From 8c7508decde0c4ebfed11da19f90399719e904ae Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Mon, 22 Jun 2026 11:05:04 -0400
Subject: [PATCH] ps2: Treat the d-pad as a hat switch at the SDL_Joystick
level.
Reference Issue #14830.
---
src/joystick/SDL_gamepad_db.h | 2 +-
src/joystick/ps2/SDL_sysjoystick.c | 57 +++++++++++++++++++++++-------
2 files changed, 45 insertions(+), 14 deletions(-)
diff --git a/src/joystick/SDL_gamepad_db.h b/src/joystick/SDL_gamepad_db.h
index c184eefe237a3..7991d319d740c 100644
--- a/src/joystick/SDL_gamepad_db.h
+++ b/src/joystick/SDL_gamepad_db.h
@@ -868,7 +868,7 @@ static const char *s_GamepadMappings[] = {
"default,*,a:b0,b:b1,back:b6,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,guide:b10,leftshoulder:b4,leftstick:b8,lefttrigger:a4,leftx:a0,lefty:a1,rightshoulder:b5,rightstick:b9,righttrigger:a5,rightx:a2,righty:a3,start:b7,x:b2,y:b3,",
#endif
#ifdef SDL_JOYSTICK_PS2
- "0000000050533220436f6e74726f6c00,PS2 Controller,crc:ed87,a:b14,b:b13,back:b0,dpdown:b6,dpleft:b7,dpright:b5,dpup:b4,leftshoulder:b10,leftstick:b1,lefttrigger:b8,leftx:a0,lefty:a1,rightshoulder:b11,rightstick:b2,righttrigger:b9,rightx:a2,righty:a3,start:b3,x:b15,y:b12,",
+ "0000000050533220436f6e74726f6c00,PS2 Controller,crc:ed87,a:b10,b:b9,back:b0,dpdown:h0.4,dpleft:h0.8,dpright:h0.2,dpup:h0.1,leftshoulder:b6,leftstick:b1,lefttrigger:b4,leftx:a0,lefty:a1,rightshoulder:b7,rightstick:b2,righttrigger:b5,rightx:a2,righty:a3,start:b3,x:b11,y:b8,",
#endif
#ifdef SDL_JOYSTICK_PSP
"00000000505350206275696c74696e00,PSP builtin joypad,crc:bb86,a:b2,b:b1,back:b10,dpdown:b6,dpleft:b7,dpright:b9,dpup:b8,leftshoulder:b4,leftx:a0,lefty:a1,rightshoulder:b5,rightx:a2,righty:a3,start:b11,x:b3,y:b0,",
diff --git a/src/joystick/ps2/SDL_sysjoystick.c b/src/joystick/ps2/SDL_sysjoystick.c
index 36a4dc09b00b1..598e66d1f4f1e 100644
--- a/src/joystick/ps2/SDL_sysjoystick.c
+++ b/src/joystick/ps2/SDL_sysjoystick.c
@@ -38,9 +38,11 @@
#define MAX_CONTROLLERS (PS2_MAX_PORT * PS2_MAX_SLOT)
#define PS2_ANALOG_STICKS 2
#define PS2_ANALOG_AXIS 2
-#define PS2_BUTTONS 16
+#define PS2_BUTTONS 16 // this is total physical buttons, but we steal the 4 from the dpad for a hat switch.
#define PS2_TOTAL_AXIS (PS2_ANALOG_STICKS * PS2_ANALOG_AXIS)
+#define PS2_HAT_MASK 0xF0 // mask out bits 4-7 (that's the dpad, which we treat as a hat elsewhere).
+
struct JoyInfo
{
uint8_t padBuf[256];
@@ -269,9 +271,9 @@ static bool PS2_JoystickOpen(SDL_Joystick *joystick, int device_index)
}
PS2_InitializePad(info->port, info->slot);
- joystick->nbuttons = PS2_BUTTONS;
+ joystick->nbuttons = PS2_BUTTONS - 4; // we steal 4 (the d-pad) for a hat switch.
joystick->naxes = PS2_TOTAL_AXIS;
- joystick->nhats = 0;
+ joystick->nhats = 1; // treat the dpad buttons as a hat.
SDL_SetBooleanProperty(SDL_GetJoystickProperties(joystick), SDL_PROP_JOYSTICK_CAP_RUMBLE_BOOLEAN, true);
@@ -347,19 +349,48 @@ static void PS2_JoystickUpdate(SDL_Joystick *joystick)
int ret = padRead(info->port, info->slot, &buttons); // port, slot, buttons
if (ret != 0) {
// Buttons
- int32_t pressed_buttons = 0xffff ^ buttons.btns;
- ;
- if (info->btns != pressed_buttons) {
- for (i = 0; i < PS2_BUTTONS; i++) {
- mask = (1 << i);
- previous = info->btns & mask;
- current = pressed_buttons & mask;
- if (previous != current) {
- SDL_SendJoystickButton(timestamp, joystick, i, (current != 0));
+ const int32_t current_buttons = (0xffff ^ buttons.btns);
+ const int32_t previous_buttons = info->btns;
+ if (previous_buttons != current_buttons) { // did any buttons change?
+ if ((previous_buttons & ~PS2_HAT_MASK) != (current_buttons & ~PS2_HAT_MASK)) { // did non-dpad buttons change?
+ uint8_t buttonidx = 0;
+ i = 0;
+ while (i < PS2_BUTTONS-4) {
+ if ((buttonidx < 4) || (buttonidx > 7)) { // skip dpad (we treat it as a hat).
+ mask = (1 << buttonidx);
+ previous = previous_buttons & mask;
+ current = current_buttons & mask;
+ if (previous != current) {
+ SDL_SendJoystickButton(timestamp, joystick, i, (current != 0));
+ }
+ i++;
+ }
+ buttonidx++;
+ }
+ }
+
+ if ((previous_buttons & PS2_HAT_MASK) != (current_buttons & PS2_HAT_MASK)) { // did dpad buttons change?
+ // The PS2 dpad looks like 4 buttons at this level, but we treat it as a hat switch, so apps that are talking to SDL_Joystick can hope to do basic directional things without a configuration step.
+ // (but they should _really_ be using the gamepad API.)
+ Uint8 hat = SDL_HAT_CENTERED;
+ #define HATSTATE(ps2bit, sdlenum) if (current_buttons & (1 << ps2bit)) { hat |= SDL_HAT_##sdlenum; }
+ HATSTATE(4, UP);
+ HATSTATE(5, RIGHT);
+ HATSTATE(6, DOWN);
+ HATSTATE(7, LEFT);
+ #undef HATSTATE
+ // this is a physical d-pad on the device, so it probably _can't_ send opposing buttons at the same time, but just in case, cancel them out.
+ if ((hat & (SDL_HAT_UP|SDL_HAT_DOWN)) == (SDL_HAT_UP|SDL_HAT_DOWN)) {
+ hat &= ~(SDL_HAT_UP|SDL_HAT_DOWN);
+ }
+ if ((hat & (SDL_HAT_LEFT|SDL_HAT_RIGHT)) == (SDL_HAT_LEFT|SDL_HAT_RIGHT)) {
+ hat &= ~(SDL_HAT_LEFT|SDL_HAT_RIGHT);
}
+ SDL_SendJoystickHat(timestamp, joystick, 0, hat);
}
+
+ info->btns = current_buttons;
}
- info->btns = pressed_buttons;
// Analog
all_axis[0] = buttons.ljoy_h;