retro++

retro++ is a simple retro-pixelart 2D game engine that aims to help to introduce anybody with knowledge of programming (specially with C++) into the world of game development without having to deal with the low-level APIs OpenGL or DirectX, or with newer APIs like Vulkan or Metal (both unsupported in this engine).

Clone the repo

git clone --recursive https://github.com/melchor629/retro

The repo has submodules on it, so it will initialize them when cloning.

CMake

To build the project, and do it consistently among Windows, Linux and macOS computers, retro++ uses CMake to generate the necessary files depending on the platform.

The CMakeFile.txt on Windows and macOS will call a script that will download the SDL2 libraries and headers for you. If one of the scripts fail, try executing them manually, specially if you are on Windows because the script is a PowerShell script and executing them requires Administrator permissions in some cases. In both platforms, using CMake GUI is enough and it is not needed to make any changes to the configuration to make it work.

On Linux, while debugging, you should set CMAKE_BUILD_TYPE to Debug using either the CMake GUI or in terminal with -DCMAKE_BUILD_TYPE=Debug.

How to prepare the project

Windows

Mingw nor Cygwin are supported, so you must use Visual Studio 2015 or 2017 with C/C++ support to compile the project. You can install the compilers only. It's up to you.

The project is created through CMake. Download the app (search for "Latest Release...") and install it (if you downloaded the installer) or decompress it anywhere (if you downloaded the zip).

If you have Windows 7, ensure that PowerShell is installed to. The CMake script executes a PowerShell script that download the libraries needed for you :)

To prepare the Visual Studio solution, open CMake. In the first text field, labelled with Where is the source code? select the path where you cloned or downloaded this repo. Then copy that path and paste it in the second text field, labelled with Where to build the source code and append /build at the end. An example:

Where is the source code? C:/Users/melchor629/Documents/GitHub/retro++
Where to build the source code? C:/Users/melchor629/Documents/GitHub/retro++/build

Once done, press the Configure button. A window will open telling you to "specify the generator for this project", and more. For that dropdown, check that says Visual Studio ?? 201? Win64 where you must select 2015 or 2017 version depending on what you have installed. Important that the generator ends with Win64. 32bit Windows is not supported. When the generator is selected, press Finish. When the configuration step is done, you can press Generate and will generate the solution. Now you can press Open Project. Happy coding :)

Debian and Ubuntu based Linux distros

First, you must install the compilers, some tools and the dependencies. This is done with the following command:

sudo apt update
sudo apt install build-essential g++ cmake libsdl2-dev libsdl2-ttf-dev libsdl2-mixer-dev timidity

Then, execute g++ --version. If the version is below 7, then you must install GNU G++ 7 (6 is untested, might work without using 7). To do it in Ubuntu and Linux Mint, execute:

sudo add-apt-repository ppa:ubuntu-toolchain-r/test
sudo apt update
sudo apt install g++-7

On Debian 8 or 9, see https://stackoverflow.com/questions/43151627/installing-g-7-0-1-on-debian-8-7.

After installing dependencies and the compilers, cd to the cloned directory. Then create a build directory (mkdir build) and cd to it. If you didn't have to install g++-7 separately, you can execute:

cmake -DCMAKE_BUILD_TYPE=Debug ..
make -j2 #You can put another number, if you have 8 cores, put 8 fe
./retro++ #This executes the game, if everything went good

If you had to install g++-7 separately, you will execute:

cmake -DCMAKE_CXX_COMPILER=$(which g++-7) -DMAKE_C_COMPILER=$(which gcc-7) -DCMAKE_BUILD_TYPE=Debug ..
make -j2 #You can put another number, if you have 8 cores, put 8 fe
./retro++ #This executes the game, if everything went good

And that's all. Now you have the project files to compile the game. Happy coding :)

To make a release build, to be able to export or install anywhere, execute the cmake command changing Debug with Release. Also could be good to specify where you want to "export" the game. That can be done by adding -DCMAKE_INSTALL_PREFIX=YOUR_PATH before the dots. Then, with make install (may need sudo) you will have an exportable version of your game.

Arch Linux based Linux distros

First, you must install the compilers, some tools and the dependencies. This is done with the following command:

sudo pacman -S cmake sdl2 sdl2_ttf sdl2_mixer #-Syu is also valid instead of -S

Then, cd to the cloned directory. Then create a build directory (mkdir build) and cd to it. Execute this:

cmake -DCMAKE_BUILD_TYPE=Debug ..
make -j2 #You can put another number, if you have 8 cores, put 8 fe
./retro++ #This executes the game, if everything went good

And that's all. Now you have the project files to compile the game. Happy coding :)

macOS

First you must install Xcode. Then download CMake app and put it where you want. When both apps are ready, open Xcode, if it is the first time you do, it will install the compilers and some tools.

