IMG_UIImage.m
author Sam Lantinga <slouken@libsdl.org>
Sun, 15 Jun 2014 13:16:42 -0700
changeset 451 48116d511e5d
parent 368 8a61842d00ce
permissions -rw-r--r--
Fixed format warnings: format not a string literal and no format arguments
     1 /*
     2  *  IMG_ImageIO.c
     3  *  SDL_image
     4  *
     5  *  Created by Eric Wing on 1/2/09.
     6  *  Copyright 2009 __MyCompanyName__. All rights reserved.
     7  *
     8  */
     9 #include "SDL_image.h"
    10 #import <UIKit/UIKit.h>
    11 #import <MobileCoreServices/MobileCoreServices.h> // for UTCoreTypes.h
    12 
    13 // Once we have our image, we need to get it into an SDL_Surface
    14 // (Copied straight from the ImageIO backend.)
    15 static SDL_Surface* Create_SDL_Surface_From_CGImage(CGImageRef image_ref)
    16 {
    17     /* This code is adapted from Apple's Documentation found here:
    18      * http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/index.html
    19      * Listing 9-4††Using a Quartz image as a texture source.
    20      * Unfortunately, this guide doesn't show what to do about
    21      * non-RGBA image formats so I'm making the rest up.
    22      * All this code should be scrutinized.
    23      */
    24 
    25     size_t w = CGImageGetWidth(image_ref);
    26     size_t h = CGImageGetHeight(image_ref);
    27     CGRect rect = {{0, 0}, {w, h}};
    28 
    29     CGImageAlphaInfo alpha = CGImageGetAlphaInfo(image_ref);
    30     //size_t bits_per_pixel = CGImageGetBitsPerPixel(image_ref);
    31     size_t bits_per_component = 8;
    32 
    33     SDL_Surface* surface;
    34     Uint32 Amask;
    35     Uint32 Rmask;
    36     Uint32 Gmask;
    37     Uint32 Bmask;
    38 
    39     CGContextRef bitmap_context;
    40     CGBitmapInfo bitmap_info;
    41     CGColorSpaceRef color_space = CGColorSpaceCreateDeviceRGB();
    42 
    43     if (alpha == kCGImageAlphaNone ||
    44         alpha == kCGImageAlphaNoneSkipFirst ||
    45         alpha == kCGImageAlphaNoneSkipLast) {
    46         bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host; /* XRGB */
    47         Amask = 0x00000000;
    48     } else {
    49         /* kCGImageAlphaFirst isn't supported */
    50         //bitmap_info = kCGImageAlphaFirst | kCGBitmapByteOrder32Host; /* ARGB */
    51         bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host; /* ARGB */
    52         Amask = 0xFF000000;
    53     }
    54 
    55     Rmask = 0x00FF0000;
    56     Gmask = 0x0000FF00;
    57     Bmask = 0x000000FF;
    58 
    59     surface = SDL_CreateRGBSurface(SDL_SWSURFACE, w, h, 32, Rmask, Gmask, Bmask, Amask);
    60     if (surface)
    61     {
    62         // Sets up a context to be drawn to with surface->pixels as the area to be drawn to
    63         bitmap_context = CGBitmapContextCreate(
    64                                                             surface->pixels,
    65                                                             surface->w,
    66                                                             surface->h,
    67                                                             bits_per_component,
    68                                                             surface->pitch,
    69                                                             color_space,
    70                                                             bitmap_info
    71                                                             );
    72 
    73         // Draws the image into the context's image_data
    74         CGContextDrawImage(bitmap_context, rect, image_ref);
    75 
    76         CGContextRelease(bitmap_context);
    77 
    78         // FIXME: Reverse the premultiplied alpha
    79         if ((bitmap_info & kCGBitmapAlphaInfoMask) == kCGImageAlphaPremultipliedFirst) {
    80             int i, j;
    81             Uint8 *p = (Uint8 *)surface->pixels;
    82             for (i = surface->h * surface->pitch/4; i--; ) {
    83 #if __LITTLE_ENDIAN__
    84                 Uint8 A = p[3];
    85                 if (A) {
    86                     for (j = 0; j < 3; ++j) {
    87                         p[j] = (p[j] * 255) / A;
    88                     }
    89                 }
    90 #else
    91                 Uint8 A = p[0];
    92                 if (A) {
    93                     for (j = 1; j < 4; ++j) {
    94                         p[j] = (p[j] * 255) / A;
    95                     }
    96                 }
    97 #endif /* ENDIAN */
    98                 p += 4;
    99             }
   100         }
   101     }
   102 
   103     if (color_space)
   104     {
   105         CGColorSpaceRelease(color_space);
   106     }
   107 
   108     return surface;
   109 }
   110 
   111 static SDL_Surface* LoadImageFromRWops(SDL_RWops* rw_ops, CFStringRef uti_string_hint)
   112 {
   113     NSAutoreleasePool* autorelease_pool = [[NSAutoreleasePool alloc] init];
   114     SDL_Surface* sdl_surface;
   115     UIImage* ui_image;
   116 
   117     int bytes_read = 0;
   118     // I don't know what a good size is.
