I have finally managed to write a fragment shader. This one in particular is the code for a cross sign. How do I rotate it please? I would like to make it look like an X. Also it it possible to scale it, lets say shrink it by 20%.

If you have any comments on the code, or if there is another simpler way, please feel free

```
#define PI 3.14159265359
mat2 rotate2d(float _angle){
return mat2(cos(_angle),-sin(_angle),
sin(_angle),cos(_angle));
}
void main() {
vec2 color = vec2(0.0);
vec2 shape = vec2(0.0);
// True (ie 1.0) if x between 0.45 and 0.55
float x_1 = 1.0 - step(0.55, gl_PointCoord.x);
float x_2 = step(0.45, gl_PointCoord.x);
// True (ie 1.0) if y between 0.45 and 0.55
float y_1 = 1.0 - step(0.55, gl_PointCoord.y);
float y_2 = step(0.45, gl_PointCoord.y);
// cross
shape = vec2(x_1 * x_2 + y_1 * y_2);
shape = shape - vec2(0.5);
shape = rotate2d( 0.25*PI ) * shape;
shape = shape + vec2(0.5);
color = vec2(1.0, 0.0);
gl_FragColor = vec4(shape * color, 0.0, 1.0);
}
```