#glslViewer
Live-coding console tool that renders GLSL Shaders. Every file you use (frag/vert shader, images and geometries) are watched for modification, so they can be updated on the fly.
Install
Installing in Ubuntu
You need to install GLFW then download the code, compile and install.
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install git-core cmake xorg-dev libglu1-mesa-dev
cd ~
git clone https://github.com/glfw/glfw.git
cd glfw
cmake .
make
sudo make install
cd ..
git clone http://github.com/patriciogonzalezvivo/glslViewer
cd glslViewer
make
sudo make install
Installing in RaspberryPi
You just need to download the code, compile and install.
cd ~
git clone http://github.com/patriciogonzalezvivo/glslViewer
cd glslViewer
make
sudo make install
Installing in Mac OSX
You need to install GLFW, pkg-config
first and then download the code, compile and install.
brew update
brew upgrade
brew tap homebrew/versions
brew install glfw3 pkg-config
cd ~
git clone http://github.com/patriciogonzalezvivo/glslViewer
cd glslViewer
make
make install
If glfw3 was installed before, after running the code above, remove glfw3 and try:
brew install glfw3 pkg-config
export PKG_CONFIG_PATH=/usr/local/lib/pkgconfig
make
make install
Use
In the most simple scenario you just want to load a fragment shader. For that you need to:
- Run the app passing the shader as an argument
glslViewer test.frag
- Then edit the shader with your favorite text editor.
vim test.frag
Note: In RaspberryPi you can avoid taking over the screen by using the -l
or --live-coding
flags so you can see the console. Also you can edit the shader file through ssh/sftp.
Note: On Linux and MacOS you may used to edit your shaders with Sublime Text 2, if thats your case you should try this Sublime Text 2 plugin that lunch glslViewer every time you open a shader.
Loading Vertex shaders and geometries
You can also load both fragments and vertex shaders. Of course modifing a vertex shader makes no sense unless you load an interesting geometry. That's why glslViewer
is can load .ply
files. Try doing:
glslViewer bunny.frag bunny.vert bunny.ply
uniforms
and varyings
Pre-Define -
uniform float u_time;
: shader playback time (in seconds) -
uniform vec2 u_resolution;
: viewport resolution (in pixels) -
uniform vec2 u_mouse;
: mouse pixel coords (xy: pos, zw: buttons) -
varying vec2 v_texcoord
: UV of the billboard ( normalized )
Textures
You can load PNGs and JPEGs images to a shader. They will be automatically loaded and asigned to an uniform name acording to the order they are pass as arguments: ex. u_tex0
, u_tex1
, etc. Also the resolution will be assigned to vec2
uniform acording the texture uniforma name: ex. u_tex0Resolution
, u_tex1Resolution
, etc.
glslViewer test.frag test.png
In case you want to assign customs names to your textures uniforms you must specify the name with a flag before the texture file. For example to pass the following uniforms uniform sampled2D imageExample;
and uniform vec2 imageExampleResolution;
is defined in this way:
glslViewer shader.frag -imageExample image.png
Others arguments
Beside for texture uniforms other arguments can be add to glslViewer
:
-
-x [pixels]
set the X position of the billboard on the screen -
-y [pixels]
set the Y position of the billboard on the screen -
-w [pixels]
or--width [pixels]
set the width of the billboard -
-h [pixels]
or--height [pixels]
set the height of the billboard -
-s [seconds]
exit app after a specific amount of seconds -
-o [image.png]
save the viewport to a image file before -
--squared
to set a squared billboard -
-l
or--live-coding
to draw a 500x500 billboard on the top right corner of the screen that let you see the code and the shader at the same time:
Inject other files
You can include other GLSL code using a traditional #include “file.glsl”
macro. Note: included files are not under watch so changes will not take effect until the main file is save.
Author
Patricio Gonzalez Vivo: github | twitter | website
Acknowledgements
Inspired by Karim’s Naaki fragTool.