From 2c11d62d17869606524235fe84e93326cd46a99f Mon Sep 17 00:00:00 2001
From: "Ryan C. Gordon" <[EMAIL REDACTED]>
Date: Tue, 2 Dec 2025 20:26:08 -0500
Subject: [PATCH] camera: Report rotation needed to account for device
orientation.
Fixes #11476.
---
include/SDL3/SDL_surface.h | 7 ++
src/camera/SDL_camera.c | 7 +-
src/camera/SDL_syscamera.h | 9 ++-
src/camera/android/SDL_camera_android.c | 33 ++++++++-
src/camera/coremedia/SDL_camera_coremedia.m | 70 ++++++++++++++++++-
src/camera/dummy/SDL_camera_dummy.c | 2 +-
src/camera/emscripten/SDL_camera_emscripten.c | 2 +-
.../SDL_camera_mediafoundation.c | 4 +-
src/camera/pipewire/SDL_camera_pipewire.c | 2 +-
src/camera/v4l2/SDL_camera_v4l2.c | 2 +-
src/camera/vita/SDL_camera_vita.c | 2 +-
test/testcamera.c | 7 +-
12 files changed, 132 insertions(+), 15 deletions(-)
diff --git a/include/SDL3/SDL_surface.h b/include/SDL3/SDL_surface.h
index 053557fc2fd05..b46491d50d552 100644
--- a/include/SDL3/SDL_surface.h
+++ b/include/SDL3/SDL_surface.h
@@ -241,6 +241,12 @@ extern SDL_DECLSPEC void SDLCALL SDL_DestroySurface(SDL_Surface *surface);
* left edge of the image, if this surface is being used as a cursor.
* - `SDL_PROP_SURFACE_HOTSPOT_Y_NUMBER`: the hotspot pixel offset from the
* top edge of the image, if this surface is being used as a cursor.
+ * - `SDL_PROP_SURFACE_ROTATION_NUMBER`: the number of degrees a surface's
+ * data is meant to be rotated clockwise to make the image
+ * right-side up. Default 0. This is used by the camera API, if a mobile
+ * device is oriented differently than what its camera provides (i.e. -
+ * the camera always provides portrait images but the phone is being held
+ * in landscape orientation). Since SDL 3.4.0.
*
* \param surface the SDL_Surface structure to query.
* \returns a valid property ID on success or 0 on failure; call
@@ -257,6 +263,7 @@ extern SDL_DECLSPEC SDL_PropertiesID SDLCALL SDL_GetSurfaceProperties(SDL_Surfac
#define SDL_PROP_SURFACE_TONEMAP_OPERATOR_STRING "SDL.surface.tonemap"
#define SDL_PROP_SURFACE_HOTSPOT_X_NUMBER "SDL.surface.hotspot.x"
#define SDL_PROP_SURFACE_HOTSPOT_Y_NUMBER "SDL.surface.hotspot.y"
+#define SDL_PROP_SURFACE_ROTATION_NUMBER "SDL.surface.rotation"
/**
* Set the colorspace used by a surface.
diff --git a/src/camera/SDL_camera.c b/src/camera/SDL_camera.c
index a8f9e8856ec3a..b3c3e5e82cc7b 100644
--- a/src/camera/SDL_camera.c
+++ b/src/camera/SDL_camera.c
@@ -150,7 +150,7 @@ static size_t GetFrameBufLen(const SDL_CameraSpec *spec)
return wxh * SDL_BYTESPERPIXEL(fmt);
}
-static SDL_CameraFrameResult ZombieAcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult ZombieAcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
const SDL_CameraSpec *spec = &device->actual_spec;
@@ -832,9 +832,10 @@ bool SDL_CameraThreadIterate(SDL_Camera *device)
SDL_Surface *output_surface = NULL;
SurfaceList *slist = NULL;
Uint64 timestampNS = 0;
+ int rotation = 0;
// AcquireFrame SHOULD NOT BLOCK, as we are holding a lock right now. Block in WaitDevice instead!
- const SDL_CameraFrameResult rc = device->AcquireFrame(device, device->acquire_surface, ×tampNS);
+ const SDL_CameraFrameResult rc = device->AcquireFrame(device, device->acquire_surface, ×tampNS, &rotation);
if (rc == SDL_CAMERA_FRAME_READY) { // new frame acquired!
#if DEBUG_CAMERA
@@ -928,6 +929,8 @@ bool SDL_CameraThreadIterate(SDL_Camera *device)
acquired->pixels = NULL;
acquired->pitch = 0;
+ SDL_SetNumberProperty(SDL_GetSurfaceProperties(output_surface), SDL_PROP_SURFACE_ROTATION_NUMBER, rotation);
+
// make the filled output surface available to the app.