   119     // Max recommended texture size is 1024x1024 on iPhone so maybe base it on that?
   120     const int block_size = 1024*4;
   121     char temp_buffer[block_size];
   122 
   123     NSMutableData* ns_data = [[NSMutableData alloc] initWithCapacity:1024*1024*4];
   124 
   125 
   126     do
   127     {
   128         bytes_read = SDL_RWread(rw_ops, temp_buffer, 1, block_size);
   129         [ns_data appendBytes:temp_buffer length:bytes_read];
   130     } while(bytes_read > 0);
   131 
   132     ui_image = [[UIImage alloc] initWithData:ns_data];
   133 
   134     sdl_surface = Create_SDL_Surface_From_CGImage([ui_image CGImage]);
   135 
   136     [ui_image release];
   137     [ns_data release];
   138 
   139     [autorelease_pool drain];
   140 
   141     return sdl_surface;
   142 }
   143 
   144 static SDL_Surface* LoadImageFromFile(const char *file)
   145 {
   146     NSAutoreleasePool* autorelease_pool = [[NSAutoreleasePool alloc] init];
   147     SDL_Surface* sdl_surface = NULL;
   148     UIImage* ui_image;
   149     NSString* ns_string;
   150 
   151     ns_string = [[NSString alloc] initWithUTF8String:file];
   152     ui_image = [[UIImage alloc] initWithContentsOfFile:ns_string];
   153     if(ui_image != NULL)
   154     {
   155         sdl_surface = Create_SDL_Surface_From_CGImage([ui_image CGImage]);
   156     }
   157 
   158     [ui_image release];
   159     [ns_string release];
   160 
   161     [autorelease_pool drain];
   162 
   163     return sdl_surface;
   164 }
   165 
   166 
   167 /* Since UIImage doesn't really support streams well, we should optimize for the file case. */
   168 SDL_Surface *IMG_Load(const char *file)
   169 {
   170     SDL_Surface* sdl_surface = NULL;
   171 
   172     sdl_surface = LoadImageFromFile(file);
   173     if(NULL == sdl_surface)
   174     {
   175         // Either the file doesn't exist or ImageIO doesn't understand the format.
   176         // For the latter case, fallback to the native SDL_image handlers.
