ImpostorSpheres::ImpostorSpheres():
num_balls(1000000){
mode = GL_TRIANGLE_STRIP;
glGenVertexArrays(1, &vertexArrayObjectHandle);
glBindVertexArray(vertexArrayObjectHandle);
GLuint positionBuffer;
glGenBuffers(1, &positionBuffer);
glBindBuffer(GL_ARRAY_BUFFER, positionBuffer);
GLfloat positions[] = {
-1.0f, -1.0f,
-1.0f, 1.0f,
1.0f, -1.0f,
1.0f, 1.0f
};
std::vector<GLfloat> instance_colors;
std::vector<GLfloat> instance_positions;
for (int i = 0; i < num_balls*4; i+=4) {
instance_colors.push_back(r_pos(1.0));
instance_colors.push_back(r_pos(1.0));
instance_colors.push_back(r_pos(1.0));
instance_colors.push_back(1);
instance_positions.push_back(r_equ(30));
instance_positions.push_back(r_equ(30));
instance_positions.push_back(r_equ(30));
instance_positions.push_back(1 + r_equ(0.5));
}
glBufferData(GL_ARRAY_BUFFER,
sizeof(positions) +
sizeof(GLfloat) * instance_colors.size() +
sizeof(GLfloat) * instance_positions.size(), NULL, GL_STATIC_DRAW);
GLuint offset = 0;
glBufferSubData(GL_ARRAY_BUFFER, offset, sizeof(positions), positions);
offset += sizeof(positions);
glBufferSubData(GL_ARRAY_BUFFER, offset, sizeof(GLfloat) * instance_colors.size(), &instance_colors[0]);
offset += sizeof(GLfloat) * instance_colors.size();
glBufferSubData(GL_ARRAY_BUFFER, offset, sizeof(GLfloat) * instance_positions.size(), &instance_positions[0]);
offset += sizeof(GLfloat) * instance_positions.size();
glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, NULL);
glVertexAttribPointer(1, 4, GL_FLOAT, GL_FALSE, 0, (GLvoid*)sizeof(positions));
glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, 0, (GLvoid*)(sizeof(positions) + sizeof(GLfloat) * instance_colors.size()));
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glEnableVertexAttribArray(2);
glVertexAttribDivisor(0,0);
glVertexAttribDivisor(1,1);
glVertexAttribDivisor(2,1);
}
void set_random_goal() {
std::uniform_real_distribution<float> r_pos(-WORLD_SIZE, +WORLD_SIZE);
goal = { r_pos(s_rnd), r_pos(s_rnd) };
}
void InstancedMeshExample::dumpSceneToVAO(const aiScene *scene) {
GLuint vbo[4];
glGenBuffers(4, vbo);
glGenVertexArrays(1, &vertexArrayObjectHandle);
glBindVertexArray(vertexArrayObjectHandle);
count = 0;
GLuint vertexCount = 0;
for(int i = 0; i < scene->mNumMeshes; i++) {
aiMesh* mesh = scene->mMeshes[i];
count += mesh->mNumFaces * 3;
vertexCount += mesh->mNumVertices;
}
GLfloat* positions = new GLfloat[vertexCount * 3];
GLfloat* normals = new GLfloat[vertexCount * 3];
GLfloat* uvs = new GLfloat[vertexCount * 2];
GLuint* indices = new GLuint[count];
int current_p = 0;
int current_n = 0;
int current_uv = 0;
int current_i = 0;
for(int i = 0; i < scene->mNumMeshes; i++) {
aiMesh* mesh = scene->mMeshes[i];
for(int i = 0; i < mesh->mNumVertices; i++) {
positions[current_p++] = mesh->mVertices[i].x;
positions[current_p++] = mesh->mVertices[i].y;
positions[current_p++] = mesh->mVertices[i].z;
}
for(int i = 0; i < mesh->mNumVertices; i++) {
uvs[current_uv++] = mesh->mTextureCoords[0][i].x;
uvs[current_uv++] = mesh->mTextureCoords[0][i].y;
}
for(int i = 0; i < mesh->mNumVertices; i++) {
normals[current_n++] = mesh->mNormals[i].x;
normals[current_n++] = mesh->mNormals[i].y;
normals[current_n++] = mesh->mNormals[i].z;
}
for(int i = 0; i < mesh->mNumFaces; i++) {
indices[current_i++] = mesh->mFaces[i].mIndices[0];
indices[current_i++] = mesh->mFaces[i].mIndices[1];
indices[current_i++] = mesh->mFaces[i].mIndices[2];
}
}
glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
glBufferData(GL_ARRAY_BUFFER, 3 * vertexCount * sizeof(GLfloat), positions, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (0);
glBindBuffer(GL_ARRAY_BUFFER, vbo[1]);
glBufferData(GL_ARRAY_BUFFER, 2 * vertexCount * sizeof(GLfloat), uvs, GL_STATIC_DRAW);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (1);
glBindBuffer(GL_ARRAY_BUFFER, vbo[2]);
glBufferData(GL_ARRAY_BUFFER, 3 * vertexCount * sizeof(GLfloat), normals, GL_STATIC_DRAW);
glVertexAttribPointer(2, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (2);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vbo[3]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, 3 * count * sizeof(GLuint), indices, GL_STATIC_DRAW);
glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (3);
std::vector<GLfloat> instance_colors;
std::vector<GLfloat> instance_positions;
for (int i = 0; i < num_balls*4; i+=4) {
instance_colors.push_back(r_pos(1.0));
instance_colors.push_back(r_pos(1.0));
instance_colors.push_back(r_pos(1.0));
instance_colors.push_back(1);
instance_positions.push_back(r(30));
instance_positions.push_back(r(30));
instance_positions.push_back(r(30));
instance_positions.push_back(abs(1 + r(0.4)) / 2.0f);
}
glBindBuffer(GL_ARRAY_BUFFER, vbo[4]);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * instance_colors.size(),
&instance_colors[0], GL_STATIC_DRAW);
glVertexAttribPointer(4, 4, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (4);
glBindBuffer(GL_ARRAY_BUFFER, vbo[5]);
glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * instance_positions.size(),
&instance_positions[0], GL_STATIC_DRAW);
glVertexAttribPointer(5, 4, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray (5);
glVertexAttribDivisor(4,1);
glVertexAttribDivisor(5,1);
glBindBuffer(GL_ARRAY_BUFFER, 0);
glBindVertexArray(0);
delete positions;
delete normals;
delete uvs;
delete indices;
}
