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This is a guide to get you started on coding for The Powder Toy. If you have any questions, just ask in the Development Assistance section on The Powder Toy forums. If you want to use the old tpt compiling tutorial (which you probably don't), not the tpt++ one, find it here.

This takes a while to setup, so be patient and follow the instructions CAREFULLY. If you get any errors, 90% of the time that means you missed a step or did something incorrectly.

Do not begin coding elements until you are able to compile a clean source.

Good luck!

Getting the source

• Go to http://github.com/The-Powder-Toy/The-Powder-Toy/
• There should be a green button somewhere that says "Clone or download". Clicking it presents you with a popup with "Download ZIP". This is a direct link to a .zip of the source. Download it and extract it to a location you will compile it from.

Setup

• Download Visual C++ 2019 Community because of it's great debugging and auto-code tools. It is completely free; if it asks for a license, see the next list item. You will need a Microsoft account to download this.
• On the Workloads tab, select "Desktop development with C++".
• Go into the Individual components tab, scroll down to the "Compilers, build tools, and runtimes" section, and select "Windows XP support for C++".
• In the same area, select "Windows 8.1 SDK" (may be named differently, like Windows 10 SDK on other versions of windows).
• Open Visual Studio. You should register it (you don't have to pay anything; it's free) with your Microsoft account if you plan on using it for more than 30 days.
• Download Required Libraries.zip. Extract contents into project root (same level as the vsproject.py file).
• You now need Python installed to run SCons and other scripts. Get Python 3 here.

Using the premade project (recommended)

• Double click the vsproject.py file and it should show a console window for a second and then close. After that, three Visual Studio files should appear.
• Open the Visual Studio solution file (the one whose name ends with .sln). If you are using the latest version of Visual Studio Community (eg. 2019), ensure the "Treat Warnings As Errors" option is set to 'No'. You can find this option in Properties -> C/C++ -> General.
• Hit F5. This should compile (takes some time) and also launch TPT, which will ask all the questions it usually asks when run for the first time. Familiar files and folders such as Saves, stamps and powder.pref will appear in your source code folder.
• If you got this far, you've successfully compiled a clean source and can start modding, hurray!

Making your own project (not recommended)

It is not recommended that you manually set up the project. It is easy to make mistakes and have compiling errors.

• Make sure you have done everything in the Setup step correctly.
• Open Visual Studio and press Press File > New > New Project from Existing Code.
• Choose the folder that contains the source code, not src/, but the folder that contains src/, build/, includes/, and a few others. Name the project whatever you want. Click Next
• Choose Windows application project if it isn't selected already and leave everything unchecked. Click Next.

• Under Preprocessor definitions, type without quotes

"WIN, X86, X86_SSE2, STABLE, GRAVFFT, LUACONSOLE, IGNORE_UPDATES, _SCL_SECURE_NO_WARNINGS" NOTE:If it gives errors while compiling try to type them manually instead of copy-pasting.

• Click Finish. The project will be created

• Under Build > Configuration Manager, open the drop-down box under "Active Solution Configuration:" and change it to "Release". (unless you have a good reason to keep it as Debug, which runs slower than Release).

• Go to Project > Properties.

• On the very top, where it says Configuration: Active(Release), open the dropdown and change it to All Configurations. This will make it easier if you want to switch to debug mode.

• Under Configuration Properties > General:
• Change Output Directory from

$(SolutionDir)$(Configuration)\

to

$(SolutionDir)Build\

(notice that there is no backslash between "$(SolutionDir)" and "Build\").

• Change Target Name to whatever name you want the compiled file to have, minus the ".exe" extension. (or just leave it be to have the file named as the project name)

• Under Configuration Properties > VC++ Directories:
• Open the drop down menu for Include Directories (if you don't see the arrow that opens the drop-down menu, try clicking on the line), click "<Edit...>", and add

$(ProjectDir)includes
$(ProjectDir)includes\SDL2
$(ProjectDir)includes\luajit-2.0
$(ProjectDir)data
$(ProjectDir)src
$(ProjectDir)generated
$(ProjectDir)resources

(type that exactly -- also note that there is no backslash between "$(ProjectDir)" and "includes", and that they are all on separate lines)

• Open the drop down menu for Library Directories, click "<Edit...>", and add

$(ProjectDir)Libraries

(note that there is no backslash between "$(ProjectDir)" and "Libraries")

• Go to Configuration Properties > C/C++.

• Under "General", open the drop-down menu for "Warning Level" and choose "Level1 (/W1)". This will make it easier if you get any errors during compiling, as you won't have to dig through a bunch of unimportant warnings to get to the errors.

• Under "General", open the drop-down menu for "Multi-processor compilation" and choose "Yes (/MP)". This will make the compiler use multiple cores instead of just one which will help speed up compile times.

