#glow_keep

1fn glow_keep(inout self, color: vec4, width: float) -> vec4

The glow_keep function applies a glowing effect to the current shape in the Sdf2d drawing context by blending a specified color with the existing result based on the glow width. This function preserves the current shape and clipping settings while applying the glow effect, allowing you to layer effects without resetting the drawing state.

#Parameters

• self (inout): A reference to the Sdf2d instance where the glow effect is applied. The function modifies the result field of self in place.
• color (vec4): An RGBA color of the glow.
• width (float): The width of the glow effect. The glow width is scaled according to the current scale_factor of the drawing context. Larger values produce a more pronounced glow.

#Returns

• vec4: The updated result color after the glow effect is applied. This color reflects the addition of the glow effect to the existing content.

#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 a circle centered at (50.0, 50.0) with a radius of 30.0.
6    sdf.circle(50.0, 50.0, 30.0);
7    
8    // Apply a red glow effect with a width of 10.0 units, preserving the shape state.
9    sdf.glow_keep(#f00, 10.0);
10    
11    // Optionally, fill the shape with another color without resetting the state.
12    sdf.fill_keep(#00f);
13    
14    // Return the final color result.
15    return sdf.result;
16}

#Explanation

In this example:

• Create Drawing Context: Initialize the Sdf2d context using the current position and size of the viewport.
• Draw Shape: Define a circle centered at (50.0, 50.0) with a radius of 30.0.
• Apply Glow Effect: Use glow_keep to apply a red glow effect (#f00) with a width of 10.0 units to the current shape. The glow_keep function adds a glow around the shape without altering the existing drawing state.
• Optional Fill: Use fill_keep to fill the shape with blue color (#00f) while preserving the shape for further operations if needed.
• Return Result: Return sdf.result, which contains the final rendered color after all drawing operations.

#Notes

• Preserving State: The glow_keep function maintains the current shape and clipping settings, allowing you to apply additional effects or fills afterward.
• Order of Operations: The order in which you apply effects and fills affects the final rendering. Define the shape first, then apply the glow and any fills as needed.
• Glow Width Scaling: The width parameter is adjusted based on the scale_factor of the Sdf2d context, ensuring consistent glow size regardless of transformations.
• Combining Effects: You can apply multiple effects sequentially by using the _keep variants of functions, preserving the drawing state between operations.