Feature request: Better diplomacy overview screen

[OptimizedForDensity]

trafficstars

It's hard to differentiate the different colors of lines on the diplomacy overview (or even to know what the colors mean since there's no legend). According to the eyedropper tool from Gimp, there are 4 colors of lines in this image yet I, who isn't even colorblind, can hardly differentiate between 2 of them unless I stare at them for a while. I think a key and more line differentiation (dotted, dashed, dot-dashed, very large differences in line thickness, black line outlines, etc.) would definitely help.

[alexban01]

Personally I think this is good. Do we really need to tell that "right" has slightly better relations with "left" than with "up"? I think knowing that "down" dislikes both "left" and "right" is important enough and I don't really need to know which one he dislikes the most.

Is there a gameplay benefit to knowing the exact relations between civs? If so what about writing the actual values somewhere beside the graph? Maybe the thickness could be increased a bit.

[zhan313]

I use this diagram and stat screen to test if allied CS bonus works for ai, for mods testing

[yairm210]

Duplicate of #7870 , discussed in more detail there