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/** CSci-4611 Assignment 5: Art Render
*/
#include "edge_mesh.h"
EdgeMesh::EdgeMesh() : gpuDirty_(true), vertexBuffer_(0), vertexArray_(0), elementBuffer_(0)
{
}
EdgeMesh::~EdgeMesh() {
}
void EdgeMesh::CreateFromMesh(const Mesh &mesh) {
// temp data holders for use while constructing the mesh in an indexed primitives mode
std::vector<Point3> vertices; // vertex positions
std::vector<Vector3> normals; // vertex normals
std::vector<Vector3> leftNormals, rightNormals; // normals of adj. faces
std::vector< std::vector<unsigned int> > triangles; // fin triangles
for (int t = 0; t < mesh.num_triangles(); t++) {
std::vector<unsigned int> tri = mesh.read_triangle_indices_data(t);
Point3 a = mesh.read_vertex_data(tri[0]);
Point3 b = mesh.read_vertex_data(tri[1]);
Point3 c = mesh.read_vertex_data(tri[2]);
Vector3 e1 = b-a;
e1.Normalize();
Vector3 e2 = c-a;
e2.Normalize();
Vector3 n = e1.Cross(e2);
//Vector3 n = ((b-a).cross(c-a)).to_unit();
//std::cout << n << std::endl;
addEdge(&vertices, &normals, &leftNormals, &rightNormals, &triangles, mesh, tri[0], tri[1], n);
addEdge(&vertices, &normals, &leftNormals, &rightNormals, &triangles, mesh, tri[1], tri[2], n);
addEdge(&vertices, &normals, &leftNormals, &rightNormals, &triangles, mesh, tri[2], tri[0], n);
}
// now transfer data to the member variable data holders
for (int i=0; i<vertices.size(); i++) {
verts_.push_back(vertices[i][0]);
verts_.push_back(vertices[i][1]);
verts_.push_back(vertices[i][2]);
norms_.push_back(normals[i][0]);
norms_.push_back(normals[i][1]);
norms_.push_back(normals[i][2]);
leftNorms_.push_back(leftNormals[i][0]);
leftNorms_.push_back(leftNormals[i][1]);
leftNorms_.push_back(leftNormals[i][2]);
rightNorms_.push_back(rightNormals[i][0]);
rightNorms_.push_back(rightNormals[i][1]);
rightNorms_.push_back(rightNormals[i][2]);
}
for (int i=0; i<triangles.size(); i++) {
indices_.push_back(triangles[i][0]);
indices_.push_back(triangles[i][1]);
indices_.push_back(triangles[i][2]);
}
gpuDirty_ = true;
}
void EdgeMesh::addEdge(std::vector<Point3> *vertices,
std::vector<Vector3> *normals,
std::vector<Vector3> *leftNormals,
std::vector<Vector3> *rightNormals,
std::vector< std::vector<unsigned int> > *triangles,
const Mesh &mesh, int v0, int v1, Vector3 n)
{
// edgeMap contains the index of the first of four consecutive vertices
// that form the quad fin
EdgeMap::iterator it = edgeMap.find(std::make_pair(v1, v0));
if (it != edgeMap.end()) { // found
int v = it->second;
(*rightNormals)[(size_t)v+0]
= (*rightNormals)[(size_t)v+1]
= (*rightNormals)[(size_t)v+2]
= (*rightNormals)[(size_t)v+3]
= n;
}
else {
int v = (int)vertices->size();
edgeMap[std::make_pair(v0, v1)] = v;
vertices->push_back(mesh.read_vertex_data(v0));
vertices->push_back(mesh.read_vertex_data(v0));
vertices->push_back(mesh.read_vertex_data(v1));
vertices->push_back(mesh.read_vertex_data(v1));
normals->push_back(Vector3());
normals->push_back(mesh.read_normal_data(v0));
normals->push_back(Vector3());
normals->push_back(mesh.read_normal_data(v1));
leftNormals->push_back(n);
leftNormals->push_back(n);
leftNormals->push_back(n);
leftNormals->push_back(n);
rightNormals->push_back(-n);
rightNormals->push_back(-n);
rightNormals->push_back(-n);
rightNormals->push_back(-n);
std::vector<unsigned int> tri1;
tri1.push_back(v+0);
tri1.push_back(v+2);
tri1.push_back(v+3);
triangles->push_back(tri1);
std::vector<unsigned int> tri2;
tri2.push_back(v+0);
tri2.push_back(v+3);
tri2.push_back(v+1);
triangles->push_back(tri2);
}
}
void EdgeMesh::UpdateGPUMemory() {
if (gpuDirty_) {
// sanity check -- for each attribute that is added make sure the number
// of triangles is equal to the number of tris in the verts array.
if (norms_.size() / 3 != num_vertices()) {
std::cerr << "EdgeMesh::UpdateGPUMemory() -- warning: the number of per vertex normals in the mesh is not equal to the number vertices in the mesh. (N = " << norms_.size() / 3 << ", V = " << num_vertices() << ")" << std::endl;
}
if (leftNorms_.size() / 3 != num_vertices()) {
std::cerr << "EdgeMesh::UpdateGPUMemory() -- warning: the number of per vertex left-normals in the mesh is not equal to the number vertices in the mesh. (LN = " << leftNorms_.size() / 3 << ", V = " << num_vertices() << ")" << std::endl;
}
if (rightNorms_.size() / 3 != num_vertices()) {
std::cerr << "EdgeMesh::UpdateGPUMemory() -- warning: the number of per vertex right-normals in the mesh is not equal to the number vertices in the mesh. (RN = " << rightNorms_.size() / 3 << ", V = " << num_vertices() << ")" << std::endl;
}
GLsizeiptr totalMemSize = 0;
GLsizeiptr vertsMemSize = verts_.size() * sizeof(float);
GLsizeiptr vertsMemOffset = 0;
totalMemSize += vertsMemSize;
GLsizeiptr normsMemSize = norms_.size() * sizeof(float);
GLsizeiptr normsMemOffset = totalMemSize;
totalMemSize += normsMemSize;
GLsizeiptr leftNormsMemSize = leftNorms_.size() * sizeof(float);
GLsizeiptr leftNormsMemOffset = totalMemSize;
totalMemSize += leftNormsMemSize;
GLsizeiptr rightNormsMemSize = rightNorms_.size() * sizeof(float);
GLsizeiptr rightNormsMemOffset = totalMemSize;
totalMemSize += rightNormsMemSize;
glGenBuffers(1, &vertexBuffer_);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer_);
glBufferData(GL_ARRAY_BUFFER, totalMemSize, NULL, GL_STATIC_DRAW);
glBufferSubData(GL_ARRAY_BUFFER, vertsMemOffset, vertsMemSize, &verts_[0]);
glBufferSubData(GL_ARRAY_BUFFER, normsMemOffset, normsMemSize, &norms_[0]);
glBufferSubData(GL_ARRAY_BUFFER, leftNormsMemOffset, leftNormsMemSize, &leftNorms_[0]);
glBufferSubData(GL_ARRAY_BUFFER, rightNormsMemOffset, rightNormsMemSize, &rightNorms_[0]);
glGenVertexArrays(1, &vertexArray_);
glBindVertexArray(vertexArray_);
glBindBuffer(GL_ARRAY_BUFFER, vertexBuffer_);
// attribute 0 = vertices (required)
int attribID = 0;
int nComponents = 3;
glEnableVertexAttribArray(attribID);
glVertexAttribPointer(attribID, nComponents, GL_FLOAT, GL_FALSE, nComponents*sizeof(GLfloat), (char*)0 + vertsMemOffset);
// attribute 1 = normals (required)
attribID = 1;
nComponents = 3;
glEnableVertexAttribArray(attribID);
glVertexAttribPointer(attribID, nComponents, GL_FLOAT, GL_TRUE, nComponents*sizeof(GLfloat), (char*)0 + normsMemOffset);
// attribute 2 = left normals (required)
attribID = 2;
nComponents = 3;
glEnableVertexAttribArray(attribID);
glVertexAttribPointer(attribID, nComponents, GL_FLOAT, GL_TRUE, nComponents*sizeof(GLfloat), (char*)0 + leftNormsMemOffset);
// attribute 3 = right normals (required)
attribID = 3;
nComponents = 3;
glEnableVertexAttribArray(attribID);
glVertexAttribPointer(attribID, nComponents, GL_FLOAT, GL_TRUE, nComponents*sizeof(GLfloat), (char*)0 + rightNormsMemOffset);
glBindVertexArray(0);
glGenBuffers(1, &elementBuffer_);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementBuffer_);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices_.size() * sizeof(unsigned int), &indices_[0], GL_STATIC_DRAW);
gpuDirty_ = false;
}
}
void EdgeMesh::Draw() {
if (gpuDirty_) {
UpdateGPUMemory();
}
// set defaults to pass to shaders any for optional attribs
glVertexAttrib3f(1, 0.0, 0.0, 1.0); // normal = +Z
glVertexAttrib3f(2, 0.0, 0.0, 1.0); // left-normal = +Z
glVertexAttrib3f(3, 0.0, 0.0, 1.0); // right-normal = +Z
glBindVertexArray(vertexArray_);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementBuffer_);
glDrawElements(GL_TRIANGLES, (GLsizei)indices_.size(), GL_UNSIGNED_INT, (void*)0);
glBindVertexArray(0);
}
int EdgeMesh::num_vertices() const {
return (int)verts_.size()/3;
}
int EdgeMesh::num_triangles() const {
return (int)indices_.size()/3;
}
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