From 7ad15c5b8f937bb759ae1f7d85f1a144a65194c6 Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Sun, 15 May 2022 09:35:52 -0700
Subject: [PATCH] Added game controller support for virtual joysticks
Fixes https://github.com/libsdl-org/SDL/issues/5662
---
src/joystick/SDL_gamecontroller.c | 97 ++++++++++++++++++++++
src/joystick/SDL_sysjoystick.h | 1 +
src/joystick/virtual/SDL_virtualjoystick.c | 71 +++++++++++++++-
3 files changed, 168 insertions(+), 1 deletion(-)
diff --git a/src/joystick/SDL_gamecontroller.c b/src/joystick/SDL_gamecontroller.c
index fad7d9a0931..50eb190a53c 100644
--- a/src/joystick/SDL_gamecontroller.c
+++ b/src/joystick/SDL_gamecontroller.c
@@ -464,6 +464,100 @@ static int SDLCALL SDL_GameControllerEventWatcher(void *userdata, SDL_Event * ev
return 1;
}
+/*
+ * Helper function to guess at a mapping for virtual controllers
+ */
+static ControllerMapping_t *SDL_CreateMappingForVirtualController(SDL_JoystickGUID guid)
+{
+ const int face_button_mask = ((1 << SDL_CONTROLLER_BUTTON_A) |
+ (1 << SDL_CONTROLLER_BUTTON_B) |
+ (1 << SDL_CONTROLLER_BUTTON_X) |
+ (1 << SDL_CONTROLLER_BUTTON_Y));
+ SDL_bool existing;
+ char mapping_string[1024];
+ int button_mask;
+ int axis_mask;
+
+ button_mask = SDL_SwapLE16(*(Uint16*)(&guid.data[sizeof(guid.data)-4]));
+ axis_mask = SDL_SwapLE16(*(Uint16*)(&guid.data[sizeof(guid.data)-2]));
+ if (!button_mask && !axis_mask) {
+ return NULL;
+ }
+ if (!(button_mask & face_button_mask)) {
+ /* We don't know what buttons or axes are supported, don't make up a mapping */
+ return NULL;
+ }
+
+ SDL_strlcpy(mapping_string, "none,*,", sizeof(mapping_string));
+
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_A)) {
+ SDL_strlcat(mapping_string, "a:b0,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_B)) {
+ SDL_strlcat(mapping_string, "b:b1,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_X)) {
+ SDL_strlcat(mapping_string, "x:b2,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_Y)) {
+ SDL_strlcat(mapping_string, "y:b3,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_BACK)) {
+ SDL_strlcat(mapping_string, "back:b4,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_GUIDE)) {
+ SDL_strlcat(mapping_string, "guide:b5,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_START)) {
+ SDL_strlcat(mapping_string, "start:b6,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_LEFTSTICK)) {
+ SDL_strlcat(mapping_string, "leftstick:b7,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_RIGHTSTICK)) {
+ SDL_strlcat(mapping_string, "rightstick:b8,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_LEFTSHOULDER)) {
+ SDL_strlcat(mapping_string, "leftshoulder:b9,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_RIGHTSHOULDER)) {
+ SDL_strlcat(mapping_string, "rightshoulder:b10,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_DPAD_UP)) {
+ SDL_strlcat(mapping_string, "dpup:b11,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_DPAD_DOWN)) {
+ SDL_strlcat(mapping_string, "dpdown:b12,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_DPAD_LEFT)) {
+ SDL_strlcat(mapping_string, "dpleft:b13,", sizeof(mapping_string));
+ }
+ if (button_mask & (1 << SDL_CONTROLLER_BUTTON_DPAD_RIGHT)) {
+ SDL_strlcat(mapping_string, "dpright:b14,", sizeof(mapping_string));
+ }
+ if (axis_mask & (1 << SDL_CONTROLLER_AXIS_LEFTX)) {
+ SDL_strlcat(mapping_string, "leftx:a0,", sizeof(mapping_string));
+ }
+ if (axis_mask & (1 << SDL_CONTROLLER_AXIS_LEFTY)) {
+ SDL_strlcat(mapping_string, "lefty:a1,", sizeof(mapping_string));
+ }
+ if (axis_mask & (1 << SDL_CONTROLLER_AXIS_RIGHTX)) {
+ SDL_strlcat(mapping_string, "rightx:a2,", sizeof(mapping_string));
+ }
+ if (axis_mask & (1 << SDL_CONTROLLER_AXIS_RIGHTY)) {
+ SDL_strlcat(mapping_string, "righty:a3,", sizeof(mapping_string));
+ }
+ if (axis_mask & (1 << SDL_CONTROLLER_AXIS_TRIGGERLEFT)) {
+ SDL_strlcat(mapping_string, "lefttrigger:a4,", sizeof(mapping_string));
+ }
+ if (axis_mask & (1 << SDL_CONTROLLER_AXIS_TRIGGERRIGHT)) {
+ SDL_strlcat(mapping_string, "righttrigger:a5,", sizeof(mapping_string));
+ }
+
