jni/sdl_image/IMG_ImageIO.c

/*
 *  IMG_ImageIO.c
 *  SDL_image
 *
 *  Created by Eric Wing on 1/1/09.
 *  Copyright 2009 __MyCompanyName__. All rights reserved.
 *
 */

#if defined(__APPLE__) && !defined(SDL_IMAGE_USE_COMMON_BACKEND)

#include "SDL_image.h"

// For ImageIO framework and also LaunchServices framework (for UTIs)
#include <ApplicationServices/ApplicationServices.h>
// Used because CGDataProviderCreate became deprecated in 10.5
#include <AvailabilityMacros.h>

/**************************************************************
 ***** Begin Callback functions for block reading *************
 **************************************************************/

// This callback reads some bytes from an SDL_rwops and copies it
// to a Quartz buffer (supplied by Apple framework).
static size_t MyProviderGetBytesCallback(void* rwops_userdata, void* quartz_buffer, size_t the_count)
{
 return (size_t)SDL_RWread((struct SDL_RWops *)rwops_userdata, quartz_buffer, 1, the_count);
}

// This callback is triggered when the data provider is released
// so you can clean up any resources.
static void MyProviderReleaseInfoCallback(void* rwops_userdata)
{
 // What should I put here?
 // I think the user and SDL_RWops controls closing, so I don't do anything.
}

static void MyProviderRewindCallback(void* rwops_userdata)
{
 SDL_RWseek((struct SDL_RWops *)rwops_userdata, 0, RW_SEEK_SET);
}

#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 // CGDataProviderCreateSequential was introduced in 10.5; CGDataProviderCreate is deprecated
off_t MyProviderSkipForwardBytesCallback(void* rwops_userdata, off_t the_count)
{
 off_t start_position = SDL_RWtell((struct SDL_RWops *)rwops_userdata);
 SDL_RWseek((struct SDL_RWops *)rwops_userdata, the_count, RW_SEEK_CUR);
    off_t end_position = SDL_RWtell((struct SDL_RWops *)rwops_userdata);
    return (end_position - start_position);
}
#else // CGDataProviderCreate was deprecated in 10.5
static void MyProviderSkipBytesCallback(void* rwops_userdata, size_t the_count)
{
 SDL_RWseek((struct SDL_RWops *)rwops_userdata, the_count, RW_SEEK_CUR);
}
#endif


/**************************************************************
 ***** End Callback functions for block reading ***************
 **************************************************************/

// This creates a CGImageSourceRef which is a handle to an image that can be used to examine information
// about the image or load the actual image data.
static CGImageSourceRef CreateCGImageSourceFromRWops(SDL_RWops* rw_ops, CFDictionaryRef hints_and_options)
{
 CGImageSourceRef source_ref;

 // Similar to SDL_RWops, Apple has their own callbacks for dealing with data streams.

#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 // CGDataProviderCreateSequential was introduced in 10.5; CGDataProviderCreate is deprecated
 CGDataProviderSequentialCallbacks provider_callbacks =
 {
        0,
   MyProviderGetBytesCallback,
   MyProviderSkipForwardBytesCallback,
   MyProviderRewindCallback,
   MyProviderReleaseInfoCallback
 };

 CGDataProviderRef data_provider = CGDataProviderCreateSequential(rw_ops, &provider_callbacks);


#else // CGDataProviderCreate was deprecated in 10.5

 CGDataProviderCallbacks provider_callbacks =
 {
   MyProviderGetBytesCallback,
   MyProviderSkipBytesCallback,
   MyProviderRewindCallback,
   MyProviderReleaseInfoCallback
 };

 CGDataProviderRef data_provider = CGDataProviderCreate(rw_ops, &provider_callbacks);
#endif
 // Get the CGImageSourceRef.
 // The dictionary can be NULL or contain hints to help ImageIO figure out the image type.
 source_ref = CGImageSourceCreateWithDataProvider(data_provider, hints_and_options);
 return source_ref;
}


/* Create a CGImageSourceRef from a file. */
/* Remember to CFRelease the created source when done. */
static CGImageSourceRef CreateCGImageSourceFromFile(const char* the_path)
{
    CFURLRef the_url = NULL;
    CGImageSourceRef source_ref = NULL;
 CFStringRef cf_string = NULL;

 /* Create a CFString from a C string */
 cf_string = CFStringCreateWithCString(
                     NULL,
                     the_path,
                     kCFStringEncodingUTF8
                     );
 if(!cf_string)
 {
   return NULL;
 }

 /* Create a CFURL from a CFString */
    the_url = CFURLCreateWithFileSystemPath(
                     NULL,
                     cf_string,
                     kCFURLPOSIXPathStyle,
                     false
                     );

