IMG_ImageIO.m
author Sam Lantinga <slouken@libsdl.org>
Fri, 30 Dec 2011 16:14:00 -0500
changeset 279 e2fa9ff13b5d
parent 270 IMG_ImageIO.c@98f97f83e203
child 283 ec183abd5996
permissions -rw-r--r--
SDL_image uses ImageIO for ios4 and osx and UIImage on ios3

Vittorio Giovara

>> The second one is a feature request to make it so that when the
>> ImageIO framework is not present the library would fallback to the
>> UIImage backend; although it would perhaps make backporting a little
>> difficult I am sure that there is still a lot of software targeting
>> pre-ios 4 that could make use of it.
>
> It's possible, and not entirely unreasonable, but iOS moves so fast
> that I haven't felt it really merited the extra effort to do so. My
> experience is that there isn't a lot of interest in 3.x. I have a
> 3.1.3 device and there are actually very few apps (that I would be
> interested in getting) that support 3.x any more and I have to be very
> careful to no upgrade my existing apps because the new versions don't
> work on my device any more. I think the percentage of devices 3.x is
> less than 10% now. Testing old devices is another difficulty. And if
> you need to start weak linking frameworks in the Xcode project, you go
> into areas most non Apple developers don't know about.
>
> -Eric

I see your point, iOS is a much faster platform than OSX and a lot of
applications are dropping support for 3.* devices, however I feel that
as SDL is a compatibility layer between architectures it should be as
compatible as possible, until major api change or build system make it
impossible/unbearable to keep it updated.
Having said that I am proposing a solution that should keep SDL_image
compatible with both the newer ImageIO for ios4 and osx and allow us
to use uiimage on ios3: what I am linking is a merge of
IMG_UIImage.m and IMG_ImageIO.c and the small changes that need to be
applied to the related xcode project files).
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/*
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 *  IMG_ImageIO.c
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 *  SDL_image
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 *
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 *  Created by Eric Wing on 1/1/09.
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 *  Copyright 2009 __MyCompanyName__. All rights reserved.
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 *
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 */
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#if defined(__APPLE__) && !defined(SDL_IMAGE_USE_COMMON_BACKEND)
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#include "SDL_image.h"
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// Used because CGDataProviderCreate became deprecated in 10.5
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#include <AvailabilityMacros.h>
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#include <TargetConditionals.h>
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#include <Foundation/Foundation.h>
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#if (TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)
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#ifdef ALLOW_UIIMAGE_FALLBACK
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#define USE_UIIMAGE_BACKEND() ([UIImage instancesRespondToSelector:@selector(initWithCGImage:scale:orientation:)] == NO)
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#else
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#define USE_UIIMAGE_BACKEND() (Internal_checkImageIOisAvailable())
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#endif
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#import <MobileCoreServices/MobileCoreServices.h> // for UTCoreTypes.h
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#import <ImageIO/ImageIO.h>
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#import <UIKit/UIImage.h>
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#else
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// For ImageIO framework and also LaunchServices framework (for UTIs)
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#include <ApplicationServices/ApplicationServices.h>
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#endif
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/**************************************************************
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 ***** Begin Callback functions for block reading *************
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 **************************************************************/
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// This callback reads some bytes from an SDL_rwops and copies it
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// to a Quartz buffer (supplied by Apple framework).
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static size_t MyProviderGetBytesCallback(void* rwops_userdata, void* quartz_buffer, size_t the_count)
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{
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    return (size_t)SDL_RWread((struct SDL_RWops *)rwops_userdata, quartz_buffer, 1, the_count);
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}
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// This callback is triggered when the data provider is released
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// so you can clean up any resources.
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static void MyProviderReleaseInfoCallback(void* rwops_userdata)
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{
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    // What should I put here? 
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    // I think the user and SDL_RWops controls closing, so I don't do anything.
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}
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static void MyProviderRewindCallback(void* rwops_userdata)
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{
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    SDL_RWseek((struct SDL_RWops *)rwops_userdata, 0, RW_SEEK_SET);
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}
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#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 // CGDataProviderCreateSequential was introduced in 10.5; CGDataProviderCreate is deprecated
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off_t MyProviderSkipForwardBytesCallback(void* rwops_userdata, off_t the_count)
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{
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    off_t start_position = SDL_RWtell((struct SDL_RWops *)rwops_userdata);
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    SDL_RWseek((struct SDL_RWops *)rwops_userdata, the_count, RW_SEEK_CUR);
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    off_t end_position = SDL_RWtell((struct SDL_RWops *)rwops_userdata);
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    return (end_position - start_position);	
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}
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#else // CGDataProviderCreate was deprecated in 10.5
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static void MyProviderSkipBytesCallback(void* rwops_userdata, size_t the_count)
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{
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    SDL_RWseek((struct SDL_RWops *)rwops_userdata, the_count, RW_SEEK_CUR);
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}
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#endif
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/**************************************************************
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 ***** End Callback functions for block reading ***************
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 **************************************************************/
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// This creates a CGImageSourceRef which is a handle to an image that can be used to examine information
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// about the image or load the actual image data.
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static CGImageSourceRef CreateCGImageSourceFromRWops(SDL_RWops* rw_ops, CFDictionaryRef hints_and_options)
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{
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    CGImageSourceRef source_ref;
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    // Similar to SDL_RWops, Apple has their own callbacks for dealing with data streams.
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#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 // CGDataProviderCreateSequential was introduced in 10.5; CGDataProviderCreate is deprecated
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    CGDataProviderSequentialCallbacks provider_callbacks =
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    {
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        0,
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        MyProviderGetBytesCallback,
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        MyProviderSkipForwardBytesCallback,
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        MyProviderRewindCallback,
