NEST.md

Nest

This and other 15-466 base code is built around a collection of useful libraries and functions which we will collectively call "nest". This name captures the goal of having the various parts and functions relatively easy to reconfigure (and remove), while still forming a good support for your game.

What Is Included

Here is a quick overview of what is included. For further information, ☺read the code☺ !

• Base code (files you will certainly edit):
  • server.cpp game server. Update game state and communicate with clients here.
  • client.cpp creates the game window and contains the main loop. Set your window title, size, and initial Mode here.
  • PlayMode.hpp, PlayMode.cpp declaration+definition for a basic game client. You'll probably build your game on it.
  • Jamfile responsible for telling FTJam how to build the project. Change this when you add additional .cpp files and to change your runtime executable's name.
  • .gitignore ignores generated files. You will need to change it if your executable name changes. (If you find yourself changing it to ignore, e.g., your editor's swap files you should probably, instead, be investigating making this change in the global git configuration.)
• Useful code (files you should investigate, but probably won't change):
  • Connection.hpp, Connection.cpp polling-based Client and Server classes which talk via sockets.
  • hex_dump.hpp, hex_dump.cpp helper for dumping binary data buffers; useful for message viewing/debugging.
  • Sound.hpp, Sound.cpp Sound namespace, functions for Sample loading and playback in 2D and 3D.
  • Mesh.hpp, Mesh.cpp mesh loading.
  • Scene.hpp, Scene.cpp scene (transform hierarchy) loading and display (hmm, you might actually edit this code a bit).
  • shaders (you might also build on these:
    • ColorProgram.hpp, ColorProgram.cpp GLSL shader that draws objects with vertex colors.
    • ColorTextureProgram.hpp, ColorTextureProgram.cpp GLSL shader that draws objects with vertex colors and textures.
    • LitColorTextureProgram.hpp, LitColorTextureProgram.cpp GLSL shader that draws objects with vertex colors, textures, and lighting.
  • DrawLines.hpp, DrawLines.cpp draw lines in a 3D scene. Very useful for debugging.
  • PathFont.hpp, PathFont.cpp line-based font, used by DrawLines for text drawing.
  • read_write_chunk.hpp templated helpers for reading chunk-based binary formats.
  • Load.hpp, Load.cpp asset loading wrapper; load things in the global scope but not until after an OpenGL context is established.
  • Mode.hpp, Mode.cpp base class for modes (things that recieve events and draw).
  • gl_compile_program.hpp, gl_compile_program.cpp helper function to compiles OpenGL shader programs.
  • load_save_png.hpp, load_save_png.cpp helper functions to load and save PNG images.
  • GL.hpp, GL.cpp includes OpenGL 3.3 prototypes without the namespace pollution of (e.g.) SDL's OpenGL header; on Windows, deals with some function pointer wrangling.
  • gl_errors.hpp provides a GL_ERRORS() macro.
  • .github/workflows/build-workflow.yml sets up the repository to be built via github actions whenever it is pushed or released.
  • Asset Viewers:
    • show-meshes.cpp, ShowMeshesMode.hpp, ShowMeshesMode.cpp -- builds scene/show-meshes which can view .pnct files.
    • show-scene.cpp, ShowSceneMode.hpp, ShowSceneMode.cpp -- builds scene/show-scene which can view .scene files.
    • shaders used by these helpers:
      • ShowMeshesProgram.hpp, ShowMeshesProgram.cpp
      • ShowSceneProgram.hpp, ShowSceneProgram.cpp
• Here be dragons (files you probably don't need to look at):
  • set-utf8-code-page.manifest embedded on windows so that the application runs in the UTF-8 code page, as per https://docs.microsoft.com/en-us/windows/apps/design/globalizing/use-utf8-code-page .
  • load_wav.hpp, load_wav.cpp helper to load wav files. (used by Sound::Sample)
  • load_opus.hpp, load_opus.cpp helper to load opus files. (used by Sound::Sample)
  • make-GL.py does what it says on the tin. Included in case you are curious. You won't need to run it.
  • glcorearb.h used by make-GL.py to produce GL.*pp
  • make-PathFont-font.py processes PathFont-font.svg to create PathFont-font.cpp (the line-based font used in the DrawLines code).
  • freetype-test.cpp just exists to check that hb/ft programs are compiling+linking properly

Build Instructions

This code is set up to build across Linux, Windows, and MacOS.

Building will be done from the command prompt, using FTJam, the freetype project's fork of Perforce's excellent "Jam" build tool (Documentation page at Perforce, for the curious).

To add or remove files from the build, read and edit the Jamfile.

Setup

Setup for your development environment should be relatively simple:

0. (Optional) Make sure your system is set up to make it easy to use your favorite code editor and git from the command prompt. So much nicer than using a GUI.
1. Install one of our target C++ compilers:
   • Linux: g++
   • MacOS: clang++ (from XCode). From the terminal: xcode-select --install
   • Windows: Visual Studio Community 2019
2. Install ftjam (or regular perforce jam) from your OS's package manager:
   • Linux: e.g. sudo apt-get install ftjam
   • MacOS: e.g. brew install jam
   • Windows: (skip this step; jam for windows is included in the nest-libs package -- see Windows Note below)
3. Extract an appropriate release of nest-libs to a sibling of this folder:
   • Linux: https://github.com/15-466/nest-libs/releases/download/v0.9/nest-libs-linux-v0.9.tar.gz
   • MacOS: https://github.com/15-466/nest-libs/releases/download/v0.9/nest-libs-macos-v0.9.tar.gz
   • Windows: https://github.com/15-466/nest-libs/releases/download/v0.9/nest-libs-windows-v0.9.zip

Once you are finished, your directory tree should looks something like this:

game-programming/ #can be called anything
	nest-libs/    #nest-libs from that repository's releases page
		windows/  #subdirectory name varies depending on platform
		...
	my-gameN/     #fork of the baseN code; can be called anything
		...
	...           #further subdirectories for other games

Building

Once you have your development environment set up, building is as simple as opening a command prompt (see Windows Note below), changing to the game directory, and running jam.

Here are a few worthwhile variations:

# Note: Always build from the game's root folder:
  $ cd game-programming
  $ cd my-game0

# Simplest build command:
  $ jam

# Variation: multiple (six, in this case) build jobs in parallel:
  $ jam -j6

# Variation: quit if any build job fails:
  $ jam -q

# Variation: run game if build succeeds:
  $ jam && dist/pong

# Variation: show commands being run (useful for debugging the Jamfile):
  $ jam -dx

# Useful: show summary of jam flags:
  $ jam -h

# Variation: this is what I generally use:
  $ jam -q -j6 && dist/pong

# Useful: delete all built files:
  $ jam clean

Windows Note: a pre-compiled jam.exe and a .bat file + .lnk to launch a VS2019 command prompt with jam in the %PATH% are included in the nest-libs/windows/jam/ directory. The README.md in that folder explains how to use them.

A Word About Github Actions

This repository is equipped with a .github/workflows/build-workflow.yml file that tells github that you would like it to build the code for you whenever you push code. This is a great way to check if things are working cross-platform and even to package releases of your game (the workflow is set up such that if you create a release through the github web UI, it will automatically build, package, and upload binaries to the release).

It can also be a frustrating and time-wasting trap to try to debug any build failures solely using github actions. Use it as a check, but not a development environment.