glfw/src/input.c

//========================================================================
// GLFW 3.3 - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2016 Camilla Löwy <elmindreda@glfw.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 "internal.h"

#include <assert.h>
#include <float.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

// Internal key state used for sticky keys
#define _GLFW_STICK 3

// Internal constants for gamepad mapping source types
#define _GLFW_JOYSTICK_AXIS     1
#define _GLFW_JOYSTICK_BUTTON   2
#define _GLFW_JOYSTICK_HATBIT   3

// Finds a mapping based on joystick GUID
//
static _GLFWmapping* findMapping(const char* guid)
{
    int i;

    for (i = 0;  i < _glfw.mappingCount;  i++)
    {
        if (strcmp(_glfw.mappings[i].guid, guid) == 0)
            return _glfw.mappings + i;
    }

    return NULL;
}

// Parses an SDL_GameControllerDB line and adds it to the mapping list
//
static GLFWbool parseMapping(_GLFWmapping* mapping, const char* string)
{
    const char* c = string;
    size_t i, length;
    struct
    {
        const char* name;
        _GLFWmapelement* element;
    } fields[] =
    {
        { "platform",      NULL },
        { "a",             mapping->buttons + GLFW_GAMEPAD_BUTTON_A },
        { "b",             mapping->buttons + GLFW_GAMEPAD_BUTTON_B },
        { "x",             mapping->buttons + GLFW_GAMEPAD_BUTTON_X },
        { "y",             mapping->buttons + GLFW_GAMEPAD_BUTTON_Y },
        { "back",          mapping->buttons + GLFW_GAMEPAD_BUTTON_BACK },
        { "start",         mapping->buttons + GLFW_GAMEPAD_BUTTON_START },
        { "guide",         mapping->buttons + GLFW_GAMEPAD_BUTTON_GUIDE },
        { "leftshoulder",  mapping->buttons + GLFW_GAMEPAD_BUTTON_LEFT_BUMPER },
        { "rightshoulder", mapping->buttons + GLFW_GAMEPAD_BUTTON_RIGHT_BUMPER },
        { "leftstick",     mapping->buttons + GLFW_GAMEPAD_BUTTON_LEFT_THUMB },
        { "rightstick",    mapping->buttons + GLFW_GAMEPAD_BUTTON_RIGHT_THUMB },
        { "dpup",          mapping->buttons + GLFW_GAMEPAD_BUTTON_DPAD_UP },
        { "dpright",       mapping->buttons + GLFW_GAMEPAD_BUTTON_DPAD_RIGHT },
        { "dpdown",        mapping->buttons + GLFW_GAMEPAD_BUTTON_DPAD_DOWN },
        { "dpleft",        mapping->buttons + GLFW_GAMEPAD_BUTTON_DPAD_LEFT },
        { "lefttrigger",   mapping->axes + GLFW_GAMEPAD_AXIS_LEFT_TRIGGER },
        { "righttrigger",  mapping->axes + GLFW_GAMEPAD_AXIS_RIGHT_TRIGGER },
        { "leftx",         mapping->axes + GLFW_GAMEPAD_AXIS_LEFT_X },
        { "lefty",         mapping->axes + GLFW_GAMEPAD_AXIS_LEFT_Y },
        { "rightx",        mapping->axes + GLFW_GAMEPAD_AXIS_RIGHT_X },
        { "righty",        mapping->axes + GLFW_GAMEPAD_AXIS_RIGHT_Y }
    };

    length = strcspn(c, ",");
    if (length != 32 || c[length] != ',')
    {
        _glfwInputError(GLFW_INVALID_VALUE, NULL);
        return GLFW_FALSE;
    }

    memcpy(mapping->guid, c, length);
    c += length + 1;

    length = strcspn(c, ",");
    if (length >= sizeof(mapping->name) || c[length] != ',')
    {
        _glfwInputError(GLFW_INVALID_VALUE, NULL);
        return GLFW_FALSE;
    }

    memcpy(mapping->name, c, length);
    c += length + 1;

    while (*c)
    {
        for (i = 0;  i < sizeof(fields) / sizeof(fields[0]);  i++)
        {
            length = strlen(fields[i].name);
            if (strncmp(c, fields[i].name, length) != 0 || c[length] != ':')
                continue;

