From 216270327d180b8f8edab11ba2a8469a1a62c2c3 Mon Sep 17 00:00:00 2001 From: Anuj Verma Date: Mon, 17 Aug 2020 11:40:57 +0530 Subject: [PATCH] [sdf] Add common elements for 'sdf' and 'bsdf' renderers. * src/sdf/ftsdfrend.h (SDF_Rendere_Module, ft_sdf_renderer_class, ft_bitmap_sdf_renderer_class): New structures. * src/sdf/ftsdfcommon.h (DEFAULT_SPREAD, MIN_SPREAD_MAX_SPREAD, USE_SQUARED_DISTANCES): New macros. (FT_INT_26D6, FT_INT_16D16, FT_26D6_16D16): New macros. (FT_CALL, VECTOR_LENGTH_16D16): New macros. (FT_26D6_Vec, FT_16D16_Vec, FT_16D16, FT_26D6, FT_6D10, FT_CBox): New typedefs. (square_root): New macro. * src/sdf/ftsdferrs.h: Add module error setup. --- ChangeLog | 17 +++++ src/sdf/ftsdfcommon.h | 143 ++++++++++++++++++++++++++++++++++++++++++ src/sdf/ftsdferrs.h | 9 +++ src/sdf/ftsdfrend.h | 89 ++++++++++++++++++++++++++ 4 files changed, 258 insertions(+) diff --git a/ChangeLog b/ChangeLog index b77634fab..ad0b9abe0 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,20 @@ +2020-08-17 Anuj Verma + + [sdf] Add common elements for 'sdf' and 'bsdf' renderers. + + * src/sdf/ftsdfrend.h (SDF_Rendere_Module, ft_sdf_renderer_class, + ft_bitmap_sdf_renderer_class): New structures. + + * src/sdf/ftsdfcommon.h (DEFAULT_SPREAD, MIN_SPREAD_MAX_SPREAD, + USE_SQUARED_DISTANCES): New macros. + (FT_INT_26D6, FT_INT_16D16, FT_26D6_16D16): New macros. + (FT_CALL, VECTOR_LENGTH_16D16): New macros. + (FT_26D6_Vec, FT_16D16_Vec, FT_16D16, FT_26D6, FT_6D10, FT_CBox): + New typedefs. + (square_root): New macro. + + * src/sdf/ftsdferrs.h: Add module error setup. + 2020-08-16 Anuj Verma [sdf] Add files for new 'sdf' module. diff --git a/src/sdf/ftsdfcommon.h b/src/sdf/ftsdfcommon.h index b8284ac68..22ec1d134 100644 --- a/src/sdf/ftsdfcommon.h +++ b/src/sdf/ftsdfcommon.h @@ -1,7 +1,150 @@ + /**************************************************** + * + * This file contains common functions and properties + * for both the 'sdf' and 'bsdf' renderers. + * + */ + #ifndef FTSDFCOMMON_H_ #define FTSDFCOMMON_H_ +#include +#include FT_CONFIG_CONFIG_H +#include + + +FT_BEGIN_HEADER + + + /************************************************************************** + * + * default values (cannot be set individually for each renderer) + * + */ + + /* default spread value */ +#define DEFAULT_SPREAD 8 + /* minimum spread supported by the renderer */ +#define MIN_SPREAD 2 + /* maximum spread supported by the renderer */ +#define MAX_SPREAD 32 + + + /************************************************************************** + * + * common definitions (cannot be set individually for each renderer) + * + */ + + /* If this macro is set to 1 the rasterizer uses squared distances for */ + /* computation. It can greatly improve the performance but there is a */ + /* chance of overflow and artifacts. You can safely use it up to a */ + /* pixel size of 128. */ +#ifndef USE_SQUARED_DISTANCES +#define USE_SQUARED_DISTANCES 0 +#endif + + + /************************************************************************** + * + * common macros + * + */ + + /* convert int to 26.6 fixed-point */ +#define FT_INT_26D6( x ) ( x * 64 ) + /* convert int to 16.16 fixed-point */ +#define FT_INT_16D16( x ) ( x * 65536 ) + /* convert 26.6 to 16.16 fixed-point */ +#define FT_26D6_16D16( x ) ( x * 1024 ) + + + /* Convenience macro to call a function; it */ + /* jumps to label `Exit` if an error occurs. */ +#define FT_CALL( x ) do \ + { \ + error = ( x ); \ + if ( error != FT_Err_Ok ) \ + goto Exit; \ + } while ( 0 ) + + + /* + * The macro `VECTOR_LENGTH_16D16` computes either squared distances or + * actual distances, depending on the value of `USE_SQUARED_DISTANCES`. + * + * By using squared distances the performance can be greatly improved but + * there is a risk of overflow. + */ +#if USE_SQUARED_DISTANCES +#define VECTOR_LENGTH_16D16( v ) ( FT_MulFix( v.x, v.x ) + \ + FT_MulFix( v.y, v.y ) ) +#else +#define VECTOR_LENGTH_16D16( v ) FT_Vector_Length( &v ) +#endif + + + /************************************************************************** + * + * common