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        MyProviderReleaseInfoCallback
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    };
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    CGDataProviderRef data_provider = CGDataProviderCreateSequential(rw_ops, &provider_callbacks);
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#else // CGDataProviderCreate was deprecated in 10.5
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    CGDataProviderCallbacks provider_callbacks =
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    {
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        MyProviderGetBytesCallback,
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        MyProviderSkipBytesCallback,
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        MyProviderRewindCallback,
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        MyProviderReleaseInfoCallback
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    };
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    CGDataProviderRef data_provider = CGDataProviderCreate(rw_ops, &provider_callbacks);
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#endif
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    // Get the CGImageSourceRef.
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    // The dictionary can be NULL or contain hints to help ImageIO figure out the image type.
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    source_ref = CGImageSourceCreateWithDataProvider(data_provider, hints_and_options);
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    return source_ref;
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}
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/* Create a CGImageSourceRef from a file. */
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/* Remember to CFRelease the created source when done. */
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static CGImageSourceRef CreateCGImageSourceFromFile(const char* the_path)
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{
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    CFURLRef the_url = NULL;
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    CGImageSourceRef source_ref = NULL;
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    CFStringRef cf_string = NULL;
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    /* Create a CFString from a C string */
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    cf_string = CFStringCreateWithCString(NULL, the_path, kCFStringEncodingUTF8);
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    if (!cf_string) {
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        return NULL;
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    }
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    /* Create a CFURL from a CFString */
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    the_url = CFURLCreateWithFileSystemPath(NULL, cf_string, kCFURLPOSIXPathStyle, false);
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    /* Don't need the CFString any more (error or not) */
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    CFRelease(cf_string);
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    if(!the_url)
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    {
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        return NULL;
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    }
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    source_ref = CGImageSourceCreateWithURL(the_url, NULL);
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    /* Don't need the URL any more (error or not) */
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    CFRelease(the_url);
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    return source_ref;
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}
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static CGImageRef CreateCGImageFromCGImageSource(CGImageSourceRef image_source)
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{
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    CGImageRef image_ref = NULL;
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    if(NULL == image_source)
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    {
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        return NULL;
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    }
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    // Get the first item in the image source (some image formats may
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    // contain multiple items).
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    image_ref = CGImageSourceCreateImageAtIndex(image_source, 0, NULL);
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    if(NULL == image_ref)
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    {
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        IMG_SetError("CGImageSourceCreateImageAtIndex() failed");
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    }
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    return image_ref;
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}
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static CFDictionaryRef CreateHintDictionary(CFStringRef uti_string_hint)
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{
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    CFDictionaryRef hint_dictionary = NULL;
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    if(uti_string_hint != NULL)
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    {
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        // Do a bunch of work to setup a CFDictionary containing the jpeg compression properties.
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        CFStringRef the_keys[1];
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        CFStringRef the_values[1];
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        the_keys[0] = kCGImageSourceTypeIdentifierHint;
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        the_values[0] = uti_string_hint;
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        // kCFTypeDictionaryKeyCallBacks or kCFCopyStringDictionaryKeyCallBacks?
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        hint_dictionary = CFDictionaryCreate(NULL, (const void**)&the_keys, (const void**)&the_values, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
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    }
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    return hint_dictionary;
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}
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// Once we have our image, we need to get it into an SDL_Surface
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static SDL_Surface* Create_SDL_Surface_From_CGImage(CGImageRef image_ref)
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{
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    /* This code is adapted from Apple's Documentation found here:
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     * http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/index.html
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     * Listing 9-4††Using a Quartz image as a texture source.
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     * Unfortunately, this guide doesn't show what to do about
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     * non-RGBA image formats so I'm making the rest up.
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     * All this code should be scrutinized.
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     */
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    size_t w = CGImageGetWidth(image_ref);
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    size_t h = CGImageGetHeight(image_ref);
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    CGRect rect = {{0, 0}, {w, h}};
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    CGImageAlphaInfo alpha = CGImageGetAlphaInfo(image_ref);
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    //size_t bits_per_pixel = CGImageGetBitsPerPixel(image_ref);
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    size_t bits_per_component = 8;
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    SDL_Surface* surface;
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    Uint32 Amask;
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    Uint32 Rmask;
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    Uint32 Gmask;
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    Uint32 Bmask;
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    CGContextRef bitmap_context;
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    CGBitmapInfo bitmap_info;
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    CGColorSpaceRef color_space = CGColorSpaceCreateDeviceRGB();
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    if (alpha == kCGImageAlphaNone ||
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        alpha == kCGImageAlphaNoneSkipFirst ||
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        alpha == kCGImageAlphaNoneSkipLast) {
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        bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host; /* XRGB */
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        Amask = 0x00000000;
