dual_kawase improved blur kernel

README.md

@@ -4,6 +4,10 @@
 
 __Compton__ is a compositor for X, and a fork of __xcompmgr-dana__.
 
+This branch includes a new blur method: The multi-pass **dual kawase blur**!
+Use it with the `--blur-method kawase` and `--blur-strength LEVEL` options.
+Only works with the `glx` backend!
+
 I was frustrated by the low amount of standalone lightweight compositors.
 Compton was forked from Dana Jansens' fork of xcompmgr and refactored.  I fixed
 whatever bug I found, and added features I wanted. Things seem stable, but don't

compton.sample.conf

@@ -32,6 +32,8 @@ alpha-step = 0.06;
 # inactive-dim-fixed = true;
 # blur-background = true;
 # blur-background-frame = true;
+blur-method = "kawase";
+# blur-strength = 15;
 blur-kern = "3x3box";
 # blur-kern = "5,5,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1";
 # blur-background-fixed = true;

man/compton.1.asciidoc

@@ -205,7 +205,17 @@ OPTIONS
 *--blur-background-fixed*::
 	Use fixed blur strength rather than adjusting according to window opacity.
 
+*--blur-method* 'ALGORITHM'::
+	Specify the algorithm for background blur. It is either one of: `convolution` (default), `kawase`.
++
+Note: `kawase` only works with the `glx` backend.
+
+*--blur-strength* 'LEVEL'::
+	Only valid for *--blur-method kawase*!
+	The strength of the kawase blur as an integer between 1 and 20. Defaults to 5.
+
 *--blur-kern* 'MATRIX'::
+	Only valid for *--blur-method convolution*!
 	Specify the blur convolution kernel, with the following format:
 +
 ----

src/common.h

@@ -229,7 +229,7 @@
 #define CGLX_MAX_BUFFER_AGE 5
 
 /// @brief Maximum passes for blur.
-#define MAX_BLUR_PASS 5
+#define MAX_BLUR_PASS 6
 
 // Window flags
 
@@ -352,6 +352,13 @@ typedef enum {
   NUM_VSYNC,
 } vsync_t;
 
+/// Possible background blur algorithms.
+enum blur_method {
+    BLRMTHD_CONV,
+    BLRMTHD_KAWASE,
+    NUM_BLRMTHD,
+};
+
 /// @brief Possible backends of compton.
 enum backend {
   BKEND_XRENDER,
@@ -467,19 +474,25 @@ typedef struct {
   GLuint frag_shader;
   /// GLSL program for blur.
   GLuint prog;
-  /// Location of uniform "offset_x" in blur GLSL program.
+  /// Location of uniform "offset_x" in conv-blur GLSL program.
   GLint unifm_offset_x;
-  /// Location of uniform "offset_y" in blur GLSL program.
+  /// Location of uniform "offset_y" in conv-blur GLSL program.
   GLint unifm_offset_y;
-  /// Location of uniform "factor_center" in blur GLSL program.
+  /// Location of uniform "factor_center" in conv-blur GLSL program.
   GLint unifm_factor_center;
+  /// Location of uniform "offset" in kawase-blur GLSL program.
+  GLint unifm_offset;
+  /// Location of uniform "halfpixel" in kawase-blur GLSL program.
+  GLint unifm_halfpixel;
+  /// Location of uniform "fulltex" in kawase-blur GLSL program.
+  GLint unifm_fulltex;
 } glx_blur_pass_t;
 
 typedef struct {
   /// Framebuffer used for blurring.
   GLuint fbo;
   /// Textures used for blurring.
-  GLuint textures[2];
+  GLuint textures[MAX_BLUR_PASS];
   /// Width of the textures.
   int width;
   /// Height of the textures.
@@ -538,6 +551,11 @@ struct _timeout_t;
 
 struct _win;
 
+typedef struct {
+  int iterations;
+  float offset;
+} blur_strength_t;
+
 typedef struct _c2_lptr c2_lptr_t;
 