SDL_LockMutex(device->lock);
slist->next = device->filled_output_surfaces.next;
diff --git a/src/camera/SDL_syscamera.h b/src/camera/SDL_syscamera.h
index 094ad0faa99d1..151f73d65a0e7 100644
--- a/src/camera/SDL_syscamera.h
+++ b/src/camera/SDL_syscamera.h
@@ -99,7 +99,7 @@ struct SDL_Camera
// These are, initially, set from camera_driver, but we might swap them out with Zombie versions on disconnect/failure.
bool (*WaitDevice)(SDL_Camera *device);
- SDL_CameraFrameResult (*AcquireFrame)(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS);
+ SDL_CameraFrameResult (*AcquireFrame)(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation);
void (*ReleaseFrame)(SDL_Camera *device, SDL_Surface *frame);
// All supported formats/dimensions for this device.
@@ -167,13 +167,18 @@ struct SDL_Camera
struct SDL_PrivateCameraData *hidden;
};
+
+// Note that for AcquireFrame, `rotation` is degrees, with positive values rotating clockwise. This is the amount to rotate an image so it would be right-side up.
+// Rotations should be in 90 degree increments at this time (landscape to portrait, or upside down to right side up, etc).
+// Most platforms won't care about this, but mobile devices might need to deal with the device itself being physically rotated, causing the fixed-orientation camera to be presenting sideways images.
+
typedef struct SDL_CameraDriverImpl
{
void (*DetectDevices)(void);
bool (*OpenDevice)(SDL_Camera *device, const SDL_CameraSpec *spec);
void (*CloseDevice)(SDL_Camera *device);
bool (*WaitDevice)(SDL_Camera *device);
- SDL_CameraFrameResult (*AcquireFrame)(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS); // set frame->pixels, frame->pitch, and *timestampNS!
+ SDL_CameraFrameResult (*AcquireFrame)(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation); // set frame->pixels, frame->pitch, *timestampNS, and *rotation!
void (*ReleaseFrame)(SDL_Camera *device, SDL_Surface *frame); // Reclaim frame->pixels and frame->pitch!
void (*FreeDeviceHandle)(SDL_Camera *device); // SDL is done with this device; free the handle from SDL_AddCamera()
void (*Deinitialize)(void);
diff --git a/src/camera/android/SDL_camera_android.c b/src/camera/android/SDL_camera_android.c
index 90eb0007c5421..e52c78f3a747b 100644
--- a/src/camera/android/SDL_camera_android.c
+++ b/src/camera/android/SDL_camera_android.c
@@ -149,6 +149,7 @@ struct SDL_PrivateCameraData
ACaptureRequest *request;
ACameraCaptureSession *session;
SDL_CameraSpec requested_spec;
+ int rotation; // degrees to rotate clockwise to get from camera's static orientation to device's native orientation. Apply this plus current phone rotation to get upright image!
};
static bool SetErrorStr(const char *what, const char *errstr, const int rc)
@@ -295,7 +296,7 @@ static bool ANDROIDCAMERA_WaitDevice(SDL_Camera *device)
return true; // this isn't used atm, since we run our own thread via onImageAvailable callbacks.
}
-static SDL_CameraFrameResult ANDROIDCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult ANDROIDCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
SDL_CameraFrameResult result = SDL_CAMERA_FRAME_READY;
media_status_t res;
@@ -366,6 +367,21 @@ static SDL_CameraFrameResult ANDROIDCAMERA_AcquireFrame(SDL_Camera *device, SDL_
pAImage_delete(image);
+ int dev_rotation = 0;
+ switch (Android_JNI_GetDisplayCurrentOrientation()) {
+ case SDL_ORIENTATION_PORTRAIT: dev_rotation = 0; break;
+ case SDL_ORIENTATION_LANDSCAPE: dev_rotation = 90; break;
+ case SDL_ORIENTATION_PORTRAIT_FLIPPED: dev_rotation = 180; break;
+ case SDL_ORIENTATION_LANDSCAPE_FLIPPED: dev_rotation = 270; break;
+ default: SDL_assert(!"Unexpected device rotation!"); dev_rotation = 0; break;
+ }
+
+ if (device->position == SDL_CAMERA_POSITION_BACK_FACING) {
+ dev_rotation = -dev_rotation; // we want to subtract this value, instead of add, if back-facing.
+ }
+
+ *rotation = dev_rotation + device->hidden->rotation; // current phone orientation, static camera orientation in relation to phone.