+ return SDL_PrivateAddMappingForGUID(guid, mapping_string,
+ &existing, SDL_CONTROLLER_MAPPING_PRIORITY_DEFAULT);
+}
+
#ifdef __ANDROID__
/*
* Helper function to guess at a mapping based on the elements reported for this controller
@@ -696,6 +790,9 @@ static ControllerMapping_t *SDL_PrivateGetControllerMappingForGUID(SDL_JoystickG
return s_pXInputMapping;
}
#endif
+ if (!mapping && SDL_IsJoystickVirtual(guid)) {
+ mapping = SDL_CreateMappingForVirtualController(guid);
+ }
#ifdef __ANDROID__
if (!mapping && !SDL_IsJoystickHIDAPI(guid)) {
mapping = SDL_CreateMappingForAndroidController(guid);
diff --git a/src/joystick/SDL_sysjoystick.h b/src/joystick/SDL_sysjoystick.h
index 37025ddde42..04b6b7a0c91 100644
--- a/src/joystick/SDL_sysjoystick.h
+++ b/src/joystick/SDL_sysjoystick.h
@@ -119,6 +119,7 @@ struct _SDL_Joystick
};
/* Device bus definitions */
+#define SDL_HARDWARE_BUS_VIRTUAL 0x00
#define SDL_HARDWARE_BUS_USB 0x03
#define SDL_HARDWARE_BUS_BLUETOOTH 0x05
diff --git a/src/joystick/virtual/SDL_virtualjoystick.c b/src/joystick/virtual/SDL_virtualjoystick.c
index 0e6525d5fb3..9be879b30aa 100644
--- a/src/joystick/virtual/SDL_virtualjoystick.c
+++ b/src/joystick/virtual/SDL_virtualjoystick.c
@@ -24,6 +24,7 @@
/* This is the virtual implementation of the SDL joystick API */
+#include "SDL_endian.h"
#include "SDL_virtualjoystick_c.h"
#include "../SDL_sysjoystick.h"
#include "../SDL_joystick_c.h"
@@ -94,6 +95,11 @@ SDL_JoystickAttachVirtualInner(SDL_JoystickType type,
{
joystick_hwdata *hwdata = NULL;
int device_index = -1;
+ const Uint16 vendor_id = 0;
+ const Uint16 product_id = 0;
+ Uint16 button_mask = 0;
+ Uint16 axis_mask = 0;
+ Uint16 *guid16;
hwdata = SDL_calloc(1, sizeof(joystick_hwdata));
if (!hwdata) {
@@ -104,7 +110,69 @@ SDL_JoystickAttachVirtualInner(SDL_JoystickType type,
hwdata->naxes = naxes;
hwdata->nbuttons = nbuttons;
hwdata->nhats = nhats;
- hwdata->name = "Virtual Joystick";
+
+ switch (type) {
+ case SDL_JOYSTICK_TYPE_GAMECONTROLLER:
+ hwdata->name = "Virtual Controller";
+ break;
+ case SDL_JOYSTICK_TYPE_WHEEL:
+ hwdata->name = "Virtual Wheel";
+ break;
+ case SDL_JOYSTICK_TYPE_ARCADE_STICK:
+ hwdata->name = "Virtual Arcade Stick";
+ break;
+ case SDL_JOYSTICK_TYPE_FLIGHT_STICK:
+ hwdata->name = "Virtual Flight Stick";
+ break;
+ case SDL_JOYSTICK_TYPE_DANCE_PAD:
+ hwdata->name = "Virtual Dance Pad";
+ break;
+ case SDL_JOYSTICK_TYPE_GUITAR:
+ hwdata->name = "Virtual Guitar";
+ break;
+ case SDL_JOYSTICK_TYPE_DRUM_KIT:
+ hwdata->name = "Virtual Drum Kit";
+ break;
+ case SDL_JOYSTICK_TYPE_ARCADE_PAD:
+ hwdata->name = "Virtual Arcade Pad";
+ break;
+ case SDL_JOYSTICK_TYPE_THROTTLE:
+ hwdata->name = "Virtual Throttle";
+ break;
+ default:
+ hwdata->name = "Virtual Joystick";
+ break;
+ }
+
+ if (type == SDL_JOYSTICK_TYPE_GAMECONTROLLER) {
+ int i;
+
+ if (naxes >= 2) {
+ axis_mask |= ((1 << SDL_CONTROLLER_AXIS_LEFTX) | (1 << SDL_CONTROLLER_AXIS_LEFTY));
+ }
+ if (naxes >= 4) {
+ axis_mask |= ((1 << SDL_CONTROLLER_AXIS_RIGHTX) | (1 << SDL_CONTROLLER_AXIS_RIGHTY));
+ }
+ if (naxes >= 6) {
+ axis_mask |= ((1 << SDL_CONTROLLER_AXIS_TRIGGERLEFT) | (1 << SDL_CONTROLLER_AXIS_TRIGGERRIGHT));
+ }
+
+ for (i = 0; i < nbuttons && i < sizeof(Uint16)*8; ++i) {
+ button_mask |= (1 << i);
+ }
+ }
+
+ /* We only need 16 bits for each of these; space them out to fill 128. */
+ /* Byteswap so devices get same GUID on little/big endian platforms. */
+ guid16 = (Uint16 *)hwdata->guid.data;
+ *guid16++ = SDL_SwapLE16(SDL_HARDWARE_BUS_VIRTUAL);
+ *guid16++ = 0;
+ *guid16++ = SDL_SwapLE16(vendor_id);
+ *guid16++ = 0;
+ *guid16++ = SDL_SwapLE16(product_id);
+ *guid16++ = 0;
+ *guid16++ = SDL_SwapLE16(button_mask);
+ *guid16++ = SDL_SwapLE16(axis_mask);
/* Note that this is a Virtual device and what subtype it is */
hwdata->guid.data[14] = 'v';
@@ -326,6 +394,7 @@ VIRTUAL_JoystickOpen(SDL_Joystick *joystick, int device_index)
return SDL_SetError("No such device");
}
if (hwdata->opened) {
+ /* This should never happen, it's handled by the higher joystick code */
return SDL_SetError("Joystick already opened");
}
joystick->instance_id = hwdata->instance_id;