From aa4c7687eeaf79552b3563cd61172b0d6a7a99e1 Mon Sep 17 00:00:00 2001
From: german <german@thesoftwareartisans.com>
Date: Wed, 30 Dec 2020 22:29:20 -0600
Subject: [PATCH] Port citra-emu/citra#5509
---
src/input_common/sdl/sdl_impl.cpp | 47 +++++++++++++++++++++++++++++--
1 file changed, 45 insertions(+), 2 deletions(-)
diff --git a/src/input_common/sdl/sdl_impl.cpp b/src/input_common/sdl/sdl_impl.cpp
index 7827e324c..d56b7587b 100644
--- a/src/input_common/sdl/sdl_impl.cpp
+++ b/src/input_common/sdl/sdl_impl.cpp
@@ -1014,11 +1014,44 @@ public:
}
return {};
}
- [[nodiscard]] std::optional<Common::ParamPackage> FromEvent(const SDL_Event& event) const {
+ [[nodiscard]] std::optional<Common::ParamPackage> FromEvent(SDL_Event& event) {
switch (event.type) {
case SDL_JOYAXISMOTION:
- if (std::abs(event.jaxis.value / 32767.0) < 0.5) {
+ if (!axis_memory.count(event.jaxis.which) ||
+ !axis_memory[event.jaxis.which].count(event.jaxis.axis)) {
+ axis_memory[event.jaxis.which][event.jaxis.axis] = event.jaxis.value;
+ axis_event_count[event.jaxis.which][event.jaxis.axis] = 1;
break;
+ } else {
+ axis_event_count[event.jaxis.which][event.jaxis.axis]++;
+ // The joystick and axis exist in our map if we take this branch, so no checks
+ // needed
+ if (std::abs(
+ (event.jaxis.value - axis_memory[event.jaxis.which][event.jaxis.axis]) /
+ 32767.0) < 0.5) {
+ break;
+ } else {
+ if (axis_event_count[event.jaxis.which][event.jaxis.axis] == 2 &&
+ IsAxisAtPole(event.jaxis.value) &&
+ IsAxisAtPole(axis_memory[event.jaxis.which][event.jaxis.axis])) {
+ // If we have exactly two events and both are near a pole, this is
+ // likely a digital input masquerading as an analog axis; Instead of
+ // trying to look at the direction the axis travelled, assume the first
+ // event was press and the second was release; This should handle most
+ // digital axes while deferring to the direction of travel for analog
+ // axes
+ event.jaxis.value = static_cast<Sint16>(
+ std::copysign(32767, axis_memory[event.jaxis.which][event.jaxis.axis]));
+ } else {
+ // There are more than two events, so this is likely a true analog axis,
+ // check the direction it travelled
+ event.jaxis.value = static_cast<Sint16>(std::copysign(
+ 32767,
+ event.jaxis.value - axis_memory[event.jaxis.which][event.jaxis.axis]));
+ }
+ axis_memory.clear();
+ axis_event_count.clear();
+ }
}
[[fallthrough]];
case SDL_JOYBUTTONUP:
@@ -1027,6 +1060,16 @@ public:
}
return std::nullopt;
}
+
+private:
+ // Determine whether an axis value is close to an extreme or center
+ // Some controllers have a digital D-Pad as a pair of analog sticks, with 3 possible values per
+ // axis, which is why the center must be considered a pole
+ bool IsAxisAtPole(int16_t value) const {
+ return std::abs(value) >= 32767 || std::abs(value) < 327;
+ }
+ std::unordered_map<SDL_JoystickID, std::unordered_map<uint8_t, int16_t>> axis_memory;
+ std::unordered_map<SDL_JoystickID, std::unordered_map<uint8_t, uint32_t>> axis_event_count;
};
class SDLMotionPoller final : public SDLPoller {