ref: bd28952e23bcd268a623ea5202e1cde4a92defe4
dir: /src/smooth/ftsmooth.c/
/***************************************************************************/ /* */ /* ftsmooth.c */ /* */ /* Anti-aliasing renderer interface (body). */ /* */ /* Copyright 2000-2017 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* 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 <ft2build.h> #include FT_INTERNAL_DEBUG_H #include FT_INTERNAL_OBJECTS_H #include FT_OUTLINE_H #include "ftsmooth.h" #include "ftgrays.h" #include "ftspic.h" #include "ftsmerrs.h" /* initialize renderer -- init its raster */ static FT_Error ft_smooth_init( FT_Renderer render ) { render->clazz->raster_class->raster_reset( render->raster, NULL, 0 ); return 0; } /* sets render-specific mode */ static FT_Error ft_smooth_set_mode( FT_Renderer render, FT_ULong mode_tag, FT_Pointer data ) { /* we simply pass it to the raster */ return render->clazz->raster_class->raster_set_mode( render->raster, mode_tag, data ); } /* transform a given glyph image */ static FT_Error ft_smooth_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 glyph's control box */ static void ft_smooth_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 ); } /* convert a slot's glyph image into a bitmap */ static FT_Error ft_smooth_render_generic( FT_Renderer render, FT_GlyphSlot slot, FT_Render_Mode mode, const FT_Vector* origin, FT_Render_Mode required_mode ) { FT_Error error; FT_Outline* outline = &slot->outline; FT_Bitmap* bitmap = &slot->bitmap; FT_Memory memory = render->root.memory; FT_BBox cbox; FT_Pos x_shift = 0; FT_Pos y_shift = 0; FT_Pos x_left, y_top; FT_Pos width, height, pitch; FT_Int hmul = ( mode == FT_RENDER_MODE_LCD ); FT_Int vmul = ( mode == FT_RENDER_MODE_LCD_V ); FT_Raster_Params params; FT_Bool have_outline_shifted = FALSE; FT_Bool have_buffer = FALSE; #ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING FT_LcdFiveTapFilter lcd_weights = { 0 }; FT_Bool have_custom_weight = FALSE; FT_Bitmap_LcdFilterFunc lcd_filter_func = NULL; if ( slot->face ) { FT_Char i; for ( i = 0; i < FT_LCD_FILTER_FIVE_TAPS; i++ ) if ( slot->face->internal->lcd_weights[i] != 0 ) { have_custom_weight = TRUE; break; } } /* * The LCD filter can be set library-wide and per-face. Face overrides * library. If the face filter weights are all zero (the default), it * means that the library default should be used. */ if ( have_custom_weight ) { /* * A per-font filter is set. It always uses the default 5-tap * in-place FIR filter. */ ft_memcpy( lcd_weights, slot->face->internal->lcd_weights, FT_LCD_FILTER_FIVE_TAPS ); lcd_filter_func = ft_lcd_filter_fir; } else { /* * The face's lcd_weights is {0, 0, 0, 0, 0}, meaning `use library * default'. If the library is set to use no LCD filtering * (lcd_filter_func == NULL), `lcd_filter_func' here is also set to * NULL and the tests further below pass over the filtering process. */ ft_memcpy( lcd_weights, slot->library->lcd_weights, FT_LCD_FILTER_FIVE_TAPS ); lcd_filter_func = slot->library->lcd_filter_func; } #endif /*FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ /* check glyph image format */ if ( slot->format != render->glyph_format ) { error = FT_THROW( Invalid_Argument ); goto Exit; } /* check mode */ if ( mode != required_mode ) { error = FT_THROW( Cannot_Render_Glyph ); goto Exit; } if ( origin ) { x_shift = origin->x; y_shift = origin->y; } /* compute the control box, and grid fit it */ /* taking into account the origin shift */ FT_Outline_Get_CBox( outline, &cbox ); #ifndef FT_CONFIG_OPTION_SUBPIXEL_RENDERING /* add minimal padding for LCD rendering */ if ( hmul ) { cbox.xMax += 21; cbox.xMin -= 21; } if ( vmul ) { cbox.yMax += 21; cbox.yMin -= 21; } #else /* FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ /* add minimal padding for LCD filter depending on specific weights */ if ( lcd_filter_func ) { if ( hmul ) { cbox.xMax += lcd_weights[4] ? 43 : lcd_weights[3] ? 22 : 0; cbox.xMin -= lcd_weights[0] ? 43 : lcd_weights[1] ? 22 : 0; } if ( vmul ) { cbox.yMax += lcd_weights[4] ? 43 : lcd_weights[3] ? 