* include/freetype/internal/ftobjs.h (ft_glyphslot_preset_bitmap):
Change return type.
* src/base/ftobjs.c (ft_glyphslot_preset_bitmap): Return the bitmap
size assessment.
* src/raster/ftrend1.c (ft_raster1_render): Use it to refuse the
rendering of enourmous or far-fetched outlines.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Ditto.
This monster commit was created by applying Nikhil's scripts
`docconverter.py' and `markify.py' to all C header and source files,
followed up by minor manual clean-up.
No change in functionality, of course.
I used commit f7419907bc6044b9b7057f9789866426c804ba82 from
https://github.com/nikramakrishnan/freetype-docs.git.
This generalizes magic outline shifts that make Harmony LCD
rendering work in terms of precise two-dimensional RGB subpixel
positions. These coordinates are now set in time of the `smooth'
module initialization and later used to shift a glyph outline for
rendering. FT_RENDER_MODE_LCD and FT_RENDER_MODE_LCD_V use the same
coordinates. The letter, however, rotates them before using.
The LCD bitmap padding is also calculated using these coordinates.
* include/freetype/internal/ftobjs.h (FT_LibraryRec): New array field
`lcd_geometry'.
* src/base/ftlcdfil.c (ft_lcd_padding): Reworked.
* src/base/ftobjs.c (ft_glyphslot_preset_bitmap): Updated accordingly.
* src/smooth/ftsmooth.c [!FT_CONFIG_OPTION_SUBPIXEL_RENDERING]
(ft_smooth_init): Initialize `lcd_geometry'.
(ft_smooth_render_generic): Formalize outline shifts.
*/* [FT_CONFIG_OPTION_PIC]: Remove all code guarded by this
preprocessor symbol.
*/*: Replace `XXX_GET' macros (which could be either a function in
PIC mode or an array in non-PIC mode) with `xxx' arrays.
* include/freetype/internal/ftpic.h, src/autofit/afpic.c,
src/autofit/afpic.h, src/base/basepic.c, src/base/basepic.h,
src/base/ftpic.c, src/cff/cffpic.c, src/cff/cffpic.h,
src/pshinter/pshpic.c, src/pshinter/pshpic.h, src/psnames/pspic.c,
src/psnames/pspic.h, src/raster/rastpic.c, src/raster/rastpic.h,
src/sfnt/sfntpic.c, src/sfnt/sfntpic.h, src/smooth/ftspic.c,
src/smooth/ftspic.h, src/truetype/ttpic.c, src/truetype/ttpic.h:
Removed.
* src/raster/ftrend1.c (ft_raster1_render): Clean up the exit.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Reduce
translations and clean up the exit.
(ft_smooth_render_lcd, ft_smooth_render_lcd): Remove unused `error'..
This mainly just extracts the code for presetting the bitmap metrics
from the monochrome, grayscale, and LCD renderers into a separate
function.
* src/base/ftobjs.c (ft_glyphslot_preset_bitmap): New function that
calculates prespective bitmap metrics for the given rendering mode.
* include/freetype/internal/ftobjs.h (ft_glyphslot_preset_bitmap):
Declare it.
* src/base/ftlcdfil.c (ft_lcd_padding): New helper function that adds
padding to CBox taking into account pecularities of LCD rendering.
* include/freetype/ftlcdfil.h (ft_lcd_padding): Declare it.
* src/raster/ftrend1.c (ft_raster1_render): Reworked to use
`ft_glyphslot_preset_bitmap'.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Ditto.
(ft_smooth_render_lcd, ft_smooth_render_lcd): The pixel_mode setting
is moved to `ft_glyphslot_preset_bitmap'.
Thing are simpler with a NULL-function pointer.
* include/freetype/internal/ftobjs.h (FT_Face_InternalRec): New
pointer to the filter function.
(FT_LibraryRec): Remove unused `lcd_filter'.
(FT_Bitmap_LcdFilterFunc, ft_lcd_filter_fir): Move from here...
* include/freetype/ftlcdfil.h (FT_Bitmap_LcdFilterFunc,
ft_lcd_filter_fir): ... to here.
* src/base/ftobjs.c (ft_open_face_internal): NULL-initialize the
per-face filter.
