteTextures(1, &textures[i]);
+	}
+
+	gl_check_err();
+
+	return result_texture;
+}
+
 /**
  * Render a region with texture data.
  *
@@ -202,7 +361,9 @@ static void _gl_compose(backend_t *base, struct gl_image *img, GLuint target,
 		return;
 	}
 
-	bool dual_texture = false;
+	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);
@@ -218,17 +379,21 @@ static void _gl_compose(backend_t *base, struct gl_image *img, GLuint target,
 	if (gd->win_shader.unifm_dim >= 0) {
 		glUniform1f(gd->win_shader.unifm_dim, (float)img->dim);
 	}
+	if (gd->win_shader.unifm_brightness >= 0) {
+		glUniform1i(gd->win_shader.unifm_brightness, 1);
+	}
+	if (gd->win_shader.unifm_max_brightness >= 0) {
+		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",
 	//          x, y, width, height, dx, dy, ptex->width, ptex->height, z);
 
 	// Bind texture
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_2D, brightness);
+	glActiveTexture(GL_TEXTURE0);
 	glBindTexture(GL_TEXTURE_2D, img->inner->texture);
-	if (dual_texture) {
-		glActiveTexture(GL_TEXTURE1);
-		glBindTexture(GL_TEXTURE_2D, img->inner->texture);
-		glActiveTexture(GL_TEXTURE0);
-	}
 
 	GLuint vao;
 	glGenVertexArrays(1, &vao);
@@ -259,15 +424,10 @@ static void _gl_compose(backend_t *base, struct gl_image *img, GLuint target,
 	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 	glDrawBuffer(GL_BACK);
 
-	if (dual_texture) {
-		glActiveTexture(GL_TEXTURE1);
-		glBindTexture(GL_TEXTURE_2D, 0);
-		glActiveTexture(GL_TEXTURE0);
-	}
-
 	glBindBuffer(GL_ARRAY_BUFFER, 0);
 	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
 	glDeleteBuffers(2, bo);
+	glDeleteTextures(1, &brightness);
 
 	glUseProgram(0);
 
@@ -597,6 +757,8 @@ static int gl_win_shader_from_string(const char *vshader_str, const char *fshade
 	ret->unifm_invert_color = glGetUniformLocationChecked(ret->prog, "invert_color");
 	ret->unifm_tex = glGetUniformLocationChecked(ret->prog, "tex");
 	ret->unifm_dim = glGetUniformLocationChecked(ret->prog, "dim");
+	ret->unifm_brightness = glGetUniformLocationChecked(ret->prog, "brightness");
+	ret->unifm_max_brightness = glGetUniformLocationChecked(ret->prog, "max_brightness");
 
 	glUseProgram(ret->prog);
 	int orig_loc = glGetUniformLocation(ret->prog, "orig");
@@ -635,6 +797,10 @@ void gl_resize(struct gl_data *gd, int width, int height) {
 	pml = glGetUniformLocationChecked(gd->present_prog, "projection");
 	glUniformMatrix4fv(pml, 1, false, projection_matrix[0]);
 
+	glUseProgram(gd->brightness_shader.prog);
+	pml = glGetUniformLocationChecked(gd->brightness_shader.prog, "projection");
+	glUniformMatrix4fv(pml, 1, false, projection_matrix[0]);
+
 	glBindTexture(GL_TEXTURE_2D, gd->back_texture);
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, width, height, 0, GL_BGR,
 	             GL_UNSIGNED_BYTE, NULL);
@@ -665,6 +831,25 @@ static const char fill_vert[] = GLSL(330,
 		gl_Position = projection * vec4(in_coord, 0, 1);
 	}
 );
+
+static const char interpolating_frag[] = GLSL(330,
+	uniform sampler2D tex;
+	in vec2 texcoord;
+	void main() {
+		gl_FragColor = vec4(texture2D(tex, vec2(texcoord.xy), 0).rgb, 1);
+	}
+);
+
+static const char interpolating_vert[] = GLSL(330,
+	uniform mat4 projection;
+	layout(location = 0) in vec2 in_coord;
+	layout(location = 1) in vec2 in_texcoord;
+	out vec2 texcoord;
+	void main() {
+		gl_Position = projection * vec4(in_coord, 0, 1);
+		texcoord = in_texcoord;
+	}
+);
 // clang-format on
 
