RE: [ft] rasterize outline with antialias or clear type

[Matteo Lanzi]

Hi Werner, 
it works fine for the antialias except that the background is gray instead
of white... any suggestion 
Anyway is there a module to use as standalone for CLEAR TYPE ? 


This is the modified coded if someone needs it (I just changed the 3 lines
about the raster ) 
If you want to use it as standalone please remember to put 
#include "freetype/fttypes.h" in ftgrays.c .. that worked for me 


                ///////////////////////////
                // RASTERIZE 
                FT_Memory mem;
                mem = new FT_MemoryRec_;
                mem->alloc = MY_Alloc_Func;
                mem->free = MY_Free_Func;
                mem->realloc = MY_Realloc_Func;


                const int width = 500;
                const int rows = 600;

                // 8 bits per pixel; must be a multiple of four.
                const int pitch_gray = width;


                FT_Bitmap bmp;
                FT_Raster raster;
                FT_Raster_Params params;


                // Allocate a chunk of memory for the render pool.
                const int kRenderPoolSize = 1024 * 768;
                unsigned char *renderPool = new unsigned
char[kRenderPoolSize];


                // Set up a pixmap.
                bmp.buffer = new unsigned char[rows * pitch_gray];
                memset(bmp.buffer, 0, rows * pitch_gray);
                bmp.width = width;
                bmp.rows = rows;
                bmp.pitch = pitch_gray;
                bmp.pixel_mode = FT_PIXEL_MODE_GRAY;
                bmp.num_grays = 0xFF;
                

                // Set up the necessary raster parameters.
                memset(&params, 0, sizeof (params));
                params.source = &outline;
                params.target = &bmp;
                params.flags = FT_RASTER_FLAG_AA | FT_RASTER_FLAG_CLIP ;

                ft_grays_raster.raster_new (mem, &raster ) ;    
                ft_grays_raster.raster_reset(raster, renderPool,
kRenderPoolSize ) ; 
                error  = ft_grays_raster.raster_render(raster, &params ) ;
                ft_grays_raster.raster_done ( raster ) ;




> -----Original Message-----
> From: Werner LEMBERG [mailto:address@hidden
> Sent: venerdì 8 ottobre 2010 00:14
> To: address@hidden
> Cc: address@hidden
> Subject: Re: [ft] rasterize outline with antialias or clear type
> 
> 
> > - Is it possible to rasterize one outline with cleartype rasterizer?
> 
> It depends what you mean with `ClearType'.  If you mean a threefold
> increase in horizontal resolution which gets squeezed back in the
> proper LCD mode, then yes.  If you mean the special handling of
> TrueType instructions, then no since it is not implemented yet (but
> there will be soon something into this direction).
> 
> > - I tried to rasterize some outline extract from a glyph with Werner
> >   Lemberg' example3 in the documentation; it works fine but there is
> >   no antialias even if I have setted
> >
> >                     bmp.pixel_mode = FT_PIXEL_MODE_GRAY;
> >                     bmp.num_grays = 256;
> 
> example3.cpp uses the B/W renderer (in ftraster.c).  You need
> ftgrays.c instead which works in standalone mode too.
> 
> 
>     Werner