(FT_Face_Properties): Set it.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Simplify.
* src/base/ftlcdfil.c (ft_lcd_filter_fir, FT_Libary_SetLcdFilter):
Minor.
This is a new technology for LCD-optimized rendering. It capitalizes
on the fact that each color channel grid is shifted by a third of a
pixel. Therefore it is logical to render 3 separate monochrome
bitmaps shifting the outline by 1/3 pixel, and then combine them.
Importantly, the resulting output does not require additional LCD
filtering.
* src/smooth/ftsmooth.c (ft_smooth_render_generic)
[!FT_CONFIG_OPTION_SUBPIXEL_RENDERING]: Implement new LCD-optimized
rendering.
* include/freetype/ftlcdfil.h, include/freetype/freetype.h,
include/freetype/config/ftoption.h, devel/ftoption.h: Updated
documentation.
Extra bitmap padding for LCD filtering depends on the filter. The
default 5-tap filter needs 2 extra subpixels. The light 3-tap filter
needs only 1 extra subpixel. This space could be already available
due to rounding. In order to optimize the padding, we now expand
CBox for the given filter weights before rounding.
This change breakes current Skia (and Firefox).
* include/freetype/internal/ftobjs.h (FT_LibraryRec)
[FT_CONFIG_OPTION_SUBPIXEL_RENDERING]: Remove `lcd_extra' field.
* src/base/ftlcdfil.c (FT_Library_SetLcdFilterWeights,
FT_Library_SetLcdFilter): Remove `lcd_extra' initializations.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Implement dymanic
LCD padding.
This mode uses fractional advance widths and doesn't scale glyphs
horizontally, only applying vertical scaling and hinting.
At the same time, the behaviour of the `light' auto-hinter gets
restored for backwards compatibility: Both vertical and horizontal
scaling is again based on rounded metrics values (this was changed
in a commit from 2017-03-30 as a side effect). To be more precise,
the behaviour is restored for TrueType fonts only; for other font
formats like Type 1, this is a new feature of the `light' hinting
mode.
* include/freetype/freetype.h (FT_LOAD_TARGET_SLIGHT): New macro.
(FT_RENDER_MODE_SLIGHT): New render mode.
* include/freetype/internal/ftobjs.h (FT_Size_InternalRec): Add
`autohint_mode' and `autohint_metrics' fields.
* src/autofit/afcjk.c (af_cjk_hints_init), src/autofit/aflatin.c
(af_latin_hints_init), src/autofit/aflatin2 (af_latin2_hints_init):
Updated.
* src/autofit/afloader.c (af_loader_embolden_glyph_in_slot): Use
`autohint_metrics'.
(af_loader_load_glyph): s/internal/slot_internal/.
Initialize `autohint_metrics' and `autohint_mode' depending on
current auto-hint mode.
Use `autohint_metrics'.
Updated.
* src/base/ftadvanc.c (LOAD_ADVANCE_FAST_CHECK): Updated.
* src/base/ftobjs.c (FT_Load_Glyph): Updated.
(FT_New_Size): Allocate `internal' object.
* src/pshinter/pshalgo.c (ps_hints_apply): Updated.
* src/smooth/ftsmooth.c (ft_smooth_render): Updated.
suggested by Alexei.
* src/pfr/pfrsbit.c (pfr_slot_load_bitmap): Prevent too
negative values in `xpos' and `ypos + ysize'.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Prevent
too negative values in `x_left' and `y_top'. Either negative
values in `width' and `height' are checked.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Translate origin
virtually by modifying cbox, actually translate outline if cumulative
shift is not zero.
This is essentially a mechanical conversion, adding inclusion of
`FT_INTERNAL_DEBUG_H' where necessary, and providing the macros for
stand-alone compiling modes of the rasterizer modules.
To convert the remaining occurrences of FT_Err_XXX and friends it is
necessary to rewrite the code. Note, however, that it doesn't harm
if some cases are not handled since FT_THROW is a no-op.
* src/smooth/ftsmooth.c (ft_smooth_render_generic): Use `FT_Pos'
instead of `FT_UInt' for some variables and update comparisons
accordingly. A detailed analysis can be found in the bug report.
Werner Lemberg