 /// Fill a given region in bound framebuffer.
@@ -960,6 +1145,8 @@ const char *win_shader_glsl = GLSL(330,
 	uniform bool invert_color;
 	in vec2 texcoord;
 	uniform sampler2D tex;
+	uniform sampler2D brightness;
+	uniform float max_brightness;
 
 	void main() {
 		vec4 c = texelFetch(tex, ivec2(texcoord), 0);
@@ -967,6 +1154,12 @@ const char *win_shader_glsl = GLSL(330,
 			c = vec4(c.aaa - c.rgb, c.a);
 		}
 		c = vec4(c.rgb * (1.0 - dim), c.a) * opacity;
+
+		vec3 rgb_brightness = texture2D(brightness, vec2(0.5, 0.5), 0).rgb;
+		float brightness = (rgb_brightness[0] + rgb_brightness[1] + rgb_brightness[2]) / 3;
+		if (brightness > max_brightness)
+			c.rgb = c.rgb * (max_brightness / brightness);
+
 		gl_FragColor = c;
 	}
 );
@@ -1026,6 +1219,15 @@ bool gl_init(struct gl_data *gd, session_t *ps) {
 	glUniform1i(glGetUniformLocationChecked(gd->present_prog, "tex"), 0);
 	glUseProgram(0);
 
+	gd->brightness_shader.prog = gl_create_program_from_str(interpolating_vert, interpolating_frag);
+	if (!gd->brightness_shader.prog) {
+		log_error("Failed to create the brightness shader");
+		return false;
+	}
+	glUseProgram(gd->brightness_shader.prog);
+	glUniform1i(glGetUniformLocationChecked(gd->brightness_shader.prog, "tex"), 0);
+	glUseProgram(0);
+
 	// Set up the size of the viewport. We do this last because it expects the blur
 	// textures are already set up.
 	gl_resize(gd, ps->root_width, ps->root_height);
@@ -1236,6 +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

@@ -20,8 +20,15 @@ typedef struct {
 	GLint unifm_invert_color;
 	GLint unifm_tex;
 	GLint unifm_dim;
+	GLint unifm_brightness;
+	GLint unifm_max_brightness;
 } gl_win_shader_t;
 
+// Program and uniforms for brightness shader
+typedef struct {
+	GLuint prog;
+} gl_brightness_shader_t;
+
 // Program and uniforms for blur shader
 typedef struct {
 	GLuint prog;
@@ -48,6 +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;
@@ -60,6 +68,7 @@ struct gl_data {
 	// Height and width of the viewport
 	int height, width;
 	gl_win_shader_t win_shader;
+	gl_brightness_shader_t brightness_shader;
 	gl_fill_shader_t fill_shader;
 	GLuint back_texture, back_fbo;
 	GLuint present_prog;

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);
 

src/utils.c

@@ -32,4 +32,20 @@ void report_allocation_failure(const char *func, const char *file, unsigned int
 	unreachable;
 }
 
+///
+/// Calculates next closest power of two of 32bit integer n
+/// ref: https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
+///
+int next_power_of_two(int n)
+{
+	n--;
+	n |= n >> 1;
+	n |= n >> 2;
+	n |= n >> 4;
+	n |= n >> 8;
+	n |= n >> 16;
+	n++;
+	return n;
+}
+
 // vim: set noet sw=8 ts=8 :

src/utils.h

@@ -261,4 +261,12 @@ allocchk_(const char *func_name, const char *file, unsigned int line, void *ptr)
 	void name##_ref(type *a);                                                        \
 	void name##_unref(type **a);
 
+
+///
+/// Calculates next closest power of two of 32bit integer n
+/// ref: https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
+///
+int next_power_of_two(int n);
+
+
 // vim: set noet sw=8 ts=8 :