I wanted a traffic light system on iwanttouse.com to visually represent feature support. Initially, I used simple CSS classes like .good (green), .ok (amber), and .bad (red), but this required clunky conditional logic to handle the color transitions based on percentage support. Paul Lewis suggested using HSL which allows for smooth transitions between red, amber, and green by adjusting the Hue value (0-359). Now, I can dynamically set the color using element.styles.color = \"hsla(\" + ((percentage / 100) * 90) + \", 50%, 50%)\"; which maps the percentage support to a Hue value between 0 (red) and 90 (green).
This post details how to use the HTML5 canvas element to dynamically create visually appealing custom markers for Google Maps. Instead of using a server to generate marker icons, we leverage the canvas API to draw rounded rectangles with gradients, center text within them and ultimately convert them into data URIs. Using the HSL color model allows for the creation of a harmonious range of colors by adjusting the hue while maintaining consistent saturation and luminance. This client-side approach offers flexibility and control over marker appearance, specifically highlighting techniques for rounded corners, gradients, and text centering. The code examples provided demonstrate the process of generating these markers and integrating them into a map.
