Re: [ft-devel] FT_New_Memory_Face crashes

[Gernot Reisinger]

Hi Louis,
if I parse your sample code correctly, your LoadFile function does not allocate a memory buffer to read in the font file. Thus you overwrite memory big style. The declaration char buf[]; only declares a pointer to a character buffer. The pointer has an undefined value (address) and  this is also where your data goes to. Thus your problem is not related to freetype library but more to a uncompleted transition from Java to bare bone C/C++ programming world.  

Quick Fix: :

unsigned char *LoadFile( char * fileName, zip_uint64_t &fileSize )
{

    int MAX_FILE_SIZE = 10485760; 
    unsigned char *buf = new char[MAX_FILE_SIZE];

    FILE *inFile = fopen("fileName","rb");
    fileSize = (zip_uint64_t)fread(buf, sizeof(unsigned char), MAX_FILE_SIZE, inFile);

    fclose(inFile);
    return buf;

}

Smart fix: first determine the actual file size with fseek / ftell prior to allocate the buffer for maximum size. Android devices are very memory limited.

br
Gernot

2011/9/7 Louis Desjardins <address@hidden>

Thanks for your reply. I am still trying to get a successful Makefile going so I have not been able to test this standalone app yet, however in case it helps, I have attached the code that should provide the crash in the meanwhile. The main program is in Standalone.cpp and crashes within FT_New_Memory_Face. I have also provided a sample ttf and the freetype library that I am using with Android (though I have added various 'printfs' for debugging).  

Thank-you

---

From: address@hidden
Date: Wed, 7 Sep 2011 13:06:36 -0400
Subject: Re: [ft-devel] FT_New_Memory_Face crashes

To: address@hidden

CC: address@hidden

It should be possible to create a self standing example that will compile on a Linux box. It might not have to be fully equivalent as long as it fails in the same way and aids in debugging

Chris

On Sep 7, 2011, at 12:23 PM, Louis Desjardins <address@hidden> wrote:

I apologize, I made a copy\paste error when providing the sample, I have corrected it below as they are in fact the same buffers in the code I'm running. 

Unfortunately I cannot provide a complete standalone sample as I am working in the Android NDK.

LD

---

From: address@hidden
To: address@hidden
Date: Wed, 7 Sep 2011 03:47:26 -0400
Subject: RE: [ft-devel] FT_New_Memory_Face crashes

In the code sample, FT_NEW_MEMORY_Face() is passed a different buffer from the one created by LoadFile().

 

---

From: address@hidden [mailto:freetype-devel-bounces+david.bevan=address@hidden] On Behalf Of Louis Desjardins
Sent: 07 September 2011 00:13
To: address@hidden
Subject: [ft-devel] FT_New_Memory_Face crashes

 

I have loaded an "arial.ttf" file (taken from my /Windows/Fonts folder) into memory, however passing this into FT_New_Memory_Face crashes (I have also tried other ttf files, and this function still crashes). Any clues as to what I might be doing wrong? Note that I am using Freetype with the Android NDK, so it is difficult to debug, however I find that eventually, the crash occurs within:

FT_New_Memory_Face -> FT_Open_Face -> FT_Stream_ReadLong -> crashes at:

if ( p )

{

       result = FT_NEXT_LONG( p ); //crashes here, in file ftstream.c, method FT_Stream_ReadLong

}

And below is my code:

unsigned char *fontBuffer = LoadFile("arial.ttf");

zip_uint64_t fSize = GetFileSize("arial.ttf"); // I checked this, and it returns the correct size

FT_Library  library;

FT_Face     face; 

int error = FT_Init_FreeType( &library ); // I checked this, this step succeeds

if( error != 0 )

    printf("FT_Init_FreeType failed");

error = FT_New_Memory_Face( library,

                            (FT_Byte*)fontBuffer,

                            fSize,                  

                            0,                      

                            &face );

_______________________________________________
Freetype-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/freetype-devel

_______________________________________________
Freetype-devel mailing list
address@hidden
https://lists.nongnu.org/mailman/listinfo/freetype-devel