RPG starting point

Signed-off-by: magic_rb <richard@brezak.sk>

COPYING

@@ -0,0 +1,674 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU General Public License is a free, copyleft license for
+software and other kinds of works.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+the GNU General Public License is intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.  We, the Free Software Foundation, use the
+GNU General Public License for most of our software; it applies also to
+any other work released this way by its authors.  You can apply it to
+your programs, too.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+  To protect your rights, we need to prevent others from denying you
+these rights or asking you to surrender the rights.  Therefore, you have
+certain responsibilities if you distribute copies of the software, or if
+you modify it: responsibilities to respect the freedom of others.
+
+  For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must pass on to the recipients the same
+freedoms that you received.  You must make sure that they, too, receive
+or can get the source code.  And you must show them these terms so they
+know their rights.
+
+  Developers that use the GNU GPL protect your rights with two steps:
+(1) assert copyright on the software, and (2) offer you this License
+giving you legal permission to copy, distribute and/or modify it.
+
+  For the developers' and authors' protection, the GPL clearly explains
+that there is no warranty for this free software.  For both users' and
+authors' sake, the GPL requires that modified versions be marked as
+changed, so that their problems will not be attributed erroneously to
+authors of previous versions.
+
+  Some devices are designed to deny users access to install or run
+modified versions of the software inside them, although the manufacturer
+can do so.  This is fundamentally incompatible with the aim of
+protecting users' freedom to change the software.  The systematic
+pattern of such abuse occurs in the area of products for individuals to
+use, which is precisely where it is most unacceptable.  Therefore, we
+have designed this version of the GPL to prohibit the practice for those
+products.  If such problems arise substantially in other domains, we
+stand ready to extend this provision to those domains in future versions
+of the GPL, as needed to protect the freedom of users.
+
+  Finally, every program is threatened constantly by software patents.
+States should not allow patents to restrict development and use of
+software on general-purpose computers, but in those that do, we wish to
+avoid the special danger that patents applied to a free program could
+make it effectively proprietary.  To prevent this, the GPL assures that
+patents cannot be used to render the program non-free.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
+  0. Definitions.
+
+  "This License" refers to version 3 of the GNU General Public License.
+
+  "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+
+  "The Program" refers to any copyrightable work licensed under this
+License.  Each licensee is addressed as "you".  "Licensees" and
+"recipients" may be individuals or organizations.
+
+  To "modify" a work means to copy from or adapt all or part of the work
+in a fashion requiring copyright permission, other than the making of an
+exact copy.  The resulting work is called a "modified version" of the
+earlier work or a work "based on" the earlier work.
+
+  A "covered work" means either the unmodified Program or a work based
+on the Program.
+
+  To "propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy.  Propagation includes copying,
+distribution (with or without modification), making available to the
+public, and in some countries other activities as well.
+
+  To "convey" a work means any kind of propagation that enables other
+parties to make or receive copies.  Mere interaction with a user through
+a computer network, with no transfer of a copy, is not conveying.
+
+  An interactive user interface displays "Appropriate Legal Notices"
+to the extent that it includes a convenient and prominently visible
+feature that (1) displays an appropriate copyright notice, and (2)
+tells the user that there is no warranty for the work (except to the
+extent that warranties are provided), that licensees may convey the
+work under this License, and how to view a copy of this License.  If
+the interface presents a list of user commands or options, such as a
+menu, a prominent item in the list meets this criterion.
+
+  1. Source Code.
+
+  The "source code" for a work means the preferred form of the work
+for making modifications to it.  "Object code" means any non-source
+form of a work.
+
+  A "Standard Interface" means an interface that either is an official
+standard defined by a recognized standards body, or, in the case of
+interfaces specified for a particular programming language, one that
+is widely used among developers working in that language.
+
+  The "System Libraries" of an executable work include anything, other
+than the work as a whole, that (a) is included in the normal form of
+packaging a Major Component, but which is not part of that Major
+Component, and (b) serves only to enable use of the work with that
+Major Component, or to implement a Standard Interface for which an
+implementation is available to the public in source code form.  A
+"Major Component", in this context, means a major essential component
+(kernel, window system, and so on) of the specific operating system
+(if any) on which the executable work runs, or a compiler used to
+produce the work, or an object code interpreter used to run it.
+
+  The "Corresponding Source" for a work in object code form means all
+the source code needed to generate, install, and (for an executable
+work) run the object code and to modify the work, including scripts to
+control those activities.  However, it does not include the work's
+System Libraries, or general-purpose tools or generally available free
+programs which are used unmodified in performing those activities but
+which are not part of the work.  For example, Corresponding Source
+includes interface definition files associated with source files for
+the work, and the source code for shared libraries and dynamically
+linked subprograms that the work is specifically designed to require,
+such as by intimate data communication or control flow between those
+subprograms and other parts of the work.
+
+  The Corresponding Source need not include anything that users
+can regenerate automatically from other parts of the Corresponding
+Source.
+
+  The Corresponding Source for a work in source code form is that
+same work.
+
+  2. Basic Permissions.
+
+  All rights granted under this License are granted for the term of
+copyright on the Program, and are irrevocable provided the stated
+conditions are met.  This License explicitly affirms your unlimited
+permission to run the unmodified Program.  The output from running a
+covered work is covered by this License only if the output, given its
+content, constitutes a covered work.  This License acknowledges your
+rights of fair use or other equivalent, as provided by copyright law.
+
+  You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remains
+in force.  You may convey covered works to others for the sole purpose
+of having them make modifications exclusively for you, or provide you
+with facilities for running those works, provided that you comply with
+the terms of this License in conveying all material for which you do
+not control copyright.  Those thus making or running the covered works
+for you must do so exclusively on your behalf, under your direction
+and control, on terms that prohibit them from making any copies of
+your copyrighted material outside their relationship with you.
+
+  Conveying under any other circumstances is permitted solely under
+the conditions stated below.  Sublicensing is not allowed; section 10
+makes it unnecessary.
+
+  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
+
+  No covered work shall be deemed part of an effective technological
+measure under any applicable law fulfilling obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+measures.
+
+  When you convey a covered work, you waive any legal power to forbid
+circumvention of technological measures to the extent such circumvention
+is effected by exercising rights under this License with respect to
+the covered work, and you disclaim any intention to limit operation or
+modification of the work as a means of enforcing, against the work's
+users, your or third parties' legal rights to forbid circumvention of
+technological measures.