            c += length + 1;

            if (fields[i].element)
            {
                if (*c == 'a')
                    fields[i].element->type = _GLFW_JOYSTICK_AXIS;
                else if (*c == 'b')
                    fields[i].element->type = _GLFW_JOYSTICK_BUTTON;
                else if (*c == 'h')
                    fields[i].element->type = _GLFW_JOYSTICK_HATBIT;
                else
                    break;

                if (fields[i].element->type == _GLFW_JOYSTICK_HATBIT)
                {
                    const unsigned int hat = strtoul(c + 1, (char**) &c, 10);
                    const unsigned int bit = strtoul(c + 1, (char**) &c, 10);
                    fields[i].element->value = (hat << 4) | bit;
                }
                else
                    fields[i].element->value = (uint8_t) strtoul(c + 1, (char**) &c, 10);
            }
            else
            {
                length = strlen(_GLFW_PLATFORM_MAPPING_NAME);
                if (strncmp(c, _GLFW_PLATFORM_MAPPING_NAME, length) != 0)
                    return GLFW_FALSE;
            }

            break;
        }

        c += strcspn(c, ",");
        c += strspn(c, ",");
    }

    for (i = 0;  i < 32;  i++)
    {
        if (mapping->guid[i] >= 'A' && mapping->guid[i] <= 'F')
            mapping->guid[i] += 'a' - 'A';
    }

    _glfwPlatformUpdateGamepadGUID(mapping->guid);
    return GLFW_TRUE;
}


//////////////////////////////////////////////////////////////////////////
//////                         GLFW event API                       //////
//////////////////////////////////////////////////////////////////////////

void _glfwInputKey(_GLFWwindow* window, int key, int scancode, int action, int mods)
{
    if (key >= 0 && key <= GLFW_KEY_LAST)
    {
        GLFWbool repeated = GLFW_FALSE;

        if (action == GLFW_RELEASE && window->keys[key] == GLFW_RELEASE)
            return;

        if (action == GLFW_PRESS && window->keys[key] == GLFW_PRESS)
            repeated = GLFW_TRUE;

        if (action == GLFW_RELEASE && window->stickyKeys)
            window->keys[key] = _GLFW_STICK;
        else
            window->keys[key] = (char) action;

        if (repeated)
            action = GLFW_REPEAT;
    }

    if (window->callbacks.key)
        window->callbacks.key((GLFWwindow*) window, key, scancode, action, mods);
}

void _glfwInputChar(_GLFWwindow* window, unsigned int codepoint, int mods, GLFWbool plain)
{
    if (codepoint < 32 || (codepoint > 126 && codepoint < 160))
        return;

    if (window->callbacks.charmods)
        window->callbacks.charmods((GLFWwindow*) window, codepoint, mods);

    if (plain)
    {
        if (window->callbacks.character)
            window->callbacks.character((GLFWwindow*) window, codepoint);
    }
}

void _glfwInputScroll(_GLFWwindow* window, double xoffset, double yoffset)
{
    if (window->callbacks.scroll)
        window->callbacks.scroll((GLFWwindow*) window, xoffset, yoffset);
}

void _glfwInputMouseClick(_GLFWwindow* window, int button, int action, int mods)
{
    if (button < 0 || button > GLFW_MOUSE_BUTTON_LAST)
        return;

    if (action == GLFW_RELEASE && window->stickyMouseButtons)
        window->mouseButtons[button] = _GLFW_STICK;
    else
        window->mouseButtons[button] = (char) action;

    if (window->callbacks.mouseButton)
        window->callbacks.mouseButton((GLFWwindow*) window, button, action, mods);
}

void _glfwInputCursorPos(_GLFWwindow* window, double xpos, double ypos)
{
    if (window->virtualCursorPosX == xpos && window->virtualCursorPosY == ypos)
        return;

    window->virtualCursorPosX = xpos;
    window->virtualCursorPosY = ypos;

    if (window->callbacks.cursorPos)
        window->callbacks.cursorPos((GLFWwindow*) window, xpos, ypos);
}

