Input reference

## Modules

| Joysticks
| Keyboard keys
| Modifier key flags
| Mouse buttons
| Standard cursor shapes

## Typedefs

typedef void(* | GLFWmousebuttonfun) (GLFWwindow *, int, int, int)
| The function signature for mouse button callbacks. More...
typedef void(* | GLFWcursorposfun) (GLFWwindow *, double, double)
| The function signature for cursor position callbacks. More...
typedef void(* | GLFWcursorenterfun) (GLFWwindow *, int)
| The function signature for cursor enter/leave callbacks. More...
typedef void(* | GLFWscrollfun) (GLFWwindow *, double, double)
| The function signature for scroll callbacks. More...
typedef void(* | GLFWkeyfun) (GLFWwindow *, int, int, int, int)
| The function signature for keyboard key callbacks. More...
typedef void(* | GLFWcharfun) (GLFWwindow *, unsigned int)
| The function signature for Unicode character callbacks. More...
typedef void(* | GLFWcharmodsfun) (GLFWwindow *, unsigned int, int)
| The function signature for Unicode character with modifiers callbacks. More...
typedef void(* | GLFWdropfun) (GLFWwindow *, int, const char **)
| The function signature for file drop callbacks. More...
typedef void(* | GLFWjoystickfun) (int, int)
| The function signature for joystick configuration callbacks. More...

## Functions

int | glfwGetInputMode (GLFWwindow *window, int mode)
| Returns the value of an input option for the specified window. More...
void | glfwSetInputMode (GLFWwindow *window, int mode, int value)
| Sets an input option for the specified window. More...
const char * | glfwGetKeyName (int key, int scancode)
| Returns the localized name of the specified printable key. More...
int | glfwGetKey (GLFWwindow *window, int key)
| Returns the last reported state of a keyboard key for the specified window. More...
int | glfwGetMouseButton (GLFWwindow *window, int button)
| Returns the last reported state of a mouse button for the specified window. More...
void | glfwGetCursorPos (GLFWwindow *window, double *xpos, double *ypos)
| Retrieves the position of the cursor relative to the client area of the window. More...
void | glfwSetCursorPos (GLFWwindow *window, double xpos, double ypos)
| Sets the position of the cursor, relative to the client area of the window. More...
GLFWcursor * | glfwCreateCursor (const GLFWimage *image, int xhot, int yhot)
| Creates a custom cursor. More...
GLFWcursor * | glfwCreateStandardCursor (int shape)
| Creates a cursor with a standard shape. More...
void | glfwDestroyCursor (GLFWcursor *cursor)
| Destroys a cursor. More...
void | glfwSetCursor (GLFWwindow *window, GLFWcursor *cursor)
| Sets the cursor for the window. More...
GLFWkeyfun | glfwSetKeyCallback (GLFWwindow *window, GLFWkeyfun cbfun)
| Sets the key callback. More...
GLFWcharfun | glfwSetCharCallback (GLFWwindow *window, GLFWcharfun cbfun)
| Sets the Unicode character callback. More...
GLFWcharmodsfun | glfwSetCharModsCallback (GLFWwindow *window, GLFWcharmodsfun cbfun)
| Sets the Unicode character with modifiers callback. More...
GLFWmousebuttonfun | glfwSetMouseButtonCallback (GLFWwindow *window, GLFWmousebuttonfun cbfun)
| Sets the mouse button callback. More...
GLFWcursorposfun | glfwSetCursorPosCallback (GLFWwindow *window, GLFWcursorposfun cbfun)
| Sets the cursor position callback. More...
GLFWcursorenterfun | glfwSetCursorEnterCallback (GLFWwindow *window, GLFWcursorenterfun cbfun)
| Sets the cursor enter/exit callback. More...
GLFWscrollfun | glfwSetScrollCallback (GLFWwindow *window, GLFWscrollfun cbfun)
| Sets the scroll callback. More...
GLFWdropfun | glfwSetDropCallback (GLFWwindow *window, GLFWdropfun cbfun)
| Sets the file drop callback. More...
int | glfwJoystickPresent (int joy)
| Returns whether the specified joystick is present. More...
const float * | glfwGetJoystickAxes (int joy, int *count)
| Returns the values of all axes of the specified joystick. More...
const unsigned char * | glfwGetJoystickButtons (int joy, int *count)
| Returns the state of all buttons of the specified joystick. More...
const char * | glfwGetJoystickName (int joy)
| Returns the name of the specified joystick. More...
GLFWjoystickfun | glfwSetJoystickCallback (GLFWjoystickfun cbfun)
| Sets the joystick configuration callback. More...
void | glfwSetClipboardString (GLFWwindow *window, const char *string)
| Sets the clipboard to the specified string. More...
const char * | glfwGetClipboardString (GLFWwindow *window)
| Returns the contents of the clipboard as a string. More...
double | glfwGetTime (void)
| Returns the value of the GLFW timer. More...
void | glfwSetTime (double time)
| Sets the GLFW timer. More...
uint64_t | glfwGetTimerValue (void)
| Returns the current value of the raw timer. More...
uint64_t | glfwGetTimerFrequency (void)
| Returns the frequency, in Hz, of the raw timer. More...

