1 /*

     2  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  *

     8  * 1.  Redistributions of source code must retain the above copyright

     9  *     notice, this list of conditions and the following disclaimer. 

    10  * 2.  Redistributions in binary form must reproduce the above copyright

    11  *     notice, this list of conditions and the following disclaimer in the

    12  *     documentation and/or other materials provided with the distribution. 

    13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

    14  *     its contributors may be used to endorse or promote products derived

    15  *     from this software without specific prior written permission. 

    16  *

    17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

    18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

    19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

    20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

    21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

    22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

    23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

    24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

    26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    27  */

    28 

    29 #import "WebGraphicsExtras.h"

    30 

    31 #import <Accelerate/Accelerate.h>

    32 #import <JavaScriptCore/Assertions.h>

    33 #import <dlfcn.h>

    34 

    35 unsigned WebConvertBGRAToARGB(unsigned char *offscreenBuffer, int rowBytes, int x, int y, int width, int height)

    36 {

    37     

    38     static vImage_Error (*softLink_vImagePermuteChannels_ARGB8888)(const vImage_Buffer *src, const vImage_Buffer *dest, const uint8_t permuteMap[4], vImage_Flags flags) = NULL;

    39 

    40     if (!softLink_vImagePermuteChannels_ARGB8888) {

    41         void *framework = dlopen("/System/Library/Frameworks/Accelerate.framework/Accelerate", RTLD_NOW);

    42         ASSERT(framework);

    43         softLink_vImagePermuteChannels_ARGB8888 = dlsym(framework, "vImagePermuteChannels_ARGB8888");

    44         ASSERT(softLink_vImagePermuteChannels_ARGB8888);

    45     }

    46         

    47     void *swizzleImageBase = offscreenBuffer + y * rowBytes + x * 4;

    48     vImage_Buffer vImage = { swizzleImageBase, height, width, rowBytes };

    49     uint8_t vImagePermuteMap[4] = { 3, 2, 1, 0 }; // Where { 0, 1, 2, 3 } would leave the channels unchanged; this map converts BGRA to ARGB

    50     vImage_Error vImageError = softLink_vImagePermuteChannels_ARGB8888(&vImage, &vImage, vImagePermuteMap, 0);

    51     if (vImageError) {

    52         LOG_ERROR("Could not convert BGRA image to ARGB: %d", vImageError);

    53         return FALSE;

    54     }

    55     

    56     return TRUE;

    57 }