 /* Don't need the CFString any more (error or not) */
 CFRelease(cf_string);

 if(!the_url)
 {
   return NULL;
 }


    source_ref = CGImageSourceCreateWithURL(the_url, NULL);
 /* Don't need the URL any more (error or not) */
 CFRelease(the_url);

 return source_ref;
}


static CGImageRef CreateCGImageFromCGImageSource(CGImageSourceRef image_source)
{
 CGImageRef image_ref = NULL;

    if(NULL == image_source)
 {
   return NULL;
 }

 // Get the first item in the image source (some image formats may
 // contain multiple items).
 image_ref = CGImageSourceCreateImageAtIndex(image_source, 0, NULL);
 return image_ref;
}

static CFDictionaryRef CreateHintDictionary(CFStringRef uti_string_hint)
{
 CFDictionaryRef hint_dictionary = NULL;

 if(uti_string_hint != NULL)
 {
   // Do a bunch of work to setup a CFDictionary containing the jpeg compression properties.
   CFStringRef the_keys[1];
   CFStringRef the_values[1];

   the_keys[0] = kCGImageSourceTypeIdentifierHint;
   the_values[0] = uti_string_hint;

   // kCFTypeDictionaryKeyCallBacks or kCFCopyStringDictionaryKeyCallBacks?
   hint_dictionary = CFDictionaryCreate(NULL, (const void**)&the_keys, (const void**)&the_values, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
 }
 return hint_dictionary;
}


static int Internal_isType(SDL_RWops* rw_ops, CFStringRef uti_string_to_test)
{
 CGImageSourceRef image_source;
 CFStringRef uti_type;
 Boolean is_type;

 CFDictionaryRef hint_dictionary = NULL;

 hint_dictionary = CreateHintDictionary(uti_string_to_test);
 image_source = CreateCGImageSourceFromRWops(rw_ops, hint_dictionary);

 if(hint_dictionary != NULL)
 {
   CFRelease(hint_dictionary);
 }

 if(NULL == image_source)
 {
   return 0;
 }

 // This will get the UTI of the container, not the image itself.
 // Under most cases, this won't be a problem.
 // But if a person passes an icon file which contains a bmp,
 // the format will be of the icon file.
 // But I think the main SDL_image codebase has this same problem so I'm not going to worry about it.
 uti_type = CGImageSourceGetType(image_source);
 //  CFShow(uti_type);

 // Unsure if we really want conformance or equality
 is_type = UTTypeConformsTo(uti_string_to_test, uti_type);

 CFRelease(image_source);

 return (int)is_type;
}

// Once we have our image, we need to get it into an SDL_Surface
static SDL_Surface* Create_SDL_Surface_From_CGImage(CGImageRef image_ref)
{
 /* This code is adapted from Apple's Documentation found here:
  * http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/index.html
  * Listing 9-4††Using a Quartz image as a texture source.
  * Unfortunately, this guide doesn't show what to do about
  * non-RGBA image formats so I'm making the rest up.
  * All this code should be scrutinized.
  */

 size_t w = CGImageGetWidth(image_ref);
 size_t h = CGImageGetHeight(image_ref);
 CGRect rect = {{0, 0}, {w, h}};

 CGImageAlphaInfo alpha = CGImageGetAlphaInfo(image_ref);
 //size_t bits_per_pixel = CGImageGetBitsPerPixel(image_ref);
 size_t bits_per_component = 8;

 SDL_Surface* surface;
 Uint32 Amask;
 Uint32 Rmask;
 Uint32 Gmask;
 Uint32 Bmask;

 CGContextRef bitmap_context;
 CGBitmapInfo bitmap_info;
 CGColorSpaceRef color_space = CGColorSpaceCreateDeviceRGB();

 if (alpha == kCGImageAlphaNone ||
     alpha == kCGImageAlphaNoneSkipFirst ||
     alpha == kCGImageAlphaNoneSkipLast) {
   bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host; /* XRGB */
   Amask = 0x00000000;
 } else {
   /* kCGImageAlphaFirst isn't supported */
   //bitmap_info = kCGImageAlphaFirst | kCGBitmapByteOrder32Host; /* ARGB */
   bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host; /* ARGB */
   Amask = 0xFF000000;
 }

 Rmask = 0x00FF0000;
 Gmask = 0x0000FF00;
 Bmask = 0x000000FF;

 surface = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32, Rmask, Gmask, Bmask, Amask);
 if (surface)
 {
   // Sets up a context to be drawn to with surface->pixels as the area to be drawn to
   bitmap_context = CGBitmapContextCreate(
                             surface->pixels,
                             surface->w,
                             surface->h,
                             bits_per_component,
                             surface->pitch,
                             color_space,
                             bitmap_info
                             );

   // Draws the image into the context's image_data
   CGContextDrawImage(bitmap_context, rect, image_ref);

   CGContextRelease(bitmap_context);