## Key and button actions

#define | GLFW_RELEASE 0
| The key or mouse button was released. More...
#define | GLFW_PRESS 1
| The key or mouse button was pressed. More...
#define | GLFW_REPEAT 2
| The key was held down until it repeated. More...

## Detailed Description

This is the reference documentation for input related functions and types. For more task-oriented information, see the Input guide.

## Macro Definition Documentation

#define GLFW_PRESS 1

The key or mouse button was pressed.

#define GLFW_RELEASE 0

The key or mouse button was released.

#define GLFW_REPEAT 2

The key was held down until it repeated.

## Typedef Documentation

typedef void(* GLFWcharfun) (GLFWwindow *, unsigned int)

This is the function signature for Unicode character callback functions.

Parameters

  [in] | window | The window that received the event.
  [in] | codepoint | The Unicode code point of the character.

See also
  Text input
  glfwSetCharCallback

Since
  Added in version 2.4.

  GLFW 3: Added window handle parameter.

typedef void(* GLFWcharmodsfun) (GLFWwindow *, unsigned int, int)

This is the function signature for Unicode character with modifiers callback functions. It is called for each input character, regardless of what modifier keys are held down.

Parameters

  [in] | window | The window that received the event.
  [in] | codepoint | The Unicode code point of the character.
  [in] | mods | Bit field describing which modifier keys were held down.

See also
  Text input
  glfwSetCharModsCallback

Since
  Added in version 3.1.

typedef void(* GLFWcursorenterfun) (GLFWwindow *, int)

This is the function signature for cursor enter/leave callback functions.

Parameters

  [in] | window | The window that received the event.
  [in] | entered | `GLFW_TRUE` if the cursor entered the window's client area, or `GLFW_FALSE` if it left it.

See also
  Cursor enter/leave events
  glfwSetCursorEnterCallback

Since
  Added in version 3.0.

typedef void(* GLFWcursorposfun) (GLFWwindow *, double, double)

This is the function signature for cursor position callback functions.

Parameters

  [in] | window | The window that received the event.
  [in] | xpos | The new cursor x-coordinate, relative to the left edge of the client area.
  [in] | ypos | The new cursor y-coordinate, relative to the top edge of the client area.

See also
  Cursor position
  glfwSetCursorPosCallback

Since
  Added in version 3.0. Replaces `GLFWmouseposfun`.

typedef void(* GLFWdropfun) (GLFWwindow *, int, const char **)

This is the function signature for file drop callbacks.

Parameters

  [in] | window | The window that received the event.
  [in] | count | The number of dropped files.
  [in] | paths | The UTF-8 encoded file and/or directory path names.

See also
  Path drop input
  glfwSetDropCallback

Since
  Added in version 3.1.

typedef void(* GLFWjoystickfun) (int, int)

This is the function signature for joystick configuration callback functions.

Parameters

  [in] | joy | The joystick that was connected or disconnected.
  [in] | event | One of `GLFW_CONNECTED` or `GLFW_DISCONNECTED`.

See also
  Joystick configuration changes
  glfwSetJoystickCallback

Since
  Added in version 3.2.

typedef void(* GLFWkeyfun) (GLFWwindow *, int, int, int, int)

This is the function signature for keyboard key callback functions.

