New output format: Rust

[Kwarf]

Hi,

I want to use this project from Rust, so I went ahead and added output support for it.

I decided to generate a byte string literal ([u8]) with an added \0 at the end instead of the usual Rust str because that makes it easier to pass on to the OpenGL functions, since str is unicode and not null-terminated either.

heart.frag generates the following output:

// Generated with Shader Minifier 1.3.2 (https://github.com/laurentlb/Shader_Minifier/)
pub const VAR_MOUSE: &'static [u8] = b"f\0";
pub const VAR_RESOLUTION: &'static [u8] = b"y\0";
pub const VAR_TIME: &'static [u8] = b"v\0";

pub const HEART_FRAG: &'static [u8] = b"\
 uniform float v;\
 uniform vec2 y;\
 uniform vec4 f;\
 void main()\
 {\
   vec2 f=(2.*gl_FragCoord.xy-y)/y.y;\
   float r=mod(v,2.)/2.,a=pow(r,.2)*.5+.5;\
   a-=a*.2*sin(r*6.2831*5.)*exp(-r*6.);\
   f*=vec2(.5,1.5)+a*vec2(.5,-.5);\
   float m=atan(f.x,f.y)/3.141593,x=length(f),e=abs(m),o=(13.*e-22.*e*e+10.*e*e*e)/(6.-5.*e),n=step(x,o)*pow(1.-x/o,.25);\
   gl_FragColor=vec4(n,0,0,1);\
 }\0";

Leading whitespaces are ignored, so no special handling of the indentation is required, as can be seen here on the Rust Playground.

[laurentlb]

Nice, thanks a lot!