void _glfwInputCursorEnter(_GLFWwindow* window, GLFWbool entered)
{
    if (window->callbacks.cursorEnter)
        window->callbacks.cursorEnter((GLFWwindow*) window, entered);
}

void _glfwInputDrop(_GLFWwindow* window, int count, const char** paths)
{
    if (window->callbacks.drop)
        window->callbacks.drop((GLFWwindow*) window, count, paths);
}

void _glfwInputJoystick(_GLFWjoystick* js, int event)
{
    const int jid = (int) (js - _glfw.joysticks);

    if (_glfw.callbacks.joystick)
        _glfw.callbacks.joystick(jid, event);
}

void _glfwInputJoystickAxis(_GLFWjoystick* js, int axis, float value)
{
    js->axes[axis] = value;
}

void _glfwInputJoystickButton(_GLFWjoystick* js, int button, char value)
{
    js->buttons[button] = value;
}

void _glfwInputJoystickHat(_GLFWjoystick* js, int hat, char value)
{
    const int base = js->buttonCount + hat * 4;

    js->buttons[base + 0] = (value & 0x01) ? GLFW_PRESS : GLFW_RELEASE;
    js->buttons[base + 1] = (value & 0x02) ? GLFW_PRESS : GLFW_RELEASE;
    js->buttons[base + 2] = (value & 0x04) ? GLFW_PRESS : GLFW_RELEASE;
    js->buttons[base + 3] = (value & 0x08) ? GLFW_PRESS : GLFW_RELEASE;

    js->hats[hat] = value;
}


//////////////////////////////////////////////////////////////////////////
//////                       GLFW internal API                      //////
//////////////////////////////////////////////////////////////////////////

_GLFWjoystick* _glfwAllocJoystick(const char* name,
                                  const char* guid,
                                  int axisCount,
                                  int buttonCount,
                                  int hatCount)
{
    int jid;
    _GLFWjoystick* js;

    for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
    {
        if (!_glfw.joysticks[jid].present)
            break;
    }

    if (jid > GLFW_JOYSTICK_LAST)
        return NULL;

    js = _glfw.joysticks + jid;
    js->present     = GLFW_TRUE;
    js->name        = strdup(name);
    js->axes        = calloc(axisCount, sizeof(float));
    js->buttons     = calloc(buttonCount + hatCount * 4, 1);
    js->hats        = calloc(hatCount, 1);
    js->axisCount   = axisCount;
    js->buttonCount = buttonCount;
    js->hatCount    = hatCount;
    js->mapping     = findMapping(guid);

    strcpy(js->guid, guid);

    return js;
}

void _glfwFreeJoystick(_GLFWjoystick* js)
{
    free(js->name);
    free(js->axes);
    free(js->buttons);
    free(js->hats);
    memset(js, 0, sizeof(_GLFWjoystick));
}


//////////////////////////////////////////////////////////////////////////
//////                        GLFW public API                       //////
//////////////////////////////////////////////////////////////////////////

GLFWAPI int glfwGetInputMode(GLFWwindow* handle, int mode)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(0);

    switch (mode)
    {
        case GLFW_CURSOR:
            return window->cursorMode;
        case GLFW_STICKY_KEYS:
            return window->stickyKeys;
        case GLFW_STICKY_MOUSE_BUTTONS:
            return window->stickyMouseButtons;
    }

    _glfwInputError(GLFW_INVALID_ENUM, "Invalid input mode 0x%08X", mode);
    return 0;
}

GLFWAPI void glfwSetInputMode(GLFWwindow* handle, int mode, int value)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT();

    if (mode == GLFW_CURSOR)
    {
        if (value != GLFW_CURSOR_NORMAL &&
            value != GLFW_CURSOR_HIDDEN &&
            value != GLFW_CURSOR_DISABLED)
        {
            _glfwInputError(GLFW_INVALID_ENUM,
                            "Invalid cursor mode 0x%08X",
                            value);
            return;
        }

        if (window->cursorMode == value)
            return;

        window->cursorMode = value;