Parameters

  [in] | window | The window that received the event.
  [in] | key | The keyboard key that was pressed or released.
  [in] | scancode | The system-specific scancode of the key.
  [in] | action | `GLFW_PRESS`, `GLFW_RELEASE` or `GLFW_REPEAT`.
  [in] | mods | Bit field describing which modifier keys were held down.

See also
  Key input
  glfwSetKeyCallback

Since
  Added in version 1.0.

  GLFW 3: Added window handle, scancode and modifier mask parameters.

typedef void(* GLFWmousebuttonfun) (GLFWwindow *, int, int, int)

This is the function signature for mouse button callback functions.

Parameters

  [in] | window | The window that received the event.
  [in] | button | The mouse button that was pressed or released.
  [in] | action | One of `GLFW_PRESS` or `GLFW_RELEASE`.
  [in] | mods | Bit field describing which modifier keys were held down.

See also
  Mouse button input
  glfwSetMouseButtonCallback

Since
  Added in version 1.0.

  GLFW 3: Added window handle and modifier mask parameters.

typedef void(* GLFWscrollfun) (GLFWwindow *, double, double)

This is the function signature for scroll callback functions.

Parameters

  [in] | window | The window that received the event.
  [in] | xoffset | The scroll offset along the x-axis.
  [in] | yoffset | The scroll offset along the y-axis.

See also
  Scroll input
  glfwSetScrollCallback

Since
  Added in version 3.0. Replaces `GLFWmousewheelfun`.

## Function Documentation

GLFWcursor* glfwCreateCursor | ( | const GLFWimage * | image,
|  | int | xhot,
|  | int | yhot
| ) |  |

Creates a new custom cursor image that can be set for a window with glfwSetCursor. The cursor can be destroyed with glfwDestroyCursor. Any remaining cursors are destroyed by glfwTerminate.

The pixels are 32-bit, little-endian, non-premultiplied RGBA, i.e. eight bits per channel. They are arranged canonically as packed sequential rows, starting from the top-left corner.

The cursor hotspot is specified in pixels, relative to the upper-left corner of the cursor image. Like all other coordinate systems in GLFW, the X-axis points to the right and the Y-axis points down.

Parameters

  [in] | image | The desired cursor image.
  [in] | xhot | The desired x-coordinate, in pixels, of the cursor hotspot.
  [in] | yhot | The desired y-coordinate, in pixels, of the cursor hotspot.

Returns
  The handle of the created cursor, or `NULL` if an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The specified image data is copied before this function returns.

Reentrancy
  This function must not be called from a callback.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor objects
  glfwDestroyCursor
  glfwCreateStandardCursor

Since
  Added in version 3.1.

GLFWcursor* glfwCreateStandardCursor | ( | int | shape | ) |

Returns a cursor with a standard shape, that can be set for a window with glfwSetCursor.

Parameters

  [in] | shape | One of the standard shapes.

Returns
  A new cursor ready to use or `NULL` if an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED, GLFW_INVALID_ENUM and GLFW_PLATFORM_ERROR.

Reentrancy
  This function must not be called from a callback.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor objects
  glfwCreateCursor

Since
  Added in version 3.1.

void glfwDestroyCursor | ( | GLFWcursor * | cursor | ) |

This function destroys a cursor previously created with glfwCreateCursor. Any remaining cursors will be destroyed by glfwTerminate.

Parameters

  [in] | cursor | The cursor object to destroy.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Reentrancy
  This function must not be called from a callback.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor objects
  glfwCreateCursor

Since
  Added in version 3.1.

const char* glfwGetClipboardString | ( | GLFWwindow * | window | ) |

This function returns the contents of the system clipboard, if it contains or is convertible to a UTF-8 encoded string. If the clipboard is empty or if its contents cannot be converted, `NULL` is returned and a GLFW_FORMAT_UNAVAILABLE error is generated.

Parameters

  [in] | window | The window that will request the clipboard contents.

Returns
  The contents of the clipboard as a UTF-8 encoded string, or `NULL` if an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The returned string is allocated and freed by GLFW. You should not free it yourself. It is valid until the next call to glfwGetClipboardString or glfwSetClipboardString, or until the library is terminated.

