COLOR_BURN

{@usesMathJax} Makes destination darker to reflect source.

\(\alpha_{out} = \alpha_{src} + \alpha_{dst} - \alpha_{src} * \alpha_{dst}\)

\begin{equation} C_{out} = \begin{cases} C_{dst} + C_{src}*(1 - \alpha_{dst}) &C_{dst} = \alpha_{dst} \\ \alpha_{dst}*(1 - \alpha_{src}) &C_{src} = 0 \\ \alpha_{src}*(\alpha_{dst} - min(\alpha_{dst}, (\alpha_{dst} - C_{dst})*\alpha_{src}/C_{src})) + C_{src} * (1 - \alpha_{dst}) + \alpha_{dst}*(1-\alpha_{src}) &otherwise \end{cases} \end{equation}