+
+  4. Conveying Verbatim Copies.
+
+  You may convey verbatim copies of the Program's source code as you
+receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy an appropriate copyright notice;
+keep intact all notices stating that this License and any
+non-permissive terms added in accord with section 7 apply to the code;
+keep intact all notices of the absence of any warranty; and give all
+recipients a copy of this License along with the Program.
+
+  You may charge any price or no price for each copy that you convey,
+and you may offer support or warranty protection for a fee.
+
+  5. Conveying Modified Source Versions.
+
+  You may convey a work based on the Program, or the modifications to
+produce it from the Program, in the form of source code under the
+terms of section 4, provided that you also meet all of these conditions:
+
+    a) The work must carry prominent notices stating that you modified
+    it, and giving a relevant date.
+
+    b) The work must carry prominent notices stating that it is
+    released under this License and any conditions added under section
+    7.  This requirement modifies the requirement in section 4 to
+    "keep intact all notices".
+
+    c) You must license the entire work, as a whole, under this
+    License to anyone who comes into possession of a copy.  This
+    License will therefore apply, along with any applicable section 7
+    additional terms, to the whole of the work, and all its parts,
+    regardless of how they are packaged.  This License gives no
+    permission to license the work in any other way, but it does not
+    invalidate such permission if you have separately received it.
+
+    d) If the work has interactive user interfaces, each must display
+    Appropriate Legal Notices; however, if the Program has interactive
+    interfaces that do not display Appropriate Legal Notices, your
+    work need not make them do so.
+
+  A compilation of a covered work with other separate and independent
+works, which are not by their nature extensions of the covered work,
+and which are not combined with it such as to form a larger program,
+in or on a volume of a storage or distribution medium, is called an
+"aggregate" if the compilation and its resulting copyright are not
+used to limit the access or legal rights of the compilation's users
+beyond what the individual works permit.  Inclusion of a covered work
+in an aggregate does not cause this License to apply to the other
+parts of the aggregate.
+
+  6. Conveying Non-Source Forms.
+
+  You may convey a covered work in object code form under the terms
+of sections 4 and 5, provided that you also convey the
+machine-readable Corresponding Source under the terms of this License,
+in one of these ways:
+
+    a) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by the
+    Corresponding Source fixed on a durable physical medium
+    customarily used for software interchange.
+
+    b) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by a
+    written offer, valid for at least three years and valid for as
+    long as you offer spare parts or customer support for that product
+    model, to give anyone who possesses the object code either (1) a
+    copy of the Corresponding Source for all the software in the
+    product that is covered by this License, on a durable physical
+    medium customarily used for software interchange, for a price no
+    more than your reasonable cost of physically performing this
+    conveying of source, or (2) access to copy the
+    Corresponding Source from a network server at no charge.
+
+    c) Convey individual copies of the object code with a copy of the
+    written offer to provide the Corresponding Source.  This
+    alternative is allowed only occasionally and noncommercially, and
+    only if you received the object code with such an offer, in accord
+    with subsection 6b.
+
+    d) Convey the object code by offering access from a designated
+    place (gratis or for a charge), and offer equivalent access to the
+    Corresponding Source in the same way through the same place at no
+    further charge.  You need not require recipients to copy the
+    Corresponding Source along with the object code.  If the place to
+    copy the object code is a network server, the Corresponding Source
+    may be on a different server (operated by you or a third party)
+    that supports equivalent copying facilities, provided you maintain
+    clear directions next to the object code saying where to find the
+    Corresponding Source.  Regardless of what server hosts the
+    Corresponding Source, you remain obligated to ensure that it is
+    available for as long as needed to satisfy these requirements.
+
+    e) Convey the object code using peer-to-peer transmission, provided
+    you inform other peers where the object code and Corresponding
+    Source of the work are being offered to the general public at no
+    charge under subsection 6d.
+
+  A separable portion of the object code, whose source code is excluded
+from the Corresponding Source as a System Library, need not be
+included in conveying the object code work.
+
+  A "User Product" is either (1) a "consumer product", which means any
+tangible personal property which is normally used for personal, family,
+or household purposes, or (2) anything designed or sold for incorporation
+into a dwelling.  In determining whether a product is a consumer product,
+doubtful cases shall be resolved in favor of coverage.  For a particular
+product received by a particular user, "normally used" refers to a
+typical or common use of that class of product, regardless of the status
+of the particular user or of the way in which the particular user
+actually uses, or expects or is expected to use, the product.  A product
+is a consumer product regardless of whether the product has substantial
+commercial, industrial or non-consumer uses, unless such uses represent
+the only significant mode of use of the product.
+
+  "Installation Information" for a User Product means any methods,
+procedures, authorization keys, or other information required to install
+and execute modified versions of a covered work in that User Product from
+a modified version of its Corresponding Source.  The information must
+suffice to ensure that the continued functioning of the modified object
+code is in no case prevented or interfered with solely because
+modification has been made.
+
+  If you convey an object code work under this section in, or with, or
+specifically for use in, a User Product, and the conveying occurs as
+part of a transaction in which the right of possession and use of the
+User Product is transferred to the recipient in perpetuity or for a
+fixed term (regardless of how the transaction is characterized), the
+Corresponding Source conveyed under this section must be accompanied
+by the Installation Information.  But this requirement does not apply
+if neither you nor any third party retains the ability to install
+modified object code on the User Product (for example, the work has
+been installed in ROM).
+
+  The requirement to provide Installation Information does not include a
+requirement to continue to provide support service, warranty, or updates
+for a work that has been modified or installed by the recipient, or for
+the User Product in which it has been modified or installed.  Access to a
+network may be denied when the modification itself materially and
+adversely affects the operation of the network or violates the rules and
+protocols for communication across the network.
+
+  Corresponding Source conveyed, and Installation Information provided,
+in accord with this section must be in a format that is publicly
+documented (and with an implementation available to the public in
+source code form), and must require no special password or key for
+unpacking, reading or copying.
+
+  7. Additional Terms.
+
+  "Additional permissions" are terms that supplement the terms of this
+License by making exceptions from one or more of its conditions.
+Additional permissions that are applicable to the entire Program shall
+be treated as though they were included in this License, to the extent
+that they are valid under applicable law.  If additional permissions
+apply only to part of the Program, that part may be used separately
+under those permissions, but the entire Program remains governed by
+this License without regard to the additional permissions.
+
+  When you convey a copy of a covered work, you may at your option
+remove any additional permissions from that copy, or from any part of
+it.  (Additional permissions may be written to require their own