Thread safety
  This function must only be called from the main thread.

See also
  Clipboard input and output
  glfwSetClipboardString

Since
  Added in version 3.0.

void glfwGetCursorPos | ( | GLFWwindow * | window,
|  | double * | xpos,
|  | double * | ypos
| ) |  |

This function returns the position of the cursor, in screen coordinates, relative to the upper-left corner of the client area of the specified window.

If the cursor is disabled (with `GLFW_CURSOR_DISABLED`) then the cursor position is unbounded and limited only by the minimum and maximum values of a `double`.

The coordinate can be converted to their integer equivalents with the `floor` function. Casting directly to an integer type works for positive coordinates, but fails for negative ones.

Any or all of the position arguments may be `NULL`. If an error occurs, all non-`NULL` position arguments will be set to zero.

Parameters

  [in] | window | The desired window.
  [out] | xpos | Where to store the cursor x-coordinate, relative to the left edge of the client area, or `NULL`.
  [out] | ypos | Where to store the cursor y-coordinate, relative to the to top edge of the client area, or `NULL`.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor position
  glfwSetCursorPos

Since
  Added in version 3.0. Replaces `glfwGetMousePos`.

int glfwGetInputMode | ( | GLFWwindow * | window,
|  | int | mode
| ) |  |

This function returns the value of an input option for the specified window. The mode must be one of `GLFW_CURSOR`, `GLFW_STICKY_KEYS` or `GLFW_STICKY_MOUSE_BUTTONS`.

Parameters

  [in] | window | The window to query.
  [in] | mode | One of `GLFW_CURSOR`, `GLFW_STICKY_KEYS` or `GLFW_STICKY_MOUSE_BUTTONS`.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_INVALID_ENUM.

Thread safety
  This function must only be called from the main thread.

See also
  glfwSetInputMode

Since
  Added in version 3.0.

const float* glfwGetJoystickAxes | ( | int | joy,
|  | int * | count
| ) |  |

This function returns the values of all axes of the specified joystick. Each element in the array is a value between -1.0 and 1.0.

Querying a joystick slot with no device present is not an error, but will cause this function to return `NULL`. Call glfwJoystickPresent to check device presence.

Parameters

  [in] | joy | The joystick to query.
  [out] | count | Where to store the number of axis values in the returned array. This is set to zero if the joystick is not present or an error occurred.

Returns
  An array of axis values, or `NULL` if the joystick is not present or an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED, GLFW_INVALID_ENUM and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The returned array is allocated and freed by GLFW. You should not free it yourself. It is valid until the specified joystick is disconnected, this function is called again for that joystick or the library is terminated.

Thread safety
  This function must only be called from the main thread.

See also
  Joystick axis states

Since
  Added in version 3.0. Replaces `glfwGetJoystickPos`.

const unsigned char* glfwGetJoystickButtons | ( | int | joy,
|  | int * | count
| ) |  |

This function returns the state of all buttons of the specified joystick. Each element in the array is either `GLFW_PRESS` or `GLFW_RELEASE`.

Querying a joystick slot with no device present is not an error, but will cause this function to return `NULL`. Call glfwJoystickPresent to check device presence.

Parameters

  [in] | joy | The joystick to query.
  [out] | count | Where to store the number of button states in the returned array. This is set to zero if the joystick is not present or an error occurred.

Returns
  An array of button states, or `NULL` if the joystick is not present or an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED, GLFW_INVALID_ENUM and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The returned array is allocated and freed by GLFW. You should not free it yourself. It is valid until the specified joystick is disconnected, this function is called again for that joystick or the library is terminated.

Thread safety
  This function must only be called from the main thread.

See also
  Joystick button states

Since
  Added in version 2.2.

  GLFW 3: Changed to return a dynamic array.

const char* glfwGetJoystickName | ( | int | joy | ) |

This function returns the name, encoded as UTF-8, of the specified joystick. The returned string is allocated and freed by GLFW. You should not free it yourself.

Querying a joystick slot with no device present is not an error, but will cause this function to return `NULL`. Call glfwJoystickPresent to check device presence.

Parameters

  [in] | joy | The joystick to query.

