Align to OTP 24

.gitignore

@@ -3,10 +3,7 @@ log
 logs
 _build
 
-doc/specs/
-doc/src/egd.xml
-doc/src/egd_ug.xml
-doc/src/ref_man.xml
+/doc/
 
 .rebar3
 _*

CHANGELOG.md

@@ -0,0 +1,14 @@
+# Change log
+
+## Version 0.10.1 (February 09, 2025)
+
+- Align to OTP 24: use `erlang:crc32/1` instead of `zlib:crc32/2`, as the later
+  one has been deprecated in OTP 24 and was removed in OTP 27.
+- Convert documentation from `erl_docgen` style XML files to `ex_doc` style
+  Markdown files.
+
+## Previous versions
+
+- 0.10.0: Add `egd_font:load_binary/1`
+- 0.9.1: Reinstate `priv_dir` with fonts
+- 0.9.0: Initial commit or [erlang/egd](https://github.com/erlang/egd)

README.md

@@ -1,10 +1,128 @@
-Erlang Graphical Drawer
-=====
+# Erlang Graphical Drawer
 
-Erlang Graphical Drawer is an interface for 2d-image rendering and is used by Percept to generate dynamic graphs to its web
-pages. All code is pure erlang, no drivers needed.
+Erlang Graphical Drawer ([egd](https://github.com/erlang/egd)) is an interface
+for 2d-image rendering and is used by
+[Percept](https://github.com/erlang/percept) to generate dynamic graphs to
+its web pages. All code is pure Erlang, no drivers needed.
 
-Build
------
+The library is intended for small to medium image sizes with low complexity for
+optimal performance. The library handles horizontal lines better then vertical
+lines.
 
-    $ rebar3 compile
+The foremost purpose for this module is to enable users to generate images from
+Erlang code and/or datasets and to send these images to either files or web
+servers.
+
+## File example
+
+Drawing examples:
+
+```erlang
+-module(img).
+
+-export([do/0]).
+
+do() ->
+    Im = egd:create(200,200),
+    Red = egd:color({255,0,0}),
+    Green = egd:color({0,255,0}),
+    Blue = egd:color({0,0,255}),
+    Black = egd:color({0,0,0}),
+    Yellow = egd:color({255,255,0}),
+
+    % Line and fillRectangle
+
+    egd:filledRectangle(Im, {20,20}, {180,180}, Red),
+    egd:line(Im, {0,0}, {200,200}, Black),
+
+    egd:save(egd:render(Im, png), "test1.png"),
+
+    egd:filledEllipse(Im, {45, 60}, {55, 70}, Yellow),
+    egd:filledEllipse(Im, {145, 60}, {155, 70}, Blue),
+
+    egd:save(egd:render(Im, png), "test2.png"),
+
+    R = 80,
+    X0 = 99,
+    Y0 = 99,
+
+    Pts = [ {X0 + trunc(R*math:cos(A*math:pi()*2/360)),
+             Y0 + trunc(R*math:sin(A*math:pi()*2/360))
+            } || A <- lists:seq(0,359,5)],
+    lists:map(
+        fun({X,Y}) ->
+            egd:rectangle(Im, {X-5, Y-5}, {X+5,Y+5}, Green)
+        end, Pts), 
+
+    egd:save(egd:render(Im, png), "test3.png"),
+
+    % Text
+    Filename = filename:join([code:priv_dir(egd), "fonts", "6x11_latin1.wingsfont"]),
+    Font = egd_font:load(Filename),
+    {W,H} = egd_font:size(Font),
+    String = "egd says hello",
+    Length = length(String),
+
+    egd:text(Im, {round(100 - W*Length/2), 200 - H - 5}, Font, String, Black),
+
+    egd:save(egd:render(Im, png), "test4.png"),
+
+    egd:destroy(Im).
+```
+
+First save:
+
+![test1.png](assets/test1.gif)
+
+Second save:
+
+![test2.png](assets/test2.gif)
+
+Third save:
+
+![test3.png](assets/test3.gif)
+
+Fourth save:
+
+![test4.png](assets/test4.gif)
+
+## ESI example
+
+Using `egd` with [inets](https://www.erlang.org/doc/apps/inets/) ESI to generate
+images on the fly:
+
+```erlang
+-module(img_esi).
+
+-export([image/3]).
+
+image(SessionID, _Env, _Input) ->
+    mod_esi:deliver(SessionID, header()),
+    Binary = my_image(),
+    mod_esi:deliver(SessionID, binary_to_list(Binary)).
+
+my_image() ->
+    Im = egd:create(300,20),
+    Black = egd:color({0,0,0}),
+    Red = egd:color({255,0,0}),
+    egd:filledRectangle(Im, {30,14}, {270,19}, Red),
+    egd:rectangle(Im, {30,14}, {270,19}, Black),
+
+    Filename = filename:join([code:priv_dir(egd), "fonts", "6x11_latin1.wingsfont"]),
+    Font = egd_font:load(Filename),
+    egd:text(Im, {30, 0}, Font, "egd with esi callback", Black),
+    Bin = egd:render(Im, png),
+    egd:destroy(Im),
+    Bin.
+
+header() ->
+    "Content-Type: image/png\r\n\r\n".
+```
+
+Result:
+
+![Example of result](assets/img_esi_result.gif)
+
+For more information regarding ESI, please see
+[inets](https://www.erlang.org/doc/apps/inets/) application
+[mod_esi](https://www.erlang.org/doc/apps/inets/mod_esi.html#).