        _glfwPlatformGetCursorPos(window,
                                  &window->virtualCursorPosX,
                                  &window->virtualCursorPosY);

        if (_glfwPlatformWindowFocused(window))
            _glfwPlatformSetCursorMode(window, value);
    }
    else if (mode == GLFW_STICKY_KEYS)
    {
        value = value ? GLFW_TRUE : GLFW_FALSE;
        if (window->stickyKeys == value)
            return;

        if (!value)
        {
            int i;

            // Release all sticky keys
            for (i = 0;  i <= GLFW_KEY_LAST;  i++)
            {
                if (window->keys[i] == _GLFW_STICK)
                    window->keys[i] = GLFW_RELEASE;
            }
        }

        window->stickyKeys = value ? GLFW_TRUE : GLFW_FALSE;
    }
    else if (mode == GLFW_STICKY_MOUSE_BUTTONS)
    {
        value = value ? GLFW_TRUE : GLFW_FALSE;
        if (window->stickyMouseButtons == value)
            return;

        if (!value)
        {
            int i;

            // Release all sticky mouse buttons
            for (i = 0;  i <= GLFW_MOUSE_BUTTON_LAST;  i++)
            {
                if (window->mouseButtons[i] == _GLFW_STICK)
                    window->mouseButtons[i] = GLFW_RELEASE;
            }
        }

        window->stickyMouseButtons = value ? GLFW_TRUE : GLFW_FALSE;
    }
    else
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid input mode 0x%08X", mode);
}

GLFWAPI const char* glfwGetKeyName(int key, int scancode)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (key != GLFW_KEY_UNKNOWN)
    {
        if (key != GLFW_KEY_KP_EQUAL &&
            (key < GLFW_KEY_KP_0 || key > GLFW_KEY_KP_ADD) &&
            (key < GLFW_KEY_APOSTROPHE || key > GLFW_KEY_WORLD_2))
        {
            return NULL;
        }

        scancode = _glfwPlatformGetKeyScancode(key);
    }

    return _glfwPlatformGetScancodeName(scancode);
}

GLFWAPI int glfwGetKeyScancode(int key)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(-1);

    if (key < GLFW_KEY_SPACE || key > GLFW_KEY_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid key %i", key);
        return GLFW_RELEASE;
    }

    return _glfwPlatformGetKeyScancode(key);
}

GLFWAPI int glfwGetKey(GLFWwindow* handle, int key)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_RELEASE);

    if (key < GLFW_KEY_SPACE || key > GLFW_KEY_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid key %i", key);
        return GLFW_RELEASE;
    }

    if (window->keys[key] == _GLFW_STICK)
    {
        // Sticky mode: release key now
        window->keys[key] = GLFW_RELEASE;
        return GLFW_PRESS;
    }

    return (int) window->keys[key];
}

GLFWAPI int glfwGetMouseButton(GLFWwindow* handle, int button)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_RELEASE);

    if (button < GLFW_MOUSE_BUTTON_1 || button > GLFW_MOUSE_BUTTON_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid mouse button %i", button);
        return GLFW_RELEASE;
    }

    if (window->mouseButtons[button] == _GLFW_STICK)
    {
        // Sticky mode: release mouse button now
        window->mouseButtons[button] = GLFW_RELEASE;
        return GLFW_PRESS;
    }

    return (int) window->mouseButtons[button];
}

GLFWAPI void glfwGetCursorPos(GLFWwindow* handle, double* xpos, double* ypos)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    if (xpos)
        *xpos = 0;
    if (ypos)
        *ypos = 0;

    _GLFW_REQUIRE_INIT();

    if (window->cursorMode == GLFW_CURSOR_DISABLED)
    {
        if (xpos)
            *xpos = window->virtualCursorPosX;
        if (ypos)
            *ypos = window->virtualCursorPosY;
    }
    else
        _glfwPlatformGetCursorPos(window, xpos, ypos);
}

