gmio_stl: add option "stl_write_triangles_only" and function gmio_stlb_write_header()

src/gmio_stl/internal/stla_write.c

@@ -129,10 +129,7 @@ static gmio_bool_t gmio_transfer_flush_buffer(gmio_transfer_t* trsf, size_t n)
 int gmio_stla_write(
         gmio_transfer_t* trsf,
         const gmio_stl_mesh_t* mesh,
-        /* Options */
+        const gmio_stl_write_options_t *options)
-        const char* solid_name,
-        gmio_float_text_format_t float32_format,
-        uint8_t float32_prec)
 {
     /* Constants */
     const uint32_t total_facet_count = mesh != NULL ? mesh->triangle_count : 0;
@@ -140,6 +137,16 @@ int gmio_stla_write(
             trsf != NULL ?
                 gmio_size_to_uint32(trsf->buffer.size / GMIO_STLA_FACET_SIZE_P2)
               : 0;
+    const char* solid_name =
+            options != NULL ? options->stla_solid_name : NULL;
+    const gmio_float_text_format_t float32_format =
+            options != NULL ?
+                options->stla_float32_format :
+                GMIO_FLOAT_TEXT_FORMAT_DECIMAL_LOWERCASE;
+    const uint8_t float32_prec =
+            options != NULL ? options->stla_float32_prec : 9;
+    const gmio_bool_t write_triangles_only =
+            options != NULL ? options->stl_write_triangles_only : GMIO_FALSE;
     /* Variables */
     uint32_t ifacet = 0;
     void* buffer_ptr = trsf != NULL ? trsf->buffer.ptr : NULL;
@@ -171,7 +178,7 @@ int gmio_stla_write(
     }
 
     /* Write solid declaration */
-    {
+    if (!write_triangles_only) {
         buffc = gmio_write_string(buffc, "solid ");
         buffc = gmio_write_string_eol(buffc, solid_name);
         if (!gmio_transfer_flush_buffer(trsf, buffc - (char*)buffer_ptr))
@@ -225,7 +232,7 @@ int gmio_stla_write(
     } /* end for (ifacet) */
 
     /* Write end of solid */
-    if (gmio_no_error(error)) {
+    if (gmio_no_error(error) && !write_triangles_only) {
         buffc = gmio_write_string(trsf->buffer.ptr, "endsolid ");
         buffc = gmio_write_string_eol(buffc, solid_name);
         if (!gmio_transfer_flush_buffer(trsf, buffc - (char*)buffer_ptr))

src/gmio_stl/internal/stla_write.h

@@ -17,6 +17,7 @@
 #define GMIO_INTERNAL_STLA_WRITE_H
 
 #include "../stl_mesh.h"
+#include "../stl_io_options.h"
 #include "../../gmio_core/text_format.h"
 #include "../../gmio_core/transfer.h"
 
@@ -29,9 +30,6 @@
 int gmio_stla_write(
         gmio_transfer_t* trsf,
         const gmio_stl_mesh_t* mesh,
-        /* Options */
+        const gmio_stl_write_options_t* options);
-        const char* solid_name,
-        gmio_float_text_format_t float32_format,
-        uint8_t float32_prec);
 
 #endif /* GMIO_INTERNAL_STLA_WRITE_H */

src/gmio_stl/internal/stlb_write.c

@@ -18,6 +18,7 @@
 #include "stl_rw_common.h"
 #include "stlb_byte_swap.h"
 #include "../stl_error.h"
+#include "../stl_io.h"
 
 #include "../../gmio_core/error.h"
 #include "../../gmio_core/internal/byte_codec.h"
@@ -67,13 +68,14 @@ static void gmio_stlb_write_facets(
 int gmio_stlb_write(
         gmio_transfer_t* trsf,
         const gmio_stl_mesh_t* mesh,
-        /* Options */
+        const gmio_stl_write_options_t* options,
-        const uint8_t* header_data,
         gmio_endianness_t byte_order)
 {
     /* Constants */
     const uint32_t facet_count =
             mesh != NULL ? mesh->triangle_count : 0;
+    const gmio_bool_t write_triangles_only =
+            options != NULL ? options->stl_write_triangles_only : GMIO_FALSE;
     /* Variables */
     void* buffer_ptr = trsf != NULL ? trsf->buffer.ptr : NULL;
     gmio_stlb_readwrite_helper_t wparams = {0};
@@ -92,25 +94,15 @@ int gmio_stlb_write(
     wparams.facet_count = gmio_size_to_uint32(
                 trsf->buffer.size / GMIO_STLB_TRIANGLE_RAWSIZE);
 