 /// Structure representing all options.
@@ -707,8 +725,12 @@ typedef struct _options_t {
   bool blur_background_fixed;
   /// Background blur blacklist. A linked list of conditions.
   c2_lptr_t *blur_background_blacklist;
+  /// Blur method.
+  enum blur_method blur_method;
   /// Blur convolution kernel.
   XFixed *blur_kerns[MAX_BLUR_PASS];
+  /// Blur strength.
+  blur_strength_t blur_strength;
   /// How much to dim an inactive window. 0.0 - 1.0, 0 to disable.
   double inactive_dim;
   /// Whether to use fixed inactive dim opacity, instead of deciding
@@ -1263,6 +1285,7 @@ typedef enum {
 extern const char * const WINTYPES[NUM_WINTYPES];
 extern const char * const VSYNC_STRS[NUM_VSYNC + 1];
 extern const char * const BACKEND_STRS[NUM_BKEND + 1];
+extern const char * const BLUR_METHOD_STRS[NUM_BLRMTHD + 1];
 extern session_t *ps_g;
 
 // == Debugging code ==
@@ -1668,6 +1691,58 @@ parse_vsync(session_t *ps, const char *str) {
   return false;
 }
 
+/**
+ * Parse a blur_method option argument.
+ */
+static inline bool
+parse_blur_method(session_t *ps, const char *str) {
+  for (enum blur_method i = 0; BLUR_METHOD_STRS[i]; ++i)
+    if (!strcasecmp(str, BLUR_METHOD_STRS[i])) {
+      ps->o.blur_method = i;
+      return true;
+    }
+
+  printf_errf("(\"%s\"): Invalid blur_method argument.", str);
+  return false;
+}
+
+/**
+ * Parse a blur_strength option argument.
+ */
+static inline bool
+parse_blur_strength(session_t *ps, const int level) {
+  static const blur_strength_t values[20] = {
+    { .iterations = 1, .offset = 1.5 },     // 1
+    { .iterations = 1, .offset = 2.0 },     // 2
+    { .iterations = 2, .offset = 2.5 },     // 3
+    { .iterations = 2, .offset = 3.0 },     // 4
+    { .iterations = 3, .offset = 2.75 },    // 5
+    { .iterations = 3, .offset = 3.5 },     // 6
+    { .iterations = 3, .offset = 4.25 },    // 7
+    { .iterations = 3, .offset = 5.0 },     // 8
+    { .iterations = 4, .offset = 3.71429 }, // 9
+    { .iterations = 4, .offset = 4.42857 }, // 10
+    { .iterations = 4, .offset = 5.14286 }, // 11
+    { .iterations = 4, .offset = 5.85714 }, // 12
+    { .iterations = 4, .offset = 6.57143 }, // 13
+    { .iterations = 4, .offset = 7.28571 }, // 14
+    { .iterations = 4, .offset = 8.0 },     // 15
+    { .iterations = 5, .offset = 6.0 },     // 16
+    { .iterations = 5, .offset = 7.0 },     // 17
+    { .iterations = 5, .offset = 8.0 },     // 18
+    { .iterations = 5, .offset = 9.0 },     // 19
+    { .iterations = 5, .offset = 10.0 },    // 20
+  };
+
+  if (level < 1 || level > 20) {
+    printf_errf("(\"%d\"): Invalid blur_strength argument. Needs to be a number between 1 and 20.", level);
+    return false;
+  }
+
+  ps->o.blur_strength = values[level - 1];
+  return true;
+}
+
 /**
  * Parse a backend option argument.
  */
@@ -2276,8 +2351,8 @@ free_glx_fbo(session_t *ps, GLuint *pfbo) {
  */
 static inline void
 free_glx_bc_resize(session_t *ps, glx_blur_cache_t *pbc) {
-  free_texture_r(ps, &pbc->textures[0]);
-  free_texture_r(ps, &pbc->textures[1]);
+  for (int i = 0; i < MAX_BLUR_PASS; i++)
+    free_texture_r(ps, &pbc->textures[i]);
   pbc->width = 0;
   pbc->height = 0;
 }

src/compton.c

@@ -43,6 +43,13 @@ const char * const VSYNC_STRS[NUM_VSYNC + 1] = {
   NULL
 };
 
