Classes/PVRTexture.m
/* |
File: PVRTexture.m |
Abstract: The PVRTexture class is responsible for loading .pvr files. |
Version: 1.6 |
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*/ |
#import "PVRTexture.h" |
#define PVR_TEXTURE_FLAG_TYPE_MASK 0xff |
static char gPVRTexIdentifier[4] = "PVR!"; |
enum |
{ |
kPVRTextureFlagTypePVRTC_2 = 24, |
kPVRTextureFlagTypePVRTC_4 |
}; |
typedef struct _PVRTexHeader |
{ |
uint32_t headerLength; |
uint32_t height; |
uint32_t width; |
uint32_t numMipmaps; |
uint32_t flags; |
uint32_t dataLength; |
uint32_t bpp; |
uint32_t bitmaskRed; |
uint32_t bitmaskGreen; |
uint32_t bitmaskBlue; |
uint32_t bitmaskAlpha; |
uint32_t pvrTag; |
uint32_t numSurfs; |
} PVRTexHeader; |
@implementation PVRTexture |
@synthesize name = _name; |
@synthesize width = _width; |
@synthesize height = _height; |
@synthesize internalFormat = _internalFormat; |
@synthesize hasAlpha = _hasAlpha; |
- (BOOL)unpackPVRData:(NSData *)data |
{ |
BOOL success = FALSE; |
PVRTexHeader *header = NULL; |
uint32_t flags, pvrTag; |
uint32_t dataLength = 0, dataOffset = 0, dataSize = 0; |
uint32_t blockSize = 0, widthBlocks = 0, heightBlocks = 0; |
uint32_t width = 0, height = 0, bpp = 4; |
uint8_t *bytes = NULL; |
uint32_t formatFlags; |
header = (PVRTexHeader *)[data bytes]; |
pvrTag = CFSwapInt32LittleToHost(header->pvrTag); |
if (gPVRTexIdentifier[0] != ((pvrTag >> 0) & 0xff) || |
gPVRTexIdentifier[1] != ((pvrTag >> 8) & 0xff) || |
gPVRTexIdentifier[2] != ((pvrTag >> 16) & 0xff) || |
gPVRTexIdentifier[3] != ((pvrTag >> 24) & 0xff)) |
{ |
return FALSE; |
} |
flags = CFSwapInt32LittleToHost(header->flags); |
formatFlags = flags & PVR_TEXTURE_FLAG_TYPE_MASK; |
if (formatFlags == kPVRTextureFlagTypePVRTC_4 || formatFlags == kPVRTextureFlagTypePVRTC_2) |
{ |
[_imageData removeAllObjects]; |
if (formatFlags == kPVRTextureFlagTypePVRTC_4) |
_internalFormat = GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG; |
else if (formatFlags == kPVRTextureFlagTypePVRTC_2) |
_internalFormat = GL_COMPRESSED_RGBA_PVRTC_2BPPV1_IMG; |
_width = width = CFSwapInt32LittleToHost(header->width); |
_height = height = CFSwapInt32LittleToHost(header->height); |
if (CFSwapInt32LittleToHost(header->bitmaskAlpha)) |
_hasAlpha = TRUE; |
else |
_hasAlpha = FALSE; |
dataLength = CFSwapInt32LittleToHost(header->dataLength); |
bytes = ((uint8_t *)[data bytes]) + sizeof(PVRTexHeader); |
// Calculate the data size for each texture level and respect the minimum number of blocks |
while (dataOffset < dataLength) |
{ |
if (formatFlags == kPVRTextureFlagTypePVRTC_4) |
{ |
blockSize = 4 * 4; // Pixel by pixel block size for 4bpp |
widthBlocks = width / 4; |
heightBlocks = height / 4; |
bpp = 4; |
} |
else |
{ |
blockSize = 8 * 4; // Pixel by pixel block size for 2bpp |
widthBlocks = width / 8; |
heightBlocks = height / 4; |
bpp = 2; |
} |
// Clamp to minimum number of blocks |
if (widthBlocks < 2) |
widthBlocks = 2; |
if (heightBlocks < 2) |
heightBlocks = 2; |
dataSize = widthBlocks * heightBlocks * ((blockSize * bpp) / 8); |
[_imageData addObject:[NSData dataWithBytes:bytes+dataOffset length:dataSize]]; |
dataOffset += dataSize; |
width = MAX(width >> 1, 1); |
height = MAX(height >> 1, 1); |
} |
success = TRUE; |
} |
return success; |
} |
- (BOOL)createGLTexture |
{ |
int width = _width; |
int height = _height; |
NSData *data; |
GLenum err; |
if ([_imageData count] > 0) |
{ |
if (_name != 0) |
glDeleteTextures(1, &_name); |
glGenTextures(1, &_name); |
glBindTexture(GL_TEXTURE_2D, _name); |
} |
if ([_imageData count] > 1) |
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR); |
else |
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); |
for (int i=0; i < [_imageData count]; i++) |
{ |
data = [_imageData objectAtIndex:i]; |
glCompressedTexImage2D(GL_TEXTURE_2D, i, _internalFormat, width, height, 0, (int)[data length], [data bytes]); |
err = glGetError(); |
if (err != GL_NO_ERROR) |
{ |
NSLog(@"Error uploading compressed texture level: %d. glError: 0x%04X", i, err); |
return FALSE; |
} |
width = MAX(width >> 1, 1); |
height = MAX(height >> 1, 1); |
} |
[_imageData removeAllObjects]; |
return TRUE; |
} |
- (id)initWithContentsOfFile:(NSString *)path |
{ |
if (self = [super init]) |
{ |
NSData *data = [NSData dataWithContentsOfFile:path]; |
_imageData = [[NSMutableArray alloc] initWithCapacity:10]; |
_name = 0; |
_width = _height = 0; |
_internalFormat = GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG; |
_hasAlpha = FALSE; |
if (!data || ![self unpackPVRData:data] || ![self createGLTexture]) |
{ |
[self release]; |
self = nil; |
} |
} |
return self; |
} |
- (id)initWithContentsOfURL:(NSURL *)url |
{ |
if (![url isFileURL]) |
{ |
[self release]; |
return nil; |
} |
return [self initWithContentsOfFile:[url path]]; |
} |
+ (id)pvrTextureWithContentsOfFile:(NSString *)path |
{ |
return [[[self alloc] initWithContentsOfFile:path] autorelease]; |
} |
+ (id)pvrTextureWithContentsOfURL:(NSURL *)url |
{ |
if (![url isFileURL]) |
return nil; |
return [PVRTexture pvrTextureWithContentsOfFile:[url path]]; |
} |
- (void)dealloc |
{ |
[_imageData release]; |
if (_name != 0) |
glDeleteTextures(1, &_name); |
[super dealloc]; |
} |
@end |
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