Re: FT Cache Subsystem: Custom caches
Hi Kelvin If you only interested in subpixels shifts and intend to cache 3 positions, you can achieve using LCD rendering and https://freetype.org/freetype2/docs/reference/ft2-lcd_rendering.html#ft_library_setlcdgeometry. It is apparent that LCD rendering is essentially 3 traditional antialiased bitmaps produced for shifted outlines and stacked together. Therefore, you have it already for 1/3-pixel shifts by default. Because everything is periodic, you can continue with the LCD output and clever reading frame shifts for subpixel positioning too. Theoretically, this should work. There is also https://freetype.org/freetype2/docs/reference/ft2-sizing_and_scaling.html#ft_set_transform . Perhaps you should wrap it into https://freetype.org/freetype2/docs/reference/ft2-cache_subsystem.html#ftc_face_requester. Alexei
Re: FT Cache Subsystem: Custom caches
Hi, sorry for the confusion; I think its better if I explain my current approach first: 1. I create a FTC_Manager, FTC_CMapCache and FTC_ImageCache, and set them up. 2. I query a glyph ID from FTC_CMapCache. 3. I get a glyph image (almost always an outline in my case) from FTC_ImageCache. 4. I copy the FT_Glyph and perform translation and other transformation on it. 5. I rasterize the transformed FT_Glyph. 6. I use the rasterized bitmap. I wasn't able to cache the rasterized glyph because FTC_SBitCache doesn't support transformations. I am looking to do one of these things: 1. Being able to apply transformations in FTC_SBitCache. The main reason I can't use FTC_SBitCache is that I need to modify the outline. I need to translate it for subpixel positioning, italicize, embolden and apply other transformations before rasterizing. I think this is a niche use case, so I'm not fully expecting the cache subsystem to support this. 2. Being able to extend / implement my own cache types. Alternatively, I want to be able to implement a custom cache type, based on FTC_Manager. Based on the draft document in the previous email, this was possible, but didn't make it to release. This new cache would behave like FTC_SBitCache, but supports the various operations I need to do on the glyph outlines before rendering. I hope this clears things up. I was looking for ways to avoid rolling my own cache if possible. Thanks. Kelvin.
Re: FT Cache Subsystem: Custom caches
> I'm trying to use FreeType cache subsystem to render glyphs. I tried > using FTC_SBitCache but I need to modify the outline before > rendering (translate and transform) so I could only use > FTC_ImageCache, modify the outline and render it. > > Is there a way to extend the cache mechanism to create my own cache > that supports all these features? Extend in which way? It's not clear to me what you want to cache... Werner
FT Cache Subsystem: Custom caches
Hi, I'm trying to use FreeType cache subsystem to render glyphs. I tried using FTC_SBitCache but I need to modify the outline before rendering (translate and transform) so I could only use FTC_ImageCache, modify the outline and render it. Is there a way to extend the cache mechanism to create my own cache that supports all these features? I Googled and found draft document: http://www.fifi.org/doc/libfreetype6/cache.html It doesn't seem to work now. Are there any way to achieve that, or is this future planned for the future? Kelvin
[ft] Cache sizes
Salutations, I was summoned to try to debug some really erratic and seemingly random issues we had with our font rendering. After many Red Bulls and debug output added to both our code and the FreeType c-code I managed to figure out why most of them was occuring, but I do not understand why. In short, as soon as we have more faces or sizes than the cache will allow, default being 2/2 as you already know, then strange things happens. First of all we receive face object where the size pointer is NULL. This causes our GetKerning routine to fail, since there is no size data to work with. This will not occur if we increase the size of the cache. Q1: Are we doing something wrong? I would assume that the cache/MRU in FT would discard the least used node and then insert the new one, and hand us that. Why are we getting face objects with NULL size pointers when this happens? Have I misunderstood something? The easy solution is to just crank up the size of the cache but before we do that I would like to know that we are not grossly misusing the whole idea of the cache. Q2: The 2/2 defaults seem awfully low, but the manual and most information I've come across seem to agree that the cache should not be increased unless absolutely required. I guess the outcome of Q1 will decide that in our case, but what is your experience when it comes to these numbers? To my limited experience and knowledge it would seem a waste to even have a cache if we have to make it at least as big as all our faces and sizes combined, kind of like making your browser cache big enough to store the entire contents of the Internet. I am assuming that I am missing out on something here. It is quite possible that we are doing something wrong on our end but I have verified that the size pointer is indeed NULL using printfs in the FreeType code and that the font we are using is the same one as when we just increase the cache and stuff worksTM. I will keep on investigating this matter but I thought I would consult this mailing list just to make sure I am not overlooking something blatantly obvious. King Regards, Daniel ___ Freetype mailing list Freetype@nongnu.org https://lists.nongnu.org/mailman/listinfo/freetype
Re: [ft] Cache sizes
