iomfsetgamma.c

   1 /* UIKit Tools - command-line utilities for UIKit
   2  * Copyright (C) 2008-2012  Jay Freeman (saurik)
   3 */
   4
   5 /* Modified BSD License {{{ */
   6 /*
   7  *        Redistribution and use in source and binary
   8  * forms, with or without modification, are permitted
   9  * provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the
  12  *    above copyright notice, this list of conditions
  13  *    and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the
  15  *    above copyright notice, this list of conditions
  16  *    and the following disclaimer in the documentation
  17  *    and/or other materials provided with the
  18  *    distribution.
  19  * 3. The name of the author may not be used to endorse
  20  *    or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS''
  24  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
  25  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  26  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  30  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  33  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
  34  * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  35  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  36  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37 */
  38 /* }}} */
  39
  40 #include <mach/mach.h>
  41
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44
  45 #include <dlfcn.h>
  46
  47 #include <IOKit/IOKitLib.h>
  48
  49 #if 0
  50 set -e
  51
  52 sdk=/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS4.3.sdk
  53
  54 /Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/g++ \
  55     -Wall -fmessage-length=0 \
  56     -arch armv6 -miphoneos-version-min=2.0 \
  57     -isysroot "${sdk}" -I. -F"${sdk}"/System/Library/PrivateFrameworks \
  58     -framework IOKit -framework IOMobileFramebuffer \
  59     -o iomfsetgamma iomfsetgamma.c
  60
  61 ldid iomfsetgamma
  62
  63 exit 0
  64 #endif
  65
  66 typedef void *IOMobileFramebufferRef;
  67
  68 kern_return_t IOMobileFramebufferOpen(io_service_t, mach_port_t, void *, IOMobileFramebufferRef *);
  69 kern_return_t IOMobileFramebufferSetGammaTable(IOMobileFramebufferRef, void *);
  70 kern_return_t (*$IOMobileFramebufferGetGammaTable)(IOMobileFramebufferRef, void *);
  71
  72 #define _assert(test) \
  73     if (!(test)) { \
  74         fprintf(stderr, "_assert(%s)\n", #test); \
  75         exit(-1); \
  76     }
  77
  78 int main(int argc, char *argv[]) {
  79     if (argc != 4) {
  80         fprintf(stderr, "usage: iomfsetgamma <red> <green> <blue>\n");
  81         fprintf(stderr, "  example: 1.00 0.78 0.64\n");
  82         return 1;
  83     }
  84
  85     unsigned rs = strtod(argv[1], NULL) * 0x100;
  86     _assert(rs <= 0x100);
  87
  88     unsigned gs = strtod(argv[2], NULL) * 0x100;
  89     _assert(gs <= 0x100);
  90
  91     unsigned bs = strtod(argv[3], NULL) * 0x100;
  92     _assert(bs <= 0x100);
  93
  94     kern_return_t error;
  95     mach_port_t self = mach_task_self();
  96
  97     io_service_t service = 0;
  98
  99     if (service == 0)
 100         service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleCLCD"));
 101     if (service == 0)
 102         service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleH1CLCD"));
 103     if (service == 0)
 104         service = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleM2CLCD"));
 105
 106     _assert(service != 0);
 107
 108     IOMobileFramebufferRef fb;
 109     error = IOMobileFramebufferOpen(service, self, 0, &fb);
 110     _assert(error == 0);
 111
 112     uint32_t data[0xc00 / sizeof(uint32_t)];
 113     memset(data, 0, sizeof(data));
 114
 115     FILE *file = fopen("/tmp/.iomfgamma.dat", "rb");
 116     if (file == NULL) {
 117         $IOMobileFramebufferGetGammaTable = dlsym(RTLD_DEFAULT, "IOMobileFramebufferGetGammaTable");
 118         _assert($IOMobileFramebufferGetGammaTable != NULL);
 119         error = $IOMobileFramebufferGetGammaTable(fb, data);
 120         _assert(error == 0);
 121
 122         file = fopen("/tmp/.iomfgamma.dat", "wb");
 123         _assert(file != NULL);
 124
 125         fwrite(data, 1, sizeof(data), file);
 126         fclose(file);
 127
 128         file = fopen("/tmp/.iomfgamma.dat", "rb");
 129         _assert(file != NULL);
 130     }
 131
 132     fread(data, 1, sizeof(data), file);
 133     fclose(file);
 134
 135     size_t i;
 136     for (i = 0; i != 256; ++i) {
 137         int j = 255 - i;
 138
 139         int r = j * rs >> 8;
 140         int g = j * gs >> 8;
 141         int b = j * bs >> 8;
 142
 143         data[j + 0x000] = data[r + 0x000];
 144         data[j + 0x100] = data[g + 0x100];
 145         data[j + 0x200] = data[b + 0x200];
 146     }
 147
 148     error = IOMobileFramebufferSetGammaTable(fb, data);
 149     _assert(error == 0);
 150
 151     return 0;
 152 }