+/// Names of blur_methods.
+const char * const BLUR_METHOD_STRS[NUM_BLRMTHD + 1] = {
+    "convolution",    // BLRMTHD_CONV
+    "kawase",         // BLRMTHD_KAWASE
+    NULL
+};
+
 /// Names of backends.
 const char * const BACKEND_STRS[NUM_BKEND + 1] = {
   "xrender",      // BKEND_XRENDER
@@ -4699,7 +4706,16 @@ usage(int ret) {
     "  Use fixed blur strength instead of adjusting according to window\n"
     "  opacity.\n"
     "\n"
+    "--blur-method algorithm\n"
+    "  Specify the algorithm for background blur. It is either one of:\n"
+    "    convolution (default), kawase\n"
+    "\n"
+    "--blur-strength level\n"
+    "  Only valid for '--blur-method kawase'!\n"
+    "  The strength of the kawase blur as an integer between 1 and 20. Defaults to 5.\n"
+    "\n"
     "--blur-kern matrix\n"
+    "  Only valid for '--blur-method convolution'!\n"
     "  Specify the blur convolution kernel, with the following format:\n"
     "    WIDTH,HEIGHT,ELE1,ELE2,ELE3,ELE4,ELE5...\n"
     "  The element in the center must not be included, it will be forever\n"
@@ -5618,6 +5634,14 @@ parse_config(session_t *ps, struct options_tmp *pcfgtmp) {
   // --blur-background-fixed
   lcfg_lookup_bool(&cfg, "blur-background-fixed",
       &ps->o.blur_background_fixed);
+  // --blur-method
+  if (config_lookup_string(&cfg, "blur-method", &sval)
+      && !parse_blur_method(ps, sval))
+    exit(1);
+  // --blur-strength
+  if (lcfg_lookup_int(&cfg, "blur-strength", &ival)
+      && !parse_blur_strength(ps, ival))
+    exit(1);
   // --blur-kern
   if (config_lookup_string(&cfg, "blur-kern", &sval)
       && !parse_conv_kern_lst(ps, sval, ps->o.blur_kerns, MAX_BLUR_PASS))
@@ -5756,6 +5780,8 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
     { "version", no_argument, NULL, 318 },
     { "no-x-selection", no_argument, NULL, 319 },
     { "no-name-pixmap", no_argument, NULL, 320 },
+    { "blur-method", required_argument, NULL, 321 },
+    { "blur-strength", required_argument, NULL, 322 },
     { "reredir-on-root-change", no_argument, NULL, 731 },
     { "glx-reinit-on-root-change", no_argument, NULL, 732 },
     // Must terminate with a NULL entry
@@ -6027,6 +6053,16 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
         ps->o.glx_fshader_win_str = mstrcpy(optarg);
         break;
       P_CASEBOOL(319, no_x_selection);
+      case 321:
+        // --blur-method
+        if (!parse_blur_method(ps, optarg))
+          exit(1);
+        break;
+      case 322:
+        // --blur-strength
+        if (!parse_blur_strength(ps, strtol(optarg, NULL, 0)))
+          exit(1);
+        break;
       P_CASEBOOL(731, reredir_on_root_change);
       P_CASEBOOL(732, glx_reinit_on_root_change);
       default:
@@ -6091,8 +6127,14 @@ get_cfg(session_t *ps, int argc, char *const *argv, bool first_pass) {
     ps->o.track_leader = true;
   }
 
+  // Blur method kawase is not compatible with the xrender backend
+  if (ps->o.backend != BKEND_GLX && ps->o.blur_method == BLRMTHD_KAWASE) {
+      printf_errf("(): Blur method 'kawase' is incompatible with the XRender backend. Fall back to default.\n");
+      ps->o.blur_method = BLRMTHD_CONV;
+  }
+
   // Fill default blur kernel
-  if (ps->o.blur_background && !ps->o.blur_kerns[0]) {
+  if (ps->o.blur_background && (BLRMTHD_CONV == ps->o.blur_method) && !ps->o.blur_kerns[0]) {
     // Convolution filter parameter (box blur)
     // gaussian or binomial filters are definitely superior, yet looks
     // like they aren't supported as of xorg-server-1.13.0
@@ -7031,7 +7073,9 @@ session_init(session_t *ps_old, int argc, char **argv) {
       .blur_background_frame = false,
       .blur_background_fixed = false,
       .blur_background_blacklist = NULL,
+      .blur_method = BLRMTHD_CONV,
       .blur_kerns = { NULL },
+      .blur_strength = { .iterations = 3, .offset = 2.75 },
       .inactive_dim = 0.0,
       .inactive_dim_fixed = false,
       .invert_color_list = NULL,