v0.1.0
Fast, portable C library for geometry input/output
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/examples/stl_read_file.c
/* -----------------------------------------------------------------------------
*
* Example: read a STL file
*
* Just give a filepath and an initialized gmio_stl_mesh_creator object to
* gmio_stl_read_file().
* The gmio_stl_mesh_creator object holds pointers to the callbacks invoked
* during the read operation.
* These callbacks creates the final mesh object.
*
* Note if you want to have control over the stream to be used, call
* gmio_stl_read() instead.
*
* -------------------------------------------------------------------------- */
#include <stdio.h>
#include <stdlib.h>
#include "3d_mesh.h"
/* Callback invoked at the beginning of mesh creation
* This is a good place to initialize your mesh object */
static void my_3d_mesh__begin_solid(
void* cookie, const struct gmio_stl_mesh_creator_infos* infos)
{
struct my_3d_mesh* my_mesh = (struct my_3d_mesh*)cookie;
size_t tri_count = 0;
if (infos->format == GMIO_STL_FORMAT_ASCII) /* Assume facet size ~230B */
tri_count = infos->stla_stream_size / 230;
else /* Binary STL */
tri_count = infos->stlb_triangle_count;
my_mesh->triangle_array =
(struct my_3d_triangle*)malloc(
tri_count * sizeof(struct my_3d_triangle));
my_mesh->triangle_array_count = 0;
my_mesh->triangle_array_capacity = tri_count;
}
/* Callback invoked sequentially for each triangle in the STL mesh */
static void my_3d_mesh__copy_triangle(
void* cookie,
uint32_t triangle_id,
const struct gmio_stl_triangle* triangle)
{
struct my_3d_mesh* my_mesh = (struct my_3d_mesh*)cookie;
if (triangle_id >= my_mesh->triangle_array_capacity) {
/* Capacity of the triangle array is too small, this can happen only
* when reading STL ascii data, where the count of triangles in not
* precisely known.
* To overcome this:
* - instead of just using general gmio_stl_read(), call
* call gmio_stl_infos_get(GMIO_STL_INFO_FLAG_FACET_COUNT) and then
* gmio_stla_read()
* - or just grow the capacity of your mesh, here the triangle array
* is grown by 12.5% */
size_t new_capacity = my_mesh->triangle_array_capacity;
new_capacity += new_capacity >> 3;
my_mesh->triangle_array =
(struct my_3d_triangle*)realloc(
my_mesh->triangle_array,
new_capacity * sizeof(struct my_3d_triangle));
my_mesh->triangle_array_capacity = new_capacity;
}
{ /* Copy new triangle */
struct my_3d_triangle* my_tri = &my_mesh->triangle_array[triangle_id];
const struct gmio_vec3f* tri_vertices = &triangle->v1;
int i;
for (i = 0; i < 3; ++i) {
my_tri->vertex[i].coords[0] = tri_vertices[i].x;
my_tri->vertex[i].coords[1] = tri_vertices[i].y;
my_tri->vertex[i].coords[2] = tri_vertices[i].z;
}
}
my_mesh->triangle_array_count = triangle_id + 1;
}
int main(int argc, char** argv)
{
int error = 0;
if (argc > 1) {
const char* filepath = argv[1];
struct my_3d_mesh my_mesh = {0};
struct gmio_stl_mesh_creator mesh_creator = {0};
/* Initialize the callback object */
mesh_creator.cookie = &my_mesh;
mesh_creator.func_begin_solid = my_3d_mesh__begin_solid;
mesh_creator.func_add_triangle = my_3d_mesh__copy_triangle;
/* Read, using default options(NULL) */
error = gmio_stl_read_file(filepath, &mesh_creator, NULL);
if (error != GMIO_ERROR_OK)
fprintf(stderr, "gmio error: 0x%X\n", error);
free(my_mesh.triangle_array);
}
return error;
}
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