/* Reads the contents of the file pointed to by stl->fp into the stl structure,
starting at facet first_facet. The second argument says if it's our first
time running this for the stl and therefore we should reset our max and min stats. */
void
stl_read(stl_file *stl, int first_facet, int first) {
stl_facet facet;
int i;
if (stl->error) return;
if(stl->stats.type == binary) {
fseek(stl->fp, HEADER_SIZE, SEEK_SET);
} else {
rewind(stl->fp);
}
for(i = first_facet; i < stl->stats.number_of_facets; i++) {
if(stl->stats.type == binary)
/* Read a single facet from a binary .STL file */
{
/* we assume little-endian architecture! */
if (fread(&facet.normal, sizeof(stl_normal), 1, stl->fp) \
+ fread(&facet.vertex, sizeof(stl_vertex), 3, stl->fp) \
+ fread(&facet.extra, sizeof(char), 2, stl->fp) != 6) {
perror("Cannot read facet");
stl->error = 1;
return;
}
} else
/* Read a single facet from an ASCII .STL file */
{
// skip solid/endsolid
// (in this order, otherwise it won't work when they are paired in the middle of a file)
fscanf(stl->fp, "endsolid\n");
fscanf(stl->fp, "solid%*[^\n]\n"); // name might contain spaces so %*s doesn't work and it also can be empty (just "solid")
if((fscanf(stl->fp, " facet normal %f %f %f\n", &facet.normal.x, &facet.normal.y, &facet.normal.z) + \
fscanf(stl->fp, " outer loop\n") + \
fscanf(stl->fp, " vertex %f %f %f\n", &facet.vertex[0].x, &facet.vertex[0].y, &facet.vertex[0].z) + \
fscanf(stl->fp, " vertex %f %f %f\n", &facet.vertex[1].x, &facet.vertex[1].y, &facet.vertex[1].z) + \
fscanf(stl->fp, " vertex %f %f %f\n", &facet.vertex[2].x, &facet.vertex[2].y, &facet.vertex[2].z) + \
fscanf(stl->fp, " endloop\n") + \
fscanf(stl->fp, " endfacet\n")) != 12) {
perror("Something is syntactically very wrong with this ASCII STL!");
stl->error = 1;
return;
}
}
/* Write the facet into memory. */
stl->facet_start[i] = facet;
stl_facet_stats(stl, facet, first);
first = 0;
}
stl->stats.size.x = stl->stats.max.x - stl->stats.min.x;
stl->stats.size.y = stl->stats.max.y - stl->stats.min.y;
stl->stats.size.z = stl->stats.max.z - stl->stats.min.z;
stl->stats.bounding_diameter = sqrt(
stl->stats.size.x * stl->stats.size.x +
stl->stats.size.y * stl->stats.size.y +
stl->stats.size.z * stl->stats.size.z
);
}
/* Reads the contents of the file pointed to by stl->fp into the stl structure,
starting at facet first_facet. The second argument says if it's our first
time running this for the stl and therefore we should reset our max and min stats. */
void
stl_read(stl_file *stl, int first_facet, int first) {
stl_facet facet;
int i;
if (stl->error) return;
if(stl->stats.type == binary) {
fseek(stl->fp, HEADER_SIZE, SEEK_SET);
} else {
rewind(stl->fp);
/* Skip the first line of the file */
while(getc(stl->fp) != '\n');
}
for(i = first_facet; i < stl->stats.number_of_facets; i++) {
if(stl->stats.type == binary)
/* Read a single facet from a binary .STL file */
{
/* we assume little-endian architecture! */
if (fread(&facet.normal, sizeof(stl_normal), 1, stl->fp) \
+ fread(&facet.vertex, sizeof(stl_vertex), 3, stl->fp) \
+ fread(&facet.extra, sizeof(char), 2, stl->fp) != 6) {
perror("Cannot read facet");
stl->error = 1;
return;
}
} else
/* Read a single facet from an ASCII .STL file */
{
if((fscanf(stl->fp, "%*s %*s %f %f %f\n", &facet.normal.x, &facet.normal.y, &facet.normal.z) + \
