Revert "Optimized scope erase"

This reverts commit 4c5583d498981698cda5800e91ca70e188096c2c.
Revert "scope drawing optimization using linear slopes"

This reverts commit 2a409144ae5f3654d260f488a9fe906e3441681c.

Conflicts:
	script.js
Fixed wrong color being used to background paint