N3DS port (squashed)

A dedicated renderer using Citro3D would likely allow for better
much better graphical performances.

src/joystick/SDL_gamecontrollerdb.h

@@ -977,6 +977,9 @@ static const char *s_ControllerMappings [] =
 #endif
 #if SDL_JOYSTICK_VITA
     "0000000050535669746120436f6e7400,PSVita Controller,crc:d598,a:b2,b:b1,back:b10,dpdown:b6,dpleft:b7,dpright:b9,dpup:b8,leftshoulder:b4,leftstick:b14,lefttrigger:a4,leftx:a0,lefty:a1,rightshoulder:b5,rightstick:b15,righttrigger:a5,rightx:a2,righty:a3,start:b11,x:b3,y:b0,",
+#endif
+#if SDL_JOYSTICK_N3DS
+    "4e696e74656e646f20334453206d6170,Nintendo 3DS,a:b0,b:b1,back:b2,dpdown:b7,dpleft:b5,dpright:b4,dpup:b6,leftshoulder:b9,leftstick:b14,leftx:a0,lefty:a1,rightshoulder:b8,rightstick:b15,rightx:a2,righty:a3,start:b3,x:b10,y:b11,",
 #endif
     "hidapi,*,a:b0,b:b1,back:b4,dpdown:b12,dpleft:b13,dpright:b14,dpup:b11,guide:b5,leftshoulder:b9,leftstick:b7,lefttrigger:a4,leftx:a0,lefty:a1,rightshoulder:b10,rightstick:b8,righttrigger:a5,rightx:a2,righty:a3,start:b6,x:b2,y:b3,",
     NULL

src/joystick/SDL_joystick.c

@@ -102,6 +102,9 @@ static SDL_JoystickDriver *SDL_joystick_drivers[] = {
 #ifdef SDL_JOYSTICK_VITA
     &SDL_VITA_JoystickDriver,
 #endif
+#ifdef SDL_JOYSTICK_N3DS
+    &SDL_N3DS_JoystickDriver
+#endif
 #if defined(SDL_JOYSTICK_DUMMY) || defined(SDL_JOYSTICK_DISABLED)
     &SDL_DUMMY_JoystickDriver
 #endif

src/joystick/SDL_sysjoystick.h

@@ -238,6 +238,7 @@ extern SDL_JoystickDriver SDL_OS2_JoystickDriver;
 extern SDL_JoystickDriver SDL_PS2_JoystickDriver;
 extern SDL_JoystickDriver SDL_PSP_JoystickDriver;
 extern SDL_JoystickDriver SDL_VITA_JoystickDriver;
+extern SDL_JoystickDriver SDL_N3DS_JoystickDriver;
 