+removal in certain cases when you modify the work.)  You may place
+additional permissions on material, added by you to a covered work,
+for which you have or can give appropriate copyright permission.
+
+  Notwithstanding any other provision of this License, for material you
+add to a covered work, you may (if authorized by the copyright holders of
+that material) supplement the terms of this License with terms:
+
+    a) Disclaiming warranty or limiting liability differently from the
+    terms of sections 15 and 16 of this License; or
+
+    b) Requiring preservation of specified reasonable legal notices or
+    author attributions in that material or in the Appropriate Legal
+    Notices displayed by works containing it; or
+
+    c) Prohibiting misrepresentation of the origin of that material, or
+    requiring that modified versions of such material be marked in
+    reasonable ways as different from the original version; or
+
+    d) Limiting the use for publicity purposes of names of licensors or
+    authors of the material; or
+
+    e) Declining to grant rights under trademark law for use of some
+    trade names, trademarks, or service marks; or
+
+    f) Requiring indemnification of licensors and authors of that
+    material by anyone who conveys the material (or modified versions of
+    it) with contractual assumptions of liability to the recipient, for
+    any liability that these contractual assumptions directly impose on
+    those licensors and authors.
+
+  All other non-permissive additional terms are considered "further
+restrictions" within the meaning of section 10.  If the Program as you
+received it, or any part of it, contains a notice stating that it is
+governed by this License along with a term that is a further
+restriction, you may remove that term.  If a license document contains
+a further restriction but permits relicensing or conveying under this
+License, you may add to a covered work material governed by the terms
+of that license document, provided that the further restriction does
+not survive such relicensing or conveying.
+
+  If you add terms to a covered work in accord with this section, you
+must place, in the relevant source files, a statement of the
+additional terms that apply to those files, or a notice indicating
+where to find the applicable terms.
+
+  Additional terms, permissive or non-permissive, may be stated in the
+form of a separately written license, or stated as exceptions;
+the above requirements apply either way.
+
+  8. Termination.
+
+  You may not propagate or modify a covered work except as expressly
+provided under this License.  Any attempt otherwise to propagate or
+modify it is void, and will automatically terminate your rights under
+this License (including any patent licenses granted under the third
+paragraph of section 11).
+
+  However, if you cease all violation of this License, then your
+license from a particular copyright holder is reinstated (a)
+provisionally, unless and until the copyright holder explicitly and
+finally terminates your license, and (b) permanently, if the copyright
+holder fails to notify you of the violation by some reasonable means
+prior to 60 days after the cessation.
+
+  Moreover, your license from a particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License (for any work) from that
+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+
+  Termination of your rights under this section does not terminate the
+licenses of parties who have received copies or rights from you under
+this License.  If your rights have been terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+
+  9. Acceptance Not Required for Having Copies.
+
+  You are not required to accept this License in order to receive or
+run a copy of the Program.  Ancillary propagation of a covered work
+occurring solely as a consequence of using peer-to-peer transmission
+to receive a copy likewise does not require acceptance.  However,
+nothing other than this License grants you permission to propagate or
+modify any covered work.  These actions infringe copyright if you do
+not accept this License.  Therefore, by modifying or propagating a
+covered work, you indicate your acceptance of this License to do so.
+
+  10. Automatic Licensing of Downstream Recipients.
+
+  Each time you convey a covered work, the recipient automatically
+receives a license from the original licensors, to run, modify and
+propagate that work, subject to this License.  You are not responsible
+for enforcing compliance by third parties with this License.
+
+  An "entity transaction" is a transaction transferring control of an
+organization, or substantially all assets of one, or subdividing an
+organization, or merging organizations.  If propagation of a covered
+work results from an entity transaction, each party to that
+transaction who receives a copy of the work also receives whatever
+licenses to the work the party's predecessor in interest had or could
+give under the previous paragraph, plus a right to possession of the
+Corresponding Source of the work from the predecessor in interest, if
+the predecessor has it or can get it with reasonable efforts.
+
+  You may not impose any further restrictions on the exercise of the
+rights granted or affirmed under this License.  For example, you may
+not impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) alleging that
+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
+
+  11. Patents.
+
+  A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based.  The
+work thus licensed is called the contributor's "contributor version".
+
+  A contributor's "essential patent claims" are all patent claims
+owned or controlled by the contributor, whether already acquired or
+hereafter acquired, that would be infringed by some manner, permitted
+by this License, of making, using, or selling its contributor version,
+but do not include claims that would be infringed only as a
+consequence of further modification of the contributor version.  For
+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
+
+  Each contributor grants you a non-exclusive, worldwide, royalty-free
+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
+propagate the contents of its contributor version.
+
+  In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not to enforce a patent
+(such as an express permission to practice a patent or covenant not to
+sue for patent infringement).  To "grant" such a patent license to a
+party means to make such an agreement or commitment not to enforce a
+patent against the party.
+
+  If you convey a covered work, knowingly relying on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this License, through a
+publicly available network server or other readily accessible means,
+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients.  "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
+country that you have reason to believe are valid.
+
+  If, pursuant to or in connection with a single transaction or
+arrangement, you convey, or propagate by procuring conveyance of, a
+covered work, and grant a patent license to some of the parties
+receiving the covered work authorizing them to use, propagate, modify
+or convey a specific copy of the covered work, then the patent license
+you grant is automatically extended to all recipients of the covered
+work and works based on it.
+
+  A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License.  You may not convey a covered
+work if you are a party to an arrangement with a third party that is
+in the business of distributing software, under which you make payment
+to the third party based on the extent of your activity of conveying
+the work, and under which the third party grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the covered work
+conveyed by you (or copies made from those copies), or (b) primarily
+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all.  For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+  13. Use with the GNU Affero General Public License.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU Affero General Public License into a single
+combined work, and to convey the resulting work.  The terms of this
+License will continue to apply to the part which is the covered work,
+but the special requirements of the GNU Affero General Public License,
+section 13, concerning interaction through a network will apply to the
+combination as such.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU General Public License from time to time.  Such new versions will
+be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<https://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<https://www.gnu.org/licenses/why-not-lgpl.html>.