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    } else {
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        /* kCGImageAlphaFirst isn't supported */
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        //bitmap_info = kCGImageAlphaFirst | kCGBitmapByteOrder32Host; /* ARGB */
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        bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host; /* ARGB */
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        Amask = 0xFF000000;
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    }
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    Rmask = 0x00FF0000;
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    Gmask = 0x0000FF00;
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    Bmask = 0x000000FF;
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    surface = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32, Rmask, Gmask, Bmask, Amask);
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    if (surface)
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    {
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        // Sets up a context to be drawn to with surface->pixels as the area to be drawn to
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        bitmap_context = CGBitmapContextCreate(
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                                               surface->pixels,
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                                               surface->w,
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                                               surface->h,
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                                               bits_per_component,
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                                               surface->pitch,
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                                               color_space,
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                                               bitmap_info
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                                               );
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        // Draws the image into the context's image_data
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        CGContextDrawImage(bitmap_context, rect, image_ref);
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        CGContextRelease(bitmap_context);
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        // FIXME: Reverse the premultiplied alpha
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        if ((bitmap_info & kCGBitmapAlphaInfoMask) == kCGImageAlphaPremultipliedFirst) {
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            int i, j;
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            Uint8 *p = (Uint8 *)surface->pixels;
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            for (i = surface->h * surface->pitch/4; i--; ) {
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#if __LITTLE_ENDIAN__
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                Uint8 A = p[3];
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                if (A) {
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                    for (j = 0; j < 3; ++j) {
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                        p[j] = (p[j] * 255) / A;
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                    }
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                }
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#else
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                Uint8 A = p[0];
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                if (A) {
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                    for (j = 1; j < 4; ++j) {
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                        p[j] = (p[j] * 255) / A;
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                    }
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                }
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#endif /* ENDIAN */
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                p += 4;
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            }
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        }
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    }
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    if (color_space)
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    {
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        CGColorSpaceRelease(color_space);			
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    }
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    return surface;
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}
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#pragma mark -
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#pragma mark IMG_Init stubs
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#if !defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1))
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static int Internal_checkImageIOisAvailable() {
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    // just check if we are running on ios 4 or more, else throw exception
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    if ([UIImage instancesRespondToSelector:@selector(initWithCGImage:scale:orientation:)])
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        return 0;
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    [NSException raise:@"UIImage fallback not enabled at compile time"
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                format:@"ImageIO is not available on your platform, please recompile SDL_Image with ALLOW_UIIMAGE_FALLBACK."];
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    return -1;
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}
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#endif
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int IMG_InitJPG()
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{
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    return 0;
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}
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void IMG_QuitJPG()
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{
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}
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int IMG_InitPNG()
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{
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    return 0;
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}
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void IMG_QuitPNG()
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{
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}
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int IMG_InitTIF()
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{
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    return 0;
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}
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void IMG_QuitTIF()
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{
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}
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#pragma mark -
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#pragma mark Get type of image
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static int Internal_isType_UIImage (SDL_RWops *rw_ops, CFStringRef uti_string_to_test)
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{
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    int is_type = 0;
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#if defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1))
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    int start = SDL_RWtell(rw_ops);
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    if ((0 == CFStringCompare(uti_string_to_test, kUTTypeICO, 0)) ||
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        (0 == CFStringCompare(uti_string_to_test, CFSTR("com.microsoft.cur"), 0))) {
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        // The Win32 ICO file header (14 bytes)
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        Uint16 bfReserved;
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        Uint16 bfType;
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        Uint16 bfCount;
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        int type = (0 == CFStringCompare(uti_string_to_test, kUTTypeICO, 0)) ? 1 : 2;
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        bfReserved = SDL_ReadLE16(rw_ops);
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        bfType = SDL_ReadLE16(rw_ops);
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        bfCount = SDL_ReadLE16(rw_ops);
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        if ((bfReserved == 0) && (bfType == type) && (bfCount != 0)) 
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            is_type = 1;
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    } else if (0 == CFStringCompare(uti_string_to_test, kUTTypeBMP, 0)) {
slouken@279
   348
        char magic[2];
slouken@279
   349
        
