feature: Rework network y-axis, linear interpolation for off-screen data (#437)

Rewrite of the y-axis labeling and scaling for the network widget, along with more customization. This still has one step to be optimized (cache results so we don't have to recalculate the legend each time), but will be done in another PR for sake of this one being too large already.

Furthermore, this change adds linear interpolation at the 0 point in the case a data point shoots too far back - this seems to have lead to ugly gaps to the left of graphs in some cases, because the left hand limit was not big enough for the data point. We address this by grabbing values just outside the time range and linearly interpolating at the leftmost limit. This affects all graph widgets (CPU, mem, network).

This can be optimized, and will hopefully be prior to release in a separate change.

1 files changed, 40 insertions, 34 deletions

diff --git a/README.md b/README.md
index 41205417..74774cc5 100644
--- a/README.md
+++ b/README.md
@@ -128,7 +128,7 @@ Or, you can just download the binary from the [latest release](https://github.co
 
 ### Nightly
 
-You can install pre-release nightly versions [here](https://github.com/ClementTsang/bottom/releases/tag/nightly).  Builds are generated every day at 00:00 UTC, based on the most recent commit on the master branch.
+You can install pre-release nightly versions [here](https://github.com/ClementTsang/bottom/releases/tag/nightly). Builds are generated every day at 00:00 UTC, based on the most recent commit on the master branch.
 
 ### Cargo
 
@@ -252,38 +252,41 @@ Run using `btm`.
 Use `btm --help` for more information.
 
 ```
-    --advanced_kill                        Shows more options when killing a process on Unix-like systems.
-    --autohide_time                        Temporarily shows the time scale in graphs.
--b, --basic                                Hides graphs and uses a more basic look.
-    --battery                              Shows the battery widget.
--S, --case_sensitive                       Enables case sensitivity by default.
--c, --celsius                              Sets the temperature type to Celsius.
-    --color <COLOR SCHEME>                 Use a color scheme, use --help for supported values.
--C, --config <CONFIG PATH>                 Sets the location of the config file.
--u, --current_usage                        Sets process CPU% to be based on current CPU%.
--t, --default_time_value <MS>              Default time value for graphs in ms.
-    --default_widget_count <INT>           Sets the n'th selected widget type as the default.
-    --default_widget_type <WIDGET TYPE>    Sets the default widget type, use --help for more info.
-    --disable_click                        Disables mouse clicks.
--m, --dot_marker                           Uses a dot marker for graphs.
--f, --fahrenheit                           Sets the temperature type to Fahrenheit.
--g, --group                                Groups processes with the same name by default.
--h, --help                                 Prints help information.  Use --help for more info.
--a, --hide_avg_cpu                         Hides the average CPU usage.
-    --hide_table_gap                       Hides the spacing between table headers and entries.
-    --hide_time                            Completely hides the time scaling.
--k, --kelvin                               Sets the temperature type to Kelvin.
--l, --left_legend                          Puts the CPU chart legend to the left side.
-    --mem_as_value                         Defaults to showing process memory usage by value.
-    --process_command                      Show processes as their commands by default.
--r, --rate <MS>                            Sets a refresh rate in ms.
--R, --regex                                Enables regex by default.
-    --show_table_scroll_position           Shows the scroll position tracker in table widgets.
--d, --time_delta <MS>                      The amount in ms changed upon zooming.
--T, --tree                                 Defaults to showing the process widget in tree mode.
-    --use_old_network_legend               DEPRECATED - uses the older network legend.
--V, --version                              Prints version information.
--W, --whole_word                           Enables whole-word matching by default.
+        --advanced_kill                        Shows more options when killing a process on Unix-like systems.
+        --autohide_time                        Temporarily shows the time scale in graphs.
+    -b, --basic                                Hides graphs and uses a more basic look.
+        --battery                              Shows the battery widget.
+    -S, --case_sensitive                       Enables case sensitivity by default.
+    -c, --celsius                              Sets the temperature type to Celsius.
+        --color <COLOR SCHEME>                 Use a color scheme, use --help for supported values.
+    -C, --config <CONFIG PATH>                 Sets the location of the config file.
+    -u, --current_usage                        Sets process CPU% to be based on current CPU%.
+    -t, --default_time_value <MS>              Default time value for graphs in ms.
+        --default_widget_count <INT>           Sets the n'th selected widget type as the default.
+        --default_widget_type <WIDGET TYPE>    Sets the default widget type, use --help for more info.
+        --disable_click                        Disables mouse clicks.
+    -m, --dot_marker                           Uses a dot marker for graphs.
+    -f, --fahrenheit                           Sets the temperature type to Fahrenheit.
+    -g, --group                                Groups processes with the same name by default.
+    -h, --help                                 Prints help information.  Use --help for more info.
+    -a, --hide_avg_cpu                         Hides the average CPU usage.
+        --hide_table_gap                       Hides the spacing between table headers and entries.
+        --hide_time                            Completely hides the time scaling.
+    -k, --kelvin                               Sets the temperature type to Kelvin.
+    -l, --left_legend                          Puts the CPU chart legend to the left side.
+        --mem_as_value                         Defaults to showing process memory usage by value.
+        --network_use_binary_prefix            Displays the network widget with binary prefixes.
+        --network_use_bytes                    Displays the network widget using bytes.
+        --network_use_log                      Displays the network widget with a log scale.
+        --process_command                      Show processes as their commands by default.
+    -r, --rate <MS>                            Sets a refresh rate in ms.
+    -R, --regex                                Enables regex by default.
+        --show_table_scroll_position           Shows the scroll position tracker in table widgets.
+    -d, --time_delta <MS>                      The amount in ms changed upon zooming.
+    -T, --tree                                 Defaults to showing the process widget in tree mode.
+        --use_old_network_legend               DEPRECATED - uses the older network legend.
+    -V, --version                              Prints version information.
+    -W, --whole_word                           Enables whole-word matching by default.
 ```
 
 ### Keybindings
@@ -464,7 +467,7 @@ As yet _another_ process/system visualization and management application, bottom
 
 - RAM and swap usage visualization
 
-- Network visualization for receiving and transmitting, on a log-graph scale
+- Network visualization for receiving and transmitting
 
 - Display information about disk capacity and I/O per second
 
@@ -599,6 +602,9 @@ These are the following supported flag config values, which correspond to the fl
 | `show_table_scroll_position` | Boolean                                                                                        | Shows the scroll position tracker in table widgets.             |
 | `process_command`            | Boolean                                                                                        | Show processes as their commands by default.                    |
 | `advanced_kill`              | Boolean                                                                                        | Shows more options when killing a process on Unix-like systems. |
+| `network_use_binary_prefix`  | Boolean                                                                                        | Displays the network widget with binary prefixes.               |
+| `network_use_bytes`          | Boolean                                                                                        | Displays the network widget using bytes.                        |
+| `network_use_log`            | Boolean                                                                                        | Displays the network widget with a log scale.                   |
 
 #### Theming