flake.nix

@@ -45,7 +45,28 @@
                     libtiff
                     libwebp
                     pkg-config
-                  ];
+                    xorg.libXinerama
+                    xorg.libX11
+                    xorg.libXcursor
+                    xorg.libXrandr
+                    xorg.libXi
+                    xorg.libXext
+                    xorg.libXdmcp
+                    libglvnd
+                    ((raylib.override { includeEverything = true; }).overrideAttrs (old: {
+                      patches = [];
+                      src = fetchFromGitHub {
+                        owner = "raysan5";
+                        repo = "raylib";
+                        rev = "b8cd10264b6d34ff4b09ccdd0b0f7b254cf3b122";
+                        sha256 = "sha256-VRNQZ0Pp1uczhLSF4Hz2QWiEini2jFtEGJDZMcLE+0w=";
+                      };
+                      postFixup = ''
+                        cp ../src/*.h $out/include/
+                      '';
+                    }))
+                    glfw
+                  ] ++ pkgs.glfw.buildInputs;
                 };
             }
         );

hie.yaml

@@ -1,5 +1,14 @@
 cradle:
   stack:
+    - path: "rpg/src"
+      component: "rpg:lib"
+
+    - path: "rpg/app/Main.hs"
+      component: "rpg:exe:rpg-exe"
+
+    - path: "rpg/test"
+      component: "rpg:test:rpg-test"
+
     - path: "snake/lib"
       component: "snake:lib"
 

rpg/.gitignore

@@ -0,0 +1,2 @@
+.stack-work/
+*~

rpg/CHANGELOG.md

@@ -0,0 +1,11 @@
+# Changelog for `rpg`
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to the
+[Haskell Package Versioning Policy](https://pvp.haskell.org/).
+
+## Unreleased
+
+## 0.1.0.0 - YYYY-MM-DD

rpg/LICENSE

@@ -0,0 +1,30 @@
+Copyright Author name here (c) 2023
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+
+    * Neither the name of Author name here nor the names of other
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

rpg/README.md

@@ -0,0 +1 @@
+# rpg

rpg/Setup.hs

@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain

rpg/app/Main.hs

@@ -0,0 +1,5 @@
+module Main where
+
+import Lib
+
+main = runGame

rpg/package.yaml

@@ -0,0 +1,75 @@
+name:                rpg
+version:             0.1.0.0
+github:              "githubuser/rpg"
+license:             BSD-3-Clause
+author:              "Author name here"
+maintainer:          "example@example.com"
+copyright:           "2023 Author name here"
+
+extra-source-files:
+- README.md
+- CHANGELOG.md
+
+# Metadata used when publishing your package
+# synopsis:            Short description of your package
+# category:            Web
+
+# To avoid duplicated efforts in documentation and dealing with the
+# complications of embedding Haddock markup inside cabal files, it is
+# common to point users to the README.md file.
+description:         Please see the README on GitHub at <https://github.com/githubuser/rpg#readme>
+
+dependencies:
+- base >= 4.7 && < 5
+- h-raylib
+- effectful
+- bytestring
+- text
+- lens
+- apecs-effectful
+- extra
+language: GHC2021
+default-extensions:
+  - OverloadedStrings
+  - DuplicateRecordFields
+  - BlockArguments
+  - OverloadedRecordDot
+  - NoFieldSelectors
+  - TemplateHaskell
+  - LambdaCase
+
+ghc-options:
+- -Wall
+- -Wcompat
+- -Widentities
+- -Wincomplete-record-updates
+- -Wincomplete-uni-patterns
+- -Wmissing-export-lists
+- -Wmissing-home-modules
+- -Wpartial-fields
+- -Wredundant-constraints
+
+library:
+  source-dirs: src
+
+executables:
+  rpg-exe:
+    main:                Main.hs
+    source-dirs:         app
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - rpg
+
+tests:
+  rpg-test:
+    main:                Spec.hs
+    source-dirs:         test
+    ghc-options:
+    - -threaded
+    - -rtsopts
+    - -with-rtsopts=-N
+    dependencies:
+    - rpg

