# Shapes Shader

A simple shader that outputs 3 shapes : A quadrilateral( square/rect ), A Circle, A Polygon (Triangle to Infinitygon).

This shader can be used in fast level designing such as the shapes available on unity. The cover image is an example of a scene i designed with this shader, it took 5 minutes.

The parameters are :

Shape – (0, 1, 2) – 0 is Circle, 1 is Rect, 2 is Polygon

Poly Count – (3 – inf) – 3 is Triangle, 4 is Square, 5 is Pentagon and so on. (Only works if shape is a Polygon)

(Ignore the fog in the cover photo :/)

##### Shader code

```
shader_type canvas_item;
uniform int shape = 0;
uniform float poly_count = 3.0;
const float PI = 3.14159265359;
const float TWO_PI = 6.28318530718;
float Circle(vec2 st)
{
vec2 center = vec2(0.5) - st;
return step(length(center), 0.5);
}
float Square(vec2 st)
{
return 1.0;
}
float Triangle(vec2 st, float width)
{
st = st * 2.0 - 1.0;
if (poly_count > 2.0)
{
if (poly_count < 4.0)
{
st.y += 0.25;
}
}
float angle = atan(st.x, st.y) + radians(180.0);
float radius = TWO_PI / float(poly_count);
float dist = cos(floor(0.5 + angle / radius) * radius - angle) * length(st);
float poly = step(width, dist);
return 1.0 - poly;
}
void fragment()
{
vec2 st = UV;
st.y = 1.0 - st.y;
float sh;
if (shape == 0)
{
sh = Circle(st);
}
else if (shape == 1)
{
sh = Square(st);
}
else if (shape == 2)
{
sh = Triangle(st, 0.5);
}
vec3 color = vec3(sh);
color = 1.0 - color;
float alpha = 1.0 - color.r;
color = 1.0 - color;
COLOR = vec4(color, alpha);
}
```

Great utility shader! However, I think you accidentally hardcoded 3.0 on line 27 instead of using the ‘poly_count’ uniform. A suggestion, make poly_count an integer. That way you can easily use the up/down arrows in the Inspector.

i made poly_count a float so that it can be used in GLES2 as GLES2 doesn’t support the “float()” function. the harcoding will be fixed in a minute.

I have updated it ðŸ™‚