Fix gamepad triggers not working on web exports

Fixes #81758

DisplayServerWeb::process_joypads handles buttons 6 and 7 of the
HTML5 Standard Gamepad as a special case by doing:
`input->joy_axis(idx, (JoyAxis)b, s_btns[b]);`

This doesn't work because there is no JoyAxis 6 or 7 in the enum

To fix this we use JoyAxis::TRIGGER_LEFT and TRIGGER_RIGHT for button 6
and 7

However since we are now lying to input->joy_axis we also need to lie in
the mappings for the standard gamepad in godotcontrollersdb.txt,
otherwise input->joy_axis will try to find a mapping to axis 4(LT) and
axis 5(RT) that's not defined.

Therefore we set lefttrigger to +a4 and righttrigger to +a5 in the
mapping, to match what we are actually sending.

A cleaner, and more involved fix to this would be modifying
input->joy_button so that it can handle analog buttons and map them to
axes preserving their value instead of converting to boolean

1 files changed, 4 insertions, 2 deletions

diff --git a/platform/web/display_server_web.cpp b/platform/web/display_server_web.cpp
index 40de4e523b..4e55cc137a 100644
--- a/platform/web/display_server_web.cpp
+++ b/platform/web/display_server_web.cpp
@@ -902,8 +902,10 @@ void DisplayServerWeb::process_joypads() {
 		for (int b = 0; b < s_btns_num; b++) {
 			// Buttons 6 and 7 in the standard mapping need to be
 			// axis to be handled as JoyAxis::TRIGGER by Godot.
-			if (s_standard && (b == 6 || b == 7)) {
-				input->joy_axis(idx, (JoyAxis)b, s_btns[b]);
+			if (s_standard && (b == 6)) {
+				input->joy_axis(idx, JoyAxis::TRIGGER_LEFT, s_btns[b]);
+			} else if (s_standard && (b == 7)) {
+				input->joy_axis(idx, JoyAxis::TRIGGER_RIGHT, s_btns[b]);
 			} else {
 				input->joy_button(idx, (JoyButton)b, s_btns[b]);
 			}