slouken@279
   350
        if ( SDL_RWread(rw_ops, magic, sizeof(magic), 1) ) {
slouken@279
   351
            if ( strncmp(magic, "BM", 2) == 0 ) {
slouken@279
   352
                is_type = 1;
slouken@279
   353
            }
slouken@279
   354
        }
slouken@279
   355
    } else if (0 == CFStringCompare(uti_string_to_test, kUTTypeGIF, 0)) {
slouken@279
   356
        char magic[6];
slouken@279
   357
        
slouken@279
   358
        if ( SDL_RWread(rw_ops, magic, sizeof(magic), 1) ) {
slouken@279
   359
            if ( (strncmp(magic, "GIF", 3) == 0) &&
slouken@279
   360
                ((memcmp(magic + 3, "87a", 3) == 0) ||
slouken@279
   361
                 (memcmp(magic + 3, "89a", 3) == 0)) ) {
slouken@279
   362
                    is_type = 1;
slouken@279
   363
                }
slouken@279
   364
        }
slouken@279
   365
    } else if (0 == CFStringCompare(uti_string_to_test, kUTTypeJPEG, 0)) {
slouken@279
   366
        int in_scan = 0;
slouken@279
   367
        Uint8 magic[4];
slouken@279
   368
        
slouken@279
   369
        // This detection code is by Steaphan Greene <stea@cs.binghamton.edu>
slouken@279
   370
        // Blame me, not Sam, if this doesn't work right. */
slouken@279
   371
        // And don't forget to report the problem to the the sdl list too! */
slouken@279
   372
        
slouken@279
   373
        if ( SDL_RWread(rw_ops, magic, 2, 1) ) {
slouken@279
   374
            if ( (magic[0] == 0xFF) && (magic[1] == 0xD8) ) {
slouken@279
   375
                is_type = 1;
slouken@279
   376
                while (is_type == 1) {
slouken@279
   377
                    if(SDL_RWread(rw_ops, magic, 1, 2) != 2) {
slouken@279
   378
                        is_type = 0;
slouken@279
   379
                    } else if( (magic[0] != 0xFF) && (in_scan == 0) ) {
slouken@279
   380
                        is_type = 0;
slouken@279
   381
                    } else if( (magic[0] != 0xFF) || (magic[1] == 0xFF) ) {
slouken@279
   382
                        /* Extra padding in JPEG (legal) */
slouken@279
   383
                        /* or this is data and we are scanning */
slouken@279
   384
                        SDL_RWseek(rw_ops, -1, SEEK_CUR);
slouken@279
   385
                    } else if(magic[1] == 0xD9) {
slouken@279
   386
                        /* Got to end of good JPEG */
slouken@279
   387
                        break;
slouken@279
   388
                    } else if( (in_scan == 1) && (magic[1] == 0x00) ) {
slouken@279
   389
                        /* This is an encoded 0xFF within the data */
slouken@279
   390
                    } else if( (magic[1] >= 0xD0) && (magic[1] < 0xD9) ) {
slouken@279
   391
                        /* These have nothing else */
slouken@279
   392
                    } else if(SDL_RWread(rw_ops, magic+2, 1, 2) != 2) {
slouken@279
   393
                        is_type = 0;
slouken@279
   394
                    } else {
slouken@279
   395
                        /* Yes, it's big-endian */
slouken@279
   396
                        Uint32 start;
slouken@279
   397
                        Uint32 size;
slouken@279
   398
                        Uint32 end;
slouken@279
   399
                        start = SDL_RWtell(rw_ops);
slouken@279
   400
                        size = (magic[2] << 8) + magic[3];
slouken@279
   401
                        end = SDL_RWseek(rw_ops, size-2, SEEK_CUR);
slouken@279
   402
                        if ( end != start + size - 2 ) is_type = 0;
slouken@279
   403
                        if ( magic[1] == 0xDA ) {
slouken@279
   404
                            /* Now comes the actual JPEG meat */
slouken@279
   405
#ifdef	FAST_IS_JPEG
slouken@279
   406
                            /* Ok, I'm convinced.  It is a JPEG. */
slouken@279
   407
                            break;
slouken@279
   408
#else
slouken@279
   409
                            /* I'm not convinced.  Prove it! */
slouken@279
   410
                            in_scan = 1;
slouken@279
   411
#endif
slouken@279
   412
                        }
slouken@279
   413
                    }
slouken@279
   414
                }
slouken@279
   415
            }
slouken@279
   416
        }
slouken@279
   417
    } else if (0 == CFStringCompare(uti_string_to_test, kUTTypePNG, 0)) {
slouken@279
   418
        Uint8 magic[4];
slouken@279
   419
        
