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#include <freetype/internal/ftobjs.h>
#include <freetype/internal/ftdebug.h>
#include "ftsdf.h"
#include "ftsdferrs.h"
/**************************************************************************
*
* useful macros
*
*/
/* Convenient macro which calls the function */
/* and returns if any error occurs. */
#define FT_CALL( x ) do \
{ \
error = ( x ); \
if ( error != FT_Err_Ok ) \
goto Exit; \
} while ( 0 )
/**************************************************************************
*
* rasterizer functions
*
*/
static FT_Error
bsdf_copy_source_to_target( const FT_Bitmap* source,
FT_Bitmap* target )
{
FT_Error error = FT_Err_Ok;
FT_Bool is_monochrome = 0;
FT_Int x_diff, y_diff;
FT_Int num_channels;
FT_Byte* t, s;
/* again check the parameters (probably unnecessary) */
if ( !source || !target )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
/* Because of the way we convert bitmap to SDF */
/* i.e. aligning the source to the center of the */
/* target, the target's width/rows must be checked */
/* before copying. */
if ( target->width < source->width ||
target->rows < source->rows )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
/* check pixel mode */
if ( source->pixel_mode == FT_PIXEL_MODE_NONE )
{
FT_ERROR(( "[bsdf] bsdf_copy_source_to_target: "
"Invalid pixel mode of source bitmap" ));
error = FT_THROW( Invalid_Argument );
goto Exit;
}
/* make sure target bitmap is 16bpp */
if ( target->pixel_mode != FT_PIXEL_MODE_GRAY16 )
{
FT_ERROR(( "[bsdf] bsdf_copy_source_to_target: "
"Invalid pixel mode of target bitmap" ));
error = FT_THROW( Invalid_Argument );
goto Exit;
}
#ifdef FT_DEBUG_LEVEL_TRACE
if ( source->pixel_mode == FT_PIXEL_MODE_MONO )
{
FT_TRACE0(( "[bsdf] bsdf_copy_source_to_target:\n"
"The `bsdf' renderer can convert monochrome bitmap\n"
"to SDF, but the results are not perfect because there\n"
"is no way to approximate actual outline from monochrome\n"
"bitmap. Consider using anti-aliased bitmap instead.\n" ));
}
#endif
/* Calculate the difference in width and rows */
/* of the target and source. */
x_diff = target->width - source->width;
y_diff = target->rows - source->rows;
x_diff /= 2;
y_diff /= 2;
t = target->buffer;
s = source->buffer;
/* For now we only support pixel mode `FT_PIXEL_MODE_MONO' */
/* and `FT_PIXEL_MODE_GRAY'. More will be added later. */
/* [NOTE]: We can also use `FT_Bitmap_Convert' to convert */
/* bitmap to 8bpp. To avoid extra allocation and */
/* since the target bitmap can be 16bpp we manually */
/* convert the source bitmap to desired bpp. */
switch ( source->pixel_mode ) {
case FT_PIXEL_MODE_MONO:
/* [TODO] */
error = FT_THROW( Unimplemented_Feature );
break;
case FT_PIXEL_MODE_GRAY:
/* [TODO] */
error = FT_THROW( Unimplemented_Feature );
break;
default:
FT_ERROR(( "[bsdf] bsdf_copy_source_to_target: "
"unsopported pixel mode of source bitmap\n" ));
error = FT_THROW( Unimplemented_Feature );
break;
}
Exit:
return error;
}
/**************************************************************************
*
* interface functions
*
*/
static FT_Error
bsdf_raster_new( FT_Memory memory,
FT_Raster* araster)
{
FT_UNUSED( memory );
FT_UNUSED( araster );
return FT_Err_Ok;
}
static void
bsdf_raster_reset( FT_Raster raster,
unsigned char* pool_base,
unsigned long pool_size )
{
/* no use of this function */
FT_UNUSED( raster );
FT_UNUSED( pool_base );
FT_UNUSED( pool_size );
}
static FT_Error
bsdf_raster_set_mode( FT_Raster raster,
unsigned long mode,
void* args )
{
FT_UNUSED( raster );
FT_UNUSED( mode );
FT_UNUSED( args );
return FT_Err_Ok;
}
static FT_Error
bsdf_raster_render( FT_Raster raster,
const FT_Raster_Params* params )
{
FT_Error error = FT_Err_Ok;
FT_Bitmap* source = NULL;
FT_Bitmap* target = NULL;
const SDF_Raster_Params* sdf_params = (const SDF_Raster_Params*)params;
FT_UNUSED( raster );
/* check for valid parameters */
if ( !params )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
/* check if the flag is set */
if ( sdf_params->root.flags != FT_RASTER_FLAG_SDF )
{
error = FT_THROW( Raster_Corrupted );
goto Exit;
}
source = sdf_params->root.source;
target = sdf_params->root.target;
/* check the source and target bitmap */
if ( !source || !target )
{
error = FT_THROW( Invalid_Argument );
goto Exit;
}
/* check if spread is set properly */
if ( sdf_params->spread > MAX_SPREAD ||
sdf_params->spread < MIN_SPREAD )
{
FT_TRACE0((
"[bsdf] bsdf_raster_render:\n"
" The `spread' field of `SDF_Raster_Params' is invalid,\n"
" the value of this field must be within [%d, %d].\n"
" Also, you must pass `SDF_Raster_Params' instead of the\n"
" default `FT_Raster_Params' while calling this function\n"
" and set the fields properly.\n"
, MIN_SPREAD, MAX_SPREAD) );
error = FT_THROW( Invalid_Argument );
goto Exit;
}
FT_CALL( bsdf_copy_source_to_target( source, target ) );
Exit:
return error;
}
static void
bsdf_raster_done( FT_Raster raster )
{
FT_UNUSED( raster );
}
FT_DEFINE_RASTER_FUNCS(
ft_bitmap_sdf_raster,
FT_GLYPH_FORMAT_BITMAP,
(FT_Raster_New_Func) bsdf_raster_new, /* raster_new */
(FT_Raster_Reset_Func) bsdf_raster_reset, /* raster_reset */
(FT_Raster_Set_Mode_Func) bsdf_raster_set_mode, /* raster_set_mode */
(FT_Raster_Render_Func) bsdf_raster_render, /* raster_render */
(FT_Raster_Done_Func) bsdf_raster_done /* raster_done */
)
/* END */
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