fscanf(stl->fp, "%*s %*s") + \
fscanf(stl->fp, "%*s %f %f %f\n", &facet.vertex[0].x, &facet.vertex[0].y, &facet.vertex[0].z) + \
fscanf(stl->fp, "%*s %f %f %f\n", &facet.vertex[1].x, &facet.vertex[1].y, &facet.vertex[1].z) + \
fscanf(stl->fp, "%*s %f %f %f\n", &facet.vertex[2].x, &facet.vertex[2].y, &facet.vertex[2].z) + \
fscanf(stl->fp, "%*s") + \
fscanf(stl->fp, "%*s")) != 12) {
perror("Something is syntactically very wrong with this ASCII STL!");
stl->error = 1;
return;
}
}
/* Write the facet into memory. */
stl->facet_start[i] = facet;
stl_facet_stats(stl, facet, first);
first = 0;
}
stl->stats.size.x = stl->stats.max.x - stl->stats.min.x;
stl->stats.size.y = stl->stats.max.y - stl->stats.min.y;
stl->stats.size.z = stl->stats.max.z - stl->stats.min.z;
stl->stats.bounding_diameter = sqrt(
stl->stats.size.x * stl->stats.size.x +
stl->stats.size.y * stl->stats.size.y +
stl->stats.size.z * stl->stats.size.z
);
}
static void
stl_read(stl_file *stl, int first_facet, int first)
{
stl_facet facet;
int i;
if(stl->stats.type == binary)
{
fseek(stl->fp, HEADER_SIZE, SEEK_SET);
}
else
{
rewind(stl->fp);
/* Skip the first line of the file */
while(getc(stl->fp) != '\n');
}
for(i = first_facet; i < stl->stats.number_of_facets; i++)
{
if(stl->stats.type == binary)
/* Read a single facet from a binary .STL file */
{
facet.normal.x = stl_get_little_float(stl->fp);
facet.normal.y = stl_get_little_float(stl->fp);
facet.normal.z = stl_get_little_float(stl->fp);
facet.vertex[0].x = stl_get_little_float(stl->fp);
facet.vertex[0].y = stl_get_little_float(stl->fp);
facet.vertex[0].z = stl_get_little_float(stl->fp);
facet.vertex[1].x = stl_get_little_float(stl->fp);
facet.vertex[1].y = stl_get_little_float(stl->fp);
facet.vertex[1].z = stl_get_little_float(stl->fp);
facet.vertex[2].x = stl_get_little_float(stl->fp);
facet.vertex[2].y = stl_get_little_float(stl->fp);
facet.vertex[2].z = stl_get_little_float(stl->fp);
facet.extra[0] = fgetc(stl->fp);
facet.extra[1] = fgetc(stl->fp);
}
else
/* Read a single facet from an ASCII .STL file */
{
fscanf(stl->fp, "%*s %*s %f %f %f\n", &facet.normal.x,
&facet.normal.y, &facet.normal.z);
fscanf(stl->fp, "%*s %*s");
fscanf(stl->fp, "%*s %f %f %f\n", &facet.vertex[0].x,
&facet.vertex[0].y, &facet.vertex[0].z);
fscanf(stl->fp, "%*s %f %f %f\n", &facet.vertex[1].x,
&facet.vertex[1].y, &facet.vertex[1].z);
fscanf(stl->fp, "%*s %f %f %f\n", &facet.vertex[2].x,
&facet.vertex[2].y, &facet.vertex[2].z);
fscanf(stl->fp, "%*s");
fscanf(stl->fp, "%*s");
}
/* Write the facet into memory. */
stl->facet_start[i] = facet;
stl_facet_stats(stl, facet, first);
first = 0;
}
stl->stats.size.x = stl->stats.max.x - stl->stats.min.x;
stl->stats.size.y = stl->stats.max.y - stl->stats.min.y;
stl->stats.size.z = stl->stats.max.z - stl->stats.min.z;
stl->stats.bounding_diameter = sqrt(
stl->stats.size.x * stl->stats.size.x +
stl->stats.size.y * stl->stats.size.y +
stl->stats.size.z * stl->stats.size.z
);
}
/* Reads the contents of the file pointed to by stl->fp into the stl structure,
starting at facet first_facet. The second argument says if it's our first
time running this for the stl and therefore we should reset our max and min stats. */
void
stl_read(stl_file *stl, int first_facet, int first) {
stl_facet facet;
int i;
if (stl->error) return;
if(stl->stats.type == binary) {