slouken@279
   420
        if ( SDL_RWread(rw_ops, magic, 1, sizeof(magic)) == sizeof(magic) ) {
slouken@279
   421
            if ( magic[0] == 0x89 &&
slouken@279
   422
                magic[1] == 'P' &&
slouken@279
   423
                magic[2] == 'N' &&
slouken@279
   424
                magic[3] == 'G' ) {
slouken@279
   425
                is_type = 1;
slouken@279
   426
            }
slouken@279
   427
        }
slouken@279
   428
    } else if (0 == CFStringCompare(uti_string_to_test, CFSTR("com.truevision.tga-image"), 0)) {
slouken@279
   429
        //TODO: fill me!
slouken@279
   430
    } else if (0 == CFStringCompare(uti_string_to_test, kUTTypeTIFF, 0)) {
slouken@279
   431
        Uint8 magic[4];
slouken@279
   432
        
slouken@279
   433
        if ( SDL_RWread(rw_ops, magic, 1, sizeof(magic)) == sizeof(magic) ) {
slouken@279
   434
            if ( (magic[0] == 'I' &&
slouken@279
   435
                  magic[1] == 'I' &&
slouken@279
   436
                  magic[2] == 0x2a &&
slouken@279
   437
                  magic[3] == 0x00) ||
slouken@279
   438
                (magic[0] == 'M' &&
slouken@279
   439
                 magic[1] == 'M' &&
slouken@279
   440
                 magic[2] == 0x00 &&
slouken@279
   441
                 magic[3] == 0x2a) ) {
slouken@279
   442
                    is_type = 1;
slouken@279
   443
                }
slouken@279
   444
        }
slouken@279
   445
    }
slouken@279
   446
    
slouken@279
   447
    // reset the file descption pointer
slouken@279
   448
    SDL_RWseek(rw_ops, start, SEEK_SET);
slouken@279
   449
slouken@279
   450
#endif  /* #if defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)) */
slouken@279
   451
    return is_type;
slouken@279
   452
}
slouken@279
   453
slouken@279
   454
static int Internal_isType_ImageIO (SDL_RWops *rw_ops, CFStringRef uti_string_to_test)
slouken@279
   455
{
slouken@279
   456
    int is_type = 0;
slouken@279
   457
    
slouken@279
   458
    CFDictionaryRef hint_dictionary = CreateHintDictionary(uti_string_to_test);	
slouken@279
   459
    CGImageSourceRef image_source = CreateCGImageSourceFromRWops(rw_ops, hint_dictionary);
slouken@279
   460
    
slouken@279
   461
    if (hint_dictionary != NULL) {
slouken@279
   462
        CFRelease(hint_dictionary);		
slouken@279
   463
    }
slouken@279
   464
    
slouken@279
   465
    if (NULL == image_source) {
slouken@279
   466
        return 0;
slouken@279
   467
    }
slouken@279
   468
    
slouken@279
   469
    // This will get the UTI of the container, not the image itself.
slouken@279
   470
    // Under most cases, this won't be a problem.
slouken@279
   471
    // But if a person passes an icon file which contains a bmp,
slouken@279
   472
    // the format will be of the icon file.
slouken@279
   473
    // But I think the main SDL_image codebase has this same problem so I'm not going to worry about it.	
slouken@279
   474
    CFStringRef uti_type = CGImageSourceGetType(image_source);
slouken@279
   475
    //	CFShow(uti_type);
slouken@279
   476
    