typedefs + * + */ + + typedef FT_Vector FT_26D6_Vec; /* with 26.6 fixed-point components */ + typedef FT_Vector FT_16D16_Vec; /* with 16.16 fixed-point components */ + + typedef FT_Fixed FT_16D16; /* 16.16 fixed-point representation */ + typedef FT_Fixed FT_26D6; /* 26.6 fixed-point representation */ + typedef FT_Short FT_6D10; /* 6.10 fixed-point representation */ + + typedef FT_BBox FT_CBox; /* control box of a curve */ + + + /************************************************************************** + * + * common functions + * + */ + + /* + * Original algorithm: + * + * https://github.com/chmike/fpsqrt + * + * Use this to compute the square root of a 16.16 fixed point number. + */ + static FT_16D16 + square_root( FT_16D16 val ) + { + FT_ULong t, q, b, r; + + + r = val; + b = 0x40000000L; + q = 0; + + while ( b > 0x40L ) + { + t = q + b; + + if ( r >= t ) + { + r -= t; + q = t + b; + } + + r <<= 1; + b >>= 1; + } + + q >>= 8; + + return q; + } + + +FT_END_HEADER #endif /* FTSDFCOMMON_H_ */ diff --git a/src/sdf/ftsdferrs.h b/src/sdf/ftsdferrs.h index d102e7fde..b9f412fe9 100644 --- a/src/sdf/ftsdferrs.h +++ b/src/sdf/ftsdferrs.h @@ -2,6 +2,15 @@ #ifndef FTSDFERRS_H_ #define FTSDFERRS_H_ +#include + +#undef FTERRORS_H_ + +#undef FT_ERR_PREFIX +#define FT_ERR_PREFIX Sdf_Err_ +#define FT_ERR_BASE FT_Mod_Err_Sdf + +#include #endif /* FTSDFERRS_H_ */ diff --git a/src/sdf/ftsdfrend.h b/src/sdf/ftsdfrend.h index 08cfa4ca2..00f02389c 100644 --- a/src/sdf/ftsdfrend.h +++ b/src/sdf/ftsdfrend.h @@ -2,6 +2,95 @@ #ifndef FTSDFREND_H_ #define FTSDFREND_H_ +#include +#include +#include + +FT_BEGIN_HEADER + + + /************************************************************************** + * + * @struct: + * SDF_Renderer_Module + * + * @description: + * This struct extends the native renderer struct `FT_RendererRec`. It + * is basically used to store various parameters required by the + * renderer and some additional parameters that can be used to tweak the + * output of the renderer. + * + * @fields: + * root :: + * The native rendere struct. + * + * spread :: + * This is an essential parameter/property required by the renderer. + * `spread` defines the maximum unsigned value that is present in the + * final SDF output. For the default value check file + * `ftsdfcommon.h`. + * + * flip_sign :: + * By default positive values indicate positions inside of contours, + * i.e., filled by a contour. If this property is true then that + * output will be the opposite of the default, i.e., negative values + * indicate positions inside of contours. + * + * flip_y :: + * Setting this parameter to true makes the output image flipped + * along the y-axis. + * + * overlaps :: + * Set this to true to generate SDF for glyphs having overlapping + * contours. The overlapping support is limited to glyphs that do not + * have self-intersecting contours. Also, removing overlaps require a + * considerable amount of extra memory; additionally, it will not work + * if generating SDF from bitmap. + * + * @note: + * All properties except `overlaps` are valid for both the 'sdf' and + * 'bsdf' renderers. + */ + typedef struct SDF_Renderer_Module_ + { + FT_RendererRec root; + FT_UInt spread; + FT_Bool flip_sign; + FT_Bool flip_y; + FT_Bool overlaps; + + } SDF_Renderer_Module, *SDF_Renderer; + + + /************************************************************************** + * + * @renderer: + * ft_sdf_renderer_class + * + * @description: + * Renderer to convert @FT_Outline to signed distance fields. + * + */ + FT_DECLARE_RENDERER( ft_sdf_renderer_class ) + + + /************************************************************************** + * + * @renderer: + * ft_bitmap_sdf_renderer_class + * + * @description: + * This is not exactly a renderer; it is just a converter that + * transforms bitmaps to signed distance fields. + * + * @note: + * This is not a separate module, it is part of the 'sdf' module. + * + */ + FT_DECLARE_RENDERER( ft_bitmap_sdf_renderer_class ) + + +FT_END_HEADER #endif /* FTSDFREND_H_ */