22 : 0; cbox.yMin -= lcd_weights[0] ? 43 : lcd_weights[1] ? 22 : 0; } } #endif /* FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ cbox.xMin = FT_PIX_FLOOR( cbox.xMin + x_shift ); cbox.yMin = FT_PIX_FLOOR( cbox.yMin + y_shift ); cbox.xMax = FT_PIX_CEIL( cbox.xMax + x_shift ); cbox.yMax = FT_PIX_CEIL( cbox.yMax + y_shift ); x_shift -= cbox.xMin; y_shift -= cbox.yMin; x_left = cbox.xMin >> 6; y_top = cbox.yMax >> 6; width = (FT_ULong)( cbox.xMax - cbox.xMin ) >> 6; height = (FT_ULong)( cbox.yMax - cbox.yMin ) >> 6; pitch = width; if ( hmul ) { width *= 3; pitch = FT_PAD_CEIL( width, 4 ); } if ( vmul ) height *= 3; /* * XXX: on 16bit system, we return an error for huge bitmap * to prevent an overflow. */ if ( x_left > FT_INT_MAX || y_top > FT_INT_MAX || x_left < FT_INT_MIN || y_top < FT_INT_MIN ) { error = FT_THROW( Invalid_Pixel_Size ); goto Exit; } /* Required check is (pitch * height < FT_ULONG_MAX), */ /* but we care realistic cases only. Always pitch <= width. */ if ( width > 0x7FFF || height > 0x7FFF ) { FT_ERROR(( "ft_smooth_render_generic: glyph too large: %u x %u\n", width, height )); error = FT_THROW( Raster_Overflow ); goto Exit; } /* release old bitmap buffer */ if ( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) { FT_FREE( bitmap->buffer ); slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP; } /* allocate new one */ if ( FT_ALLOC( bitmap->buffer, (FT_ULong)( pitch * height ) ) ) goto Exit; else have_buffer = TRUE; slot->internal->flags |= FT_GLYPH_OWN_BITMAP; slot->format = FT_GLYPH_FORMAT_BITMAP; slot->bitmap_left = (FT_Int)x_left; slot->bitmap_top = (FT_Int)y_top; bitmap->pixel_mode = FT_PIXEL_MODE_GRAY; bitmap->num_grays = 256; bitmap->width = (unsigned int)width; bitmap->rows = (unsigned int)height; bitmap->pitch = pitch; /* translate outline to render it into the bitmap */ if ( x_shift || y_shift ) { FT_Outline_Translate( outline, x_shift, y_shift ); have_outline_shifted = TRUE; } /* set up parameters */ params.target = bitmap; params.source = outline; params.flags = FT_RASTER_FLAG_AA; #ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING /* implode outline if needed */ { FT_Vector* points = outline->points; FT_Vector* points_end = points + outline->n_points; FT_Vector* vec; if ( hmul ) for ( vec = points; vec < points_end; vec++ ) vec->x *= 3; if ( vmul ) for ( vec = points; vec < points_end; vec++ ) vec->y *= 3; } /* render outline into the bitmap */ error = render->raster_render( render->raster, ¶ms ); /* deflate outline if needed */ { FT_Vector* points = outline->points; FT_Vector* points_end = points + outline->n_points; FT_Vector* vec; if ( hmul ) for ( vec = points; vec < points_end; vec++ ) vec->x /= 3; if ( vmul ) for ( vec = points; vec < points_end; vec++ ) vec->y /= 3; } if ( error ) goto Exit; if ( lcd_filter_func ) lcd_filter_func( bitmap, mode, lcd_weights ); #else /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ if ( hmul ) /* lcd */ { FT_Byte* line; FT_Byte* temp; FT_Int i, j; /* Render 3 separate monochrome bitmaps, shifting the outline */ /* by 1/3 pixel. */ width /= 3; FT_Outline_Translate( outline, 21, 0 ); error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; FT_Outline_Translate( outline, -21, 0 ); bitmap->buffer += width; error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; FT_Outline_Translate( outline, -21, 0 ); bitmap->buffer += width; error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; FT_Outline_Translate( outline, 21, 0 ); bitmap->buffer -= 2 * width; /* XXX: Rearrange the bytes according to FT_PIXEL_MODE_LCD. */ /* XXX: It is more efficient to render every third byte above. */ if ( FT_ALLOC( temp, (FT_ULong)pitch ) ) goto Exit; for ( i = 0; i < height; i++ ) { line = bitmap->buffer + i * pitch; for ( j = 0; j < width; j++ ) { temp[3 * j ] = line[j]; temp[3 * j + 1] = line[j + width]; temp[3 * j + 2] = line[j + width + width]; } FT_MEM_COPY( line, temp, pitch ); } FT_FREE( temp ); } else if ( vmul ) /* lcd_v */ { /* Render 3 separate monochrome bitmaps, shifting the outline */ /* by 1/3 pixel. Triple