slouken@279
   477
    // Unsure if we really want conformance or equality
slouken@279
   478
    is_type = (int)UTTypeConformsTo(uti_string_to_test, uti_type);
slouken@279
   479
    
slouken@279
   480
    CFRelease(image_source);
slouken@279
   481
    return is_type;
slouken@279
   482
}
slouken@279
   483
slouken@279
   484
static int Internal_isType (SDL_RWops *rw_ops, CFStringRef uti_string_to_test)
slouken@279
   485
{
slouken@279
   486
    if (rw_ops == NULL)
slouken@279
   487
        return 0;
slouken@279
   488
    
slouken@279
   489
#if (TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)
slouken@279
   490
    if (USE_UIIMAGE_BACKEND())
slouken@279
   491
        return Internal_isType_UIImage(rw_ops, uti_string_to_test);
slouken@279
   492
    else
slouken@279
   493
#endif
slouken@279
   494
        return Internal_isType_ImageIO(rw_ops, uti_string_to_test);
slouken@279
   495
}
slouken@279
   496
slouken@195
   497
int IMG_isCUR(SDL_RWops *src)
slouken@195
   498
{
slouken@279
   499
    /* FIXME: Is this a supported type? */
slouken@279
   500
    return Internal_isType(src, CFSTR("com.microsoft.cur"));
slouken@195
   501
}
slouken@195
   502
slouken@195
   503
int IMG_isICO(SDL_RWops *src)
slouken@195
   504
{
slouken@279
   505
    return Internal_isType(src, kUTTypeICO);
slouken@195
   506
}
slouken@195
   507
slouken@187
   508
int IMG_isBMP(SDL_RWops *src)
slouken@187
   509
{
slouken@279
   510
    return Internal_isType(src, kUTTypeBMP);
slouken@187
   511
}
slouken@187
   512
slouken@187
   513
int IMG_isGIF(SDL_RWops *src)
slouken@187
   514
{
slouken@279
   515
    return Internal_isType(src, kUTTypeGIF);
slouken@187
   516
}
slouken@195
   517
slouken@187
   518
// Note: JPEG 2000 is kUTTypeJPEG2000
slouken@187
   519
int IMG_isJPG(SDL_RWops *src)
slouken@187
   520
{
slouken@279
   521
    return Internal_isType(src, kUTTypeJPEG);
slouken@187
   522
}
slouken@187
   523
slouken@187
   524
int IMG_isPNG(SDL_RWops *src)
slouken@187
   525
{
slouken@279
   526
    return Internal_isType(src, kUTTypePNG);
slouken@187
   527
}
slouken@187
   528
slouken@187
   529
// This isn't a public API function. Apple seems to be able to identify tga's.
slouken@187
   530
int IMG_isTGA(SDL_RWops *src)
slouken@187
   531
{
slouken@279
   532
    return Internal_isType(src, CFSTR("com.truevision.tga-image"));
slouken@187
   533
}
slouken@187
   534
slouken@187
   535
int IMG_isTIF(SDL_RWops *src)
slouken@187
   536
{
slouken@279
   537
    return Internal_isType(src, kUTTypeTIFF);
slouken@187
   538
}
slouken@187
   539
slouken@279
   540
#pragma mark -
slouken@279
   541
#pragma mark Load image engine
slouken@279
   542
static SDL_Surface *LoadImageFromRWops_UIImage (SDL_RWops* rw_ops, CFStringRef uti_string_hint)
slouken@195
   543
{
slouken@279
   544
    SDL_Surface *sdl_surface = NULL;
slouken@279
   545
slouken@279
   546
#if defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1))
slouken@279
   547
    NSAutoreleasePool* autorelease_pool = [[NSAutoreleasePool alloc] init];
slouken@279
   548
    UIImage *ui_image;
slouken@279
   549
    int bytes_read = 0;
slouken@279
   550
    // I don't know what a good size is. 
slouken@279
   551
    // Max recommended texture size is 1024x1024 on iPhone so maybe base it on that?
slouken@279
   552
    const int block_size = 1024*4;
slouken@279
   553
    char temp_buffer[block_size];
slouken@279
   554
    
slouken@279
   555
    NSMutableData* ns_data = [[NSMutableData alloc] initWithCapacity:1024*1024*4];
slouken@279
   556
    do {
slouken@279
   557
        bytes_read = SDL_RWread(rw_ops, temp_buffer, 1, block_size);
slouken@279
   558
        [ns_data appendBytes:temp_buffer length:bytes_read];
slouken@279
   559
    } while (bytes_read > 0);
slouken@279
   560
    