 /* Ends C function definitions when using C++ */
 #ifdef __cplusplus

src/joystick/n3ds/SDL_sysjoystick.c

@@ -0,0 +1,367 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+#ifdef SDL_JOYSTICK_N3DS
+
+/* This is the N3DS implementation of the SDL joystick API */
+
+#include <3ds.h>
+
+#include "../SDL_sysjoystick.h"
+#include "SDL_events.h"
+
+#define NB_BUTTONS 23
+
+/*
+  N3DS sticks values are roughly within +/-160
+  which is too small to pass the jitter tolerance.
+  This correction factor is applied to axis values
+  so they fit better in SDL's value range.
+*/
+#define CORRECTION_FACTOR_X SDL_JOYSTICK_AXIS_MAX / 160
+
+/*
+  The Y axis needs to be flipped because SDL's "up"
+  is reversed compared to libctru's "up"
+*/
+#define CORRECTION_FACTOR_Y -CORRECTION_FACTOR_X
+
+/*
+  Factors used to convert touchscreen coordinates to
+  SDL's 0-1 values. Note that the N3DS's screen is
+  internally in a portrait disposition so the
+  GSP_SCREEN constants are flipped.
+*/
+#define TOUCHPAD_SCALE_X 1.0f / GSP_SCREEN_HEIGHT_BOTTOM
+#define TOUCHPAD_SCALE_Y 1.0f / GSP_SCREEN_WIDTH
+
+typedef struct N3DSJoystickState
+{
+    u32 kDown;
+    u32 kUp;
+    circlePosition circlePos;
+    circlePosition cStickPos;
+    accelVector acceleration;
+    angularRate rate;
+} N3DSJoystickState;
+
+SDL_FORCE_INLINE void UpdateAxis(SDL_Joystick *joystick, N3DSJoystickState *previous_state);
+SDL_FORCE_INLINE void UpdateButtons(SDL_Joystick *joystick, N3DSJoystickState *previous_state);
+SDL_FORCE_INLINE void UpdateSensors(SDL_Joystick *joystick, N3DSJoystickState *previous_state);
+SDL_FORCE_INLINE void UpdateTouch(SDL_Joystick *joystick);
+
+static N3DSJoystickState current_state;
+static SDL_bool sensors_enabled = SDL_FALSE;
+
+static int
+N3DS_JoystickInit(void)
+{
+    hidInit();
+    HIDUSER_EnableAccelerometer();
+    HIDUSER_EnableGyroscope();
+    return 0;
+}
+
+static const char *
+N3DS_JoystickGetDeviceName(int device_index)
+{
+    return "Nintendo 3DS";
+}
+
+static int
+N3DS_JoystickGetCount(void)
+{
+    return 1;
+}
+
+static SDL_JoystickGUID
+N3DS_JoystickGetDeviceGUID(int device_index)
+{
+    /* GUID corresponds to the name "Nintendo 3DS map" */
+    SDL_JoystickGUID guid = { { 0x4e, 0x69, 0x6e, 0x74, 0x65, 0x6e, 0x64, 0x6f, 0x20, 0x33, 0x44, 0x53, 0x20, 0x6d, 0x61, 0x70 } };
+    return guid;
+}
+
+static SDL_JoystickID
+N3DS_JoystickGetDeviceInstanceID(int device_index)
+{
+    return device_index;
+}
+
+static int
+N3DS_JoystickOpen(SDL_Joystick *joystick, int device_index)
+{
+    joystick->nbuttons = NB_BUTTONS;
+    joystick->naxes = 4;
+    joystick->nhats = 0;
+    joystick->instance_id = device_index;
+
+    SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_ACCEL, 0.0f);
+    SDL_PrivateJoystickAddSensor(joystick, SDL_SENSOR_GYRO, 0.0f);
+    SDL_PrivateJoystickAddTouchpad(joystick, 1);
+
+    return 0;
+}
+
+static int
+N3DS_JoystickSetSensorsEnabled(SDL_Joystick *joystick, SDL_bool enabled)
+{
+    sensors_enabled = enabled;
+    return 0;
+}
+
+static void
+N3DS_JoystickUpdate(SDL_Joystick *joystick)
+{
+    N3DSJoystickState previous_state = current_state;
+    hidScanInput();
+
+    UpdateAxis(joystick, &previous_state);
+    UpdateButtons(joystick, &previous_state);
+    UpdateTouch(joystick);
+
+    if (sensors_enabled) {
+        UpdateSensors(joystick, &previous_state);
+    }
+}
+
+SDL_FORCE_INLINE void
+UpdateAxis(SDL_Joystick *joystick, N3DSJoystickState *previous_state)
+{
+    hidCircleRead(&current_state.circlePos);
