Implement installed size representation.

README.rst

@@ -64,11 +64,13 @@ Usage
 
 Run ``pacwall``.
 
-The blue dots are manually (explicitly) installed packages, the red ones are
-automatically (implicitly) installed packages. The green dots are packages not found
-in the official non-testing repositories (e.g. from the AUR). The outlined teal dots
-are orphans, the outlined yellow dots are outdated packages. The outlined magenta
-dots are packages with unresolved `.pacnew files`_ (it's time to run ``pacdiff``).
+The circles represent packages, where the area of a circle is proportional to the
+size of the package.
+The blue circles are manually (explicitly) installed packages, the red ones are
+automatically (implicitly) installed packages. The green circles are packages not found
+in the official non-testing repositories (e.g. from the AUR). The outlined teal circles
+are orphans, the outlined yellow circles are outdated packages. The outlined magenta
+circles are packages with unresolved `.pacnew files`_ (it's time to run ``pacdiff``).
 The dashed edges represent optional dependencies, the normal edges represent strict
 (hard, direct) dependencies. The appearance is customizable, see Customization_.
 
@@ -253,6 +255,26 @@ List of settings
 
       The attributes that are applied to optional dependencies (separated by commas).
 
+* ``features`` (group)
+
+  The group that contains settings that control optional features.
+
+  * ``installed-size`` (group) (default::
+
+        enabled: true
+        delta: 2e-5
+    )
+
+    The group that contains settings that control the installed size representation
+    feature. If ``enabled`` is true, the ``height`` and ``width`` attributes of nodes
+    are overwritten so that the area covered by a node is proportional to the size of
+    the installed package. The formula is::
+
+        width in inches = height in inches = (installed size in bytes)^(1/2) * delta
+
+    Note that the values of these settings are not strings and omit the quotes enclosing
+    them.
+
 ---------------
 Tips and tricks
 ---------------

src/Makefile

@@ -2,7 +2,7 @@ DEPS = libalpm libconfig
 
 CFLAGS ?= -g -Wall
 CFLAGS += $(shell pkg-config --cflags $(DEPS))
-LDLIBS += $(shell pkg-config --libs-only-l $(DEPS))
+LDLIBS += $(shell pkg-config --libs-only-l $(DEPS)) -lm
 LDFLAGS += $(shell pkg-config --libs-only-other $(DEPS))
 
 pacwall: pacwall.o generate.o opts.o

src/generate.c

@@ -1,6 +1,7 @@
 #include "generate.h"
 #include "util.h"
 #include <alpm.h>
+#include <math.h>
 #include <unistd.h>
 
 static void write_updates(FILE *file, const struct opts *opts) {
@@ -127,6 +128,13 @@ void generate_graph(pid_t fetch_pid, const struct opts *opts) {
                     opts->attributes.dependency.optional);
         }
 
+        /* Installed size representation */
+        if (opts->features.installed_size.enabled) {
+            double size =
+                sqrt(alpm_pkg_get_isize(pkg)) * opts->features.installed_size.delta;
+            fprintf(file, "\"%s\" [width=%lf, height=%lf];\n", name, size, size);
+        }
+
         FREELIST(requiredby);
         FREELIST(optionalfor);
     }

src/opts.c

@@ -82,6 +82,12 @@ struct opts parse_opts(int argc, char **argv) {
                 .optional = "arrowhead=empty, style=dashed",
             }
         },
+        .features = {
+            .installed_size = {
+                .enabled = 1,
+                .delta = 2e-5
+            }
+        },
         ._skip_fetch = 0,
         ._skip_generate = 0,
         ._skip_hook = 0
@@ -154,6 +160,12 @@ struct opts parse_opts(int argc, char **argv) {
             "color=\"#859900aa\"";
     }
 
+    /* Parsing the features group */
+    config_lookup_bool(&cfg, "features.installed-size.enabled",
+                       &opts.features.installed_size.enabled);
+    config_lookup_float(&cfg, "features.installed-size.delta",
+                        &opts.features.installed_size.delta);
+
     config_destroy(&cfg);
 
     parse_cli_opts(&opts, argc, argv);

src/opts.h

@@ -32,6 +32,12 @@ struct opts {
             const char *optional;
         } dependency;
     } attributes;
+    struct {
+        struct {
+            int enabled;
+            double delta;
+        } installed_size;
+    } features;
     int _skip_fetch;
     int _skip_generate;
     int _skip_hook;