Edit
kc3-lang/freetype/src/sdf/ftsdfrend.c
Alexei Podtelezhnikov
- src/sdf/ftsdfrend.c
-
/**************************************************************************** * * ftsdfrend.c * * Signed Distance Field renderer interface (body). * * Copyright (C) 2020-2024 by * David Turner, Robert Wilhelm, and Werner Lemberg. * * Written by Anuj Verma. * * This file is part of the FreeType project, and may only be used, * modified, and distributed under the terms of the FreeType project * license, LICENSE.TXT. By continuing to use, modify, or distribute * this file you indicate that you have read the license and * understand and accept it fully. * */ #include <freetype/internal/ftdebug.h> #include <freetype/internal/ftobjs.h> #include <freetype/internal/services/svprop.h> #include <freetype/ftoutln.h> #include <freetype/ftbitmap.h> #include "ftsdfrend.h" #include "ftsdf.h" #include "ftsdferrs.h" /************************************************************************** * * The macro FT_COMPONENT is used in trace mode. It is an implicit * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log * messages during execution. */ #undef FT_COMPONENT #define FT_COMPONENT sdf /************************************************************************** * * macros and default property values * */ #define SDF_RENDERER( rend ) ( (SDF_Renderer)rend ) /************************************************************************** * * for setting properties * */ /* property setter function */ static FT_Error sdf_property_set( FT_Module module, const char* property_name, const void* value, FT_Bool value_is_string ) { FT_Error error = FT_Err_Ok; SDF_Renderer render = SDF_RENDERER( FT_RENDERER( module ) ); FT_UNUSED( value_is_string ); if ( ft_strcmp( property_name, "spread" ) == 0 ) { FT_Int val = *(const FT_Int*)value; if ( val > MAX_SPREAD || val < MIN_SPREAD ) { FT_TRACE0(( "[sdf] sdf_property_set:" " the `spread' property can have a value\n" )); FT_TRACE0(( " " " within range [%d, %d] (value provided: %d)\n", MIN_SPREAD, MAX_SPREAD, val )); error = FT_THROW( Invalid_Argument ); goto Exit; } render->spread = (FT_UInt)val; FT_TRACE7(( "[sdf] sdf_property_set:" " updated property `spread' to %d\n", val )); } else if ( ft_strcmp( property_name, "flip_sign" ) == 0 ) { FT_Int val = *(const FT_Int*)value; render->flip_sign = val ? 1 : 0; FT_TRACE7(( "[sdf] sdf_property_set:" " updated property `flip_sign' to %d\n", val )); } else if ( ft_strcmp( property_name, "flip_y" ) == 0 ) { FT_Int val = *(const FT_Int*)value; render->flip_y = val ? 1 : 0; FT_TRACE7(( "[sdf] sdf_property_set:" " updated property `flip_y' to %d\n", val )); } else if ( ft_strcmp( property_name, "overlaps" ) == 0 ) { FT_Bool val = *(const FT_Bool*)value; render->overlaps = val; FT_TRACE7(( "[sdf] sdf_property_set:" " updated property `overlaps' to %d\n", val )); } else { FT_TRACE0(( "[sdf] sdf_property_set:" " missing property `%s'\n", property_name )); error = FT_THROW( Missing_Property ); } Exit: return error; } /* property getter function */ static FT_Error sdf_property_get( FT_Module module, const char* property_name, void* value ) { FT_Error error = FT_Err_Ok; SDF_Renderer render = SDF_RENDERER( FT_RENDERER( module ) ); if ( ft_strcmp( property_name, "spread" ) == 0 ) { FT_UInt* val = (FT_UInt*)value; *val = render->spread; } else if ( ft_strcmp( property_name, "flip_sign" ) == 0 ) { FT_Int* val = (FT_Int*)value; *val = render->flip_sign; } else if ( ft_strcmp( property_name, "flip_y" ) == 0 ) { FT_Int* val = (FT_Int*)value; *val = render->flip_y; } else if ( ft_strcmp( property_name, "overlaps" ) == 0 ) { FT_Int* val = (FT_Int*)value; *val = render->overlaps; } else { FT_TRACE0(( "[sdf] sdf_property_get:" " missing property `%s'\n", property_name )); error = FT_THROW( Missing_Property ); } return error; } FT_DEFINE_SERVICE_PROPERTIESREC( sdf_service_properties, (FT_Properties_SetFunc)sdf_property_set, /* set_property */ (FT_Properties_GetFunc)sdf_property_get ) /* get_property */ FT_DEFINE_SERVICEDESCREC1( sdf_services, FT_SERVICE_ID_PROPERTIES, &sdf_service_properties ) static FT_Module_Interface ft_sdf_requester( FT_Module module, const char* module_interface ) { FT_UNUSED( module ); return ft_service_list_lookup( sdf_services, module_interface ); } /*************************************************************************/ /*************************************************************************/ /** **/ /** OUTLINE TO SDF CONVERTER **/ /** **/ /*************************************************************************/ /*************************************************************************/ /************************************************************************** * * interface functions * */ static FT_Error ft_sdf_init( FT_Module module ) /* SDF_Renderer */ { SDF_Renderer sdf_render = SDF_RENDERER( module ); sdf_render->spread = DEFAULT_SPREAD; sdf_render->flip_sign = 0; sdf_render->flip_y = 0; sdf_render->overlaps = 0; return FT_Err_Ok; } static void ft_sdf_done( FT_Module module ) { FT_UNUSED( module ); } /* generate signed distance field from a glyph's slot image */ static FT_Error ft_sdf_render( FT_Renderer module, FT_GlyphSlot slot, FT_Render_Mode mode, const FT_Vector* origin ) { FT_Error error = FT_Err_Ok; FT_Outline* outline = &slot->outline; FT_Bitmap* bitmap = &slot->bitmap; FT_Memory memory = NULL; FT_Renderer render = NULL; FT_Pos x_shift = 0; FT_Pos y_shift = 0; FT_Pos x_pad = 0; FT_Pos y_pad = 0; SDF_Raster_Params params; SDF_Renderer sdf_module = SDF_RENDERER( module ); render = &sdf_module->root; memory = render->root.memory; /* check whether slot format is correct before rendering */ if ( slot->format != render->glyph_format ) { error = FT_THROW( Invalid_Glyph_Format ); goto Exit; } /* check whether render mode is correct */ if ( mode != FT_RENDER_MODE_SDF ) { error = FT_THROW( Cannot_Render_Glyph ); goto Exit; } /* deallocate the previously allocated bitmap */ if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) { FT_FREE( bitmap->buffer ); slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP; } /* preset the bitmap using the glyph's outline; */ /* the sdf bitmap is similar to an anti-aliased bitmap */ /* with a slightly bigger size and different pixel mode */ if ( ft_glyphslot_preset_bitmap( slot, FT_RENDER_MODE_NORMAL, origin ) ) { error = FT_THROW( Raster_Overflow ); goto Exit; } /* nothing to render */ if ( !bitmap->rows || !bitmap->pitch ) goto Exit; /* 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 */ bitmap->rows += y_pad * 2; bitmap->width += x_pad * 2; /* ignore the pitch, pixel mode and set custom */ bitmap->pixel_mode = FT_PIXEL_MODE_GRAY; bitmap->pitch = (int)( bitmap->width ); bitmap->num_grays = 255; /* allocate new buffer */ if ( FT_ALLOC_MULT( bitmap->buffer, bitmap->rows, bitmap->pitch ) ) goto Exit; slot->internal->flags |= FT_GLYPH_OWN_BITMAP; slot->bitmap_top += y_pad; slot->bitmap_left -= x_pad; x_shift = 64 * -slot->bitmap_left; y_shift = 64 * -slot->bitmap_top; y_shift += 64 * (FT_Int)bitmap->rows; if ( origin ) { x_shift += origin->x; y_shift += origin->y; } /* translate outline to render it into the bitmap */ if ( x_shift || y_shift ) FT_Outline_Translate( outline, x_shift, y_shift ); /* set up parameters */ params.root.target = bitmap; params.root.source = outline; 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; params.overlaps = sdf_module->overlaps; /* render the outline */ error = render->raster_render( render->raster, (const FT_Raster_Params*)¶ms ); /* transform the outline back to the original state */ if ( x_shift || y_shift ) FT_Outline_Translate( outline, -x_shift, -y_shift ); Exit: if ( !error ) { /* the glyph is successfully rendered to a bitmap */ slot->format = FT_GLYPH_FORMAT_BITMAP; } else if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) { FT_FREE( bitmap->buffer ); slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP; } return error; } /* transform the glyph using matrix and/or delta */ static FT_Error ft_sdf_transform( FT_Renderer render, FT_GlyphSlot slot, const FT_Matrix* matrix, const FT_Vector* delta ) { FT_Error error = FT_Err_Ok; if ( slot->format != render->glyph_format ) { error = FT_THROW( Invalid_Argument ); goto Exit; } if ( matrix ) FT_Outline_Transform( &slot->outline, matrix ); if ( delta ) FT_Outline_Translate( &slot->outline, delta->x, delta->y ); Exit: return error; } /* return the control box of a glyph's outline */ static void ft_sdf_get_cbox( FT_Renderer render, FT_GlyphSlot slot, FT_BBox* cbox ) { FT_ZERO( cbox ); if ( slot->format == render->glyph_format ) FT_Outline_Get_CBox( &slot->outline, cbox ); } /* set render specific modes or attributes */ static FT_Error ft_sdf_set_mode( FT_Renderer render, FT_ULong mode_tag, FT_Pointer data ) { /* pass it to the rasterizer */ return render->clazz->raster_class->raster_set_mode( render->raster, mode_tag, data ); } FT_DEFINE_RENDERER( ft_sdf_renderer_class, FT_MODULE_RENDERER, sizeof ( SDF_Renderer_Module ), "sdf", 0x10000L, 0x20000L, NULL, (FT_Module_Constructor)ft_sdf_init, (FT_Module_Destructor) ft_sdf_done, (FT_Module_Requester) ft_sdf_requester, FT_GLYPH_FORMAT_OUTLINE, (FT_Renderer_RenderFunc) ft_sdf_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_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_Memory memory = NULL; FT_Bitmap* bitmap = &slot->bitmap; 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 whether slot format is correct before rendering */ if ( slot->format != render->glyph_format ) { error = FT_THROW( Invalid_Glyph_Format ); goto Exit; } /* check whether render mode is correct */ if ( mode != FT_RENDER_MODE_SDF ) { error = FT_THROW( Cannot_Render_Glyph ); goto Exit; } if ( origin ) { FT_ERROR(( "ft_bsdf_render: can't translate the bitmap\n" )); error = FT_THROW( Unimplemented_Feature ); goto Exit; } /* nothing to render */ if ( !bitmap->rows || !bitmap->pitch ) goto Exit; /* Do not generate SDF if the bitmap is not owned by the */ /* glyph: it might be that the source buffer is already freed. */ if ( !( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) ) { FT_ERROR(( "ft_bsdf_render: can't generate SDF from" " unowned source bitmap\n" )); error = FT_THROW( Invalid_Argument ); goto Exit; } FT_Bitmap_New( &target ); /* padding will simply be equal to `spread` */ x_pad = sdf_module->spread; y_pad = sdf_module->spread; /* apply padding, which extends to all directions */ target.rows = bitmap->rows + y_pad * 2; target.width = bitmap->width + x_pad * 2; /* set up the target bitmap */ target.pixel_mode = FT_PIXEL_MODE_GRAY; target.pitch = (int)( target.width ); target.num_grays = 255; 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->bitmap = target; slot->bitmap_top += y_pad; slot->bitmap_left -= x_pad; if ( target.buffer ) 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 */