N3DS port (squashed)

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

src/thread/SDL_thread_c.h

@@ -38,6 +38,8 @@
 #include "psp/SDL_systhread_c.h"
 #elif SDL_THREAD_VITA
 #include "vita/SDL_systhread_c.h"
+#elif SDL_THREAD_N3DS
+#include "n3ds/SDL_systhread_c.h"
 #elif SDL_THREAD_STDCPP
 #include "stdcpp/SDL_systhread_c.h"
 #elif SDL_THREAD_OS2

src/thread/n3ds/SDL_syscond.c

@@ -0,0 +1,133 @@
+/*
+  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_THREAD_N3DS
+
+/* An implementation of condition variables using libctru's CondVar */
+
+#include "SDL_sysmutex_c.h"
+
+struct SDL_cond
+{
+    CondVar cond_variable;
+};
+
+/* Create a condition variable */
+SDL_cond *
+SDL_CreateCond(void)
+{
+    SDL_cond *cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
+    if (cond) {
+        CondVar_Init(&cond->cond_variable);
+    } else {
+        SDL_OutOfMemory();
+    }
+    return cond;
+}
+
+/* Destroy a condition variable */
+void
+SDL_DestroyCond(SDL_cond *cond)
+{
+    if (cond) {
+        SDL_free(cond);
+    }
+}
+
+/* Restart one of the threads that are waiting on the condition variable */
+int
+SDL_CondSignal(SDL_cond *cond)
+{
+    if (!cond) {
+        return SDL_SetError("Passed a NULL condition variable");
+    }
+
+    CondVar_Signal(&cond->cond_variable);
+    return 0;
+}
+
+/* Restart all threads that are waiting on the condition variable */
+int
+SDL_CondBroadcast(SDL_cond *cond)
+{
+    if (!cond) {
+        return SDL_SetError("Passed a NULL condition variable");
+    }
+
+    CondVar_Broadcast(&cond->cond_variable);
+    return 0;
+}
+
+/* Wait on the condition variable for at most 'ms' milliseconds.
+   The mutex must be locked before entering this function!
+   The mutex is unlocked during the wait, and locked again after the wait.
+
+Typical use:
+
+Thread A:
+    SDL_LockMutex(lock);
+    while ( ! condition ) {
+        SDL_CondWait(cond, lock);
+    }
+    SDL_UnlockMutex(lock);
+
+Thread B:
+    SDL_LockMutex(lock);
+    ...
+    condition = true;
+    ...
+    SDL_CondSignal(cond);
+    SDL_UnlockMutex(lock);
+ */
+int
+SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)
+{
+    Result res;
+
+    if (!cond) {
+        return SDL_SetError("Passed a NULL condition variable");
+    }
+    if (!mutex) {
+        return SDL_SetError("Passed a NULL mutex");
+    }
+
+    res = 0;
+    if (ms == SDL_MUTEX_MAXWAIT) {
+        CondVar_Wait(&cond->cond_variable, &mutex->lock.lock);
+    } else {
+        res = CondVar_WaitTimeout(&cond->cond_variable, &mutex->lock.lock,
+                                  (s64) ms * 1000000LL);
+    }
+
+    return R_SUCCEEDED(res) ? 0 : SDL_MUTEX_TIMEDOUT;
+}
+
+/* Wait on the condition variable forever */
+int
+SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex)
+{
+    return SDL_CondWaitTimeout(cond, mutex, SDL_MUTEX_MAXWAIT);
+}
+
+#endif /* SDL_THREAD_N3DS */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */

src/thread/n3ds/SDL_sysmutex.c

@@ -0,0 +1,93 @@
+/*
+  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_THREAD_N3DS
+
+/* An implementation of mutexes using libctru's RecursiveLock */
+
+#include "SDL_sysmutex_c.h"
+
+/* Create a mutex */
+SDL_mutex *
+SDL_CreateMutex(void)
+{
+    SDL_mutex *mutex;
+
+    /* Allocate mutex memory */
+    mutex = (SDL_mutex *) SDL_malloc(sizeof(*mutex));
+    if (mutex) {
+        RecursiveLock_Init(&mutex->lock);
+    } else {
+        SDL_OutOfMemory();
+    }
+    return mutex;
+}
+
+/* Free the mutex */
+void
+SDL_DestroyMutex(SDL_mutex *mutex)
+{
+    if (mutex) {
+        SDL_free(mutex);
+    }
+}
+
+/* Lock the mutex */
+int
+SDL_LockMutex(SDL_mutex *mutex)
+{
+    if (mutex == NULL) {
+        return SDL_SetError("Passed a NULL mutex");
+    }
+
+    RecursiveLock_Lock(&mutex->lock);
+
+    return 0;
+}
+
+/* try Lock the mutex */
+int
+SDL_TryLockMutex(SDL_mutex *mutex)
+{
+    if (mutex == NULL) {
+        return SDL_SetError("Passed a NULL mutex");
+    }
+
+    return RecursiveLock_TryLock(&mutex->lock);
+}
+
+/* Unlock the mutex */
+int
+SDL_mutexV(SDL_mutex *mutex)
+{
+    if (mutex == NULL) {
+        return SDL_SetError("Passed a NULL mutex");
+    }
+
+    RecursiveLock_Unlock(&mutex->lock);
+
+    return 0;
+}
+
+#endif /* SDL_THREAD_N3DS */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */

