4k Demo Oven

... with which you'll bake 4k demos for the Cookie Demoparty or other demoparties!

This framework originates from iq with some parts from wsmind, halcy, and maybe others.

Requirements:

• Windows only.
• Crinkler as linker.
• Node.js for the toolchain.
• Synthclipse as IDE.
• Visual Studio for the C++ compiler.

Recommended:

• 4klang or Oidos as synthesizer.
• 7-Zip to zip the demo.
• Ffmpeg to capture the demo into a video.
• NASM as ASM compiler, needed by the synthesizers.

Setting up a new demo

Fork the repository on GitHub.

Clone your repository on your computer. I'll call XXX this directory's path.

Open a VS x86 tools prompt and execute:

cd XXX
npm install --production

The demo settings are stored in demo\config.yml for shared settings, and in demo\config.local.yml for the settings specific to your computer. The latter file is ignored by git.

By default, tools are searched on the PATH. You can explicit them in demo\config.local.yml, for instance:

paths:
  7z: C:\\Program Files\\7-Zip\\7z.exe
  crinkler: path\\to\\crinkler.exe
  oidos: path\\to\\oidos

The demo template uses Oidos as synthesizer. If you don't want to use it, set demo:audioTool as none in demo\config.yml.

In the VS x86 tools prompt, execute:

npm run build

After a few seconds, the build should be successful, and running dist\template.exe should display spinning balls. Quit by pressing escape.

If 7-Zip is installed and the path to 7z is available, the demo is zipped, together with the contents of dist\static.

Open Synthclipse. You are prompted to choose a workspace. This is where Synthclipse will store metadata about your projects within the IDE. If you have no particular needs, keeping the default value is fine.

Create a new Synthclipse project. Type in a title for your demo. Uncheck the default location, and choose XXX\demo. Click on Finish.

You're good to go. Take a cookie and start developping your demo.

Before releasing, check the demo's name in config.yml, update static\file_id.diz, and add some other files in static if needed.

Developing the demo

In Synthclipse, edit shader.stoy. This is your demo.

Click on the Play button to compile the shader.

In order to automatically build when a file changes, execute in a VS x86 tools prompt:

npm run watch

Whenever you save any fle in the project, a build is triggered in the background, and a notification displays the final size in bytes. Clicking on this notification will run the demo.

In Synthclipse, uniforms' values can be controlled thanks to comment annotations. Have a look at the available controls.

The framework embraces this feature and allows you to set values, which become constant values during the building process. For instance in the template project, BPM is adjustable through a uniform, but its value is hardcoded in the actual embedded shader.

Save the controls' values into a preset. By default, the framework will compile the values from the preset named Default.

The shader shall contain the line // begin. During the build process, the contents before the line is removed, and replaced by a generated block defining uniforms and consts as set in config.yml.

Debugging & Minifying

You can enable debugging by adding the parameter debug to the build process :

npm run build debug

It will add #define DEBUG in the engine code, which will display : openGL version, shader copile errors, uniform indices in console and/or message box.

If you don't want your shader to be minified, for debugging purpose, you can add the parameter nominify :

npm run build debug nominify

Usage of multiple buffers

If you wish to add multiple buffers feature, you can enable it by adding demo:bufferCount: 3 in the config file to have 3 buffers.

The engine will execute multiple renders to texture, which you will be able to sample from your shader. To do so, you will need to declare uniform sampler2D buffer_n as many time as there are buffers. As the uniform are not bind with the variable name but with their indices, your declaration will need to respect the order of the buffers (use debug parameter to watch that uniforms indices are matching the code in entry.cpp).

Only one shader is used for the multiple buffer passes, the uniform int PASSINDEX will tells which passes is being rendered. Only the last buffer pass will be displayed to the screen, the other ones will be rendered off-screen. (With 3 buffers, the displayed one will be code under the condition : if (PASSINDEX == 2))

Additional notes :

• All buffers are the same size as the screen, but you can modify the code to suit you needs, as well as texture filtering, mipmaps...
• Render passes use dual buffers to allow simultaneous read/writing to the same pass.
• If you don't need multiple buffers but want to sample backbuffer (last frame) use : demo:bufferCount: 1
• If you don't need multiple buffers and don't need to sample backbuffer, use : demo:bufferCount: 0

Audio tools

An audio tool can be set in the config file at demo:audioTool. none is a fallback tool which plays no music. The framework supports the following tools.

4klang

Modular synthesizer by Dominik 'Gopher' Ries and Paul 'pOWL' Kraus of Alcatraz. It comes in two flavors: 4klang and 8klang, the latter is more powerful but takes more space.

Getting started video

Within the VST, record and export the song into the demo directory. This will generate 4klang.h and 4klang.inc files.

Give the path to 4klang or 8klang sources, in config.local.yml as paths:4klang or paths:8klang. There shall be a file 4klang.asm inside.

Oidos

Additive synthesizer by Aske Simon 'Blueberry' Christensen. Follow the Pouet thread for precompiled releases.

Oidos converts the Renoise song into an assembly code. Python 2 is required for that. If python is not available in the PATH, give the path to it in config.local.yml as paths:python2.

Give the path to Oidos sources in config.local.yml as paths:oidos. There shall be directories convert and player inside.

Shader

Lets you make your own sound wave with a fragment shader. By default a 2048^2 pixels texture will be generated. At 44100, the whole texture can hold 190 seconds of sound. You can enable audio shader by setting the value of demo:audioTool to shader in the config file. See details of implementation in shader.stoy, entry.cpp and audio-shader.cpp.

Capture

By default, the recording is done at 60 FPS at 1920x1080, including the audio from music.wav. Customize in config.yml.

Execute in a VS x86 tools prompt:

npm run capture

The demo is built with the special capture settings, then runs while saving each frame on disk, and finally these frames are merged into a video in the dist directory.

Tips

Configure Synthclipse to compile the shader on save.

Use the beat time to be synchronized with the music, cf. beat in the template demo.

Have a look at build\shader.glsl and build\shader.min.glsl to understand how the shader is rewritten during the build process.

Add your own uniforms computed on CPU side.

Configure your antivirus to ignore XXX, because the demos may be recognized as viruses.

Config reference

• capture: used for the capture only.
  • audioFilename: the rendered music in demo which plays with the captured demo. Default music.wav. Set to null to disable audio.
  • fps: default 60.
  • height: default 1080.
  • width: default 1920.
• cl:
  • args: array of cli arguments.
• crinkler:
  • args: array of cli arguments.
• demo:
  • audioFilename: needed for some synthesizers.
    • Oidos: default music.xrns.
  • audioTool: 4klang, 8klang, none, oidos. Default none.
  • closeWhenFinished: default false.
  • name: used for the dist file names.
  • resolution: used to force a resolution for dev purpose.
    • height
    • scale
    • width
• paths: by default, applications are searched in the PATH.
  • 4klang: path to source directory, if using 4klang.
  • 7z: recommended to zip the build.
  • 8klang: path to source directory, if using 8klang.
  • crinkler
  • ffmpeg: for the capture.
  • nasm
  • oidos: path to source directory, if using oidos.
  • python2: if using oidos.
• shader:
  • constantsPreset: name of the preset used to transform uniforms to constants. Default Default.
  • filename: default shader.stoy.
  • globals: map type -> array of strings.
  • time: used to provide the beat time. Set to null to disable. Automatically disabled if the beat const is not used.
    • beatConstant: const name receiving the beat time. Default beat.
    • bpmUniform: uniform name in Synthclipse stating the BPM. Default BPM.
  • uniforms: array of strings. time is always prepended to the list.;