GLFWAPI void glfwSetCursorPos(GLFWwindow* handle, double xpos, double ypos)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT();

    if (xpos != xpos || xpos < -DBL_MAX || xpos > DBL_MAX ||
        ypos != ypos || ypos < -DBL_MAX || ypos > DBL_MAX)
    {
        _glfwInputError(GLFW_INVALID_VALUE,
                        "Invalid cursor position %f %f",
                        xpos, ypos);
        return;
    }

    if (!_glfwPlatformWindowFocused(window))
        return;

    if (window->cursorMode == GLFW_CURSOR_DISABLED)
    {
        // Only update the accumulated position if the cursor is disabled
        window->virtualCursorPosX = xpos;
        window->virtualCursorPosY = ypos;
    }
    else
    {
        // Update system cursor position
        _glfwPlatformSetCursorPos(window, xpos, ypos);
    }
}

GLFWAPI GLFWcursor* glfwCreateCursor(const GLFWimage* image, int xhot, int yhot)
{
    _GLFWcursor* cursor;

    assert(image != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    cursor = calloc(1, sizeof(_GLFWcursor));
    cursor->next = _glfw.cursorListHead;
    _glfw.cursorListHead = cursor;

    if (!_glfwPlatformCreateCursor(cursor, image, xhot, yhot))
    {
        glfwDestroyCursor((GLFWcursor*) cursor);
        return NULL;
    }

    return (GLFWcursor*) cursor;
}

GLFWAPI GLFWcursor* glfwCreateStandardCursor(int shape)
{
    _GLFWcursor* cursor;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (shape != GLFW_ARROW_CURSOR &&
        shape != GLFW_IBEAM_CURSOR &&
        shape != GLFW_CROSSHAIR_CURSOR &&
        shape != GLFW_HAND_CURSOR &&
        shape != GLFW_HRESIZE_CURSOR &&
        shape != GLFW_VRESIZE_CURSOR)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid standard cursor 0x%08X", shape);
        return NULL;
    }

    cursor = calloc(1, sizeof(_GLFWcursor));
    cursor->next = _glfw.cursorListHead;
    _glfw.cursorListHead = cursor;

    if (!_glfwPlatformCreateStandardCursor(cursor, shape))
    {
        glfwDestroyCursor((GLFWcursor*) cursor);
        return NULL;
    }

    return (GLFWcursor*) cursor;
}

GLFWAPI void glfwDestroyCursor(GLFWcursor* handle)
{
    _GLFWcursor* cursor = (_GLFWcursor*) handle;

    _GLFW_REQUIRE_INIT();

    if (cursor == NULL)
        return;

    // Make sure the cursor is not being used by any window
    {
        _GLFWwindow* window;

        for (window = _glfw.windowListHead;  window;  window = window->next)
        {
            if (window->cursor == cursor)
                glfwSetCursor((GLFWwindow*) window, NULL);
        }
    }

    _glfwPlatformDestroyCursor(cursor);

    // Unlink cursor from global linked list
    {
        _GLFWcursor** prev = &_glfw.cursorListHead;

        while (*prev != cursor)
            prev = &((*prev)->next);

        *prev = cursor->next;
    }

    free(cursor);
}

GLFWAPI void glfwSetCursor(GLFWwindow* windowHandle, GLFWcursor* cursorHandle)
{
    _GLFWwindow* window = (_GLFWwindow*) windowHandle;
    _GLFWcursor* cursor = (_GLFWcursor*) cursorHandle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT();

    window->cursor = cursor;

    _glfwPlatformSetCursor(window, cursor);
}

GLFWAPI GLFWkeyfun glfwSetKeyCallback(GLFWwindow* handle, GLFWkeyfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.key, cbfun);
    return cbfun;
}

GLFWAPI GLFWcharfun glfwSetCharCallback(GLFWwindow* handle, GLFWcharfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.character, cbfun);
    return cbfun;
}

GLFWAPI GLFWcharmodsfun glfwSetCharModsCallback(GLFWwindow* handle, GLFWcharmodsfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.charmods, cbfun);
    return cbfun;
}

GLFWAPI GLFWmousebuttonfun glfwSetMouseButtonCallback(GLFWwindow* handle,
                                                      GLFWmousebuttonfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.mouseButton, cbfun);
    return cbfun;
}

GLFWAPI GLFWcursorposfun glfwSetCursorPosCallback(GLFWwindow* handle,
                                                  GLFWcursorposfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.cursorPos, cbfun);
    return cbfun;
}