   // FIXME: Reverse the premultiplied alpha
   if ((bitmap_info & kCGBitmapAlphaInfoMask) == kCGImageAlphaPremultipliedFirst) {
     int i, j;
     Uint8 *p = (Uint8 *)surface->pixels;
     for (i = surface->h * surface->pitch/4; i--; ) {
#if __LITTLE_ENDIAN__
       Uint8 A = p[3];
       if (A) {
         for (j = 0; j < 3; ++j) {
           p[j] = (p[j] * 255) / A;
         }
       }
#else
       Uint8 A = p[0];
       if (A) {
         for (j = 1; j < 4; ++j) {
           p[j] = (p[j] * 255) / A;
         }
       }
#endif /* ENDIAN */
       p += 4;
     }
   }
 }

 if (color_space)
 {
   CGColorSpaceRelease(color_space);
 }

 return surface;
}


static SDL_Surface* LoadImageFromRWops(SDL_RWops* rw_ops, CFStringRef uti_string_hint)
{
 SDL_Surface* sdl_surface;
 CGImageSourceRef image_source;
 CGImageRef image_ref = NULL;
 CFDictionaryRef hint_dictionary = NULL;

 hint_dictionary = CreateHintDictionary(uti_string_hint);
 image_source = CreateCGImageSourceFromRWops(rw_ops, hint_dictionary);

 if(hint_dictionary != NULL)
 {
   CFRelease(hint_dictionary);
 }

 if(NULL == image_source)
 {
   return NULL;
 }

 image_ref = CreateCGImageFromCGImageSource(image_source);
 CFRelease(image_source);

 if(NULL == image_ref)
 {
   return NULL;
 }

 sdl_surface = Create_SDL_Surface_From_CGImage(image_ref);
 CFRelease(image_ref);
 return sdl_surface;

}


static SDL_Surface* LoadImageFromFile(const char* file)
{
 SDL_Surface* sdl_surface = NULL;
 CGImageSourceRef image_source = NULL;
 CGImageRef image_ref = NULL;

 // First ImageIO
 image_source = CreateCGImageSourceFromFile(file);

 if(NULL == image_source)
 {
   return NULL;
 }

 image_ref = CreateCGImageFromCGImageSource(image_source);
 CFRelease(image_source);

 if(NULL == image_ref)
 {
   return NULL;
 }

 sdl_surface = Create_SDL_Surface_From_CGImage(image_ref);
 CFRelease(image_ref);
 return sdl_surface;
}

int IMG_InitJPG()
{
 return 0;
}

void IMG_QuitJPG()
{
}

int IMG_InitPNG()
{
 return 0;
}

void IMG_QuitPNG()
{
}

int IMG_InitTIF()
{
 return 0;
}

void IMG_QuitTIF()
{
}

int IMG_isCUR(SDL_RWops *src)
{
 /* FIXME: Is this a supported type? */
 return Internal_isType(src, CFSTR("com.microsoft.cur"));
}

int IMG_isICO(SDL_RWops *src)
{
 return Internal_isType(src, kUTTypeICO);
}

int IMG_isBMP(SDL_RWops *src)
{
 return Internal_isType(src, kUTTypeBMP);
}

int IMG_isGIF(SDL_RWops *src)
{
 return Internal_isType(src, kUTTypeGIF);
}

// Note: JPEG 2000 is kUTTypeJPEG2000
int IMG_isJPG(SDL_RWops *src)
{
 return Internal_isType(src, kUTTypeJPEG);
}

int IMG_isPNG(SDL_RWops *src)
{
 return Internal_isType(src, kUTTypePNG);
}

// This isn't a public API function. Apple seems to be able to identify tga's.
int IMG_isTGA(SDL_RWops *src)
{
 return Internal_isType(src, CFSTR("com.truevision.tga-image"));
}

int IMG_isTIF(SDL_RWops *src)
{
 return Internal_isType(src, kUTTypeTIFF);
}

SDL_Surface* IMG_LoadCUR_RW(SDL_RWops *src)
{
 /* FIXME: Is this a supported type? */
 return LoadImageFromRWops(src, CFSTR("com.microsoft.cur"));
}
SDL_Surface* IMG_LoadICO_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, kUTTypeICO);
}
SDL_Surface* IMG_LoadBMP_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, kUTTypeBMP);
}
SDL_Surface* IMG_LoadGIF_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, kUTTypeGIF);
}
SDL_Surface* IMG_LoadJPG_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, kUTTypeJPEG);
}
SDL_Surface* IMG_LoadPNG_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, kUTTypePNG);
}
SDL_Surface* IMG_LoadTGA_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, CFSTR("com.truevision.tga-image"));
}
SDL_Surface* IMG_LoadTIF_RW(SDL_RWops *src)
{
 return LoadImageFromRWops(src, kUTTypeTIFF);
}

// Apple provides both stream and file loading functions in ImageIO.
// Potentially, Apple can optimize for either case.
SDL_Surface* IMG_Load(const char *file)
{
 SDL_Surface* sdl_surface = NULL;

 sdl_surface = LoadImageFromFile(file);
 if(NULL == sdl_surface)
 {
   // Either the file doesn't exist or ImageIO doesn't understand the format.
   // For the latter case, fallback to the native SDL_image handlers.
   SDL_RWops *src = SDL_RWFromFile(file, "rb");
   char *ext = strrchr(file, '.');
   if(ext) {
     ext++;
   }
   if(!src) {
     /* The error message has been set in SDL_RWFromFile */
     return NULL;
   }
   sdl_surface = IMG_LoadTyped_RW(src, 1, ext);
 }
 return sdl_surface;
}

#endif /* defined(__APPLE__) && !defined(SDL_IMAGE_USE_COMMON_BACKEND) */