Added SDL_GetDisplayOrientation() to get the display orientation, and added a new event SDL_DISPLAYEVENT to notify the application when the orientation changes.

Documented the values returned by the accelerometer and gyroscope sensors

include/SDL_events.h

@@ -85,6 +85,9 @@ typedef enum
                                      Called on Android in onResume()
                                 */
 
+    /* Display events */
+    SDL_DISPLAYEVENT   = 0x150,  /**< Display state change */
+
     /* Window events */
     SDL_WINDOWEVENT    = 0x200, /**< Window state change */
     SDL_SYSWMEVENT,             /**< System specific event */
@@ -171,6 +174,21 @@ typedef struct SDL_CommonEvent
     Uint32 timestamp;   /**< In milliseconds, populated using SDL_GetTicks() */
 } SDL_CommonEvent;
 
+/**
+ *  \brief Display state change event data (event.display.*)
+ */
+typedef struct SDL_DisplayEvent
+{
+    Uint32 type;        /**< ::SDL_DISPLAYEVENT */
+    Uint32 timestamp;   /**< In milliseconds, populated using SDL_GetTicks() */
+    Uint32 display;     /**< The associated display index */
+    Uint8 event;        /**< ::SDL_DisplayEventID */
+    Uint8 padding1;
+    Uint8 padding2;
+    Uint8 padding3;
+    Sint32 data1;       /**< event dependent data */
+} SDL_DisplayEvent;
+
 /**
  *  \brief Window state change event data (event.window.*)
  */
@@ -540,6 +558,7 @@ typedef union SDL_Event
 {
     Uint32 type;                    /**< Event type, shared with all events */
     SDL_CommonEvent common;         /**< Common event data */
+    SDL_DisplayEvent display;       /**< Window event data */
     SDL_WindowEvent window;         /**< Window event data */
     SDL_KeyboardEvent key;          /**< Keyboard event data */
     SDL_TextEditingEvent edit;      /**< Text editing event data */

include/SDL_sensor.h

@@ -68,6 +68,51 @@ typedef enum
     SDL_SENSOR_GYRO,            /**< Gyroscope */
 } SDL_SensorType;
 
+/**
+ * Accelerometer sensor
+ *
+ * The accelerometer returns the current acceleration in SI meters per
+ * second squared. This includes gravity, so a device at rest will have
+ * an acceleration of SDL_STANDARD_GRAVITY straight down.
+ *
+ * values[0]: Acceleration on the x axis
+ * values[1]: Acceleration on the y axis
+ * values[2]: Acceleration on the z axis
+ *
+ * For phones held in portrait mode, the axes are defined as follows:
+ * -X ... +X : left ... right
+ * -Y ... +Y : bottom ... top
+ * -Z ... +Z : farther ... closer
+ * 
+ * The axis data is not changed when the phone is rotated.
+ *
+ * \sa SDL_GetDisplayOrientation()
+ */
+#define SDL_STANDARD_GRAVITY    9.80665f
+
+/**
+ * Gyroscope sensor
+ *
+ * The gyroscope returns the current rate of rotation in radians per second.
+ * The rotation is positive in the counter-clockwise direction. That is,
+ * an observer looking from a positive location on one of the axes would
+ * see positive rotation on that axis when it appeared to be rotating
+ * counter-clockwise.
+ *
+ * values[0]: Angular speed around the x axis
+ * values[1]: Angular speed around the y axis
+ * values[2]: Angular speed around the z axis
+ *
+ * For phones held in portrait mode, the axes are defined as follows:
+ * -X ... +X : left ... right
+ * -Y ... +Y : bottom ... top
+ * -Z ... +Z : farther ... closer
+ * 
+ * The axis data is not changed when the phone is rotated.
+ *
+ * \sa SDL_GetDisplayOrientation()
+ */
+
 /* Function prototypes */
 
 /**

include/SDL_video.h

@@ -169,6 +169,24 @@ typedef enum
     SDL_WINDOWEVENT_HIT_TEST        /**< Window had a hit test that wasn't SDL_HITTEST_NORMAL. */
 } SDL_WindowEventID;
 
+/**
+ *  \brief Event subtype for display events
+ */
+typedef enum
+{
+    SDL_DISPLAYEVENT_NONE,          /**< Never used */
+    SDL_DISPLAYEVENT_ORIENTATION,   /**< Display orientation has changed to data1 */
+} SDL_DisplayEventID;
+
+typedef enum
+{
+    SDL_ORIENTATION_UNKNOWN,            /**< The display orientation can't be determined */
+    SDL_ORIENTATION_LANDSCAPE,          /**< The display is in landscape mode, with the right side up, relative to portrait mode */
+    SDL_ORIENTATION_LANDSCAPE_FLIPPED,  /**< The display is in landscape mode, with the left side up, relative to portrait mode */
+    SDL_ORIENTATION_PORTRAIT,           /**< The display is in portrait mode */
+    SDL_ORIENTATION_PORTRAIT_FLIPPED,   /**< The display is in portrait mode, upside down */
+} SDL_DisplayOrientation;
+
 /**
  *  \brief An opaque handle to an OpenGL context.
  */
@@ -316,18 +334,6 @@ extern DECLSPEC const char * SDLCALL SDL_GetDisplayName(int displayIndex);
  */
 extern DECLSPEC int SDLCALL SDL_GetDisplayBounds(int displayIndex, SDL_Rect * rect);
 
-/**
- *  \brief Get the dots/pixels-per-inch for a display
- *
- *  \note Diagonal, horizontal and vertical DPI can all be optionally
- *        returned if the parameter is non-NULL.
- *
- *  \return 0 on success, or -1 if no DPI information is available or the index is out of range.
- *
- *  \sa SDL_GetNumVideoDisplays()
- */
-extern DECLSPEC int SDLCALL SDL_GetDisplayDPI(int displayIndex, float * ddpi, float * hdpi, float * vdpi);
-
 /**
  *  \brief Get the usable desktop area represented by a display, with the
  *         primary display located at 0,0
@@ -347,6 +353,27 @@ extern DECLSPEC int SDLCALL SDL_GetDisplayDPI(int displayIndex, float * ddpi, fl
  */
 extern DECLSPEC int SDLCALL SDL_GetDisplayUsableBounds(int displayIndex, SDL_Rect * rect);
 
+/**
+ *  \brief Get the dots/pixels-per-inch for a display
+ *
+ *  \note Diagonal, horizontal and vertical DPI can all be optionally
+ *        returned if the parameter is non-NULL.
+ *
+ *  \return 0 on success, or -1 if no DPI information is available or the index is out of range.
+ *
+ *  \sa SDL_GetNumVideoDisplays()
+ */
+extern DECLSPEC int SDLCALL SDL_GetDisplayDPI(int displayIndex, float * ddpi, float * hdpi, float * vdpi);
+
+/**
+ *  \brief Get the orientation of a display
+ *
+ *  \return The orientation of the display, or SDL_ORIENTATION_UNKNOWN if it isn't available.
+ *
+ *  \sa SDL_GetNumVideoDisplays()
+ */
+extern DECLSPEC SDL_DisplayOrientation SDLCALL SDL_GetDisplayOrientation(int displayIndex);
+
 /**
  *  \brief Returns the number of available display modes.
  *