Hello Daniel! In short, as soon as we have more faces or sizes than the cache will allow, default being 2/2 as you already know, then strange things happens. First of all we receive face object where the size pointer is NULL. This causes our GetKerning routine to fail, since there is no size data to work with. This will not occur if we increase the size of the cache. Given that FreeType's cache code is still in beta, there might be bugs. Q1: Are we doing something wrong? I don't think so. However, it would tremendously help us if you could provide a simple demo program (to be run on the console) that exhibits the problems you are experiencing. Werner ___ Freetype mailing list Freetype@nongnu.org https://lists.nongnu.org/mailman/listinfo/freetype
[ft] Cache management tutorial
Hi. Is there any specific cache management tutorial out there? By the way, is the cache manager *officialy* supported? Regards. Inaki. ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype
Re: [ft-devel] Determining Upper Bound of memory consumption for a system using FT cache subsystem
I think you are misunderstood. The cache subsystem memory bounding only accounts for the objects stored in the cache itself (i.e. glyph outlines, bitmaps, charmaps), but not the FT_Face and FT_Size objects themselves. Iirc, you can purge the latter if you want without purging the cache objects themselves. Trying to memory-bound the FT_Face and FT_Size objects themselves is pretty impossible due to the nature of the font format we're trying to support. Also, the memory bounding does not account for malloc-specific memory block padding and other stuff like that, so even getting an absolutely correct estimates of all the bytes consumed is impossible. Hope this helps. - David Turner 2010/3/10 Maggy Anastasia maggymaggyma...@gmail.com Dear FreeType Developers, I have a few questions regarding freetype memory consumption upper bound; I am using Freetyper version 2.3.7 (1) static array: currently we know that all memory consumption by freetype is done through malloc calls and its variants. However, is there any other memory used in freetype, such as global arrays, which are used for memory allocation? If so, do they need any kind of configuration? (2) Is there a way for determining the upper bound of memory usage for freetype when cache is being used. I know that we can set the upper bound for cache nodes (glyph image, cmap, sbitchace, etc.), but is there a way to determine the memory consumption for FT_FACE and FT_SIZE? From what I have seen regarding this, we can only limit the number of FT_FACE and FT_SIZE; however, how to determine the memory requirements for a given number of allowable FT_FACE and FT_SIZE. I am using freetype for an embedded system at the moment, thus, memory is really a constraint, and it's very important for me to be able to determine the size of the heap. best regards Maggy Anastasia Suryanto ___ Freetype-devel mailing list Freetype-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype-devel ___ Freetype-devel mailing list Freetype-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype-devel
Re: [ft-devel] Determining Upper Bound of memory consumption for a system using FT cache subsystem
Hi Werner Thanks alot for the reply. I have looked at your suggestion and tried to understand how it works. I have one question regarding this. I understand that after we set env variable FT2_ALLOC_COUNT_MAX and FT2_DEBUG_MEMORY on runtime, the value for FT2_ALLOC_COUNT_MAX will be assigned to table-alloc_total_max inside ft_mem_debug_init() (in ftdbgmem.c). This value will later on be used to bound the memory allocation. However I am confused that inside function ft_mem_debug_alloc() there is the following check: if ( table-bound_total table-alloc_total_max - table-alloc_current (FT_ULong)size ) return NULL; Does the above check aim to bound memory allocation to up to table-alloc_total_max? If that is the case, should the check be the following instead: if ( table-bound_total table-alloc_total_max - table-alloc_current (FT_ULong)size ) return NULL; Please let me know if I understand wrongly. best regards Maggy Anastasia Suryanto On Sat, Mar 13, 2010 at 8:06 PM, Werner LEMBERG w...@gnu.org wrote: (1) static array: currently we know that all memory consumption by freetype is done through malloc calls and its variants. However, is there any other memory used in freetype, such as global arrays, which are used for memory allocation? If so, do they need any kind of configuration? Yes, there are static arrays, see for example src/psnames/pstables.h. However, they can be put into read-only memory since all of them are tagged with the `const' modifier. (2) Is there a way for determining the upper bound of memory usage for freetype when cache is being used. I know that we can set the upper bound for cache nodes (glyph image, cmap, sbitchace, etc.), but is there a way to determine the memory consumption for FT_FACE and FT_SIZE? From what I have seen regarding this, we can only limit the number of FT_FACE and FT_SIZE; however, how to determine the memory requirements for a given number of allowable FT_FACE and FT_SIZE. I am using freetype for an embedded system at the moment, thus, memory is really a constraint, and it's very important for me to be able to determine the size of the heap. I suggest that you use the FreeType memory debugger (see the FT_DEBUG_MEMORY option in docs/DEBUG). For debugging, the heap size can be limited with the FT2_ALLOC_TOTAL_MAX environment variable. Its results can be then used for your own memory allocation routines. Werner ___ Freetype-devel mailing list Freetype-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype-devel