rpg/rpg.cabal

@@ -0,0 +1,120 @@
+cabal-version: 2.2
+
+-- This file has been generated from package.yaml by hpack version 0.35.2.
+--
+-- see: https://github.com/sol/hpack
+
+name:           rpg
+version:        0.1.0.0
+description:    Please see the README on GitHub at <https://github.com/githubuser/rpg#readme>
+homepage:       https://github.com/githubuser/rpg#readme
+bug-reports:    https://github.com/githubuser/rpg/issues
+author:         Author name here
+maintainer:     example@example.com
+copyright:      2023 Author name here
+license:        BSD-3-Clause
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    CHANGELOG.md
+
+source-repository head
+  type: git
+  location: https://github.com/githubuser/rpg
+
+library
+  exposed-modules:
+      Component.Box
+      Component.Camera
+      Component.Player
+      Component.Position
+      Effectful.Raylib
+      Effectful.State.Static.Local.Lens
+      Lib
+      System.Renderer
+      World
+  other-modules:
+      Paths_rpg
+  autogen-modules:
+      Paths_rpg
+  hs-source-dirs:
+      src
+  default-extensions:
+      OverloadedStrings
+      DuplicateRecordFields
+      BlockArguments
+      OverloadedRecordDot
+      NoFieldSelectors
+      TemplateHaskell
+      LambdaCase
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
+  build-depends:
+      apecs-effectful
+    , base >=4.7 && <5
+    , bytestring
+    , effectful
+    , extra
+    , h-raylib
+    , lens
+    , text
+  default-language: GHC2021
+
+executable rpg-exe
+  main-is: Main.hs
+  other-modules:
+      Paths_rpg
+  autogen-modules:
+      Paths_rpg
+  hs-source-dirs:
+      app
+  default-extensions:
+      OverloadedStrings
+      DuplicateRecordFields
+      BlockArguments
+      OverloadedRecordDot
+      NoFieldSelectors
+      TemplateHaskell
+      LambdaCase
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      apecs-effectful
+    , base >=4.7 && <5
+    , bytestring
+    , effectful
+    , extra
+    , h-raylib
+    , lens
+    , rpg
+    , text
+  default-language: GHC2021
+
+test-suite rpg-test
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
+  other-modules:
+      Paths_rpg
+  autogen-modules:
+      Paths_rpg
+  hs-source-dirs:
+      test
+  default-extensions:
+      OverloadedStrings
+      DuplicateRecordFields
+      BlockArguments
+      OverloadedRecordDot
+      NoFieldSelectors
+      TemplateHaskell
+      LambdaCase
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      apecs-effectful
+    , base >=4.7 && <5
+    , bytestring
+    , effectful
+    , extra
+    , h-raylib
+    , lens
+    , rpg
+    , text
+  default-language: GHC2021

rpg/src/Component/Box.hs

@@ -0,0 +1,15 @@
+{-# LANGUAGE TypeFamilies #-}
+
+module Component.Box (BoxComponent(..)) where
+
+import qualified Raylib.Types as RL
+import Apecs.Effectful
+
+data BoxComponent
+  = Box
+  { color :: RL.Color
+  , offset :: (Float, Float)
+  , size :: (Float, Float)
+  }
+  deriving Show
+instance Component BoxComponent where type Storage BoxComponent = Map BoxComponent

rpg/src/Component/Camera.hs

@@ -0,0 +1,14 @@
+{-# LANGUAGE TypeFamilies #-}
+
+module Component.Camera (CameraComponent(..)) where
+
+import Apecs.Effectful
+
+data CameraComponent
+  = Camera
+  { zoom :: Int
+  , offset :: (Float, Float)
+  }
+  deriving Show
+instance Component CameraComponent where type Storage CameraComponent = Map CameraComponent
+

rpg/src/Component/Player.hs

@@ -0,0 +1,11 @@
+{-# LANGUAGE TypeFamilies #-}
+
+module Component.Player (PlayerComponent(..)) where
+
+import Apecs.Effectful
+
+data PlayerComponent
+  = Player
+  {}
+  deriving Show
+instance Component PlayerComponent where type Storage PlayerComponent = Map PlayerComponent

rpg/src/Component/Position.hs

@@ -0,0 +1,14 @@
+{-# LANGUAGE TypeFamilies #-}
+
+module Component.Position (PositionComponent(..)) where
+
+import Apecs.Effectful
+
+data PositionComponent
+  = Position
+  { x :: Float
+  , y :: Float
+  }
+  deriving Show
+instance Component PositionComponent where type Storage PositionComponent = Map PositionComponent
+

