pa7/heatmap.js — pull request #90 by Woracheth (2013-12-31 15:58:12+00:00)
Title: Fix heat transfer between overlapping heat sources.

Blending function of CSS shadow is not averaging as blurring applied but it is addition, so it creates exaggerated heat at overlapping area between two heat sources, even exceed the center of a heat source.

Heat transfer between sources should be gradually blend like normal color, RGB, then I made it on G channel and used Math.min() to make sure the edge still feathering to transparent.

![bangkok](https://f.cloud.github.com/assets/6293218/1827433/1e53c948-7234-11e3-860f-22536686624e.png)