Re: [ft-devel] Determining Upper Bound of memory consumption for a system using FT cache subsystem
Does the above check aim to bound memory allocation to up to table-alloc_total_max? If that is the case, should the check be the following instead: if ( table-bound_total table-alloc_total_max - table-alloc_current (FT_ULong)size ) return NULL; Honestly, I've never used this. David Turner has written the code, but he has no more time to handle FreeType issues. It's easily possible that you've found a bug. Please test whether your patch is the right one. Werner ___ Freetype-devel mailing list Freetype-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype-devel
Re: [ft-devel] Determining Upper Bound of memory consumption for a system using FT cache subsystem
(1) static array: currently we know that all memory consumption by freetype is done through malloc calls and its variants. However, is there any other memory used in freetype, such as global arrays, which are used for memory allocation? If so, do they need any kind of configuration? Yes, there are static arrays, see for example src/psnames/pstables.h. However, they can be put into read-only memory since all of them are tagged with the `const' modifier. (2) Is there a way for determining the upper bound of memory usage for freetype when cache is being used. I know that we can set the upper bound for cache nodes (glyph image, cmap, sbitchace, etc.), but is there a way to determine the memory consumption for FT_FACE and FT_SIZE? From what I have seen regarding this, we can only limit the number of FT_FACE and FT_SIZE; however, how to determine the memory requirements for a given number of allowable FT_FACE and FT_SIZE. I am using freetype for an embedded system at the moment, thus, memory is really a constraint, and it's very important for me to be able to determine the size of the heap. I suggest that you use the FreeType memory debugger (see the FT_DEBUG_MEMORY option in docs/DEBUG). For debugging, the heap size can be limited with the FT2_ALLOC_TOTAL_MAX environment variable. Its results can be then used for your own memory allocation routines. Werner ___ Freetype-devel mailing list Freetype-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype-devel
[ft-devel] Determining Upper Bound of memory consumption for a system using FT cache subsystem
Dear FreeType Developers, I have a few questions regarding freetype memory consumption upper bound; I am using Freetyper version 2.3.7 (1) static array: currently we know that all memory consumption by freetype is done through malloc calls and its variants. However, is there any other memory used in freetype, such as global arrays, which are used for memory allocation? If so, do they need any kind of configuration? (2) Is there a way for determining the upper bound of memory usage for freetype when cache is being used. I know that we can set the upper bound for cache nodes (glyph image, cmap, sbitchace, etc.), but is there a way to determine the memory consumption for FT_FACE and FT_SIZE? From what I have seen regarding this, we can only limit the number of FT_FACE and FT_SIZE; however, how to determine the memory requirements for a given number of allowable FT_FACE and FT_SIZE. I am using freetype for an embedded system at the moment, thus, memory is really a constraint, and it's very important for me to be able to determine the size of the heap. best regards Maggy Anastasia Suryanto ___ Freetype-devel mailing list Freetype-devel@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype-devel
FW: [ft] cache manager
Hi there. I am reposting this to the list since I got not a single response. Maybe something went wrong. These are issues of some importance. 1) is important in our application since the node ID is actually a strong reference to an application object that needs to be released when the CM doesn't know about it any more. 2) is perhaps more important. The CM is only truly useful if one can hook into its loading and transformation stage to provide custom slanting and embolding and perhaps other effects. Somewhere in the archives someone mentioned subclassing in this context. Any more infor on that? K -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Kristján V. Jónsson Sent: 3. júlí 2006 14:17 To: freetype@nongnu.org Subject: [ft] cache manager Hello there. I am new to this list although I have been using freetype for a while now. So, please excuse me if this has been covered before. I use the cache manager interface to freetype for convenience. However, there are two things there which I find sorely missing: 1) I need CM to tell me when a node goes out of cache. 2) I need to be able to hook into the glyph rendering process so that I can provide gransformations for the glyph before caching. This is to allow me to embolden and slant the glyph, for example. Is there a way to do this? Or is it simple to enhance freetype to support this? Cheers, Kristjan ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype
Re: [ft] cache
Freetype has a big branch of cache functions, that described in part of manual, named Cache Sub-System. I doubt, if I don't say FTC_Manager_New, FTC_SBitCache_New etc., if I dont't work with freetype through FTC_Manager_LookupSize, FTC_SBitCache_Lookup etc., is nothing cashe using in freetype? Or freetype optimize its work itself?? FreeType can be used without the cache sub-system (which is still experimental; right now it is going to be rewritten), but then you should do the caching by yourself. Since rendering is a quite time consuming process, you'll get a great performance improvement. Werner ___ Freetype mailing list Freetype@nongnu.org http://lists.nongnu.org/mailman/listinfo/freetype