   177 
   178         SDL_RWops *src = SDL_RWFromFile(file, "rb");
   179         char *ext = strrchr(file, '.');
   180         if(ext) {
   181             ext++;
   182         }
   183         if(!src) {
   184             /* The error message has been set in SDL_RWFromFile */
   185             return NULL;
   186         }
   187         sdl_surface = IMG_LoadTyped_RW(src, 1, ext);
   188     }
   189     return sdl_surface;
   190 }
   191 
   192 
   193 int IMG_InitJPG()
   194 {
   195     return 0;
   196 }
   197 
   198 void IMG_QuitJPG()
   199 {
   200 }
   201 
   202 int IMG_InitPNG()
   203 {
   204     return 0;
   205 }
   206 
   207 void IMG_QuitPNG()
   208 {
   209 }
   210 
   211 int IMG_InitTIF()
   212 {
   213     return 0;
   214 }
   215 
   216 void IMG_QuitTIF()
   217 {
   218 }
   219 
   220 /* Copied straight from other files so I don't have to alter them. */
   221 static int IMG_isICOCUR(SDL_RWops *src, int type)
   222 {
   223     int start;
   224     int is_ICOCUR;
   225 
   226     /* The Win32 ICO file header (14 bytes) */
   227     Uint16 bfReserved;
   228     Uint16 bfType;
   229     Uint16 bfCount;
   230 
   231     if ( !src )
   232         return 0;
   233     start = SDL_RWtell(src);
   234     is_ICOCUR = 0;
   235     bfReserved = SDL_ReadLE16(src);
   236     bfType = SDL_ReadLE16(src);
   237     bfCount = SDL_ReadLE16(src);
   238     if ((bfReserved == 0) && (bfType == type) && (bfCount != 0))
   239         is_ICOCUR = 1;
   240     SDL_RWseek(src, start, SEEK_SET);
   241 
   242     return (is_ICOCUR);
   243 }
   244 
   245 int IMG_isICO(SDL_RWops *src)
   246 {
   247     return IMG_isICOCUR(src, 1);
   248 }
   249 
   250 int IMG_isCUR(SDL_RWops *src)
   251 {
   252     return IMG_isICOCUR(src, 2);
   253 }
   254 
   255 int IMG_isBMP(SDL_RWops *src)
   256 {
   257     int start;
   258     int is_BMP;
   259     char magic[2];
   260 
   261     if ( !src )
   262         return 0;
   263     start = SDL_RWtell(src);
   264     is_BMP = 0;
   265     if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
   266         if ( strncmp(magic, "BM", 2) == 0 ) {
   267             is_BMP = 1;
   268         }
   269     }
   270     SDL_RWseek(src, start, SEEK_SET);
   271     return(is_BMP);
   272 }
   273 
   274 int IMG_isGIF(SDL_RWops *src)
   275 {
   276     int start;
   277     int is_GIF;
   278     char magic[6];
   279 
   280     if ( !src )
   281         return 0;
   282     start = SDL_RWtell(src);
   283     is_GIF = 0;
   284     if ( SDL_RWread(src, magic, sizeof(magic), 1) ) {
   285         if ( (strncmp(magic, "GIF", 3) == 0) &&
   286             ((memcmp(magic + 3, "87a", 3) == 0) ||
   287              (memcmp(magic + 3, "89a", 3) == 0)) ) {
   288             is_GIF = 1;
   289         }
   290     }
   291     SDL_RWseek(src, start, SEEK_SET);
   292     return(is_GIF);
   293 }
   294 
   295 int IMG_isJPG(SDL_RWops *src)
   296 {
   297     int start;
   298     int is_JPG;
   299     int in_scan;
   300     Uint8 magic[4];
   301 
   302     /* This detection code is by Steaphan Greene <stea@cs.binghamton.edu> */
   303     /* Blame me, not Sam, if this doesn't work right. */
   304     /* And don't forget to report the problem to the the sdl list too! */
   305 
   306     if ( !src )
   307         return 0;
   308     start = SDL_RWtell(src);
   309     is_JPG = 0;
   310     in_scan = 0;
   311     if ( SDL_RWread(src, magic, 2, 1) ) {
   312         if ( (magic[0] == 0xFF) && (magic[1] == 0xD8) ) {
   313             is_JPG = 1;
   314             while (is_JPG == 1) {
   315                 if(SDL_RWread(src, magic, 1, 2) != 2) {
   316                     is_JPG = 0;
   317                 } else if( (magic[0] != 0xFF) && (in_scan == 0) ) {
   318                     is_JPG = 0;
   319                 } else if( (magic[0] != 0xFF) || (magic[1] == 0xFF) ) {
   320                     /* Extra padding in JPEG (legal) */
   321                     /* or this is data and we are scanning */
   322                     SDL_RWseek(src, -1, SEEK_CUR);
