/*

 File: Utility.c

 Abstract: Common utiltity functions

 Version: <1.0>

 © Copyright 2005 Apple Computer, Inc. All rights reserved.

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 original Apple software (the "Apple Software"), 

 to use, reproduce, modify and redistribute the 

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 logos of Apple Computer, Inc. may be used to 

 endorse or promote products derived from the 

 Apple Software without specific prior written 

 permission from Apple.  Except as expressly 

 stated in this notice, no other rights or 

 licenses, express or implied, are granted by 

 Apple herein, including but not limited to any 

 patent rights that may be infringed by your 

 derivative works or by other works in which the 

 Apple Software may be incorporated.

 The Apple Software is provided by Apple on an "AS 

 IS" basis.  APPLE MAKES NO WARRANTIES, EXPRESS OR 

 IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED 

 WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY 

 AND FITNESS FOR A PARTICULAR PURPOSE, REGARDING 

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 IN NO EVENT SHALL APPLE BE LIABLE FOR ANY 

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 DAMAGES (INCLUDING, BUT NOT LIMITED TO, 

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 */

#include "Utility.h"

#include <mach/mach_time.h>

unsigned char r = 0xff;

//

// Allocate a bitmap buffer and fill it with a gradient

//

unsigned char * createGradientARGBBuffer(size_t W, size_t H)

{

    int i, j;

    unsigned char * p, *data;

    size_t bytesPerRow, size, skipBytes;

    // Allocate the 3K by 3K image

    bytesPerRow = ((W * 32) + 7) / 8;

    skipBytes = bytesPerRow - W * 4;

    size = bytesPerRow * H;

    p = data = malloc(size);

    if (data == NULL) return NULL;

    r = 0xff - r;

    // Fill the image with a color gradient

    for (i=0; i < H; i++) {

        for (j=0; j < W; j++) {

            *p++ = 0xff;                // A

            *p++ = r;                                           // R

            *p++ = 0x00 + ((float)i / H) * 0xff;    // G

            *p++ = 0xff - ((float)j / W) * 0xff;    // B

        }

        p += skipBytes;

    }

    return data;

}

//

//  Create a 32 bit XRGB CGImageRef based on the width, height and bitmap data

//

CGImageRef createImage(size_t W, size_t H, unsigned char *data)

{

    CGImageRef image;

    size_t bytesPerRow, size, skipBytes;

    CGColorSpaceRef csGeneric;

    CGDataProviderRef provider;

    // Allocate the 3K by 3K image

    bytesPerRow = ((W * 32) + 7) / 8;

    skipBytes = bytesPerRow - W * 4;

    size = bytesPerRow * H;

    // Use GenericRGB as the colorspace for the source image

    csGeneric = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);

    // Create a data provider for the bitmap data

    provider = CGDataProviderCreateWithData(NULL, data, size, NULL);

    // Create the source image as a 32 bit XRGB image

    image = CGImageCreate(W, H, 8, 32, bytesPerRow, csGeneric, kCGImageAlphaNoneSkipFirst,

                        provider, NULL, true, kCGRenderingIntentDefault);

    CFRelease(csGeneric);   // no longer need the colorspace

    CFRelease(provider);    // no longer need the data provider

    return(image);

}

//

// Returns the current time in seconds

// 

double currentTime(void)

{

    static double scale = 0;

    if (scale == 0) {

        mach_timebase_info_data_t info;

        mach_timebase_info(&info);

        scale = info.numer / info.denom * 1e-9;

    }

    return mach_absolute_time() * scale;

}

//

// Create a colorspace for the main display

// 

CGColorSpaceRef getDisplayRGBColorSpace(void)

{

    CMProfileRef sysprof = NULL;

    CGColorSpaceRef dispColorSpace = NULL;

    // Get the system profile (which represents the profile for the main display

    if (CMGetSystemProfile(&sysprof) == noErr)

    {

    // Build a CGColorSpaceRef from the system profile

    dispColorSpace = CGColorSpaceCreateWithPlatformColorSpace(sysprof);

    CMCloseProfile(sysprof);

    }

    return dispColorSpace;

}