fseek(stl->fp, HEADER_SIZE, SEEK_SET);
} else {
rewind(stl->fp);
}
for(i = first_facet; i < stl->stats.number_of_facets; i++) {
if(stl->stats.type == binary)
/* Read a single facet from a binary .STL file */
{
/* we assume little-endian architecture! */
if (fread(&facet, 1, SIZEOF_STL_FACET, stl->fp) != SIZEOF_STL_FACET) {
stl->error = 1;
return;
}
} else
/* Read a single facet from an ASCII .STL file */
{
// skip solid/endsolid
// (in this order, otherwise it won't work when they are paired in the middle of a file)
fscanf(stl->fp, "endsolid\n");
fscanf(stl->fp, "solid%*[^\n]\n"); // name might contain spaces so %*s doesn't work and it also can be empty (just "solid")
if((fscanf(stl->fp, " facet normal %f %f %f\n", &facet.normal.x, &facet.normal.y, &facet.normal.z) + \
fscanf(stl->fp, " outer loop\n") + \
fscanf(stl->fp, " vertex %f %f %f\n", &facet.vertex[0].x, &facet.vertex[0].y, &facet.vertex[0].z) + \
fscanf(stl->fp, " vertex %f %f %f\n", &facet.vertex[1].x, &facet.vertex[1].y, &facet.vertex[1].z) + \
fscanf(stl->fp, " vertex %f %f %f\n", &facet.vertex[2].x, &facet.vertex[2].y, &facet.vertex[2].z) + \
fscanf(stl->fp, " endloop\n") + \
fscanf(stl->fp, " endfacet\n")) != 12) {
perror("Something is syntactically very wrong with this ASCII STL!");
stl->error = 1;
return;
}
}
#if 0
// Report close to zero vertex coordinates. Due to the nature of the floating point numbers,
// close to zero values may be represented with singificantly higher precision than the rest of the vertices.
// It may be worth to round these numbers to zero during loading to reduce the number of errors reported
// during the STL import.
for (size_t j = 0; j < 3; ++ j) {
if (facet.vertex[j].x > -1e-12f && facet.vertex[j].x < 1e-12f)
printf("stl_read: facet %d.x = %e\r\n", j, facet.vertex[j].x);
if (facet.vertex[j].y > -1e-12f && facet.vertex[j].y < 1e-12f)
printf("stl_read: facet %d.y = %e\r\n", j, facet.vertex[j].y);
if (facet.vertex[j].z > -1e-12f && facet.vertex[j].z < 1e-12f)
printf("stl_read: facet %d.z = %e\r\n", j, facet.vertex[j].z);
}
#endif
#if 1
{
// Positive and negative zeros are possible in the floats, which are considered equal by the FP unit.
// When using a memcmp on raw floats, those numbers report to be different.
// Unify all +0 and -0 to +0 to make the floats equal under memcmp.
uint32_t *f = (uint32_t*)&facet;
for (int j = 0; j < 12; ++ j, ++ f) // 3x vertex + normal: 4x3 = 12 floats
if (*f == 0x80000000)
// Negative zero, switch to positive zero.
*f = 0;
}
#else
{
// Due to the nature of the floating point numbers, close to zero values may be represented with singificantly higher precision
// than the rest of the vertices. Round them to zero.
float *f = (float*)&facet;
for (int j = 0; j < 12; ++ j, ++ f) // 3x vertex + normal: 4x3 = 12 floats
if (*f > -1e-12f && *f < 1e-12f)
// Negative zero, switch to positive zero.
*f = 0;
}
#endif
/* Write the facet into memory. */
memcpy(stl->facet_start+i, &facet, SIZEOF_STL_FACET);
stl_facet_stats(stl, facet, first);
first = 0;
}
stl->stats.size.x = stl->stats.max.x - stl->stats.min.x;
stl->stats.size.y = stl->stats.max.y - stl->stats.min.y;
stl->stats.size.z = stl->stats.max.z - stl->stats.min.z;
stl->stats.bounding_diameter = sqrt(
stl->stats.size.x * stl->stats.size.x +
stl->stats.size.y * stl->stats.size.y +
stl->stats.size.z * stl->stats.size.z
);
}