Returns
  The UTF-8 encoded name of the joystick, or `NULL` if the joystick is not present or an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED, GLFW_INVALID_ENUM and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The returned string is allocated and freed by GLFW. You should not free it yourself. It is valid until the specified joystick is disconnected, this function is called again for that joystick or the library is terminated.

Thread safety
  This function must only be called from the main thread.

See also
  Joystick name

Since
  Added in version 3.0.

int glfwGetKey | ( | GLFWwindow * | window,
|  | int | key
| ) |  |

This function returns the last state reported for the specified key to the specified window. The returned state is one of `GLFW_PRESS` or `GLFW_RELEASE`. The higher-level action `GLFW_REPEAT` is only reported to the key callback.

If the `GLFW_STICKY_KEYS` input mode is enabled, this function returns `GLFW_PRESS` the first time you call it for a key that was pressed, even if that key has already been released.

The key functions deal with physical keys, with key tokens named after their use on the standard US keyboard layout. If you want to input text, use the Unicode character callback instead.

The modifier key bit masks are not key tokens and cannot be used with this function.

Do not use this function to implement text input.

Parameters

  [in] | window | The desired window.
  [in] | key | The desired keyboard key. `GLFW_KEY_UNKNOWN` is not a valid key for this function.

Returns
  One of `GLFW_PRESS` or `GLFW_RELEASE`.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_INVALID_ENUM.

Thread safety
  This function must only be called from the main thread.

See also
  Key input

Since
  Added in version 1.0.

  GLFW 3: Added window handle parameter.

const char* glfwGetKeyName | ( | int | key,
|  | int | scancode
| ) |  |

This function returns the localized name of the specified printable key. This is intended for displaying key bindings to the user.

If the key is `GLFW_KEY_UNKNOWN`, the scancode is used instead, otherwise the scancode is ignored. If a non-printable key or (if the key is `GLFW_KEY_UNKNOWN`) a scancode that maps to a non-printable key is specified, this function returns `NULL`.

This behavior allows you to pass in the arguments passed to the key callback without modification.

The printable keys are:

- `GLFW_KEY_APOSTROPHE`
- `GLFW_KEY_COMMA`
- `GLFW_KEY_MINUS`
- `GLFW_KEY_PERIOD`
- `GLFW_KEY_SLASH`
- `GLFW_KEY_SEMICOLON`
- `GLFW_KEY_EQUAL`
- `GLFW_KEY_LEFT_BRACKET`
- `GLFW_KEY_RIGHT_BRACKET`
- `GLFW_KEY_BACKSLASH`
- `GLFW_KEY_WORLD_1`
- `GLFW_KEY_WORLD_2`
- `GLFW_KEY_0` to `GLFW_KEY_9`
- `GLFW_KEY_A` to `GLFW_KEY_Z`
- `GLFW_KEY_KP_0` to `GLFW_KEY_KP_9`
- `GLFW_KEY_KP_DECIMAL`
- `GLFW_KEY_KP_DIVIDE`
- `GLFW_KEY_KP_MULTIPLY`
- `GLFW_KEY_KP_SUBTRACT`
- `GLFW_KEY_KP_ADD`
- `GLFW_KEY_KP_EQUAL`

Parameters

  [in] | key | The key to query, or `GLFW_KEY_UNKNOWN`.
  [in] | scancode | The scancode of the key to query.

Returns
  The localized name of the key, or `NULL`.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The returned string is allocated and freed by GLFW. You should not free it yourself. It is valid until the next call to glfwGetKeyName, or until the library is terminated.

Thread safety
  This function must only be called from the main thread.

See also
  Key names

Since
  Added in version 3.2.

int glfwGetMouseButton | ( | GLFWwindow * | window,
|  | int | button
| ) |  |

This function returns the last state reported for the specified mouse button to the specified window. The returned state is one of `GLFW_PRESS` or `GLFW_RELEASE`.

If the `GLFW_STICKY_MOUSE_BUTTONS` input mode is enabled, this function `GLFW_PRESS` the first time you call it for a mouse button that was pressed, even if that mouse button has already been released.

Parameters

  [in] | window | The desired window.
  [in] | button | The desired mouse button.

Returns
  One of `GLFW_PRESS` or `GLFW_RELEASE`.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_INVALID_ENUM.

