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Simplified image conversion code even more. The alpha channel is a go…
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…ner...
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@slouken
slouken committed Nov 10, 2009
1 parent 7abc7de commit c882ec1
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Showing 2 changed files with 76 additions and 90 deletions.
83 changes: 38 additions & 45 deletions IMG_ImageIO.c
View file
Expand Up @@ -227,78 +227,71 @@ static SDL_Surface* Create_SDL_Surface_From_CGImage(CGImageRef image_ref)
* All this code should be scrutinized.
*/

size_t the_width = CGImageGetWidth(image_ref);
size_t the_height = CGImageGetHeight(image_ref);
CGRect the_rect = {{0, 0}, {the_width, the_height}};
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* sdl_surface = NULL;
SDL_Surface* surface;
Uint32 Amask;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint32 Amask;

CGContextRef bitmap_context = NULL;
CGColorSpaceRef color_space = NULL;
CGBitmapInfo bitmap_info = CGImageGetBitmapInfo(image_ref);

switch (bits_per_pixel)
{
case 32:
{
color_space = CGColorSpaceCreateDeviceRGB();
//bitmap_info = kCGImageAlphaFirst | kCGBitmapByteOrder32Host; /* ARGB */
bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host; /* ARGB */

Amask = 0xFF000000;
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;

sdl_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, the_width, the_height, 32, Rmask, Gmask, Bmask, Amask);
break;
}
default:
{
color_space = CGColorSpaceCreateDeviceRGB();
bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host; /* XRGB */
Amask = 0x00000000;
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;

sdl_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, the_width, the_height, 32, Rmask, Gmask, Bmask, Amask);
break;
}
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;
}

if (sdl_surface)
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 sdl_surface->pixels as the area to be drawn to
// Sets up a context to be drawn to with surface->pixels as the area to be drawn to
bitmap_context = CGBitmapContextCreate(
sdl_surface->pixels,
the_width,
the_height,
surface->pixels,
surface->w,
surface->h,
bits_per_component,
sdl_surface->pitch,
surface->pitch,
color_space,
bitmap_info
);

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

CGContextRelease(bitmap_context);

// FIXME: Reverse the premultiplied alpha
if ((bitmap_info & kCGBitmapAlphaInfoMask) == kCGImageAlphaPremultipliedFirst) {
// Errr, alpha premultiplication is lossy...
}
}

if (color_space)
{
CGColorSpaceRelease(color_space);
}

return sdl_surface;
return surface;
}


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83 changes: 38 additions & 45 deletions IMG_UIImage.m
View file
Expand Up @@ -22,78 +22,71 @@
* All this code should be scrutinized.
*/

size_t the_width = CGImageGetWidth(image_ref);
size_t the_height = CGImageGetHeight(image_ref);
CGRect the_rect = {{0, 0}, {the_width, the_height}};
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* sdl_surface = NULL;
SDL_Surface* surface;
Uint32 Amask;
Uint32 Rmask;
Uint32 Gmask;
Uint32 Bmask;
Uint32 Amask;

CGContextRef bitmap_context = NULL;
CGColorSpaceRef color_space = NULL;
CGBitmapInfo bitmap_info = CGImageGetBitmapInfo(image_ref);

switch (bits_per_pixel)
{
case 32:
{
color_space = CGColorSpaceCreateDeviceRGB();
//bitmap_info = kCGImageAlphaFirst | kCGBitmapByteOrder32Host; /* ARGB */
bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host; /* ARGB */

Amask = 0xFF000000;
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;

sdl_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, the_width, the_height, 32, Rmask, Gmask, Bmask, Amask);
break;
}
default:
{
color_space = CGColorSpaceCreateDeviceRGB();
bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host; /* XRGB */
Amask = 0x00000000;
Rmask = 0x00FF0000;
Gmask = 0x0000FF00;
Bmask = 0x000000FF;

sdl_surface = SDL_CreateRGBSurface(SDL_SWSURFACE, the_width, the_height, 32, Rmask, Gmask, Bmask, Amask);
break;
}
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;
}

if (sdl_surface)
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 sdl_surface->pixels as the area to be drawn to
// Sets up a context to be drawn to with surface->pixels as the area to be drawn to
bitmap_context = CGBitmapContextCreate(
sdl_surface->pixels,
the_width,
the_height,
surface->pixels,
surface->w,
surface->h,
bits_per_component,
sdl_surface->pitch,
surface->pitch,
color_space,
bitmap_info
);

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

CGContextRelease(bitmap_context);

// FIXME: Reverse the premultiplied alpha
if ((bitmap_info & kCGBitmapAlphaInfoMask) == kCGImageAlphaPremultipliedFirst) {
// Errr, alpha premultiplication is lossy...
}
}

if (color_space)
{
CGColorSpaceRelease(color_space);
}

return sdl_surface;
return surface;
}

static SDL_Surface* LoadImageFromRWops(SDL_RWops* rw_ops, CFStringRef uti_string_hint)
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