slouken@279
   561
    ui_image = [[UIImage alloc] initWithData:ns_data];
slouken@279
   562
    if (ui_image != nil)
slouken@279
   563
        sdl_surface = Create_SDL_Surface_From_CGImage([ui_image CGImage]);
slouken@279
   564
    [ui_image release];
slouken@279
   565
    [ns_data release];          
slouken@279
   566
    [autorelease_pool drain];
slouken@279
   567
slouken@279
   568
#endif  /* #if defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)) */
slouken@279
   569
    return sdl_surface;
slouken@187
   570
}
slouken@187
   571
slouken@279
   572
static SDL_Surface *LoadImageFromRWops_ImageIO (SDL_RWops *rw_ops, CFStringRef uti_string_hint)
slouken@279
   573
{
slouken@279
   574
    CFDictionaryRef hint_dictionary = CreateHintDictionary(uti_string_hint);
slouken@279
   575
    CGImageSourceRef image_source = CreateCGImageSourceFromRWops(rw_ops, hint_dictionary);
slouken@279
   576
slouken@279
   577
    if (hint_dictionary != NULL)
slouken@279
   578
        CFRelease(hint_dictionary);		
slouken@279
   579
slouken@279
   580
    if (NULL == image_source)
slouken@279
   581
        return NULL;
slouken@279
   582
    
slouken@279
   583
    CGImageRef image_ref = CreateCGImageFromCGImageSource(image_source);
slouken@279
   584
    CFRelease(image_source);
slouken@279
   585
slouken@279
   586
    if (NULL == image_ref)
slouken@279
   587
        return NULL;
slouken@279
   588
    SDL_Surface *sdl_surface = Create_SDL_Surface_From_CGImage(image_ref);
slouken@279
   589
    CFRelease(image_ref);
slouken@279
   590
slouken@279
   591
    return sdl_surface;
slouken@279
   592
}
slouken@279
   593
slouken@279
   594
static SDL_Surface *LoadImageFromRWops (SDL_RWops *rw_ops, CFStringRef uti_string_hint)
slouken@279
   595
{
slouken@279
   596
#if (TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)
slouken@279
   597
    if (USE_UIIMAGE_BACKEND()) 
slouken@279
   598
        return LoadImageFromRWops_UIImage(rw_ops, uti_string_hint);
slouken@279
   599
    else
slouken@279
   600
#endif
slouken@279
   601
        return LoadImageFromRWops_ImageIO(rw_ops, uti_string_hint);
slouken@279
   602
}
slouken@279
   603
slouken@279
   604
static SDL_Surface* LoadImageFromFile_UIImage (const char *file)
slouken@279
   605
{
slouken@279
   606
    SDL_Surface *sdl_surface = NULL;
slouken@279
   607
slouken@279
   608
#if defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1))
slouken@279
   609
    NSAutoreleasePool* autorelease_pool = [[NSAutoreleasePool alloc] init];
slouken@279
   610
    NSString *ns_string = [[NSString alloc] initWithUTF8String:file];
slouken@279
   611
    UIImage *ui_image = [[UIImage alloc] initWithContentsOfFile:ns_string];
slouken@279
   612
    if (ui_image != nil)
slouken@279
   613
        sdl_surface = Create_SDL_Surface_From_CGImage([ui_image CGImage]);
slouken@279
   614
    [ui_image release];
slouken@279
   615
    [ns_string release];
slouken@279
   616
    [autorelease_pool drain];
slouken@279
   617
slouken@279
   618
#endif  /* #if defined(ALLOW_UIIMAGE_FALLBACK) && ((TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)) */
slouken@279
   619
    return sdl_surface;	
slouken@279
   620
}
slouken@279
   621
slouken@279
   622
static SDL_Surface* LoadImageFromFile_ImageIO (const char *file)
slouken@279
   623
{
slouken@279
   624
    CGImageSourceRef image_source = NULL;
slouken@279
   625
slouken@279
   626
    image_source = CreateCGImageSourceFromFile(file);
slouken@279
   627
slouken@279
   628
    if(NULL == image_source)
slouken@279
   629
        return NULL;
slouken@279
   630
    
