refactor html mouse action

This reduces the source complexity of the html_mouse_action()
 previously this was a single function of several thousand
 lines with over 30 local variables allocated on the stack.

Variables are now mostly held in a single static structure which
 drasticaly reduces the size of stack frame required and improves
 lookup locality.

The generated code does cause two additional function calls as the
 compiler avoids inlining the sub functions. The optimiser seems to
 produce somewhat better code within the sub functions.

In the final analysis there appears to be no significant performance
 loss or gain with this change, just more readable source.

0 files changed, 0 insertions, 0 deletions