From 56e4100aad97d76fe7464bc444d6f58efdbc049f Mon Sep 17 00:00:00 2001 From: Anuj Verma Date: Thu, 20 Aug 2020 21:57:43 -0700 Subject: [PATCH] [sdf] Added the `bsdf' renderer to the `sdf' module. * src/sdf/ftsdfrend.c (ft_bsdf_render): Added the `bsdf' renderer, render function which is essentially what is called from the FreeType core to render a glyph. * src/sdf/ftsdfrend.c (ft_bitmap_sdf_renderer_class): Added the `bsdf' renderer definition. --- src/sdf/ftsdfrend.c | 141 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) diff --git a/src/sdf/ftsdfrend.c b/src/sdf/ftsdfrend.c index 1a2797c88..d65d28083 100644 --- a/src/sdf/ftsdfrend.c +++ b/src/sdf/ftsdfrend.c @@ -398,4 +398,145 @@ (FT_Raster_Funcs*)&ft_sdf_raster /* raster_class */ ) + /*************************************************************************/ + /*************************************************************************/ + /** **/ + /** BITMAP TO SDF CONVERTER **/ + /** **/ + /*************************************************************************/ + /*************************************************************************/ + + /* 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_Error error = FT_Err_Ok; + FT_Bitmap* bitmap = &slot->bitmap; + FT_Memory memory = NULL; + FT_Renderer render = NULL; + FT_Bitmap target; + + FT_Pos x_pad = 0; + FT_Pos y_pad = 0; + + SDF_Raster_Params params; + SDF_Renderer sdf_module = SDF_RENDERER( module ); + + + /* initialize the bitmap in case any error occurs */ + FT_Bitmap_Init( &target ); + + render = &sdf_module->root; + memory = render->root.memory; + + /* check if slot format is correct before rendering */ + if ( slot->format != render->glyph_format ) + { + FT_ERROR(( "[bsdf] ft_bsdf_render: " + "bsdf renderer require the slot " + "format to be a bitmap\n" )); + error = FT_THROW( Invalid_Glyph_Format ); + goto Exit; + } + + /* check if render mode is correct */ + if ( mode != FT_RENDER_MODE_SDF ) + { + FT_ERROR(( "[bsdf] ft_bsdf_render: " + "sdf module only render when " + "using `FT_RENDER_MODE_SDF'\n" )); + error = FT_THROW( Cannot_Render_Glyph ); + goto Exit; + } + + if ( origin ) + { + FT_ERROR(( "[bsdf] ft_bsdf_render: " + "bsdf renderer can't translate " + "the bitmap\n" )); + error = FT_THROW( Unimplemented_Feature ); + goto Exit; + } + + if ( !bitmap->rows || !bitmap->pitch ) + goto Exit; + + FT_Bitmap_New( &target ); + + /* the padding will simply be equal to the `spread' */ + x_pad = sdf_module->spread; + y_pad = sdf_module->spread; + + /* apply the padding, will be in all the directions */ + target.rows = bitmap->rows + y_pad * 2; + target.width = bitmap->width + x_pad * 2; + + /* setup the target bitmap */ + target.pixel_mode = FT_PIXEL_MODE_GRAY16; + target.pitch = target.width * 2; + target.num_grays = 65535; + + if ( FT_ALLOC_MULT( target.buffer, target.rows, target.pitch ) ) + goto Exit; + + /* set up parameters */ + params.root.target = ⌖ + params.root.source = bitmap; + params.root.flags = FT_RASTER_FLAG_SDF; + params.spread = sdf_module->spread; + params.flip_sign = sdf_module->flip_sign; + params.flip_y = sdf_module->flip_y; + + error = render->raster_render( render->raster, + (const FT_Raster_Params*)¶ms ); + Exit: + if ( !error ) + { + /* the glyph is successfully converted to a SDF */ + if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) + { + FT_FREE( bitmap->buffer ); + slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP; + } + + slot->bitmap = target; + slot->internal->flags |= FT_GLYPH_OWN_BITMAP; + } + else if ( target.buffer ) + { + FT_FREE( target.buffer ); + } + + return error; + } + + FT_DEFINE_RENDERER( + ft_bitmap_sdf_renderer_class, + + FT_MODULE_RENDERER, + sizeof( SDF_Renderer_Module ), + + "bsdf", + 0x10000L, + 0x20000L, + + NULL, + + (FT_Module_Constructor) ft_sdf_init, + (FT_Module_Destructor) ft_sdf_done, + (FT_Module_Requester) ft_sdf_requester, + + FT_GLYPH_FORMAT_BITMAP, + + (FT_Renderer_RenderFunc) ft_bsdf_render, /* render_glyph */ + (FT_Renderer_TransformFunc) ft_sdf_transform, /* transform_glyph */ + (FT_Renderer_GetCBoxFunc) ft_sdf_get_cbox, /* get_glyph_cbox */ + (FT_Renderer_SetModeFunc) ft_sdf_set_mode, /* set_mode */ + + (FT_Raster_Funcs*)&ft_bitmap_sdf_raster /* raster_class */ + ) + /* END */