README.md: Update according to ESP32 port

Surprisingly, esp-idf #includes files such as sys/types.h when pulling
other standard header files, even when not explicitly defined. While
this is not a serious issue, incredibly their sys/types.h implementation
uses "#define quad", therefore breaking user code such as anything
related to "struct quad".

README.md

@@ -112,7 +112,7 @@ building `enet`.
 A stripped version of the executable, as well as game assets, will be
 located in `build/cdimg`.
 
-#### Dependencies
+##### Dependencies
 
 A cross-compiled `i386-mingw32` version of all required dependencies
 is needed before building `jancity`.
@@ -126,6 +126,32 @@ of this writing, so it is provisionally provided on
 Read [the documentation](doc/BUILD-win9x.md) for further reference on
 how to build the dependencies from source.
 
+#### Espressif ESP32
+
+```sh
+. $IDF_PATH/export.sh
+ENETDIR=<enet-prefix> \
+    cmake -B build -DCMAKE_TOOLCHAIN_FILE=cmake/win9x-toolchain.cmake
+cmake --build build
+```
+
+Where:
+
+- `ENETDIR` is the path to the cross-compiled version for `enet`.
+
+##### Dependencies
+
+[`esp-idf`](https://github.com/espressif/esp-idf) is required to build this
+or any ESP32-related project. The `release/v5.1` branch is assumed here.
+As pointed out by
+[their documentation](https://docs.espressif.com/projects/esp-idf/en/v5.1.2/esp32/api-guides/build-system.html?highlight=idf_path#initialization),
+remember to assign the `IDF_PATH` environment variable to the directory
+where `esp-idf` is located.
+
+`esp-idf` requires to build `enet` using a custom CMake wrapper on top of it.
+For this project, this has been provided by the
+[`enet-esp32`](https://gitea.privatedns.org/xavi/enet-esp32) repository.
+
 ## License
 
 Unless stated otherwise, **jancity** follows the license described by the

cmake/FindGeekbit.cmake

@@ -0,0 +1,84 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+FindGeekbit
+-----------
+
+Find Geekbit (an open source software development kit for the Geekbit
+handheld video game console) libraries and header files.
+
+Imported targets
+^^^^^^^^^^^^^^^^
+
+This module defines the following :prop_tgt:`IMPORTED` targets:
+
+  ``geekbit::geekbit``,
+  The geekbit library, if found.
+
+Result variables
+^^^^^^^^^^^^^^^^
+
+This module will set the following variables in your project:
+
+``GEEKBIT_FOUND``
+  true if geekbit libraries and header files were found.
+``GEEKBIT_VERSION``
+  geekbit release version
+``GEEKBIT_INCLUDE_DIRS``
+  the directory containing the geekbit headers; note
+  ``GEEKBIT_INCLUDE_DIRS`` is also required
+``GEEKBIT_LIBRARIES``
+  geekbit libraries to be linked; note ``GEEKBIT_LIBRARIES`` is also
+  required
+
+#]=======================================================================]
+
+find_path(GEEKBIT_INCLUDE_DIRS
+    NAMES
+        geekbit/gb.h
+    HINTS
+        ENV GEEKBIT_PATH
+    PATH_SUFFIXES
+        include
+)
+
+find_library(GEEKBIT_LIBRARIES
+    NAMES geekbit
+    HINTS
+        ENV GEEKBIT_PATH
+    PATH_SUFFIXES
+        lib
+)
+
+# Header files are meant to be included as "geekbit/<file>.h". Therefore,
+# the "geekbit" directory must not be referred to by GEEKBIT_INCLUDE_DIRS.
+string(REGEX REPLACE "include/geekbit[/]*$"
+    "include" GEEKBIT_INCLUDE_DIRS ${GEEKBIT_INCLUDE_DIRS})
+
+if(GEEKBIT_INCLUDE_DIRS AND EXISTS "${GEEKBIT_INCLUDE_DIRS}/geekbit/version.h")
+    set(version_regex "^#define[ \t]+GEEKBIT_VERSION_STRING[ \t]+\"([0-9\.]+)\"$")
+    file(STRINGS "${GEEKBIT_INCLUDE_DIRS}/geekbit/version.h" GEEKBIT_VERSION_LINE REGEX ${version_regex})
+    string(REGEX REPLACE ${version_regex} "\\1" GEEKBIT_VERSION "${GEEKBIT_VERSION_LINE}")
+    unset(GEEKBIT_VERSION_LINE)
+    unset(version_regex)
+endif()
+
+include(FindPackageHandleStandardArgs)
+
+find_package_handle_standard_args(Geekbit
+    REQUIRED_VARS
+        GEEKBIT_LIBRARIES GEEKBIT_INCLUDE_DIRS
+    VERSION_VAR
+        GEEKBIT_VERSION
+)
+
+if(GEEKBIT_FOUND)
+    if(NOT TARGET Geekbit::Geekbit)
+        add_library(Geekbit::Geekbit INTERFACE IMPORTED)
+        target_include_directories(Geekbit::Geekbit
+            INTERFACE "${GEEKBIT_INCLUDE_DIRS}")
+        set_target_properties(Geekbit::Geekbit PROPERTIES
+            IMPORTED_LOCATION "${GEEKBIT_LIBRARIES}")
+    endif()
+endif()