Thread safety
  This function must only be called from the main thread.

See also
  Mouse button input

Since
  Added in version 1.0.

  GLFW 3: Added window handle parameter.

double glfwGetTime | ( | void |  | ) |

This function returns the value of the GLFW timer. Unless the timer has been set using glfwSetTime, the timer measures time elapsed since GLFW was initialized.

The resolution of the timer is system dependent, but is usually on the order of a few micro- or nanoseconds. It uses the highest-resolution monotonic time source on each supported platform.

Returns
  The current value, in seconds, or zero if an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function may be called from any thread. Reading and writing of the internal timer offset is not atomic, so it needs to be externally synchronized with calls to glfwSetTime.

See also
  Time input

Since
  Added in version 1.0.

uint64_t glfwGetTimerFrequency | ( | void |  | ) |

This function returns the frequency, in Hz, of the raw timer.

Returns
  The frequency of the timer, in Hz, or zero if an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function may be called from any thread.

See also
  Time input
  glfwGetTimerValue

Since
  Added in version 3.2.

uint64_t glfwGetTimerValue | ( | void |  | ) |

This function returns the current value of the raw timer, measured in 1 / frequency seconds. To get the frequency, call glfwGetTimerFrequency.

Returns
  The value of the timer, or zero if an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function may be called from any thread.

See also
  Time input
  glfwGetTimerFrequency

Since
  Added in version 3.2.

int glfwJoystickPresent | ( | int | joy | ) |

This function returns whether the specified joystick is present.

Parameters

  [in] | joy | The joystick to query.

Returns
  `GLFW_TRUE` if the joystick is present, or `GLFW_FALSE` otherwise.

Errors
  Possible errors include GLFW_NOT_INITIALIZED, GLFW_INVALID_ENUM and GLFW_PLATFORM_ERROR.

Thread safety
  This function must only be called from the main thread.

See also
  Joystick input

Since
  Added in version 3.0. Replaces `glfwGetJoystickParam`.

GLFWcharfun glfwSetCharCallback | ( | GLFWwindow * | window,
|  | GLFWcharfun | cbfun
| ) |  |

This function sets the character callback of the specified window, which is called when a Unicode character is input.

The character callback is intended for Unicode text input. As it deals with characters, it is keyboard layout dependent, whereas the key callback is not. Characters do not map 1:1 to physical keys, as a key may produce zero, one or more characters. If you want to know whether a specific physical key was pressed or released, see the key callback instead.

The character callback behaves as system text input normally does and will not be called if modifier keys are held down that would prevent normal text input on that platform, for example a Super (Command) key on OS X or Alt key on Windows. There is a character with modifiers callback that receives these events.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Text input

Since
  Added in version 2.4.

  GLFW 3: Added window handle parameter and return value.

GLFWcharmodsfun glfwSetCharModsCallback | ( | GLFWwindow * | window,
|  | GLFWcharmodsfun | cbfun
| ) |  |

This function sets the character with modifiers callback of the specified window, which is called when a Unicode character is input regardless of what modifier keys are used.

The character with modifiers callback is intended for implementing custom Unicode character input. For regular Unicode text input, see the character callback. Like the character callback, the character with modifiers callback deals with characters and is keyboard layout dependent. Characters do not map 1:1 to physical keys, as a key may produce zero, one or more characters. If you want to know whether a specific physical key was pressed or released, see the key callback instead.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or an error occurred.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Text input

Since
  Added in version 3.1.

void glfwSetClipboardString | ( | GLFWwindow * | window,
|  | const char * | string
| ) |  |

This function sets the system clipboard to the specified, UTF-8 encoded string.

Parameters

  [in] | window | The window that will own the clipboard contents.
  [in] | string | A UTF-8 encoded string.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Pointer lifetime
  The specified string is copied before this function returns.

Thread safety
  This function must only be called from the main thread.

See also
  Clipboard input and output
  glfwGetClipboardString

Since
  Added in version 3.0.

void glfwSetCursor | ( | GLFWwindow * | window,
|  | GLFWcursor * | cursor
| ) |  |

This function sets the cursor image to be used when the cursor is over the client area of the specified window. The set cursor will only be visible when the cursor mode of the window is `GLFW_CURSOR_NORMAL`.