+    if (previous_state->circlePos.dx != current_state.circlePos.dx) {
+        SDL_PrivateJoystickAxis(joystick,
+                                0,
+                                current_state.circlePos.dx * CORRECTION_FACTOR_X);
+    }
+    if (previous_state->circlePos.dy != current_state.circlePos.dy) {
+        SDL_PrivateJoystickAxis(joystick,
+                                1,
+                                current_state.circlePos.dy * CORRECTION_FACTOR_Y);
+    }
+
+    hidCstickRead(&current_state.cStickPos);
+    if (previous_state->cStickPos.dx != current_state.cStickPos.dx) {
+        SDL_PrivateJoystickAxis(joystick,
+                                2,
+                                current_state.cStickPos.dx * CORRECTION_FACTOR_X);
+    }
+    if (previous_state->cStickPos.dy != current_state.cStickPos.dy) {
+        SDL_PrivateJoystickAxis(joystick,
+                                3,
+                                current_state.cStickPos.dy * CORRECTION_FACTOR_Y);
+    }
+}
+
+SDL_FORCE_INLINE void
+UpdateButtons(SDL_Joystick *joystick, N3DSJoystickState *previous_state)
+{
+    u32 updated_down, updated_up;
+
+    current_state.kDown = hidKeysDown();
+    updated_down = previous_state->kDown ^ current_state.kDown;
+    if (updated_down) {
+        for (Uint8 i = 0; i < joystick->nbuttons; i++) {
+            if (current_state.kDown & BIT(i) & updated_down) {
+                SDL_PrivateJoystickButton(joystick, i, SDL_PRESSED);
+            }
+        }
+    }
+
+    current_state.kUp = hidKeysUp();
+    updated_up = previous_state->kUp ^ current_state.kUp;
+    if (updated_up) {
+        for (Uint8 i = 0; i < joystick->nbuttons; i++) {
+            if (current_state.kUp & BIT(i) & updated_up) {
+                SDL_PrivateJoystickButton(joystick, i, SDL_RELEASED);
+            }
+        }
+    }
+}
+
+SDL_FORCE_INLINE void
+UpdateTouch(SDL_Joystick *joystick)
+{
+    touchPosition touch;
+    Uint8 state;
+    hidTouchRead(&touch);
+    state = (touch.px == 0 && touch.py == 0) ? SDL_RELEASED : SDL_PRESSED;
+
+    SDL_PrivateJoystickTouchpad(joystick,
+                                0,
+                                0,
+                                state,
+                                touch.px * TOUCHPAD_SCALE_X,
+                                touch.py * TOUCHPAD_SCALE_Y,
+                                state == SDL_PRESSED ? 1.0f : 0.0f);
+}
+
+SDL_FORCE_INLINE void
+UpdateSensors(SDL_Joystick *joystick, N3DSJoystickState *previous_state)
+{
+    float data[3];
+
+    hidAccelRead(&current_state.acceleration);
+    if (SDL_memcmp(&previous_state->acceleration, &current_state.acceleration, sizeof(accelVector)) != 0) {
+        SDL_memcpy(&previous_state->acceleration, &current_state.acceleration, sizeof(accelVector));
+        data[0] = (float) current_state.acceleration.x * SDL_STANDARD_GRAVITY;
+        data[1] = (float) current_state.acceleration.y * SDL_STANDARD_GRAVITY;
+        data[2] = (float) current_state.acceleration.z * SDL_STANDARD_GRAVITY;
+        SDL_PrivateJoystickSensor(joystick, SDL_SENSOR_ACCEL, data, sizeof data);
+    }
+
+    hidGyroRead(&current_state.rate);
+    if (SDL_memcmp(&previous_state->rate, &current_state.rate, sizeof(angularRate)) != 0) {
+        SDL_memcpy(&previous_state->rate, &current_state.rate, sizeof(angularRate));
+        data[0] = (float) current_state.rate.y;
+        data[1] = (float) current_state.rate.z;
