OOPNGTextureLoader Class Reference

#include <OOPNGTextureLoader.h>

Inheritance diagram for OOPNGTextureLoader:

Collaboration diagram for OOPNGTextureLoader:

Instance Methods
(void)	- loadTexture [implementation]
(void)	- dealloc [implementation]
(void)	- doLoadTexture [implementation]
(void)	- readBytes:count: [implementation]
Instance Methods inherited from OOTextureLoader
(BOOL)	- isReady
(BOOL)	- getResult:format:originalWidth:originalHeight:
(NSString *)	- cacheKey
(id)	- initWithPath:options:
(NSString *)	- path
(NSString *)	- descriptionComponents [implementation]
(NSString *)	- shortDescriptionComponents [implementation]
(void)	- performAsyncTask [implementation]
(void)	- generateMipMapsForCubeMap [implementation]
(void)	- applySettings [implementation]
(void)	- getDesiredWidth:andHeight: [implementation]
(void)	- completeAsyncTask [implementation]

Private Attributes
png_structp	png
png_infop	pngInfo
png_infop	pngEndInfo
NSData *	fileData
size_t	length
size_t	offset

Additional Inherited Members
Class Methods inherited from OOTextureLoader
(id)	+ loaderWithPath:options:
(id)	+ loaderWithTextureSpecifier:extraOptions:folder:
(void)	+ setUp [implementation]
Protected Attributes inherited from OOTextureLoader
NSString *	_path
OOTextureFlags	_options
uint8_t	_generateMipMaps: 1
uint8_t	_scaleAsNormalMap: 1
uint8_t	_avoidShrinking: 1
uint8_t	_noScalingWhatsoever: 1
uint8_t	_extractChannel: 1
uint8_t	_allowCubeMap: 1
uint8_t	_isCubeMap: 1
uint8_t	_ready: 1
uint8_t	_extractChannelIndex
OOTextureDataFormat	_format
void *	_data
uint32_t	_width
uint32_t	_height
uint32_t	_originalWidth
uint32_t	_originalHeight
uint32_t	_shrinkThreshold
uint32_t	_maxSize
size_t	_rowBytes

Detailed Description

Definition at line 34 of file OOPNGTextureLoader.h.

Method Documentation

dealloc

- (void) dealloc

implementation

Reimplemented from OOTextureLoader.

Definition at line 66 of file OOPNGTextureLoader.m.

{
    [fileData release];
    if (png != NULL)
    {
        png_destroy_read_struct(&png, &pngInfo, &pngEndInfo);
    }
    
    [super dealloc];
}

References dealloc, OOTextureLoader::dealloc, png, pngEndInfo, and pngInfo.

Referenced by dealloc.

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doLoadTexture

- (void) doLoadTexture

implementation

Provided by category OOPNGTextureLoader(OOPrivate).

Definition at line 82 of file OOPNGTextureLoader.m.

{
    png_bytepp                  rows = NULL;
    png_uint_32                 pngWidth,
                                pngHeight;
    int                         depth,
                                colorType;
    uint32_t                    i;
    
    // Set up PNG decoding
    png = png_create_read_struct(PNG_LIBPNG_VER_STRING, self, PNGError, PNGWarning);
    if (png != NULL)  pngInfo = png_create_info_struct(png);
    if (pngInfo != NULL)  pngEndInfo = png_create_info_struct(png);
    if (pngEndInfo == NULL)
    {
        OOLog(@"texture.load.png.setup.failed", @"***** Error preparing to read %@.", _path);
        goto FAIL;
    }
    
    if (EXPECT_NOT(setjmp(png_jmpbuf(png))))
    {
        // libpng will jump here on error.
        if (_data)
        {
            free(_data);
            _data = NULL;
        }
        goto FAIL;
    }
    
    png_set_read_fn(png, self, PNGRead);
    
    png_read_info(png, pngInfo);
    // Read header, get format info and check that it meets our expectations.
    if (EXPECT_NOT(!png_get_IHDR(png, pngInfo, &pngWidth, &pngHeight, &depth, &colorType, NULL, NULL, NULL)))
    {
        OOLog(@"texture.load.png.failed", @"Failed to get metadata from PNG %@", _path);
        goto FAIL;
    }
    png_set_strip_16(png);           // 16 bits per channel -> 8 bpc
    if (depth < 8 || colorType == PNG_COLOR_TYPE_PALETTE)
    {
        png_set_expand(png);     // Paletted -> RGB, greyscale -> 8 bpc
    }
    
    if (colorType == PNG_COLOR_TYPE_GRAY)
    {
        _format = kOOTextureDataGrayscale;
    }
    else if (colorType == PNG_COLOR_TYPE_GRAY_ALPHA)
    {
        _format = kOOTextureDataGrayscaleAlpha;
    }
    else
    {
        _format = kOOTextureDataRGBA;
        
