diff options
| -rw-r--r-- | [GSoC]ChangeLog | 24 | ||||
| -rw-r--r-- | src/sdf/ftbsdf.c | 266 | ||||
| -rw-r--r-- | src/sdf/ftsdfrend.c | 8 |
3 files changed, 284 insertions, 14 deletions
diff --git a/[GSoC]ChangeLog b/[GSoC]ChangeLog index ba15dc49c..28a7efb35 100644 --- a/[GSoC]ChangeLog +++ b/[GSoC]ChangeLog @@ -1,3 +1,27 @@ +2020-07-26 Anuj Verma <anujv@iitbhilai.ac.in> + + [sdf -> bsdf] Added first pass of the '8SED' algorithm. + + Added the first pass of the 8SED algorithm. The first pass + transverse the bitmap from top to bottom and for each row + it sweeps forward and backward assigning distances to the + grid points. + + * src/sdf/ftbsdf.c (ED): Added additional parameter `sign'. + + * src/sdf/ftbsdf.c (edt8): Added function to convert bitmap + to SDF using the 8SED algorithm. + + * src/sdf/ftbsdf.c (first_pass): Added function to do the + first pass of the 8SED algorithm on the bitmap. + + * src/sdf/ftbsdf.c (finalize_sdf): Added function to assign + the final SDF data to the target bitmap. + + * src/sdf/ftbsdf.c (*): Various minor or experimental changes. + + * src/sdf/ftsdfrend.c (ft_bsdf_render): Fix spacing. + 2020-07-25 Anuj Verma <anujv@iitbhilai.ac.in> * src/sdf/ftbsdf.c (*): Rename `SDF_TRaster' => `BSDF_TRaster'. diff --git a/src/sdf/ftbsdf.c b/src/sdf/ftbsdf.c index 6514cf70d..46461f5c2 100644 --- a/src/sdf/ftbsdf.c +++ b/src/sdf/ftbsdf.c @@ -21,6 +21,8 @@ goto Exit; \ } while ( 0 ) + #define ONE 65536 /* 1 in 16.16 */ + /************************************************************************** * * typedefs @@ -48,7 +50,8 @@ typedef struct ED_ { FT_16D16 dist; /* distance at `near' */ - FT_16D16_Vec near; /* nearest point */ + FT_16D16_Vec near; /* nearest point */ + FT_Char sign; /* outside or inside */ } ED; @@ -65,6 +68,15 @@ /************************************************************************** * + * initializer + * + */ + + static + const ED zero_ed = { 0, { 0, 0 }, 0 }; + + /************************************************************************** + * * rasterizer functions * */ @@ -180,17 +192,22 @@ { FT_Int t_index = t_j * t_width + t_i; FT_Int s_index; - FT_Short pixel_value; + FT_Byte pixel_value; + + t[t_index] = zero_ed; s_i = t_i - x_diff; s_j = t_j - y_diff; - /* assign INT_MAX to the padding */ + /* Assign 0 to padding similar to */ + /* the source bitmap. */ if ( s_i < 0 || s_i >= s_width || s_j < 0 || s_j >= s_rows ) { - t[t_index].dist = FT_INT_MAX; + t[t_index].near.x = 100000; + t[t_index].near.y = 100000; + t[t_index].dist = 100000; continue; } @@ -199,7 +216,9 @@ else s_index = s_j * s_width + s_i; - pixel_value = (FT_Short)s[s_index]; + pixel_value = s[s_index]; + + #if 0 /* to make the fractional value 1 */ /* for completely filled pixels */ @@ -211,7 +230,17 @@ /* shift the value by 8. */ pixel_value <<= 8; - t[t_index].dist = pixel_value; + #else + if ( pixel_value ) + t[t_index].dist = 0; + else + { + t[t_index].near.x = 100000; + t[t_index].near.y = 100000; + t[t_index].dist = 100000; + } + + #endif } } @@ -227,7 +256,222 @@ Exit: return error; } - + + /************************************************************************** + * + * @Function: + * first_pass + * + * @Description: + * [TODO] + * + * @Input: + * [TODO] + * + * @Return: + * [TODO] + */ + static void + first_pass( BSDF_Worker* worker ) + { + FT_Int i, j; /* iterators */ + FT_Int w, r; /* width, rows */ + ED* dm; /* distance map */ + + + dm = worker->distance_map; + w = worker->width; + r = worker->rows; + + /* Start scanning from top to bottom and sweep each */ + /* row back and forth comparing the distances of the */ + /* neighborhood. Leave the first row as it has no top */ + /* neighbor, it will be covered in the 2nd scan of */ + /* the image, that is from bottom to top. */ + for ( j = 1; j < r; j++ ) + { + FT_Int index; + FT_16D16 dist; + FT_16D16_Vec dist_vec; + ED* to_check; + ED* current; + + + /* Forward pass of rows (left -> right), leave, the */ + /* first column, will be covered in backward pass. */ + for ( i = 1; i < w; i++ ) + { + index = j * w + i; + current = dm + index; + + /* left-up */ + to_check = current - w - 1; + dist_vec = to_check->near; + dist_vec.x -= ONE; + dist_vec.y -= ONE; + dist = FT_Vector_Length( &dist_vec ); + if ( dist < current->dist ) + { + current->dist = dist; + current->near = dist_vec; + } + + /* up */ + to_check = current - w; + dist_vec = to_check->near; + dist_vec.y -= ONE; + dist = FT_Vector_Length( &dist_vec ); + if ( dist < current->dist ) + { + current->dist = dist; + current->near = dist_vec; + } + + /* up-right */ + to_check = current - w + 1; + dist_vec = to_check->near; + dist_vec.x += ONE; + dist_vec.y -= ONE; + dist = FT_Vector_Length( &dist_vec ); + if ( dist < current->dist ) + { + current->dist = dist; + current->near = dist_vec; + } + + /* left */ + to_check = current - 1; + dist_vec = to_check->near; + dist_vec.x -= ONE; + dist = FT_Vector_Length( &dist_vec ); + if ( dist < current->dist ) + { + current->dist = dist; + current->near = dist_vec; + } + } + + /* Backward pass of rows (right -> left), leave, the */ + /* last column, already covered in the forward pass. */ + for ( i = w - 2; i >= 0; i-- ) + { + index = j * w + i; + current = dm + index; + + /* right */ + to_check = current + 1; + dist_vec = to_check->near; + dist_vec.x += ONE; + dist = FT_Vector_Length( &dist_vec ); + if ( dist < current->dist ) + { + current->dist = dist; + current->near = dist_vec; + } + } + } + } + + /************************************************************************** + * + * @Function: + * edt8 + * + * @Description: + * [TODO] + * + * @Input: + * [TODO] + * + * @Return: + * [TODO] + */ + static FT_Error + edt8( BSDF_Worker* worker ) + { + FT_Error error = FT_Err_Ok; + + + if ( !worker || !worker->distance_map ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + /* first scan of the image */ + first_pass( worker ); + + /* second scan of the image */ + /* [TODO] */ + + Exit: + return error; + } + + /************************************************************************** + * + * @Function: + * finalize_sdf + * + * @Description: + * [TODO] + * + * @Input: + * [TODO] + * + * @Return: + * [TODO] + */ + static FT_Error + finalize_sdf( BSDF_Worker* worker, + FT_Bitmap* target ) + { + FT_Error error = FT_Err_Ok; + FT_Int w, r; + FT_Int i, j; + FT_6D10* t_buffer; + + if ( !worker || !target ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + w = target->width; + r = target->rows; + t_buffer = (FT_6D10*)target->buffer; + + if ( w != worker->width || + r != worker->rows ) + { + error = FT_THROW( Invalid_Argument ); + goto Exit; + } + + for ( j = 0; j < r; j++ ) + { + for ( i = 0; i < w; i++ ) + { + FT_Int index; + FT_16D16 dist; + FT_6D10 final_dist; + + + index = j * w + i; + dist = worker->distance_map[index].dist; + /* convert from 16.16 to 6.10 */ + dist /= 64; + final_dist = (FT_6D10)(dist & 0x0000FFFF); + + /* [TODO]: Assing the sign properly. */ + + t_buffer[index] = final_dist; + } + } + + Exit: + return error; + } /************************************************************************** * @@ -338,7 +582,7 @@ " 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) ); + , MIN_SPREAD, MAX_SPREAD )); error = FT_THROW( Invalid_Argument ); goto Exit; } @@ -346,8 +590,8 @@ /* setup the worker */ /* allocate the distance map */ - if ( !FT_QALLOC_MULT( worker.distance_map, target->rows, - target->width * sizeof( *worker.distance_map ) ) ) + if ( FT_QALLOC_MULT( worker.distance_map, target->rows, + target->width * sizeof( *worker.distance_map ) ) ) goto Exit; worker.width = target->width; @@ -355,6 +599,8 @@ worker.params = *sdf_params; FT_CALL( bsdf_init_distance_map( source, &worker ) ); + FT_CALL( edt8( &worker ) ); + FT_CALL( finalize_sdf( &worker, target ) ); Exit: return error; diff --git a/src/sdf/ftsdfrend.c b/src/sdf/ftsdfrend.c index bc7bcabf9..f2a34b1d8 100644 --- a/src/sdf/ftsdfrend.c +++ b/src/sdf/ftsdfrend.c @@ -404,10 +404,10 @@ /* generate signed distance field from glyph's bitmap */ static FT_Error - ft_bsdf_render( FT_Renderer module, - FT_GlyphSlot slot, - FT_Render_Mode mode, - const FT_Vector* origin ) + ft_bsdf_render( FT_Renderer module, + FT_GlyphSlot slot, + FT_Render_Mode mode, + const FT_Vector* origin ) { FT_Error error = FT_Err_Ok; FT_Bitmap* bitmap = &slot->bitmap; |