+
return result;
}
@@ -494,10 +510,23 @@ static bool PrepareCamera(SDL_Camera *device)
imglistener.context = device;
imglistener.onImageAvailable = onImageAvailable;
+
+ const char *devid = (const char *) device->handle;
+
+ device->hidden->rotation = 0;
+ ACameraMetadata *metadata = NULL;
+ ACameraMetadata_const_entry orientationentry;
+ if (pACameraManager_getCameraCharacteristics(cameraMgr, devid, &metadata) == ACAMERA_OK) {
+ if (pACameraMetadata_getConstEntry(metadata, ACAMERA_SENSOR_ORIENTATION, &orientationentry) == ACAMERA_OK) {
+ device->hidden->rotation = (int) (*orientationentry.data.i32 % 360);
+ }
+ pACameraMetadata_free(metadata);
+ }
+
// just in case SDL_OpenCamera is overwriting device->spec as CameraPermissionCallback runs, we work from a different copy.
const SDL_CameraSpec *spec = &device->hidden->requested_spec;
- if ((res = pACameraManager_openCamera(cameraMgr, (const char *) device->handle, &dev_callbacks, &device->hidden->device)) != ACAMERA_OK) {
+ if ((res = pACameraManager_openCamera(cameraMgr, devid, &dev_callbacks, &device->hidden->device)) != ACAMERA_OK) {
return SetCameraError("Failed to open camera", res);
} else if ((res2 = pAImageReader_new(spec->width, spec->height, format_sdl_to_android(spec->format), 10 /* nb buffers */, &device->hidden->reader)) != AMEDIA_OK) {
return SetMediaError("Error AImageReader_new", res2);
diff --git a/src/camera/coremedia/SDL_camera_coremedia.m b/src/camera/coremedia/SDL_camera_coremedia.m
index 94b71109704f4..b50ceba953008 100644
--- a/src/camera/coremedia/SDL_camera_coremedia.m
+++ b/src/camera/coremedia/SDL_camera_coremedia.m
@@ -29,6 +29,14 @@
#import <AVFoundation/AVFoundation.h>
#import <CoreMedia/CoreMedia.h>
+#if defined(SDL_PLATFORM_IOS) && !defined(SDL_PLATFORM_TVOS)
+#define USE_UIKIT_DEVICE_ROTATION
+#endif
+
+#ifdef USE_UIKIT_DEVICE_ROTATION
+#import <UIKit/UIKit.h>
+#endif
+
/*
* Need to link with:: CoreMedia CoreVideo
*
@@ -77,6 +85,9 @@ @interface SDLPrivateCameraData : NSObject
@property(nonatomic, retain) AVCaptureSession *session;
@property(nonatomic, retain) SDLCaptureVideoDataOutputSampleBufferDelegate *delegate;
@property(nonatomic, assign) CMSampleBufferRef current_sample;
+#ifdef USE_UIKIT_DEVICE_ROTATION
+@property(nonatomic, assign) UIDeviceOrientation last_device_orientation;
+#endif
@end
@implementation SDLPrivateCameraData
@@ -146,7 +157,7 @@ static bool COREMEDIA_WaitDevice(SDL_Camera *device)
return true; // this isn't used atm, since we run our own thread out of Grand Central Dispatch.
}
-static SDL_CameraFrameResult COREMEDIA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult COREMEDIA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
SDL_CameraFrameResult result = SDL_CAMERA_FRAME_READY;
SDLPrivateCameraData *hidden = (__bridge SDLPrivateCameraData *) device->hidden;
@@ -219,6 +230,37 @@ static SDL_CameraFrameResult COREMEDIA_AcquireFrame(SDL_Camera *device, SDL_Surf
CVPixelBufferUnlockBaseAddress(image, 0);
+ #ifdef USE_UIKIT_DEVICE_ROTATION
+ UIDeviceOrientation device_orientation = [[UIDevice currentDevice] orientation];
+ if (!UIDeviceOrientationIsValidInterfaceOrientation(device_orientation)) {
+ device_orientation = hidden.last_device_orientation; // possible the phone is laying flat or something went wrong, just stay with the last known-good orientation.
+ } else {
+ hidden.last_device_orientation = device_orientation; // update the last known-good orientation for later.
+ }
+
+ const UIInterfaceOrientation ui_orientation = [UIApplication sharedApplication].statusBarOrientation;
+
+ // there is probably math for this, but this is easy to slap into a table.
