Fragula lets you view your fragment shader changes in real time. Simply save your fragment shader while editing and watch your changes appear in the Fragula window in real-time.
To install Fragula run cargo install fragula in a terminal prompt.
```
USAGE:
fragula [OPTIONS]
FLAGS: -h, --help Prints help information -V, --version Prints version information
OPTIONS:
-t, --texture
ARGS:
```
To use Fragula you can run fragula in a terminal with the path to the
OBJ file and fragment shader you would like to use:
$ fragula examples/suzanne.obj examples/fragment.glsl
If you have an image texture that you would like to use in your
fragment shader you can use the --texture or -t flag:
$ fragula examples/spot.obj examples/fragment.glsl -t examples/spot_texture.png
The left mouse button can be used to rotate the model about the x and y axes. However, for finer control of the model the following key bindings are available:
R: Reset the model back to its original state
W: Rotate the model counter clockwise about the x axis
S: Rotate the model clockwise about the x axis
D: Rotate the model counter clockwise about the y axis
A: Rotate the model clockwise about the y axis
Q: Rotate the model counter clockwise about the z axis
E: Rotate the model clockwise about the z axis
Z: Scale the model in negative increments
X: Scale the model in positive increments
Up: Transalte the model in the positive y direction
Down: Translate the model in the negative y direction
Left: Translate the model in the negative x direction
Right: Translate the model in the positive x direction
The vertex shader can be found in the src directory and contains the following code:
```glsl
in vec3 position;
in vec3 texture;
in vec3 normal;
uniform mat4 model; uniform mat4 view; uniform mat4 projection;
out vec3 vertexnormal; out vec3 texturecoordinate;
void main() { vertexnormal = normalize(view * model * vec4(normal, 0.0)).xyz; texturecoordinate = texture; gl_Position = projection * view * model * vec4(position, 1.0); } ```
Apart from the transformation matrices, uniform float time and uniform vec2 resolution are
available as uniform variables.
