ref: 9bbb3611b35b5619cca9b1eba5b6297597beccfa
parent: c6f394bf7d94b5a4d662bda68e9ed1c4310803c1
author: Anuj Verma <anujv@iitbhilai.ac.in>
date: Thu Aug 20 05:17:38 EDT 2020
[sdf] Add essential structures for the 'bsdf' rasterizer. * src/sdf/ftbsdf.c (ONE): New macro. (BSDF_TRaster, ED, BSDF_Worker): New structures. (zero_ed): New constant.
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
2020-08-20 Anuj Verma <anujv@iitbhilai.ac.in>
+ [sdf] Add essential structures for the 'bsdf' rasterizer.
+
+ * src/sdf/ftbsdf.c (ONE): New macro.
+ (BSDF_TRaster, ED, BSDF_Worker): New structures.
+ (zero_ed): New constant.
+
+2020-08-20 Anuj Verma <anujv@iitbhilai.ac.in>
+
[sdf] Add 'sdf' module to non-gnumake build systems.
* include/freetype/config/ftmodule.h: Add both the 'sfd' and 'bsfd'
--- a/src/sdf/ftbsdf.c
+++ b/src/sdf/ftbsdf.c
@@ -1,3 +1,132 @@
+#include <freetype/internal/ftobjs.h>
+#include <freetype/internal/ftdebug.h>
+#include <freetype/internal/ftmemory.h>
+#include <freetype/fttrigon.h>
+
+#include "ftsdf.h"
+#include "ftsdferrs.h"
+#include "ftsdfcommon.h"
+
+
+ /**************************************************************************
+ *
+ * useful macros
+ *
+ */
+
+#define ONE 65536 /* 1 in 16.16 */
+
+
+ /**************************************************************************
+ *
+ * structs
+ *
+ */
+
+
+ /**************************************************************************
+ *
+ * @Struct:
+ * BSDF_TRaster
+ *
+ * @Description:
+ * This struct is used in place of @FT_Raster and is stored within the
+ * internal FreeType renderer struct. While rasterizing this is passed
+ * to the @FT_Raster_RenderFunc function, which then can be used however
+ * we want.
+ *
+ * @Fields:
+ * memory ::
+ * Used internally to allocate intermediate memory while raterizing.
+ *
+ */
+ typedef struct BSDF_TRaster_
+ {+ FT_Memory memory;
+
+ } BSDF_TRaster;
+
+
+ /**************************************************************************
+ *
+ * @Struct:
+ * ED
+ *
+ * @Description:
+ * Euclidean distance. It gets used for Euclidean distance transforms;
+ * it can also be interpreted as an edge distance.
+ *
+ * @Fields:
+ * dist ::
+ * Vector length of the `near` parameter. Can be squared or absolute
+ * depending on the `USE_SQUARED_DISTANCES` macro defined in file
+ * `ftsdfcommon.h`.
+ *
+ * near ::
+ * Vector to the nearest edge. Can also be interpreted as shortest
+ * distance of a point.
+ *
+ * alpha ::
+ * Alpha value of the original bitmap from which we generate SDF.
+ * Needed for computing the gradient and determining the proper sign
+ * of a pixel.
+ *
+ */
+ typedef struct ED_
+ {+ FT_16D16 dist;
+ FT_16D16_Vec near;
+ FT_Byte alpha;
+
+ } ED;
+
+
+ /**************************************************************************
+ *
+ * @Struct:
+ * BSDF_Worker
+ *
+ * @Description:
+ * A convenience struct that is passed to functions while generating
+ * SDF; most of those functions require the same parameters.
+ *
+ * @Fields:
+ * distance_map ::
+ * A one-dimensional array that gets interpreted as two-dimensional
+ * one. It contains the Euclidean distances of all points of the
+ * bitmap.
+ *
+ * width ::
+ * Width of the above `distance_map`.
+ *
+ * rows ::
+ * Number of rows in the above `distance_map`.
+ *
+ * params ::
+ * Internal parameters and properties required by the rasterizer. See
+ * file `ftsdf.h` for more.
+ *
+ */
+ typedef struct BSDF_Worker_
+ {+ ED* distance_map;
+
+ FT_Int width;
+ FT_Int rows;
+
+ SDF_Raster_Params params;
+
+ } BSDF_Worker;
+
+
+ /**************************************************************************
+ *
+ * initializer
+ *
+ */
+
+ static const ED zero_ed = { 0, { 0, 0 }, 0 };+
/* END */