+        data[2] = (float) current_state.rate.x;
+        SDL_PrivateJoystickSensor(joystick, SDL_SENSOR_GYRO, data, sizeof data);
+    }
+}
+
+static void
+N3DS_JoystickClose(SDL_Joystick *joystick)
+{
+}
+
+static void
+N3DS_JoystickQuit(void)
+{
+    HIDUSER_DisableGyroscope();
+    HIDUSER_DisableAccelerometer();
+    hidExit();
+}
+
+static SDL_bool
+N3DS_JoystickGetGamepadMapping(int device_index, SDL_GamepadMapping *out)
+{
+    /* There is only one possible mapping. */
+    *out = (SDL_GamepadMapping){
+        .a = { EMappingKind_Button, 0 },
+        .b = { EMappingKind_Button, 1 },
+        .x = { EMappingKind_Button, 10 },
+        .y = { EMappingKind_Button, 11 },
+        .back = { EMappingKind_Button, 2 },
+        .guide = { EMappingKind_None, 255 },
+        .start = { EMappingKind_Button, 3 },
+        .leftstick = { EMappingKind_None, 255 },
+        .rightstick = { EMappingKind_None, 255 },
+        .leftshoulder = { EMappingKind_Button, 9 },
+        .rightshoulder = { EMappingKind_Button, 8 },
+        .dpup = { EMappingKind_Button, 6 },
+        .dpdown = { EMappingKind_Button, 7 },
+        .dpleft = { EMappingKind_Button, 5 },
+        .dpright = { EMappingKind_Button, 4 },
+        .misc1 = { EMappingKind_None, 255 },
+        .paddle1 = { EMappingKind_None, 255 },
+        .paddle2 = { EMappingKind_None, 255 },
+        .paddle3 = { EMappingKind_None, 255 },
+        .paddle4 = { EMappingKind_None, 255 },
+        .leftx = { EMappingKind_Axis, 0 },
+        .lefty = { EMappingKind_Axis, 1 },
+        .rightx = { EMappingKind_Axis, 2 },
+        .righty = { EMappingKind_Axis, 3 },
+        .lefttrigger = { EMappingKind_Button, 14 },
+        .righttrigger = { EMappingKind_Button, 15 },
+    };
+    return SDL_TRUE;
+}
+
+static void
+N3DS_JoystickDetect(void)
+{
+}
+
+static const char *
+N3DS_JoystickGetDevicePath(int device_index)
+{
+    return NULL;
+}
+
+static int
+N3DS_JoystickGetDevicePlayerIndex(int device_index)
+{
+    return -1;
+}
+
+static void
+N3DS_JoystickSetDevicePlayerIndex(int device_index, int player_index)
+{
+}
+
+static Uint32
+N3DS_JoystickGetCapabilities(SDL_Joystick *joystick)
+{
+    return 0;
+}
+
+static int
+N3DS_JoystickRumble(SDL_Joystick *joystick, Uint16 low_frequency_rumble, Uint16 high_frequency_rumble)
+{
+    return SDL_Unsupported();
+}
+
+static int
+N3DS_JoystickRumbleTriggers(SDL_Joystick *joystick, Uint16 left_rumble, Uint16 right_rumble)
+{
+    return SDL_Unsupported();
+}
+
+static int
+N3DS_JoystickSetLED(SDL_Joystick *joystick, Uint8 red, Uint8 green, Uint8 blue)
+{
+    return SDL_Unsupported();
+}
+
+static int
+N3DS_JoystickSendEffect(SDL_Joystick *joystick, const void *data, int size)
+{
+    return SDL_Unsupported();
+}
+
+SDL_JoystickDriver SDL_N3DS_JoystickDriver = {
+    N3DS_JoystickInit,
+    N3DS_JoystickGetCount,
+    N3DS_JoystickDetect,
+    N3DS_JoystickGetDeviceName,
+    N3DS_JoystickGetDevicePath,
+    N3DS_JoystickGetDevicePlayerIndex,
+    N3DS_JoystickSetDevicePlayerIndex,
+    N3DS_JoystickGetDeviceGUID,
+    N3DS_JoystickGetDeviceInstanceID,
+    N3DS_JoystickOpen,
+    N3DS_JoystickRumble,
+    N3DS_JoystickRumbleTriggers,
+    N3DS_JoystickGetCapabilities,
+    N3DS_JoystickSetLED,
+    N3DS_JoystickSendEffect,
+    N3DS_JoystickSetSensorsEnabled,
+    N3DS_JoystickUpdate,
+    N3DS_JoystickClose,
+    N3DS_JoystickQuit,
+    N3DS_JoystickGetGamepadMapping
+};
+
+#endif /* SDL_JOYSTICK_N3DS */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */