bullet3/examples/Importers/ImportSTLDemo/LoadMeshFromSTL.h

110 lines
2.8 KiB
C

#ifndef LOAD_MESH_FROM_STL_H
#define LOAD_MESH_FROM_STL_H
#include "../../OpenGLWindow/GLInstanceGraphicsShape.h"
#include <stdio.h> //fopen
#include "Bullet3Common/b3AlignedObjectArray.h"
struct MySTLTriangle
{
float normal[3];
float vertex0[3];
float vertex1[3];
float vertex2[3];
};
static GLInstanceGraphicsShape* LoadMeshFromSTL(const char* relativeFileName)
{
GLInstanceGraphicsShape* shape = 0;
FILE* file = fopen(relativeFileName,"rb");
if (file)
{
int size=0;
if (fseek(file, 0, SEEK_END) || (size = ftell(file)) == EOF || fseek(file, 0, SEEK_SET))
{
b3Warning("Error: Cannot access file to determine size of %s\n", relativeFileName);
} else
{
if (size)
{
//b3Warning("Open STL file of %d bytes\n",size);
char* memoryBuffer = new char[size+1];
int actualBytesRead = fread(memoryBuffer,1,size,file);
if (actualBytesRead!=size)
{
b3Warning("Error reading from file %s",relativeFileName);
} else
{
int numTriangles = *(int*)&memoryBuffer[80];
if (numTriangles)
{
{
//perform a sanity check instead of crashing on invalid triangles/STL files
int expectedBinaryFileSize = numTriangles* 50 + 84;
if (expectedBinaryFileSize != size)
{
return 0;
}
}
shape = new GLInstanceGraphicsShape;
// b3AlignedObjectArray<GLInstanceVertex>* m_vertices;
// int m_numvertices;
// b3AlignedObjectArray<int>* m_indices;
// int m_numIndices;
// float m_scaling[4];
shape->m_scaling[0] = 1;
shape->m_scaling[1] = 1;
shape->m_scaling[2] = 1;
shape->m_scaling[3] = 1;
int index = 0;
shape->m_indices = new b3AlignedObjectArray<int>();
shape->m_vertices = new b3AlignedObjectArray<GLInstanceVertex>();
for (int i=0;i<numTriangles;i++)
{
char* curPtr = &memoryBuffer[84+i*50];
MySTLTriangle tmp;
memcpy(&tmp,curPtr,sizeof(MySTLTriangle));
GLInstanceVertex v0,v1,v2;
v0.uv[0] = v1.uv[0] = v2.uv[0] = 0.5;
v0.uv[1] = v1.uv[1] = v2.uv[1] = 0.5;
for (int v=0;v<3;v++)
{
v0.xyzw[v] = tmp.vertex0[v];
v1.xyzw[v] = tmp.vertex1[v];
v2.xyzw[v] = tmp.vertex2[v];
v0.normal[v] = v1.normal[v] = v2.normal[v] = tmp.normal[v];
}
v0.xyzw[3] = v1.xyzw[3] = v2.xyzw[3] = 0.f;
shape->m_vertices->push_back(v0);
shape->m_vertices->push_back(v1);
shape->m_vertices->push_back(v2);
shape->m_indices->push_back(index++);
shape->m_indices->push_back(index++);
shape->m_indices->push_back(index++);
}
}
}
delete[] memoryBuffer;
}
}
fclose(file);
}
if (shape)
{
shape->m_numIndices = shape->m_indices->size();
shape->m_numvertices = shape->m_vertices->size();
}
return shape;
}
#endif //LOAD_MESH_FROM_STL_H