rpg/src/Effectful/Raylib.hs

@@ -0,0 +1,107 @@
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE TypeFamilies #-}
+module Effectful.Raylib
+  ( setTargetFPS
+  , windowShouldClose
+  , isKeyDown
+  , runDraw
+  , clearBackground
+  , runDraw2D
+  , drawText
+  , drawRectangle
+  , runRaylibWindow
+  , Raylib
+  , RaylibDraw
+  , RaylibDraw2D
+  ) where
+
+import Effectful
+import qualified Raylib.Types as RL
+import Data.Text (Text)
+import Effectful.Dispatch.Dynamic
+import qualified Raylib.Core as RL
+import qualified Data.Text as T
+import qualified Raylib.Core.Text as RL
+import qualified Raylib.Core.Shapes as RL
+import GHC.Float
+
+data Raylib :: Effect where
+  SetTargetFPS :: Int -> Raylib (Eff es) ()
+  WindowShouldClose :: Raylib (Eff es) Bool
+  IsKeyDown :: RL.KeyboardKey -> Raylib (Eff es) Bool
+  RunDraw :: (IOE :> es) => Eff (RaylibDraw : es) a -> Raylib (Eff es) a
+type instance DispatchOf Raylib = Dynamic
+
+data RaylibDraw :: Effect where
+  ClearBackground  :: RL.Color -> RaylibDraw (Eff es) ()
+  RunDraw2D :: (IOE :> es) => RL.Camera2D -> Eff (RaylibDraw2D : es) a -> RaylibDraw (Eff es) a
+type instance DispatchOf RaylibDraw = Dynamic
+
+data RaylibDraw2D :: Effect where
+  DrawText :: Text -> Int -> Int -> Int -> RL.Color -> RaylibDraw2D (Eff es) ()
+  DrawRectangle :: Float -> Float -> Float -> Float -> RL.Color -> RaylibDraw2D (Eff es) ()
+type instance DispatchOf RaylibDraw2D = Dynamic
+
+setTargetFPS :: (HasCallStack, Raylib :> es) => Int -> Eff es ()
+setTargetFPS fps = send (SetTargetFPS fps)
+
+windowShouldClose :: (HasCallStack, Raylib :> es) => Eff es Bool
+windowShouldClose = send WindowShouldClose
+
+isKeyDown :: (HasCallStack, Raylib :> es) => RL.KeyboardKey -> Eff es Bool
+isKeyDown key = send (IsKeyDown key)
+
+runDraw :: (HasCallStack, IOE :> es, Raylib :> es) => Eff (RaylibDraw : es) a -> Eff es a
+runDraw effect = send (RunDraw effect)
+
+clearBackground :: (HasCallStack, RaylibDraw :> es) => RL.Color -> Eff es ()
+clearBackground color = send (ClearBackground color)
+
+runDraw2D :: (HasCallStack, IOE :> es, RaylibDraw :> es) => RL.Camera2D -> Eff (RaylibDraw2D : es) a -> Eff es a
+runDraw2D camera effect = send (RunDraw2D camera effect)
+
+drawText :: (HasCallStack, RaylibDraw2D :> es) => Text -> Int -> Int -> Int -> RL.Color -> Eff es ()
+drawText text posX posY fontSize color = send (DrawText text posX posY fontSize color)
+
+drawRectangle :: (HasCallStack, RaylibDraw2D :> es) => Float -> Float -> Float -> Float -> RL.Color -> Eff es ()
+drawRectangle posX posY width height color = send (DrawRectangle posX posY width height color)
+
+runRaylibWindow :: (IOE :> es) => Int -> Int -> Text -> Eff (Raylib : es) () -> Eff es ()
+runRaylibWindow width height name effect = do
+  window <- liftIO $ RL.initWindow width height (T.unpack name)
+
+  interpret' effect $ \env eff -> localSeqUnlift env \unlift ->
+    case eff of
+      WindowShouldClose -> liftIO $ RL.windowShouldClose
+      SetTargetFPS fps -> liftIO $ RL.setTargetFPS fps
+      IsKeyDown key -> liftIO $ RL.isKeyDown key
+      RunDraw drawEffect -> unlift $ runRaylibDrawing drawEffect
+
+  liftIO $ RL.closeWindow window
+   where
+     runRaylibDrawing :: (IOE :> es) => Eff (RaylibDraw : es) a -> Eff es a
+     runRaylibDrawing effect' = do
+       liftIO RL.beginDrawing
+       res <- interpret' effect' $ \env eff -> localSeqUnlift env \unlift ->
+         case eff of
+           ClearBackground color -> liftIO $ RL.clearBackground color
+           RunDraw2D camera draw2dEffect -> unlift $ runRaylibDrawing2d camera draw2dEffect
+       liftIO RL.endDrawing
+       pure res
+
+     runRaylibDrawing2d :: (IOE :> es) => RL.Camera2D -> Eff (RaylibDraw2D : es) a -> Eff es a
+     runRaylibDrawing2d camera effect' = do
+       liftIO (RL.beginMode2D camera)
+       res <- interpret' effect' $ \env eff -> localSeqUnlift env \unlift ->
+         case eff of
+           DrawText text posX posY fontSize color -> liftIO $ RL.drawText (T.unpack text) posX posY fontSize color
+           DrawRectangle posX posY width height color -> liftIO $ RL.drawRectangleV (RL.Vector2 posX posY) (RL.Vector2 width height) color
+       liftIO RL.endMode2D
+       pure res
+
+     interpret'
+       :: DispatchOf e ~ Dynamic
+       => Eff (e ': es) a
+       -> EffectHandler e es
+       -> Eff es a
+     interpret' eff handler = interpret handler eff

rpg/src/Effectful/State/Static/Local/Lens.hs

@@ -0,0 +1,17 @@
+module Effectful.State.Static.Local.Lens ((.=), (%=), (%.=)) where
+
+import Effectful
+import Effectful.State.Static.Local
+import Control.Lens hiding ((%=), (.=))
+
+(.=) :: State s :> es => ASetter s s a b -> b -> Eff es ()
+l .= b = modify (l .~ b)
+{-# INLINE (.=) #-}
+
+(%=) :: State s :> es => ASetter s s a b -> (a -> b) -> Eff es ()
+l %= f = modify (l %~ f)
+{-# INLINE (%=) #-}
+
+(%.=) :: State s :> es => Lens s s a b -> (s -> b) -> Eff es ()
+l %.= f = modify (\s -> l %~ const (f s) $ s)
+{-# INLINE (%.=) #-}

rpg/src/Lib.hs

@@ -0,0 +1,157 @@
+{-# LANGUAGE ImportQualifiedPost #-}
+{-# LANGUAGE BlockArguments #-}
+{-# LANGUAGE GADTs #-}
+{-# LANGUAGE DataKinds #-}
+{-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE RankNTypes #-}
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeApplications #-}
+
+module Lib
+    ( runGame
+    ) where
+
+import Raylib.Core qualified as RL
+import Raylib.Types qualified as RL
+import Raylib.Util.Colors qualified as RL
+import Control.Monad.Extra
+import Control.Lens hiding ((.=))
+import qualified Raylib.Core.Text as RL
+import Effectful
+import Data.Text (Text)
+import Effectful.Dispatch.Dynamic
+import qualified Data.Text as T
+import Effectful.State.Static.Local
+import qualified Raylib.Core.Shapes as RL
+import Apecs.Effectful qualified as AE
+import GHC.Float
+import Effectful.Reader.Dynamic
+import World
+import Component.Player
+import Component.Position
+import Component.Camera
+import Component.Box
+import Effectful.State.Static.Local.Lens
+import Effectful.Raylib
+import System.Renderer
+
+data GameConfig
+  = GameConfig
+  {
+  }
+
+data GameState
+  = GameState
+  { dimX :: Int
+  , dimY :: Int
+  , camera :: RL.Camera2D
+  , playerEntity :: AE.Entity
+  , cameraEntity :: AE.Entity
+  }
+  deriving Show
+makeLensesFor [ ("dimX", "dimX")
+              , ("dimY", "dimY")
+              , ("camera", "camera")
+              , ("playerEntity", "playerEntity")
+              , ("cameraEntity", "cameraEntity")
+              ] ''GameState
+
+spawnPlayer
+  :: ( AE.ECS World :> es )
+  => RL.Color
+  -> Eff es AE.Entity
+spawnPlayer color = AE.newEntity @World (Player, Position 0 0, Camera 20 (0, 0), Box color (-0.5, -0.5) (1, 1))
+
+movePlayer
+  :: ( AE.ECS World :> es )
+  => Eff es AE.Entity
+  -> (Float, Float)
+  -> Eff es ()
+movePlayer eff (x, y) = do
+  entity <- eff
+
+  AE.modify @World @PositionComponent @PositionComponent entity (\p -> Position (p.x + x) (p.y + y))
+
+spawnBox
+  :: ( AE.ECS World :> es )
+  => (Float, Float)
+  -> RL.Color
+  -> (Float, Float)
+  -> Eff es AE.Entity
+spawnBox (posx, posy) color size = AE.newEntity @World (Box color size (0, 0), Position posx posy)
+
+getCamera
+  :: ( AE.ECS World :> es
+     , State GameState :> es
+     , Reader GameConfig :> es
+     )
+  => Eff es AE.Entity
+  -> Eff es RL.Camera2D
+getCamera eff = do
+  entity <- eff
+  (c, p) <- AE.get @World @(CameraComponent, PositionComponent) entity
+  gameState <- get @GameState
+  gameConfig <- ask @GameConfig
+
+  pure $ RL.Camera2D
+    { RL.camera2D'offset = RL.Vector2 (int2Float gameState.dimX / 2) (int2Float gameState.dimY / 2)
+    , RL.camera2D'target = RL.Vector2 (p.x + fst c.offset) (p.y + snd c.offset)
+    , RL.camera2D'rotation = 0.0
+    , RL.camera2D'zoom = int2Float (min gameState.dimX gameState.dimY) / int2Float c.zoom
+    }
+
+initialise
+  :: ( Raylib :> es
+     , State GameState :> es
+     , AE.ECS World :> es )
+  => Eff es ()
+initialise = do
+  setTargetFPS 60
+
+  player <- spawnPlayer RL.blue
+  playerEntity .= player
+  cameraEntity .= player
+
+  pure ()
+
+runGame :: IO ()
+runGame = do
+  let gameConfig
+        = GameConfig
+        {
+        }
+      gameState
+        = GameState
+        { dimX = 800
+        , dimY = 450
+        , playerEntity = undefined
+        , cameraEntity = undefined
+        }
+
+  RL.setTraceLogLevel RL.LogWarning
+  runEff . AE.runECS initWorld . evalState gameState . runReader gameConfig . runRaylibWindow gameState.dimX gameState.dimY "App" $ initialise >> whileM do
+    isKeyDown RL.KeyA >>= flip when (movePlayer (gets @GameState (\s -> s.playerEntity)) (-0.1, 0))
+    isKeyDown RL.KeyD >>= flip when (movePlayer (gets @GameState (\s -> s.playerEntity)) (0.1, 0))
+    isKeyDown RL.KeyS >>= flip when (movePlayer (gets @GameState (\s -> s.playerEntity)) (0, 0.1))
+    isKeyDown RL.KeyW >>= flip when (movePlayer (gets @GameState (\s -> s.playerEntity)) (0, -0.11))
+
+    cameraEntity <- (gets @GameState (\s -> s.cameraEntity))
+    isKeyDown RL.KeyKpAdd >>= flip when ( AE.modify @World @CameraComponent @CameraComponent cameraEntity (\c -> c { zoom = c.zoom + 1}))
+    isKeyDown RL.KeyKpSubtract >>= flip when ( AE.modify @World @CameraComponent @CameraComponent cameraEntity (\c -> c { zoom = c.zoom - 1}))
+
+    c <- getCamera (gets @GameState (\s -> s.cameraEntity))
+    liftIO $ print c
+    runDraw . runDraw2D c $ do
+
+      clearBackground RL.rayWhite
+      -- drawText "Congrats! You created your first window!" 190 200 20 RL.lightGray
+      render
+      drawRectangle 0 0 1 1 RL.lightGray
+      drawRectangle 2 0 1 1 RL.lightGray
+      not <$> windowShouldClose
+
+  pure ()

rpg/src/System/Renderer.hs

@@ -0,0 +1,17 @@
+module System.Renderer (render) where
+
+import Effectful
+import qualified Apecs.Effectful as AE
+import World
+import Component.Position
+import Component.Box
+import Effectful.Raylib
+
+render
+  :: ( AE.ECS World :> es
+     , RaylibDraw2D :> es )
+  => Eff es ()
+render = do
+  AE.cmapM_ @World @(PositionComponent, BoxComponent)
+    \(pos, Box color offset size) -> drawRectangle (pos.x + fst offset) (pos.y + snd offset) (fst size) (snd size) color
+  pure ()

rpg/src/World.hs

@@ -0,0 +1,12 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE FieldSelectors #-}
+
+module World (World, initWorld) where
+
+import Apecs.Effectful
+import Component.Position
+import Component.Player
+import Component.Camera
+import Component.Box
+
+makeWorld "World" [''PositionComponent, ''PlayerComponent, ''CameraComponent, ''BoxComponent]

rpg/test/Spec.hs

@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "Test suite not yet implemented"

stack.yaml

@@ -30,6 +30,7 @@ resolver: nightly-2023-09-22
 #   - wai
 packages:
   - snake
+  - rpg
 # Dependency packages to be pulled from upstream that are not in the resolver.
 # These entries can reference officially published versions as well as
 # forks / in-progress versions pinned to a git hash. For example:
@@ -39,10 +40,20 @@ packages:
 # - git: https://github.com/commercialhaskell/stack.git
 #   commit: e7b331f14bcffb8367cd58fbfc8b40ec7642100a
 #
-# extra-deps: []
+extra-deps:
+  - git: /home/main/repos/h-raylib # https://github.com/MagicRB/h-raylib
+    commit: f59e961df46e3c06598fd60aa7c1491a2c40f124
+  - git: https://github.com/typedbyte/apecs-effectful
+    commit: 3a5249d1b2a52c3fed512596689d001ee479c100
+  - lens-5.2.2@sha256:e01d5732173645b80f23a189a0f7e1f5cd0b2286de0ce20baf941cbf5c3b8435,15158
+  - effectful-2.2.2.0@sha256:1d5682727c2d5ebd83f7a7ae0ef809369422ccd37d4157ae7e2084f2a1cf6cfd,6044
+  - effectful-core-2.2.2.2@sha256:ebbf61f024a08c7bb5e569b1c6856c0ca92687d6a5ff01d24d28567948c402fc,3477
 
 # Override default flag values for local packages and extra-deps
-# flags: {}
+flags:
+  h-raylib:
+    detect-platform: false
+    platform-nixos: true
 
 # Extra package databases containing global packages
 # extra-package-dbs: []

stack.yaml.lock

@@ -3,7 +3,50 @@
 # For more information, please see the documentation at:
 #   https://docs.haskellstack.org/en/stable/lock_files
 
-packages: []
+packages:
+- completed:
+    commit: f59e961df46e3c06598fd60aa7c1491a2c40f124
+    git: /home/main/repos/h-raylib
+    name: h-raylib
+    pantry-tree:
+      sha256: 152857764b80818e36f31b4168c55767f5419b8162b1381ddfb80993c2ee6c2e
+      size: 86344
+    version: 4.6.0.7
+  original:
+    commit: f59e961df46e3c06598fd60aa7c1491a2c40f124
+    git: /home/main/repos/h-raylib
+- completed:
+    commit: 3a5249d1b2a52c3fed512596689d001ee479c100
+    git: https://github.com/typedbyte/apecs-effectful
+    name: apecs-effectful
+    pantry-tree:
+      sha256: 38e62afb64af51bd8908dcf451d21d40d50d189909df5732b60063a0aa652bfb
+      size: 372
+    version: 0.1.0.0
+  original:
+    commit: 3a5249d1b2a52c3fed512596689d001ee479c100
+    git: https://github.com/typedbyte/apecs-effectful
+- completed:
+    hackage: lens-5.2.2@sha256:e01d5732173645b80f23a189a0f7e1f5cd0b2286de0ce20baf941cbf5c3b8435,15158
+    pantry-tree:
+      sha256: b69117901be8d6fb47cf106504af0065a5271a10bdbf9d8ab89acbd0508c4653
+      size: 8216
+  original:
+    hackage: lens-5.2.2@sha256:e01d5732173645b80f23a189a0f7e1f5cd0b2286de0ce20baf941cbf5c3b8435,15158
+- completed:
+    hackage: effectful-2.2.2.0@sha256:1d5682727c2d5ebd83f7a7ae0ef809369422ccd37d4157ae7e2084f2a1cf6cfd,6044
+    pantry-tree:
+      sha256: 3719fc29567eb572128ba36da8ff19f71756bd2a2e86b9a3622084a78807da09
+      size: 2549
+  original:
+    hackage: effectful-2.2.2.0@sha256:1d5682727c2d5ebd83f7a7ae0ef809369422ccd37d4157ae7e2084f2a1cf6cfd,6044
+- completed:
+    hackage: effectful-core-2.2.2.2@sha256:ebbf61f024a08c7bb5e569b1c6856c0ca92687d6a5ff01d24d28567948c402fc,3477
+    pantry-tree:
+      sha256: 518687a306562d3e9c93a6363a8304481a11d77460f1f84e7129895f01b240cb
+      size: 1918
+  original:
+    hackage: effectful-core-2.2.2.2@sha256:ebbf61f024a08c7bb5e569b1c6856c0ca92687d6a5ff01d24d28567948c402fc,3477
 snapshots:
 - completed:
     sha256: 93137bc0122de394fa2c43e933971b2996cd7dc600989b721ad971810b9a2f3f