slouken@279
   631
    CGImageRef image_ref = CreateCGImageFromCGImageSource(image_source);
slouken@279
   632
    CFRelease(image_source);
slouken@279
   633
slouken@279
   634
    if (NULL == image_ref)
slouken@279
   635
        return NULL;
slouken@279
   636
    SDL_Surface *sdl_surface = Create_SDL_Surface_From_CGImage(image_ref);
slouken@279
   637
    CFRelease(image_ref);
slouken@279
   638
    return sdl_surface;	
slouken@279
   639
}
slouken@279
   640
slouken@279
   641
static SDL_Surface* LoadImageFromFile (const char *file)
slouken@279
   642
{
slouken@279
   643
#if (TARGET_OS_IPHONE == 1) || (TARGET_IPHONE_SIMULATOR == 1)
slouken@279
   644
    if (USE_UIIMAGE_BACKEND())
slouken@279
   645
        return LoadImageFromFile_UIImage(file);
slouken@279
   646
    else
slouken@279
   647
#endif
slouken@279
   648
        return LoadImageFromFile_ImageIO(file);
slouken@279
   649
}
slouken@279
   650
slouken@279
   651
SDL_Surface* IMG_LoadCUR_RW (SDL_RWops *src)
slouken@279
   652
{
slouken@279
   653
    /* FIXME: Is this a supported type? */
slouken@279
   654
    return LoadImageFromRWops(src, CFSTR("com.microsoft.cur"));
slouken@279
   655
}
slouken@279
   656
slouken@279
   657
SDL_Surface* IMG_LoadICO_RW (SDL_RWops *src)
slouken@279
   658
{
slouken@279
   659
    return LoadImageFromRWops(src, kUTTypeICO);
slouken@279
   660
}
slouken@279
   661
slouken@279
   662
SDL_Surface* IMG_LoadBMP_RW (SDL_RWops *src)
slouken@279
   663
{
slouken@279
   664
    return LoadImageFromRWops(src, kUTTypeBMP);
slouken@279
   665
}
slouken@279
   666
slouken@279
   667
SDL_Surface* IMG_LoadGIF_RW (SDL_RWops *src)
slouken@279
   668
{
slouken@279
   669
    return LoadImageFromRWops (src, kUTTypeGIF);
slouken@279
   670
}
slouken@279
   671
slouken@279
   672
SDL_Surface* IMG_LoadJPG_RW (SDL_RWops *src)
slouken@279
   673
{
slouken@279
   674
    return LoadImageFromRWops (src, kUTTypeJPEG);
slouken@279
   675
}
slouken@279
   676
slouken@279
   677
SDL_Surface* IMG_LoadPNG_RW (SDL_RWops *src)
slouken@279
   678
{
slouken@279
   679
    return LoadImageFromRWops (src, kUTTypePNG);
slouken@279
   680
}
slouken@279
   681
slouken@279
   682
SDL_Surface* IMG_LoadTGA_RW (SDL_RWops *src)
slouken@279
   683
{
slouken@279
   684
    return LoadImageFromRWops(src, CFSTR("com.truevision.tga-image"));
slouken@279
   685
}
slouken@279
   686
slouken@279
   687
SDL_Surface* IMG_LoadTIF_RW (SDL_RWops *src)
slouken@279
   688
{
slouken@279
   689
    return LoadImageFromRWops(src, kUTTypeTIFF);
slouken@279
   690
}
slouken@279
   691
slouken@279
   692
// Since UIImage doesn't really support streams well, we should optimize for the file case.
slouken@187
   693
// Apple provides both stream and file loading functions in ImageIO.
slouken@187
   694
// Potentially, Apple can optimize for either case.
slouken@279
   695
SDL_Surface* IMG_Load (const char *file)
slouken@187
   696
{
slouken@279
   697
    SDL_Surface* sdl_surface = NULL;
slouken@279
   698
    
slouken@279
   699
    sdl_surface = LoadImageFromFile(file);
slouken@279
   700
    if(NULL == sdl_surface)
slouken@279
   701
    {
slouken@279
   702
        // Either the file doesn't exist or ImageIO doesn't understand the format.
slouken@279
   703
        // For the latter case, fallback to the native SDL_image handlers.
slouken@279
   704
        SDL_RWops *src = SDL_RWFromFile(file, "rb");
slouken@279
   705
        char *ext = strrchr(file, '.');
slouken@279
   706
        if (ext) {
slouken@279
   707
            ext++;
slouken@279
   708
        }
slouken@279
   709
        if (!src) {
slouken@279
   710
            /* The error message has been set in SDL_RWFromFile */
slouken@279
   711
            return NULL;
slouken@279
   712
        }
slouken@279
   713
        sdl_surface = IMG_LoadTyped_RW(src, 1, ext);
slouken@279
   714
    }
slouken@279
   715
    return sdl_surface;
slouken@187
   716
}
slouken@187
   717
slouken@240
   718
#endif /* defined(__APPLE__) && !defined(SDL_IMAGE_USE_COMMON_BACKEND) */