Then, open CMake. In the first text field, labelled with Where is the source code? select the path where you cloned or downloaded this repo. Then copy that path and paste it in the second text field, labelled with Where to build the source code and append /build at the end. An example:

Where is the source code? /Users/melchor629/Documents/GitHub/retro++
Where to build the source code? /Users/melchor629/Documents/GitHub/retro++/build

Once done, press the Configure button. A window will open telling you to "specify the generator for this project", and more. For that dropdown, check that says Xcode, it is usually selected. You can also use Makefile if you prefer the Linux approach. When the generator is selected, press Finish. When the configuration step is done, you can press Generate and will generate the Xcode project, or the Makefiles. Now you can press Open Project in case of select Xcode, and compile from terminal if you selected Makefiles. In Xcode, search for the Play - Stop buttons at the top-left corner, and change the target from ALL_BUILD to retro++. Happy coding :)

Note: If you select Makefile, search the property CMAKE_BUILD_TYPE and write Debug.

For export an .app of your game, first search in CMake the property CMAKE_INSTALL_PREFIX and put where you want to export your game. If you selected Makefile as the generator, also modify CMAKE_BUILD_TYPE to Release. Then press generate. In Xcode, change the target (its near the Play - Stop buttons) from retro++ to INSTALL, and press the Play button. For Makefile, execute make install. Game exported.

Android

To make an Android version of your game, first follow the following tutorial for your platform da tutorial. After this, download the sources for SDL2, SDL_ttf and SDL_mixer. Put them under the folder jni. Then, create symbolic links of src/base, src/editor, src/game, lib/glm, lib/json, lib/stb and lib/utfcpp.

#It's only an example, for illustrate you
ln -s "/Users/melchor9000/Desktop/retro++/src/base" "/Users/melchor9000/Desktop/retro++/src/editor" "/Users/melchor9000/Desktop/retro++/src/game" .
ln -s "/Users/melchor9000/Desktop/retro++/lib/glm" "/Users/melchor9000/Desktop/retro++/lib/json" "/Users/melchor9000/Desktop/retro++/lib/stb" "/Users/melchor9000/Desktop/retro++/lib/utfcpp" .

And then, modify app/src/main/jni/src/Android.mk to look like the one that you can find in android/app/src/main/jni/src/Android.mk.

Modify app/src/main/jni/Application.mk to look like this one android/app/src/main/jni/Application.mk.

Also modify app/src/AndroidManifest.xml, following the commentaries found there.

Copy the contents of android/app/src/main/java/ (from the repo) into your project. Contains only an Activity. That activity calls some C++ code required for the engine. While editing the manifest, create a new Activity that extends me.melchor9000.retro.RetroActivity, in your desired package. Make that new activity your default activity.

If you get an error compiling SDL_mixer, try to download SDL_mixer from there.

iOS

To make an iOS version of your game, first download the sources for SDL2, SDL_ttf and SDL_mixer. Put them under the root folder of the iOS project. Then, create symbolic links of src/base, src/editor, src/game, lib/glm, lib/json, lib/stb and lib/utfcpp.

#It's only an example, for illustrate you
ln -s "/Users/melchor9000/Desktop/retro++/src/base" "/Users/melchor9000/Desktop/retro++/src/editor" "/Users/melchor9000/Desktop/retro++/src/game" .
ln -s "/Users/melchor9000/Desktop/retro++/lib/glm" "/Users/melchor9000/Desktop/retro++/lib/json" "/Users/melchor9000/Desktop/retro++/lib/stb" "/Users/melchor9000/Desktop/retro++/lib/utfcpp" .

Then, go to SDL2-2.0.7/Xcode-iOS/Template/SDL iOS Application and copy that folder to SDL2-2.0.7/SDL iOS Application. Remove the Xcode project and paste the one inside ios. Should work correctly.

The Xcode project defines the macro __IOS__ to differentiate between macOS and iOS.

inspect.py

This Python 3 script allows you to use the Inspection API quickly. To send commands, write them argument as arguments. If you want to modify an attribute, add at the end =THE_VALUE. If the value is an object, use JSON format.

python3 inspect.py game::currentLevel::uiObjects::0::text="Some text" game::currentLevel::uiObjects::0::font='{"size": 10}'

Where's the resources?

You can find the resources in this link. Download it, and extract it in res.

Libraries

retro++ uses the following great libraries:

melchor629 / retro