src/thread/n3ds/SDL_sysmutex_c.h

@@ -0,0 +1,37 @@
+/*
+  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"
+
+#ifndef SDL_sysmutex_c_h_
+#define SDL_sysmutex_c_h_
+
+#include <3ds.h>
+
+#include "SDL_mutex.h"
+
+struct SDL_mutex
+{
+    RecursiveLock lock;
+};
+
+#endif /* SDL_sysmutex_c_h */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */

src/thread/n3ds/SDL_syssem.c

@@ -0,0 +1,134 @@
+/*
+  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_THREAD_N3DS
+
+/* An implementation of semaphores using libctru's LightSemaphore */
+
+#include <3ds.h>
+
+#include "SDL_thread.h"
+
+struct SDL_semaphore
+{
+    LightSemaphore semaphore;
+};
+
+SDL_sem *
+SDL_CreateSemaphore(Uint32 initial_value)
+{
+    SDL_sem *sem;
+
+    if (initial_value > SDL_MAX_SINT16) {
+        SDL_SetError("Initial semaphore value too high for this platform");
+        return NULL;
+    }
+
+    sem = (SDL_sem *) SDL_malloc(sizeof(*sem));
+    if (!sem) {
+        SDL_OutOfMemory();
+        return NULL;
+    }
+
+    LightSemaphore_Init(&sem->semaphore, initial_value, SDL_MAX_SINT16);
+
+    return sem;
+}
+
+/* WARNING:
+   You cannot call this function when another thread is using the semaphore.
+*/
+void
+SDL_DestroySemaphore(SDL_sem *sem)
+{
+    if (sem) {
+        SDL_free(sem);
+    }
+}
+
+int
+SDL_SemTryWait(SDL_sem *sem)
+{
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+
+    return SDL_SemWaitTimeout(sem, 0);
+}
+
+int
+SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
+{
+    int retval;
+
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+
+    if (timeout == SDL_MUTEX_MAXWAIT) {
+        LightSemaphore_Acquire(&sem->semaphore, 1);
+        retval = 0;
+    } else {
+        int return_code = LightSemaphore_TryAcquire(&sem->semaphore, 1);
+        if (return_code != 0) {
+            for (u32 i = 0; i < timeout; i++) {
+                svcSleepThread(1000000LL);
+                return_code = LightSemaphore_TryAcquire(&sem->semaphore, 1);
+                if (return_code == 0) {
+                    break;
+                }
+            }
+        }
+        retval = return_code != 0 ? SDL_MUTEX_TIMEDOUT : 0;
+    }
+
+    return retval;
+}
+
+int
+SDL_SemWait(SDL_sem *sem)
+{
+    return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
+}
+
+Uint32
+SDL_SemValue(SDL_sem *sem)
+{
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+    return sem->semaphore.current_count;
+}
+
+int
+SDL_SemPost(SDL_sem *sem)
+{
+    if (!sem) {
+        return SDL_SetError("Passed a NULL semaphore");
+    }
+    LightSemaphore_Release(&sem->semaphore, 1);
+    return 0;
+}
+
+#endif /* SDL_THREAD_N3DS */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */

src/thread/n3ds/SDL_systhread.c

@@ -0,0 +1,148 @@
+/*
+  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_THREAD_N3DS
+
+/* Thread management routines for SDL */
+
+#include "../SDL_systhread.h"
+
+/* N3DS has very limited RAM (128MB), so we put a limit on thread stack size. */
+#define N3DS_THREAD_STACK_SIZE_MAX     (16 * 1024)
+#define N3DS_THREAD_STACK_SIZE_DEFAULT (4 * 1024)
+
+#define N3DS_THREAD_PRIORITY_LOW           0x3F /**< Minimum priority */
+#define N3DS_THREAD_PRIORITY_MEDIUM        0x2F /**< Slightly higher than main thread (0x30) */
+#define N3DS_THREAD_PRIORITY_HIGH          0x19 /**< High priority for non-video work */
+#define N3DS_THREAD_PRIORITY_TIME_CRITICAL 0x18 /**< Highest priority */
+
+static size_t GetStackSize(size_t requested_size);
+
+static void
+ThreadEntry(void *arg)
+{
+    SDL_RunThread((SDL_Thread *) arg);
+    threadExit(0);
+}
+
+#ifdef SDL_PASSED_BEGINTHREAD_ENDTHREAD
+#error "SDL_PASSED_BEGINTHREAD_ENDTHREAD is not supported on N3DS"
+#endif
+
+int
+SDL_SYS_CreateThread(SDL_Thread *thread)
+{
+    s32 priority = N3DS_THREAD_PRIORITY_MEDIUM;
+    size_t stack_size = GetStackSize(thread->stacksize);
+
+    thread->handle = threadCreate(ThreadEntry,
+                                  thread,
+                                  stack_size,
+                                  priority,
+                                  -1,
+                                  false);
+
+    if (thread->handle == NULL) {
+        return SDL_SetError("Couldn't create thread");
+    }
+
+    return 0;
+}
+
+static size_t
+GetStackSize(size_t requested_size)
+{
+    if (requested_size == 0) {
+        return N3DS_THREAD_STACK_SIZE_DEFAULT;
+    }
+
+    if (requested_size > N3DS_THREAD_STACK_SIZE_MAX) {
+        SDL_LogWarn(SDL_LOG_CATEGORY_SYSTEM,
+                    "Requested a thread size of %zu,"
+                    " falling back to the maximum supported of %zu\n",
+                    requested_size,
+                    N3DS_THREAD_STACK_SIZE_MAX);
+        requested_size = N3DS_THREAD_STACK_SIZE_MAX;
+    }
+    return requested_size;
+}
+
+void
+SDL_SYS_SetupThread(const char *name)
+{
+    return;
+}
+
+SDL_threadID
+SDL_ThreadID(void)
+{
+    u32 thread_ID = 0;
+    svcGetThreadId(&thread_ID, CUR_THREAD_HANDLE);
+    return (SDL_threadID) thread_ID;
+}
+
+int
+SDL_SYS_SetThreadPriority(SDL_ThreadPriority sdl_priority)
+{
+    s32 svc_priority;
+    switch (sdl_priority) {
+    case SDL_THREAD_PRIORITY_LOW:
+        svc_priority = N3DS_THREAD_PRIORITY_LOW;
+        break;
+    case SDL_THREAD_PRIORITY_NORMAL:
+        svc_priority = N3DS_THREAD_PRIORITY_MEDIUM;
+        break;
+    case SDL_THREAD_PRIORITY_HIGH:
+        svc_priority = N3DS_THREAD_PRIORITY_HIGH;
+        break;
+    case SDL_THREAD_PRIORITY_TIME_CRITICAL:
+        svc_priority = N3DS_THREAD_PRIORITY_TIME_CRITICAL;
+        break;
+    default:
+        svc_priority = N3DS_THREAD_PRIORITY_MEDIUM;
+    }
+    return (int) svcSetThreadPriority(CUR_THREAD_HANDLE, svc_priority);
+}
+
+void
+SDL_SYS_WaitThread(SDL_Thread *thread)
+{
+    Result res = threadJoin(thread->handle, U64_MAX);
+
+    /*
+      Detached threads can be waited on, but should NOT be cleaned manually
+      as it would result in a fatal error.
+    */
+    if (R_SUCCEEDED(res) && SDL_AtomicGet(&thread->state) != SDL_THREAD_STATE_DETACHED) {
+        threadFree(thread->handle);
+    }
+}
+
+void
+SDL_SYS_DetachThread(SDL_Thread *thread)
+{
+    threadDetach(thread->handle);
+}
+
+#endif /* SDL_THREAD_N3DS */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */

src/thread/n3ds/SDL_systhread_c.h

@@ -0,0 +1,32 @@
+/*
+  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"
+
+#ifndef SDL_systhread_c_h_
+#define SDL_systhread_c_h_
+
+#include <3ds.h>
+
+typedef Thread SYS_ThreadHandle;
+
+#endif /* SDL_systhread_c_h_ */
+
+/* vi: set sts=4 ts=4 sw=4 expandtab: */