glfw/src/cocoa_gamma.c

//========================================================================
// GLFW 3.1 OS X - www.glfw.org
//------------------------------------------------------------------------
// Copyright (c) 2010 Camilla Berglund <elmindreda@elmindreda.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 <limits.h>
#include <stdlib.h>
#include <string.h>

#include <ApplicationServices/ApplicationServices.h>


//////////////////////////////////////////////////////////////////////////
//////                       GLFW platform API                      //////
//////////////////////////////////////////////////////////////////////////

void _glfwPlatformGetGammaRamp(_GLFWmonitor* monitor, GLFWgammaramp* ramp)
{
    uint32_t i, size = CGDisplayGammaTableCapacity(monitor->ns.displayID);
    CGGammaValue* values = calloc(size * 3, sizeof(CGGammaValue));

    CGGetDisplayTransferByTable(monitor->ns.displayID,
                                size,
                                values,
                                values + size,
                                values + size * 2,
                                &size);

    _glfwAllocGammaArrays(ramp, size);

    for (i = 0; i < size; i++)
    {
        ramp->red[i]   = (unsigned short) (values[i] * 65535);
        ramp->green[i] = (unsigned short) (values[i + size] * 65535);
        ramp->blue[i]  = (unsigned short) (values[i + size * 2] * 65535);
    }

    free(values);
}

void _glfwPlatformSetGammaRamp(_GLFWmonitor* monitor, const GLFWgammaramp* ramp)
{
    int i;
    CGGammaValue* values = calloc(ramp->size * 3, sizeof(CGGammaValue));

    for (i = 0;  i < ramp->size;  i++)
    {
        values[i]                  = ramp->red[i] / 65535.f;
        values[i + ramp->size]     = ramp->green[i] / 65535.f;
        values[i + ramp->size * 2] = ramp->blue[i] / 65535.f;
    }

    CGSetDisplayTransferByTable(monitor->ns.displayID,
                                ramp->size,
                                values,
                                values + ramp->size,
                                values + ramp->size * 2);

    free(values);
}