Apple has just accepted my application on AppStore: QLMesh. It is a QuickLook plugin for displaying a preview of many 3d formats, base on Open Assets Import Library. All 3d formats are supported plus some 2d compressed textures.
[attachment=31149:qlmesh1.png]
Mipmaps are displayed with multi-page view - quite handy and useful feature - also because you can browse within mipmaps directly in finder.
[attachment=31150:mipmaps.png]
CGContextRef kcontext = QLPreviewRequestCreatePDFContext(preview, NULL, NULL, properties);
...
CGImageRef cimage = ...;
// Fill 3/4 of the rect
const float enlarge = 1.0 + 0.48*i*i;
CGRect canvasRect = CGRectMake((image[0].width - w*enlarge)/2, (image[0].height - h*enlarge)/2, w*enlarge, h*enlarge);
CGContextBeginPage(kcontext, &pageRect);
CGContextDrawImage(kcontext, canvasRect, cimage);
CGContextEndPage(kcontext);
Part of the QLMesh is control application for quicklook plugin.
[attachment=31151:qlmesh5.png]
Usually that would not be anything special, however for MacStore applications this is a very different story. MacStore applications are all sanboxed. There are ways to communicate and share data between such applications, eg. using App groups, but quicklook plugins do not support that feature. After struggling for some time with this problem I came out with this simple solution:
CGImageRef _decodeDictToCGImage(CFDictionaryRef dictref, const int thsize)
{
NSDictionary *dict = (__bridge NSDictionary *)dictref;
// Get a color space
CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
NSData *decodedData = [NSKeyedArchiver archivedDataWithRootObject:dict];
const long decodedDataSize = decodedData.length;
NSMutableData *paddedData = [NSMutableData dataWithBytes:&decodedDataSize length:sizeof(long)];
[paddedData appendData:decodedData];
int sz = thsize; // min. thumbnail size
if (decodedData.length < sz*sz*3)
[paddedData increaseLengthBy:sz*sz*3-decodedData.length];
else {
sz = ceil(sqrtf(decodedData.length/3));
[paddedData increaseLengthBy:sz*sz*3-decodedData.length];
}
const char* rgb = [paddedData bytes];
char* rgba = (char*)malloc(sz*sz*4);
for(int i=0; i < sz*sz; ++i)
{
rgba[4*i] = rgb[3*i];
rgba[4*i+1] = rgb[3*i+1];
rgba[4*i+2] = rgb[3*i+2];
rgba[4*i+3] = 0xff;
}
// Assuming the decoded data is only pixel data
CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, rgba, sz*sz*4, NULL);
// Given size_t width, height which you should already have somehow
CGImageRef image = CGImageCreate(
sz, sz,
/* bpc */ 8, /* bpp */ 32, /* pitch */ sz*4,
colorSpace, kCGBitmapByteOrderDefault|kCGImageAlphaNone,
dataProvider, /* decode array */ NULL, /* interpolate? */ FALSE,
kCGRenderingIntentDefault /* adjust intent according to use */ );
if (image == nil)
NSLog(@"Failed to create image from %@.", decodedData);
#if 0
NSData *data = (id)CFBridgingRelease(CGDataProviderCopyData(CGImageGetDataProvider(image)));
NSLog(@"output image: %zux%zu %zu, %zu, %@ %lu",
CGImageGetWidth(image), CGImageGetHeight(image),
CGImageGetBitsPerPixel(image), CGImageGetBitsPerComponent(image),
data, [(id)data length]);
#endif
// Release things the image took ownership of.
CGDataProviderRelease(dataProvider);
CGColorSpaceRelease(colorSpace);
if (rgba) free(rgba);
return image;
}
What's next:
2. I am working on may optimisations - mostly related to speeding-up file loading. Current Xcode QL generator for OBJ models seems to be much faster in many cases.
3. Texture access in sandboxed environment - tricky but some workarounds could be found.
Best regards