+ // rotation = rotations[uiorientation-1][devorientation-1];
+ if (device->position == SDL_CAMERA_POSITION_BACK_FACING) {
+ static const int back_rotations[4][4] = {
+ { 90, 90, 90, 90 }, // ui portrait
+ { 270, 270, 270, 270 }, // ui portait upside down
+ { 0, 0, 0, 0 }, // ui landscape left
+ { 180, 180, 180, 180 } // ui landscape right
+ };
+ *rotation = back_rotations[ui_orientation - 1][device_orientation - 1];
+ } else {
+ static const int front_rotations[4][4] = {
+ { 90, 90, 270, 270 }, // ui portrait
+ { 270, 270, 90, 90 }, // ui portait upside down
+ { 0, 0, 180, 180 }, // ui landscape left
+ { 180, 180, 0, 0 } // ui landscape right
+ };
+ *rotation = front_rotations[ui_orientation - 1][device_orientation - 1];
+ }
+ #endif
+
return result;
}
@@ -231,6 +273,10 @@ static void COREMEDIA_ReleaseFrame(SDL_Camera *device, SDL_Surface *frame)
static void COREMEDIA_CloseDevice(SDL_Camera *device)
{
if (device && device->hidden) {
+ #ifdef USE_UIKIT_DEVICE_ROTATION
+ [[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications];
+ #endif
+
SDLPrivateCameraData *hidden = (SDLPrivateCameraData *) CFBridgingRelease(device->hidden);
device->hidden = NULL;
@@ -358,6 +404,28 @@ static bool COREMEDIA_OpenDevice(SDL_Camera *device, const SDL_CameraSpec *spec)
hidden.session = session;
hidden.delegate = delegate;
hidden.current_sample = NULL;
+
+ #ifdef USE_UIKIT_DEVICE_ROTATION
+ // When using a camera, we turn on device orientation tracking. The docs note that this turns on
+ // the device's accelerometer, so I assume this burns power, so we don't leave this running all
+ // the time. These calls nest, so we just need to call the matching `end` message when we close.
+ // You _can_ get an actual events through this mechanism, but we just want to be able to call
+ // -[UIDevice orientation], which will update with real info while notificatons are enabled.
+ UIDevice *uidevice = [UIDevice currentDevice];
+ [uidevice beginGeneratingDeviceOrientationNotifications];
+ hidden.last_device_orientation = uidevice.orientation;
+ if (!UIDeviceOrientationIsValidInterfaceOrientation(hidden.last_device_orientation)) {
+ // accelerometer isn't ready yet or the phone is laying flat or something. Just try to guess from how the UI is oriented at the moment.
+ switch ([UIApplication sharedApplication].statusBarOrientation) {
+ case UIInterfaceOrientationPortrait: hidden.last_device_orientation = UIDeviceOrientationPortrait; break;
+ case UIInterfaceOrientationPortraitUpsideDown: hidden.last_device_orientation = UIDeviceOrientationPortraitUpsideDown; break;
+ case UIInterfaceOrientationLandscapeLeft: hidden.last_device_orientation = UIDeviceOrientationLandscapeRight; break; // Apple docs say UI and device orientations are reversed in landscape.
+ case UIInterfaceOrientationLandscapeRight: hidden.last_device_orientation = UIDeviceOrientationLandscapeLeft; break;
+ default: hidden.last_device_orientation = UIDeviceOrientationPortrait; break; // oh well.
+ }
+ }
+ #endif
+
device->hidden = (struct SDL_PrivateCameraData *)CFBridgingRetain(hidden);
[session startRunning]; // !!! FIXME: docs say this can block while camera warms up and shouldn't be done on main thread. Maybe push through `queue`?