On some platforms, the set cursor may not be visible unless the window also has input focus.

Parameters

  [in] | window | The window to set the cursor for.
  [in] | cursor | The cursor to set, or `NULL` to switch back to the default arrow cursor.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor objects

Since
  Added in version 3.1.

GLFWcursorenterfun glfwSetCursorEnterCallback | ( | GLFWwindow * | window,
|  | GLFWcursorenterfun | cbfun
| ) |  |

This function sets the cursor boundary crossing callback of the specified window, which is called when the cursor enters or leaves the client area of the window.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor enter/leave events

Since
  Added in version 3.0.

void glfwSetCursorPos | ( | GLFWwindow * | window,
|  | double | xpos,
|  | double | ypos
| ) |  |

This function sets the position, in screen coordinates, of the cursor relative to the upper-left corner of the client area of the specified window. The window must have input focus. If the window does not have input focus when this function is called, it fails silently.

Do not use this function to implement things like camera controls. GLFW already provides the `GLFW_CURSOR_DISABLED` cursor mode that hides the cursor, transparently re-centers it and provides unconstrained cursor motion. See glfwSetInputMode for more information.

If the cursor mode is `GLFW_CURSOR_DISABLED` then the cursor position is unconstrained and limited only by the minimum and maximum values of a `double`.

Parameters

  [in] | window | The desired window.
  [in] | xpos | The desired x-coordinate, relative to the left edge of the client area.
  [in] | ypos | The desired y-coordinate, relative to the top edge of the client area.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_PLATFORM_ERROR.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor position
  glfwGetCursorPos

Since
  Added in version 3.0. Replaces `glfwSetMousePos`.

GLFWcursorposfun glfwSetCursorPosCallback | ( | GLFWwindow * | window,
|  | GLFWcursorposfun | cbfun
| ) |  |

This function sets the cursor position callback of the specified window, which is called when the cursor is moved. The callback is provided with the position, in screen coordinates, relative to the upper-left corner of the client area of the window.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Cursor position

Since
  Added in version 3.0. Replaces `glfwSetMousePosCallback`.

GLFWdropfun glfwSetDropCallback | ( | GLFWwindow * | window,
|  | GLFWdropfun | cbfun
| ) |  |

This function sets the file drop callback of the specified window, which is called when one or more dragged files are dropped on the window.

Because the path array and its strings may have been generated specifically for that event, they are not guaranteed to be valid after the callback has returned. If you wish to use them after the callback returns, you need to make a deep copy.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new file drop callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Path drop input

Since
  Added in version 3.1.

void glfwSetInputMode | ( | GLFWwindow * | window,
|  | int | mode,
|  | int | value
| ) |  |

This function sets an input mode option for the specified window. The mode must be one of `GLFW_CURSOR`, `GLFW_STICKY_KEYS` or `GLFW_STICKY_MOUSE_BUTTONS`.

If the mode is `GLFW_CURSOR`, the value must be one of the following cursor modes:

- `GLFW_CURSOR_NORMAL` makes the cursor visible and behaving normally.
- `GLFW_CURSOR_HIDDEN` makes the cursor invisible when it is over the client area of the window but does not restrict the cursor from leaving.
- `GLFW_CURSOR_DISABLED` hides and grabs the cursor, providing virtual and unlimited cursor movement. This is useful for implementing for example 3D camera controls.

If the mode is `GLFW_STICKY_KEYS`, the value must be either `GLFW_TRUE` to enable sticky keys, or `GLFW_FALSE` to disable it. If sticky keys are enabled, a key press will ensure that glfwGetKey returns `GLFW_PRESS` the next time it is called even if the key had been released before the call. This is useful when you are only interested in whether keys have been pressed but not when or in which order.

If the mode is `GLFW_STICKY_MOUSE_BUTTONS`, the value must be either `GLFW_TRUE` to enable sticky mouse buttons, or `GLFW_FALSE` to disable it. If sticky mouse buttons are enabled, a mouse button press will ensure that glfwGetMouseButton returns `GLFW_PRESS` the next time it is called even if the mouse button had been released before the call. This is useful when you are only interested in whether mouse buttons have been pressed but not when or in which order.

