Fix the input zone drawing in input settings

[john-peterson]

gc stick input zone

this is the correct input zone assuming https://github.com/mirror/libogc/blob/master/libogc/pad.c /PAD_Clamp is correct. everything outside it is clamped down to the input zone

for the main stick __pad_clampstick remove 15 (dead zone) and clamp everything above 72, 40 (maximum, diagonal). these irregular dodecagon vertex coordinates (x, y) are therefore the minimum stick values (x, y) that still output the maximum clamped ones (in brackets). all higher values are clamped down to the values in the brackets

0, -15[ 0]   87[ 72]
1,  15[ 0]   87[ 72]
2,  55[ 40]  55[ 40]
3,  87[ 72]  15[  0]
4,  87[ 72] -15[  0]
5, -55[-40] -55[-40]

the input zone is therefore 72+15, 40+15

the c-stick clamp values are 59, 31 and the input zone is therefore 59+15, 31+15

this is tested in https://github.com/john-peterson/dolphin-test/blob/master/pad.cpp /test_area by writing all clamped stick coordinates (red), the clamped value (blue), and the maximum radius circle (green):

it's also tested in Source/TestSuite/PAD in https://github.com/mirror/dolphin-emu/pull/31/files

wii stick has no clamping

the nunchuk and classic controller stick input zone should be an octagon that fill the input square because it has no clamping beyond its octagonal shape that confine the stick

this is tested for the nunchuk stick (wd->exp.nunchuk.js.pos.x, wd->exp.nunchuk.js.pos.y) in Source/TestSuite/WPAD/source/dolphintest_wpad.cpp in https://github.com/mirror/dolphin-emu/pull/31/files that use https://github.com/mirror/libogc/blob/master/gc/wiiuse/wiiuse.h

optimal gc stick radius setting

the optimal gc stick radius (that fill the input zone) is therefore around

• main stick: (87 / 128) * 1.1 = 0.75
• c-stick: (74 / 128) * 1.1 = 0.64

where 1.1 is a margin to ensure that all angles can reach the input zone edge

[skidau]

@dolphin-emu-bot rebuild

[JMC47]

This seems like it'll be really nice for helping people setup controllers to work best in games.

[skidau]

@dolphin-emu-bot rebuild

[john-peterson]

@lioncash done

[lioncash]

Looks good, thanks.

@dolphin-emu-bot rebuild

[Sonicadvance1]

@dolphin-emu-bot rebuild