diff --git a/src/camera/dummy/SDL_camera_dummy.c b/src/camera/dummy/SDL_camera_dummy.c
index b2a4dc136aa84..981c2cecb8739 100644
--- a/src/camera/dummy/SDL_camera_dummy.c
+++ b/src/camera/dummy/SDL_camera_dummy.c
@@ -38,7 +38,7 @@ static bool DUMMYCAMERA_WaitDevice(SDL_Camera *device)
return SDL_Unsupported();
}
-static SDL_CameraFrameResult DUMMYCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult DUMMYCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
SDL_Unsupported();
return SDL_CAMERA_FRAME_ERROR;
diff --git a/src/camera/emscripten/SDL_camera_emscripten.c b/src/camera/emscripten/SDL_camera_emscripten.c
index 42c5aba4a1ee1..8eb67b7f845f6 100644
--- a/src/camera/emscripten/SDL_camera_emscripten.c
+++ b/src/camera/emscripten/SDL_camera_emscripten.c
@@ -39,7 +39,7 @@ static bool EMSCRIPTENCAMERA_WaitDevice(SDL_Camera *device)
return false;
}
-static SDL_CameraFrameResult EMSCRIPTENCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult EMSCRIPTENCAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
void *rgba = SDL_malloc(device->actual_spec.width * device->actual_spec.height * 4);
if (!rgba) {
diff --git a/src/camera/mediafoundation/SDL_camera_mediafoundation.c b/src/camera/mediafoundation/SDL_camera_mediafoundation.c
index a059b131feb15..4abe2294d4026 100644
--- a/src/camera/mediafoundation/SDL_camera_mediafoundation.c
+++ b/src/camera/mediafoundation/SDL_camera_mediafoundation.c
@@ -430,7 +430,7 @@ static void SDLCALL CleanupIMFMediaBuffer(void *userdata, void *value)
SDL_free(objs);
}
-static SDL_CameraFrameResult MEDIAFOUNDATION_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult MEDIAFOUNDATION_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
SDL_assert(device->hidden->current_sample != NULL);
@@ -562,7 +562,7 @@ static SDL_CameraFrameResult MEDIAFOUNDATION_CopyFrame(SDL_Surface *frame, const
return SDL_CAMERA_FRAME_READY;
}
-static SDL_CameraFrameResult MEDIAFOUNDATION_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult MEDIAFOUNDATION_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
SDL_assert(device->hidden->current_sample != NULL);
diff --git a/src/camera/pipewire/SDL_camera_pipewire.c b/src/camera/pipewire/SDL_camera_pipewire.c
index a5644736fe4fe..610cd71fabfab 100644
--- a/src/camera/pipewire/SDL_camera_pipewire.c
+++ b/src/camera/pipewire/SDL_camera_pipewire.c
@@ -577,7 +577,7 @@ static bool PIPEWIRECAMERA_WaitDevice(SDL_Camera *device)
return true;
}
-static SDL_CameraFrameResult PIPEWIRECAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult PIPEWIRECAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
struct pw_buffer *b;
diff --git a/src/camera/v4l2/SDL_camera_v4l2.c b/src/camera/v4l2/SDL_camera_v4l2.c
index fe2491b61952e..0fd078bb309dc 100644
--- a/src/camera/v4l2/SDL_camera_v4l2.c
+++ b/src/camera/v4l2/SDL_camera_v4l2.c
@@ -125,7 +125,7 @@ static bool V4L2_WaitDevice(SDL_Camera *device)
return false;
}
-static SDL_CameraFrameResult V4L2_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult V4L2_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
const int fd = device->hidden->fd;
const io_method io = device->hidden->io;
diff --git a/src/camera/vita/SDL_camera_vita.c b/src/camera/vita/SDL_camera_vita.c
index 813f2a1a5fbfd..ff492b383afc6 100644
--- a/src/camera/vita/SDL_camera_vita.c
+++ b/src/camera/vita/SDL_camera_vita.c
@@ -190,7 +190,7 @@ static bool VITACAMERA_WaitDevice(SDL_Camera *device)
return true;
}
-static SDL_CameraFrameResult VITACAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS)
+static SDL_CameraFrameResult VITACAMERA_AcquireFrame(SDL_Camera *device, SDL_Surface *frame, Uint64 *timestampNS, int *rotation)
{
SceCameraRead read = {0};
read.size = sizeof(SceCameraRead);
diff --git a/test/testcamera.c b/test/testcamera.c
index b27092112a447..985852575160f 100644
--- a/test/testcamera.c
+++ b/test/testcamera.c
@@ -360,12 +360,17 @@ SDL_AppResult SDL_AppIterate(void *appstate)
texture_updated = true;
}
+ // the image might be coming from a mobile device that provides images in only one orientation, but the
+ // device might be rotated to a different one (like an iPhone providing portrait images even if you hold
+ // the phone in landscape mode). The rotation is how far to rotate the image clockwise to put it right-side
+ // up, for how the user would expect it to be for how they are holding the device.
+ const int rotation = (int) SDL_GetNumberProperty(SDL_GetSurfaceProperties(frame_current), SDL_PROP_SURFACE_ROTATION_NUMBER, 0);
SDL_GetRenderOutputSize(renderer, &win_w, &win_h);
d.x = ((win_w - texture->w) / 2.0f);
d.y = ((win_h - texture->h) / 2.0f);
d.w = (float)texture->w;
d.h = (float)texture->h;
- SDL_RenderTexture(renderer, texture, NULL, &d);
+ SDL_RenderTextureRotated(renderer, texture, NULL, &d, rotation, NULL, SDL_FLIP_NONE);
}
/* !!! FIXME: Render a "flip" icon if front_camera and back_camera are both != 0. */