Parameters

  [in] | window | The window whose input mode to set.
  [in] | mode | One of `GLFW_CURSOR`, `GLFW_STICKY_KEYS` or `GLFW_STICKY_MOUSE_BUTTONS`.
  [in] | value | The new value of the specified input mode.

Errors
  Possible errors include GLFW_NOT_INITIALIZED, GLFW_INVALID_ENUM and GLFW_PLATFORM_ERROR.

Thread safety
  This function must only be called from the main thread.

See also
  glfwGetInputMode

Since
  Added in version 3.0. Replaces `glfwEnable` and `glfwDisable`.

GLFWjoystickfun glfwSetJoystickCallback | ( | GLFWjoystickfun | cbfun | ) |

This function sets the joystick configuration callback, or removes the currently set callback. This is called when a joystick is connected to or disconnected from the system.

Parameters

  [in] | cbfun | The new callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Joystick configuration changes

Since
  Added in version 3.2.

GLFWkeyfun glfwSetKeyCallback | ( | GLFWwindow * | window,
|  | GLFWkeyfun | cbfun
| ) |  |

This function sets the key callback of the specified window, which is called when a key is pressed, repeated or released.

The key functions deal with physical keys, with layout independent key tokens named after their values in the standard US keyboard layout. If you want to input text, use the character callback instead.

When a window loses input focus, it will generate synthetic key release events for all pressed keys. You can tell these events from user-generated events by the fact that the synthetic ones are generated after the focus loss event has been processed, i.e. after the window focus callback has been called.

The scancode of a key is specific to that platform or sometimes even to that machine. Scancodes are intended to allow users to bind keys that don't have a GLFW key token. Such keys have `key` set to `GLFW_KEY_UNKNOWN`, their state is not saved and so it cannot be queried with glfwGetKey.

Sometimes GLFW needs to generate synthetic key events, in which case the scancode may be zero.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new key callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Key input

Since
  Added in version 1.0.

  GLFW 3: Added window handle parameter and return value.

GLFWmousebuttonfun glfwSetMouseButtonCallback | ( | GLFWwindow * | window,
|  | GLFWmousebuttonfun | cbfun
| ) |  |

This function sets the mouse button callback of the specified window, which is called when a mouse button is pressed or released.

When a window loses input focus, it will generate synthetic mouse button release events for all pressed mouse buttons. You can tell these events from user-generated events by the fact that the synthetic ones are generated after the focus loss event has been processed, i.e. after the window focus callback has been called.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Mouse button input

Since
  Added in version 1.0.

  GLFW 3: Added window handle parameter and return value.

GLFWscrollfun glfwSetScrollCallback | ( | GLFWwindow * | window,
|  | GLFWscrollfun | cbfun
| ) |  |

This function sets the scroll callback of the specified window, which is called when a scrolling device is used, such as a mouse wheel or scrolling area of a touchpad.

The scroll callback receives all scrolling input, like that from a mouse wheel or a touchpad scrolling area.

Parameters

  [in] | window | The window whose callback to set.
  [in] | cbfun | The new scroll callback, or `NULL` to remove the currently set callback.

Returns
  The previously set callback, or `NULL` if no callback was set or the library had not been initialized.

Errors
  Possible errors include GLFW_NOT_INITIALIZED.

Thread safety
  This function must only be called from the main thread.

See also
  Scroll input

Since
  Added in version 3.0. Replaces `glfwSetMouseWheelCallback`.

void glfwSetTime | ( | double | time | ) |

This function sets the value of the GLFW timer. It then continues to count up from that value. The value must be a positive finite number less than or equal to 18446744073.0, which is approximately 584.5 years.

Parameters

  [in] | time | The new value, in seconds.

Errors
  Possible errors include GLFW_NOT_INITIALIZED and GLFW_INVALID_VALUE.

Remarks
  The upper limit of the timer is calculated as floor((264 - 1) / 109) and is due to implementations storing nanoseconds in 64 bits. The limit may be increased in the future.

Thread safety
  This function may be called from any thread. Reading and writing of the internal timer offset is not atomic, so it needs to be externally synchronized with calls to glfwGetTime.

See also
  Time input

Since
  Added in version 2.2.