cmake/esp32.cmake

@@ -1,3 +1,4 @@
+find_package(Geekbit 0.0.1 REQUIRED)
 set(cdroot ${CMAKE_BINARY_DIR})
 
 if(NOT DEFINED ENV{IDF_PATH})

src/CMakeLists.txt

@@ -35,7 +35,7 @@ set(interfaces
 
 target_compile_options(${PROJECT_NAME} PUBLIC ${cflags})
 # Dependencies for main.c
-target_link_libraries(${PROJECT_NAME} PRIVATE main system menu)
+target_link_libraries(${PROJECT_NAME} PRIVATE main)
 
 foreach(c ${components})
     add_subdirectory("${c}")

src/gfx/esp32/inc/gfx/port.h

@@ -3,6 +3,8 @@
 
 #include <stdbool.h>
 
+#undef quad
+
 #ifdef __cplusplus
 extern "C"
 {

src/gfx/esp32/src/quad.c

@@ -4,6 +4,8 @@
 #include <stddef.h>
 #include <stdlib.h>
 
+#undef quad
+
 int quad_from_sprite(const struct sprite *const s, struct quad *const q)
 {
     return -1;

src/gfx/inc/gfx.h

@@ -1,9 +1,9 @@
 #ifndef GFX_H
 #define GFX_H
 
-#include <gfx/port.h>
 #include <stdbool.h>
 #include <stdio.h>
+#include <gfx/port.h>
 
 #ifdef __cplusplus
 extern "C"

src/main/std/src/main.c

@@ -1,14 +1,6 @@
-#include <menu.h>
-#include <system.h>
-#include <stdlib.h>
+#include <engine_main.h>
 
 int main(void)
 {
-    int ret = EXIT_SUCCESS;
-
-    if (system_init() || menu())
-        ret = EXIT_FAILURE;
-
-    system_deinit();
-    return ret;
+    return engine_main();
 }

src/system/CMakeLists.txt

@@ -21,6 +21,7 @@ elseif(ESP32_BUILD)
     set(src "esp32/src/system.c")
     set(inc ${inc} "esp32/inc")
     set(privinc ${privinc} "esp32/privinc")
+    set(privdeps ${privdeps} Geekbit::Geekbit)
 endif()
 
 add_library(system ${src})

src/system/esp32/src/system.c

@@ -1,5 +1,6 @@
 #include <system.h>
 #include <system_private.h>
+#include <geekbit/gb.h>
 #include <gfx.h>
 #include <net.h>
 #include <sfx.h>
@@ -21,5 +22,5 @@ void system_deinit(void)
 
 int system_init(void)
 {
-    return -1;
+    return gb_init();
 }