   323                 } else if(magic[1] == 0xD9) {
   324                     /* Got to end of good JPEG */
   325                     break;
   326                 } else if( (in_scan == 1) && (magic[1] == 0x00) ) {
   327                     /* This is an encoded 0xFF within the data */
   328                 } else if( (magic[1] >= 0xD0) && (magic[1] < 0xD9) ) {
   329                     /* These have nothing else */
   330                 } else if(SDL_RWread(src, magic+2, 1, 2) != 2) {
   331                     is_JPG = 0;
   332                 } else {
   333                     /* Yes, it's big-endian */
   334                     Uint32 start;
   335                     Uint32 size;
   336                     Uint32 end;
   337                     start = SDL_RWtell(src);
   338                     size = (magic[2] << 8) + magic[3];
   339                     end = SDL_RWseek(src, size-2, SEEK_CUR);
   340                     if ( end != start + size - 2 ) is_JPG = 0;
   341                     if ( magic[1] == 0xDA ) {
   342                         /* Now comes the actual JPEG meat */
   343 #ifdef  FAST_IS_JPEG
   344                         /* Ok, I'm convinced.  It is a JPEG. */
   345                         break;
   346 #else
   347                         /* I'm not convinced.  Prove it! */
   348                         in_scan = 1;
   349 #endif
   350                     }
   351                 }
   352             }
   353         }
   354     }
   355     SDL_RWseek(src, start, SEEK_SET);
   356     return(is_JPG);
   357 }
   358 
   359 int IMG_isPNG(SDL_RWops *src)
   360 {
   361     int start;
   362     int is_PNG;
   363     Uint8 magic[4];
   364 
   365     if ( !src )
   366         return 0;
   367     start = SDL_RWtell(src);
   368     is_PNG = 0;
   369     if ( SDL_RWread(src, magic, 1, sizeof(magic)) == sizeof(magic) ) {
   370         if ( magic[0] == 0x89 &&
   371             magic[1] == 'P' &&
   372             magic[2] == 'N' &&
   373             magic[3] == 'G' ) {
   374             is_PNG = 1;
   375         }
   376     }
   377     SDL_RWseek(src, start, SEEK_SET);
   378     return(is_PNG);
   379 }
   380 
   381 int IMG_isTIF(SDL_RWops* src)
   382 {
   383     int start;
   384     int is_TIF;
   385     Uint8 magic[4];
   386 
   387     if ( !src )
   388         return 0;
   389     start = SDL_RWtell(src);
   390     is_TIF = 0;
   391     if ( SDL_RWread(src, magic, 1, sizeof(magic)) == sizeof(magic) ) {
   392         if ( (magic[0] == 'I' &&
   393               magic[1] == 'I' &&
   394               magic[2] == 0x2a &&
   395               magic[3] == 0x00) ||
   396             (magic[0] == 'M' &&
   397              magic[1] == 'M' &&
   398              magic[2] == 0x00 &&
   399              magic[3] == 0x2a) ) {
   400             is_TIF = 1;
   401         }
   402     }
   403     SDL_RWseek(src, start, SEEK_SET);
   404     return(is_TIF);
   405 }
   406 
   407 SDL_Surface* IMG_LoadCUR_RW(SDL_RWops *src)
   408 {
   409     /* FIXME: Is this a supported type? */
   410     return LoadImageFromRWops(src, CFSTR("com.microsoft.cur"));
   411 }
   412 SDL_Surface* IMG_LoadICO_RW(SDL_RWops *src)
   413 {
   414     return LoadImageFromRWops(src, kUTTypeICO);
   415 }
   416 SDL_Surface* IMG_LoadBMP_RW(SDL_RWops *src)
   417 {
   418     return LoadImageFromRWops(src, kUTTypeBMP);
   419 }
   420 SDL_Surface* IMG_LoadGIF_RW(SDL_RWops *src)
   421 {
   422     return LoadImageFromRWops(src, kUTTypeGIF);
   423 }
   424 SDL_Surface* IMG_LoadJPG_RW(SDL_RWops *src)
   425 {
   426     return LoadImageFromRWops(src, kUTTypeJPEG);
   427 }
   428 SDL_Surface* IMG_LoadPNG_RW(SDL_RWops *src)
   429 {
   430     return LoadImageFromRWops(src, kUTTypePNG);
   431 }
   432 SDL_Surface* IMG_LoadTGA_RW(SDL_RWops *src)
   433 {
   434     return LoadImageFromRWops(src, CFSTR("com.truevision.tga-image"));
   435 }
   436 SDL_Surface* IMG_LoadTIF_RW(SDL_RWops *src)
   437 {
   438     return LoadImageFromRWops(src, kUTTypeTIFF);
   439 }
   440