-    /* Write header */
+    if (!write_triangles_only) {
-    if (header_data == NULL) {
+        error = gmio_stlb_write_header(
-        /* Use buffer to store an empty header (filled with zeroes) */
+                    &trsf->stream,
-        memset(buffer_ptr, 0, GMIO_STLB_HEADER_SIZE);
+                    byte_order,
-        header_data = (const uint8_t*)buffer_ptr;
+                    options != NULL ? options->stlb_header_data : NULL,
+                    facet_count);
+        if (gmio_error(error))
+            return error;
     }
-    if (gmio_stream_write(&trsf->stream, header_data, GMIO_STLB_HEADER_SIZE, 1)
-            != 1)
-    {
-        return GMIO_ERROR_STREAM;
-    }
-
-    /* Write facet count */
-    if (byte_order == GMIO_ENDIANNESS_LITTLE)
-        gmio_encode_uint32_le(facet_count, buffer_ptr);
-    else
-        gmio_encode_uint32_be(facet_count, buffer_ptr);
-    if (gmio_stream_write(&trsf->stream, buffer_ptr, sizeof(uint32_t), 1) != 1)
-        return GMIO_ERROR_STREAM;
 
     /* Write triangles */
     for (i_facet = 0;

src/gmio_stl/internal/stlb_write.h

@@ -17,6 +17,7 @@
 #define GMIO_INTERNAL_STLB_WRITE_H
 
 #include "../stl_mesh.h"
+#include "../stl_io_options.h"
 #include "../../gmio_core/endian.h"
 #include "../../gmio_core/transfer.h"
 
@@ -29,8 +30,7 @@
 int gmio_stlb_write(
         gmio_transfer_t* trsf,
         const gmio_stl_mesh_t* mesh,
-        /* Options */
+        const gmio_stl_write_options_t* options,
-        const uint8_t* header_data,
         gmio_endianness_t byte_order);
 
 #endif /* GMIO_INTERNAL_STLB_WRITE_H */

src/gmio_stl/stl_io.c

@@ -22,6 +22,7 @@
 #include "../gmio_core/error.h"
 #include "../gmio_core/stream.h"
 #include "../gmio_core/transfer.h"
+#include "../gmio_core/internal/byte_codec.h"
 #include "../gmio_core/internal/helper_stream.h"
 
 int gmio_stl_read_file(
@@ -118,32 +119,20 @@ int gmio_stl_write(
         const gmio_stl_mesh_t *mesh,
         const gmio_stl_write_options_t *options)
 {
-    const uint8_t* header_data =
-            options != NULL ? options->stlb_header_data : NULL;
     int error = GMIO_ERROR_OK;
 
     if (trsf != NULL) {
         switch (format) {
         case GMIO_STL_FORMAT_ASCII: {
-            const char* solid_name =
+            error = gmio_stla_write(trsf, mesh, options);
-                    options != NULL ? options->stla_solid_name : NULL;
-            const gmio_float_text_format_t float_fmt =
-                    options != NULL ? options->stla_float32_format :
-                                      GMIO_FLOAT_TEXT_FORMAT_DECIMAL_LOWERCASE;
-            const uint8_t float_prec =
-                    options != NULL ? options->stla_float32_prec : 9;
-            error = gmio_stla_write(
-                        trsf, mesh, solid_name, float_fmt, float_prec);
             break;
         }
         case GMIO_STL_FORMAT_BINARY_BE: {
-            error = gmio_stlb_write(
+            error = gmio_stlb_write(trsf, mesh, options, GMIO_ENDIANNESS_BIG);
-                        trsf, mesh, header_data, GMIO_ENDIANNESS_BIG);
             break;
         }
         case GMIO_STL_FORMAT_BINARY_LE: {
-            error = gmio_stlb_write(
+            error = gmio_stlb_write(trsf, mesh, options, GMIO_ENDIANNESS_LITTLE);
-                        trsf, mesh, header_data, GMIO_ENDIANNESS_LITTLE);
             break;
         }
         case GMIO_STL_FORMAT_UNKNOWN: {
@@ -157,3 +146,36 @@ int gmio_stl_write(
 