the pitch to render on each third row. */ bitmap->pitch *= 3; bitmap->rows /= 3; FT_Outline_Translate( outline, 0, 21 ); bitmap->buffer += 2 * pitch; error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; FT_Outline_Translate( outline, 0, -21 ); bitmap->buffer -= pitch; error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; FT_Outline_Translate( outline, 0, -21 ); bitmap->buffer -= pitch; error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; FT_Outline_Translate( outline, 0, 21 ); bitmap->pitch /= 3; bitmap->rows *= 3; } else /* grayscale */ { error = render->raster_render( render->raster, ¶ms ); if ( error ) goto Exit; } #endif /* !FT_CONFIG_OPTION_SUBPIXEL_RENDERING */ /* everything is fine; don't deallocate buffer */ have_buffer = FALSE; error = FT_Err_Ok; Exit: if ( have_outline_shifted ) FT_Outline_Translate( outline, -x_shift, -y_shift ); if ( have_buffer ) { FT_FREE( bitmap->buffer ); slot->internal->flags &= ~FT_GLYPH_OWN_BITMAP; } return error; } /* convert a slot's glyph image into a bitmap */ static FT_Error ft_smooth_render( FT_Renderer render, FT_GlyphSlot slot, FT_Render_Mode mode, const FT_Vector* origin ) { if ( mode == FT_RENDER_MODE_LIGHT ) mode = FT_RENDER_MODE_NORMAL; return ft_smooth_render_generic( render, slot, mode, origin, FT_RENDER_MODE_NORMAL ); } /* convert a slot's glyph image into a horizontal LCD bitmap */ static FT_Error ft_smooth_render_lcd( FT_Renderer render, FT_GlyphSlot slot, FT_Render_Mode mode, const FT_Vector* origin ) { FT_Error error; error = ft_smooth_render_generic( render, slot, mode, origin, FT_RENDER_MODE_LCD ); if ( !error ) slot->bitmap.pixel_mode = FT_PIXEL_MODE_LCD; return error; } /* convert a slot's glyph image into a vertical LCD bitmap */ static FT_Error ft_smooth_render_lcd_v( FT_Renderer render, FT_GlyphSlot slot, FT_Render_Mode mode, const FT_Vector* origin ) { FT_Error error; error = ft_smooth_render_generic( render, slot, mode, origin, FT_RENDER_MODE_LCD_V ); if ( !error ) slot->bitmap.pixel_mode = FT_PIXEL_MODE_LCD_V; return error; } FT_DEFINE_RENDERER( ft_smooth_renderer_class, FT_MODULE_RENDERER, sizeof ( FT_RendererRec ), "smooth", 0x10000L, 0x20000L, NULL, /* module specific interface */ (FT_Module_Constructor)ft_smooth_init, /* module_init */ (FT_Module_Destructor) NULL, /* module_done */ (FT_Module_Requester) NULL, /* get_interface */ FT_GLYPH_FORMAT_OUTLINE, (FT_Renderer_RenderFunc) ft_smooth_render, /* render_glyph */ (FT_Renderer_TransformFunc)ft_smooth_transform, /* transform_glyph */ (FT_Renderer_GetCBoxFunc) ft_smooth_get_cbox, /* get_glyph_cbox */ (FT_Renderer_SetModeFunc) ft_smooth_set_mode, /* set_mode */ (FT_Raster_Funcs*)&FT_GRAYS_RASTER_GET /* raster_class */ ) FT_DEFINE_RENDERER( ft_smooth_lcd_renderer_class, FT_MODULE_RENDERER, sizeof ( FT_RendererRec ), "smooth-lcd", 0x10000L, 0x20000L, NULL, /* module specific interface */ (FT_Module_Constructor)ft_smooth_init, /* module_init */ (FT_Module_Destructor) NULL, /* module_done */ (FT_Module_Requester) NULL, /* get_interface */ FT_GLYPH_FORMAT_OUTLINE, (FT_Renderer_RenderFunc) ft_smooth_render_lcd, /* render_glyph */ (FT_Renderer_TransformFunc)ft_smooth_transform, /* transform_glyph */ (FT_Renderer_GetCBoxFunc) ft_smooth_get_cbox, /* get_glyph_cbox */ (FT_Renderer_SetModeFunc) ft_smooth_set_mode, /* set_mode */ (FT_Raster_Funcs*)&FT_GRAYS_RASTER_GET /* raster_class */ ) FT_DEFINE_RENDERER( ft_smooth_lcdv_renderer_class, FT_MODULE_RENDERER, sizeof ( FT_RendererRec ), "smooth-lcdv", 0x10000L, 0x20000L, NULL, /* module specific interface */ (FT_Module_Constructor)ft_smooth_init, /* module_init */ (FT_Module_Destructor) NULL, /* module_done */ (FT_Module_Requester) NULL, /* get_interface */ FT_GLYPH_FORMAT_OUTLINE, (FT_Renderer_RenderFunc) ft_smooth_render_lcd_v, /* render_glyph */ (FT_Renderer_TransformFunc)ft_smooth_transform, /* transform_glyph */ (FT_Renderer_GetCBoxFunc) ft_smooth_get_cbox, /* get_glyph_cbox */ (FT_Renderer_SetModeFunc) ft_smooth_set_mode, /* set_mode */ (FT_Raster_Funcs*)&FT_GRAYS_RASTER_GET /* raster_class */ ) /* END */