• If you are using the latest version of Visual Studio Community (eg. 2019), ensure the "Treat Warnings As Errors" option under "General" is set to 'No'.

• Under "Code Generation", open up the drop-down menu for "Floating Point Model" and set it to Fast. (this will get you a noticeable speed improvement). Also, right above it, change "Enable Enhanced Instruction Set" to SSE2.

• Go to Configuration Properties > Linker > Input.

• Open the drop down menu for "Additional Dependencies," click "<Edit...>", and enter the following text

shell32.lib
ws2_32.lib
SDL2.lib
SDL2main.lib
libbz2.lib
pthreadVC2.lib
luajit2.0.lib
libfftw3f-3.lib
zlib.lib

• Press OK until you close the project properties.

• Hit the F7 key on your keyboard, or click Build > Build Solution. You can also click the green "Start Debugging" arrow.
• If something goes wrong (i.e. you get an error of some sort), ask on The Powder Toy forums.

• The resulting executable and its required DLLs can be found in the "Build" folder in your source code directory.

Optional: Compile statically

When statically compiling TPT, you do not need to have the DLLs to run it, or distribute them with your project. The official TPT does it this way. It takes longer to compile though, so you might only want to do this for release versions.

If you are using the premade project, it already has the Static option built in. On the top bar, click the dropdown that says "Debug" and select "Static", then hit F7 to compile TPT again with this new setting. That's it, you're done; only continue reading this section if you made your own project.

• Under Build > Configuration Manager, go under Active Solution Configuration and hit New. Name it Static (or whatever you want to call it), and select to Copy the settings from Release. Also don't forget to change the default mode from X64 to X86.

• Under Configuration Properties > VC++ Directories, open the drop down menu for Library Directories, click "<Edit...>", and change it from $(ProjectDir)Libraries to:

$(ProjectDir)Staticlibs

• Go to Configuration Properties > Linker > Input, open the drop down menu for "Additional Dependencies," and click "<Edit...>", and add these to the list:

winmm.lib
imm32.lib
version.lib

• Go to Configuration Properties > C/C++ > Preprocessor, open the drop down menu for Preprocessor definitions, click "<Edit...>", and add these to the list:

PTW32_STATIC_LIB
ZLIB_WINAPI

• Under "Code Generation", change "Runtime Library" to "Multi-Threaded (/MT)"

• Go to Configuration Properties > Linker > Advanced, change "Image Has Safe Exception Handlers" to "No (/SAFESEH:NO)"

You will now be able to easily change between compiling in "Debug" mode, for quick, normal testing, and "Static" mode, for when you want to release an exe for people to use.

Optional: Set up Git

If you use GitHub, you can easily keep up to date with the current changes. This way, your mod won't be out of date, and you won't have to copy everything over just to update to a newer version. You can find the tutorial with this link.

Adding a new element

• Double click newelement.py. This will open a console window asking for an element name, which should only contain uppercase letters, digits and hyphens (you can have a more exotic name show up in the menus, but it's not recommended). Type the name of the element and press Enter. You'll be asked to add a piece of code to src/simulation/ElementNumbers.h; when you're done with that and press Enter, the window will close and your element will be created: its source will appear as src/simulation/elements/NAME.cpp.
• In Visual Studio, navigate to The-Powder-Toy/src/simulation/elements in the Solution Explorer and add the newly created .cpp file (preferably to the correct subfolder) (see here for how to do it.), then hit F7 to compile TPT again with the new element. This will take relatively long.
• Every time you change something in that file, hit F7 to compile (or F5 to compile and run) TPT. If you only change this file, the compilation step will take significantly shorter than when adding a new element.

Removing a new element

• Right click the .cpp file of your element in the Solution Explorer, click Remove and select Delete in the dialog that pops up.
• Undo the change newelement.py made you apply when creating the element; in other words, remove the relevant piece of code from src/simulation/ElementNumbers.h.
• In Visual Studio, hit F7 to compile TPT again without the element.

Making TPT faster

You may have noticed that the performance of your freshly compiled TPT is, to say the least, abysmal. To fix this, click the dropdown on the top bar that says "Debug" and select "Release", then hit F7 to compile TPT again.

With this you essentially trade ease of debugging for speed, meaning that while TPT will become faster, if there's a serious bug and Visual Studio happens to catch a crash, you won't be able to figure out why it happened, at least not easily. When that happens, just switch back to Debug, compile again and try to reproduce the crash.

SCons

You can use SCons from the command line to compile with the visual studio compiler. This option probably isn't useful in most cases but is still there. Use the command "scons.py --msvc" and it will attempt to find and use a 32 bit msvc compiler. It supports most of the options in the SConscript, including --static which should generate completely static binaries (not even needing msvcr120.dll like this guide needs)