GLFWAPI GLFWcursorenterfun glfwSetCursorEnterCallback(GLFWwindow* handle,
                                                      GLFWcursorenterfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.cursorEnter, cbfun);
    return cbfun;
}

GLFWAPI GLFWscrollfun glfwSetScrollCallback(GLFWwindow* handle,
                                            GLFWscrollfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.scroll, cbfun);
    return cbfun;
}

GLFWAPI GLFWdropfun glfwSetDropCallback(GLFWwindow* handle, GLFWdropfun cbfun)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(window->callbacks.drop, cbfun);
    return cbfun;
}

GLFWAPI int glfwJoystickPresent(int jid)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return GLFW_FALSE;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return GLFW_FALSE;

    return _glfwPlatformPollJoystick(js, _GLFW_POLL_PRESENCE);
}

GLFWAPI const float* glfwGetJoystickAxes(int jid, int* count)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);
    assert(count != NULL);

    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return NULL;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return NULL;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_AXES))
        return NULL;

    *count = js->axisCount;
    return js->axes;
}

GLFWAPI const unsigned char* glfwGetJoystickButtons(int jid, int* count)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);
    assert(count != NULL);

    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return NULL;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return NULL;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_BUTTONS))
        return NULL;

    if (_glfw.hints.init.hatButtons)
        *count = js->buttonCount + js->hatCount * 4;
    else
        *count = js->buttonCount;

    return js->buttons;
}

GLFWAPI const unsigned char* glfwGetJoystickHats(int jid, int* count)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);
    assert(count != NULL);

    *count = 0;

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return NULL;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return NULL;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_BUTTONS))
        return NULL;

    *count = js->hatCount;
    return js->hats;
}

GLFWAPI const char* glfwGetJoystickName(int jid)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return NULL;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return NULL;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_PRESENCE))
        return NULL;

    return js->name;
}

GLFWAPI const char* glfwGetJoystickGUID(int jid)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return NULL;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return NULL;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_PRESENCE))
        return NULL;

    return js->guid;
}

GLFWAPI GLFWjoystickfun glfwSetJoystickCallback(GLFWjoystickfun cbfun)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    _GLFW_SWAP_POINTERS(_glfw.callbacks.joystick, cbfun);
    return cbfun;
}

GLFWAPI int glfwUpdateGamepadMappings(const char* string)
{
    int jid;
    const char* c = string;

    assert(string != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);

    while (*c)
    {
        if (isxdigit(*c))
        {
            char line[1024];

            const size_t length = strcspn(c, "\r\n");
            if (length < sizeof(line))
            {
                _GLFWmapping mapping = {{0}};

                memcpy(line, c, length);
                line[length] = '\0';

                if (parseMapping(&mapping, line))
                {
                    _GLFWmapping* previous = findMapping(mapping.guid);
                    if (previous)
                        *previous = mapping;
                    else
                    {
                        _glfw.mappingCount++;
                        _glfw.mappings =
                            realloc(_glfw.mappings,
                                    sizeof(_GLFWmapping) * _glfw.mappingCount);
                        _glfw.mappings[_glfw.mappingCount - 1] = mapping;
                    }
                }
            }

            c += length;
        }
        else
        {
            c += strcspn(c, "\r\n");
            c += strspn(c, "\r\n");
        }
    }

    for (jid = 0;  jid <= GLFW_JOYSTICK_LAST;  jid++)
    {
        _GLFWjoystick* js = _glfw.joysticks + jid;
        if (js->present)
            js->mapping = findMapping(js->guid);
    }

    return GLFW_TRUE;
}

GLFWAPI int glfwJoystickIsGamepad(int jid)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return GLFW_FALSE;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return GLFW_FALSE;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_PRESENCE))
        return GLFW_FALSE;

    return js->mapping != NULL;
}

GLFWAPI const char* glfwGetGamepadName(int jid)
{
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return NULL;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return NULL;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_PRESENCE))
        return NULL;

    if (!js->mapping)
        return NULL;

    return js->mapping->name;
}

GLFWAPI int glfwGetGamepadState(int jid, GLFWgamepadstate* state)
{
    int i;
    _GLFWjoystick* js;

    assert(jid >= GLFW_JOYSTICK_1);
    assert(jid <= GLFW_JOYSTICK_LAST);
    assert(state != NULL);

    memset(state, 0, sizeof(GLFWgamepadstate));