#if OOLITE_BIG_ENDIAN
        png_set_bgr(png);
        png_set_swap_alpha(png);     // RGBA->ARGB
        png_set_filler(png, 0xFF, PNG_FILLER_BEFORE);
#elif OOLITE_LITTLE_ENDIAN
        png_set_filler(png, 0xFF, PNG_FILLER_AFTER);
#else
#error Unknown handle byte order.
#endif
    }
    
    png_read_update_info(png, pngInfo);
    png_set_interlace_handling(png);
    
    // Metadata is acceptable; load data.
    _width = pngWidth;
    _height = pngHeight;
    _rowBytes = png_get_rowbytes(png, pngInfo);
    
    // png_read_png
    rows = malloc(sizeof *rows * _height);
    _data = malloc(_rowBytes * _height);
    if (EXPECT_NOT(rows == NULL || _data == NULL))
    {
        if (rows != NULL)
        {
            free(rows);
            rows = NULL;
        }
        if (_data != NULL)
        {
            free(_data);
            _data = NULL;
        }
        OOLog(kOOLogAllocationFailure, @"Failed to allocate space (%zu bytes) for texture %@", _rowBytes * _height, _path);
        goto FAIL;
    }
    
    for (i = 0; i != _height; ++i)
    {
        rows[i] = ((png_bytep)_data) + i * _rowBytes;
    }
    png_read_image(png, rows);
    png_read_end(png, pngEndInfo);
    
FAIL:
    free(rows);
    png_destroy_read_struct(&png, &pngInfo, &pngEndInfo);
}

Referenced by loadTexture.

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loadTexture

- (void) loadTexture

implementation

Reimplemented from OOTextureLoader.

Definition at line 52 of file OOPNGTextureLoader.m.

{
    // Get data from file
    fileData = [[NSData oo_dataWithOXZFile:_path] retain];
    if (fileData == nil)  return;
    length = [fileData length];
    
    [self doLoadTexture];
    
    [fileData release];
    fileData = nil;
}

References doLoadTexture, fileData, length, loadTexture, and nil.

Referenced by loadTexture.

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readBytes:count:

- (void) readBytes: (png_bytep) bytes count: (png_size_t) count

implementation

Provided by category OOPNGTextureLoader(OOPrivate).

Definition at line 190 of file OOPNGTextureLoader.m.

                 :(png_bytep)bytes count:(png_size_t)count
{
    // Check that we're within the file's bounds
    if (EXPECT_NOT(length - offset < count))
    {
        NSString *message = [NSString stringWithFormat:@"attempt to read beyond end of file (%@), file may be truncated.", _path];
        png_error(png, [message UTF8String]);    // Will not return
    }
    
    assert(bytes != NULL);
    
    // Copy bytes
    memcpy(bytes, [fileData bytes] + offset, count);
    offset += count;
}

Referenced by PNGRead().

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Member Data Documentation

fileData

- (NSData*) fileData

private

Definition at line 40 of file OOPNGTextureLoader.h.

Referenced by loadTexture.

length

- (size_t) length

private

Definition at line 41 of file OOPNGTextureLoader.h.

Referenced by loadTexture.

offset

- (size_t) offset

private

Definition at line 42 of file OOPNGTextureLoader.h.

png

- (png_structp) png

private

Definition at line 37 of file OOPNGTextureLoader.h.

Referenced by dealloc.

pngEndInfo

- (png_infop) pngEndInfo

private

Definition at line 39 of file OOPNGTextureLoader.h.

Referenced by dealloc.

pngInfo

- (png_infop) pngInfo

private

Definition at line 38 of file OOPNGTextureLoader.h.

Referenced by dealloc.

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The documentation for this class was generated from the following files:

• src/Core/Materials/OOPNGTextureLoader.h
• src/Core/Materials/OOPNGTextureLoader.m