greathmaster/earthquake-mapping

Mapping of earthquakes with USGS data using Javascript D3 visualization library and ES6 Promise based code

earthquake-mapping's Issues

When mouse is moved quickly after hovering the spinning earth does not re-animate sometimes

Incorrect info card data in some situations

There is incorrect info card data in some situations. See screenshot.

The reason is the algorithm used for detecting the earthquake location being hovered over. It uses a second hidden canvas with each of the dots given a different rgb blue value. For example location 0 is given rgb(0, 0, 0) while location 1 is given rgb(0, 0, 1) etc. Upon hover the color is retrieved from the hover location to determine the earthquake id.

This usually works well.

However, if there are dots in close proximity due to anti-aliasing the pixels on the outer edge may actually be a rgb shade resulting in the wrong data being displayed by the info card.

Could consider using putImageData and manually set the hidden canvas pixel colors as a solution.

Additional resources:

• https://stackoverflow.com/questions/195262/can-i-turn-off-antialiasing-on-an-html-canvas-element
• https://talk.observablehq.com/t/what-is-the-best-way-to-overlay-an-svg-over-a-canvas/277/4

When window viewport is resized the visualization and styling appears deformed

Tooltip shows off screen on some points