    _GLFW_REQUIRE_INIT_OR_RETURN(GLFW_FALSE);

    if (jid < 0 || jid > GLFW_JOYSTICK_LAST)
    {
        _glfwInputError(GLFW_INVALID_ENUM, "Invalid joystick ID %i", jid);
        return GLFW_FALSE;
    }

    js = _glfw.joysticks + jid;
    if (!js->present)
        return GLFW_FALSE;

    if (!_glfwPlatformPollJoystick(js, _GLFW_POLL_ALL))
        return GLFW_FALSE;

    if (!js->mapping)
        return GLFW_FALSE;

    for (i = 0;  i <= GLFW_GAMEPAD_BUTTON_LAST;  i++)
    {
        if (js->mapping->buttons[i].type == _GLFW_JOYSTICK_AXIS)
        {
            if (fabs(js->axes[js->mapping->buttons[i].value]) > 0.5)
                state->buttons[i] = GLFW_PRESS;
        }
        else if (js->mapping->buttons[i].type == _GLFW_JOYSTICK_HATBIT)
        {
            const unsigned int hat = js->mapping->buttons[i].value >> 4;
            const unsigned int bit = js->mapping->buttons[i].value & 0xf;
            if (js->hats[hat] & bit)
                state->buttons[i] = GLFW_PRESS;
        }
        else if (js->mapping->buttons[i].type == _GLFW_JOYSTICK_BUTTON)
            state->buttons[i] = js->buttons[js->mapping->buttons[i].value];
    }

    for (i = 0;  i <= GLFW_GAMEPAD_AXIS_LAST;  i++)
    {
        if (js->mapping->axes[i].type == _GLFW_JOYSTICK_AXIS)
            state->axes[i] = js->axes[js->mapping->axes[i].value];
        else if (js->mapping->buttons[i].type == _GLFW_JOYSTICK_HATBIT)
        {
            const unsigned int hat = js->mapping->buttons[i].value >> 4;
            const unsigned int bit = js->mapping->buttons[i].value & 0xf;
            if (js->hats[hat] & bit)
                state->axes[i] = 1.f;
        }
        else if (js->mapping->buttons[i].type == _GLFW_JOYSTICK_BUTTON)
            state->axes[i] = (float) js->buttons[js->mapping->axes[i].value];
    }

    return GLFW_TRUE;
}

GLFWAPI void glfwSetClipboardString(GLFWwindow* handle, const char* string)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);
    assert(string != NULL);

    _GLFW_REQUIRE_INIT();
    _glfwPlatformSetClipboardString(window, string);
}

GLFWAPI const char* glfwGetClipboardString(GLFWwindow* handle)
{
    _GLFWwindow* window = (_GLFWwindow*) handle;
    assert(window != NULL);

    _GLFW_REQUIRE_INIT_OR_RETURN(NULL);
    return _glfwPlatformGetClipboardString(window);
}

GLFWAPI double glfwGetTime(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0.0);
    return (double) (_glfwPlatformGetTimerValue() - _glfw.timer.offset) /
        _glfwPlatformGetTimerFrequency();
}

GLFWAPI void glfwSetTime(double time)
{
    _GLFW_REQUIRE_INIT();

    if (time != time || time < 0.0 || time > 18446744073.0)
    {
        _glfwInputError(GLFW_INVALID_VALUE, "Invalid time %f", time);
        return;
    }

    _glfw.timer.offset = _glfwPlatformGetTimerValue() -
        (uint64_t) (time * _glfwPlatformGetTimerFrequency());
}

GLFWAPI uint64_t glfwGetTimerValue(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0);
    return _glfwPlatformGetTimerValue();
}

GLFWAPI uint64_t glfwGetTimerFrequency(void)
{
    _GLFW_REQUIRE_INIT_OR_RETURN(0);
    return _glfwPlatformGetTimerFrequency();
}