     return error;
 }
+
+static const uint8_t internal_stlb_zero_header[GMIO_STLB_HEADER_SIZE] = { 0 };
+
+int gmio_stlb_write_header(
+        gmio_stream_t *stream,
+        gmio_endianness_t byte_order,
+        const uint8_t *header,
+        uint32_t facet_count)
+{
+    uint8_t facet_count_bytes[sizeof(uint32_t)];
+    const uint8_t* non_null_header =
+            header != NULL ? header : &internal_stlb_zero_header[0];
+
+    /* Write 80-byte header */
+    if (gmio_stream_write(stream, non_null_header, GMIO_STLB_HEADER_SIZE, 1)
+            != 1)
+    {
+        return GMIO_ERROR_STREAM;
+    }
+
+    /* Write facet count */
+    if (byte_order == GMIO_ENDIANNESS_LITTLE)
+        gmio_encode_uint32_le(facet_count, &facet_count_bytes[0]);
+    else
+        gmio_encode_uint32_be(facet_count, &facet_count_bytes[0]);
+    if (gmio_stream_write(stream, &facet_count_bytes[0], sizeof(uint32_t), 1)
+            != 1)
+    {
+        return GMIO_ERROR_STREAM;
+    }
+
+    return GMIO_ERROR_OK;
+}

src/gmio_stl/stl_io.h

@@ -141,6 +141,27 @@ int gmio_stlb_read(
         gmio_stl_mesh_creator_t* creator,
         gmio_endianness_t byte_order);
 
+/*! Writes STL binary header data to stream
+ *
+ *  This functions only writes the 80-bytes header array and the count of facets
+ *  in the mesh(with respect of the specified byte order).
+ *
+ *  \param stream Output stream where is written the header data
+ *  \param byte_order Byte order of the output STL data
+ *  \param header 80-bytes array of header data, can be safely set to NULL (to
+ *         generate an array of zeroes)
+ *  \param facet_count Total count of facets (triangles) in the mesh to be
+ *         written
+ *
+ *  \return Error code (see error.h and stl_error.h)
+ */
+GMIO_LIBSTL_EXPORT
+int gmio_stlb_write_header(
+        gmio_stream_t* stream,
+        gmio_endianness_t byte_order,
+        const uint8_t* header,
+        uint32_t facet_count);
+
 GMIO_C_LINKAGE_END
 
 #endif /* GMIO_STL_IO_H */

src/gmio_stl/stl_io_options.h

@@ -27,6 +27,17 @@
 /*! Options for gmio_stl_write() */
 struct gmio_stl_write_options
 {
+    /*! Flag allowing to skip writting of any header/footer data, but just
+     *  triangles
+     *
+     *  If set to \c GMIO_TRUE then :
+     *    \li for STL ASCII format, <tt>"solid <name>"</tt> and
+     *        <tt>"endsolid"</tt> will no be written to output stream
+     *    \li for STL binary format, the 80 bytes header followed bt the mesh
+     *        facet count (4bytes) will no be written to output stream
+     */
+    gmio_bool_t stl_write_triangles_only;
+
     /*! Name of the solid to appear in "solid <name> \n facet normal ..."
      *
      *  Option useful only with STL ascii format (GMIO_STL_FORMAT_ASCII).
@@ -54,7 +65,7 @@ struct gmio_stl_write_options
      */
     uint8_t stla_float32_prec;
 
-    /*! Header data consisting of 80 bytes
+    /*! Header data whose first 80 bytes have to be written
      *
      *  Option useful only with STL binary formats (GMIO_STL_FORMAT_BINARY_LE
      *  or GMIO_STL_FORMAT_BINARY_BE).