#intersect

1fn intersect(inout self)

The intersect function modifies the current shape in the Sdf2d drawing context by intersecting it with the previously stored shape. The result is a new shape that represents the area where both shapes overlap. This operation is useful when you want to create complex shapes by combining simpler ones based on their overlapping regions.

#Parameters

• self (inout): A reference to the Sdf2d instance. The function modifies the internal shape and old_shape fields of self to reflect the intersection of the shapes.

#Returns

• void: This function does not return a value but updates the internal state of self to represent the intersected shape.

#Example

1fn pixel(self) -> vec4 {
2    // Create an Sdf2d drawing context for the current viewport.
3    let sdf = Sdf2d::viewport(self.pos * self.rect_size);
4
5    // Draw the first circle at position (40.0, 50.0) with a radius of 30.0.
6    sdf.circle(40.0, 50.0, 30.0);
7
8    // Store the current shape for intersection.
9    sdf.union(); // Store the first shape.
10
11    // Draw the second circle at position (60.0, 50.0) with a radius of 30.0.
12    sdf.circle(60.0, 50.0, 30.0);
13
14    // Perform intersection between the current shape and the stored shape.
15    sdf.intersect();
16
17    // Fill the intersected area with a solid red color.
18    sdf.fill(#f00);
19
20    // Return the final color result.
21    return sdf.result;
22}

#Explanation

In this example:

• Create Drawing Context: We initialize an Sdf2d drawing context scaled to the size of the current rectangle (self.rect_size).

• First Shape: We draw a circle centered at (40.0, 50.0) with a radius of 30.0.

• Store Shape: By calling sdf.union(), we save the current shape into self.old_shape. This prepares it for the intersection operation.

• Second Shape: We draw another circle centered at (60.0, 50.0) with the same radius.

• Apply Intersection: Using sdf.intersect(), we modify the shape field to represent the intersection between the current shape (second circle) and the stored shape (first circle). The result is the overlapping area of the two circles.

• Fill Shape: We fill the intersected area with red color using sdf.fill(#f00).

• Return Result: The function returns sdf.result, which contains the final rendered image showing the intersected shape.

#Notes

• Shape Composition: The intersect function is useful when you need to create shapes based on the common area of multiple shapes, allowing for more complex designs.

• Order of Operations: Ensure that you store the initial shape using sdf.union() before drawing the second shape and applying sdf.intersect().

• Transformation: You can apply transformations like translate, rotate, or scale to manipulate the shapes before intersecting them.

• Combining Shapes: The intersect function is part of a set of Boolean operations that allows you to combine shapes in various ways. Other related functions include sdf.union() and sdf.subtract().

• Further Effects: After intersecting shapes, you can apply effects like sdf.glow() or sdf.stroke() to enhance the visual appearance.