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homework2, render opencv 3d logo, support shade flat/smooth and smoot…
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…hing group
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@sleeplessai
sleeplessai committed Jul 28, 2023
1 parent 6a30adf commit 8b96a5b
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Showing 3 changed files with 44 additions and 48 deletions.
5 changes: 2 additions & 3 deletions include/OBJ.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7,10 +7,9 @@
struct OBJ {
std::vector<glm::vec3> vertices;
std::vector<glm::uvec3> faces;
std::unordered_map<unsigned int, std::vector<unsigned int>> face_groups;
std::unordered_map<unsigned int, std::vector<unsigned int>> smoothing_groups;

void load_obj(std::string path, bool enable_group = false);
void load_obj(std::string path, bool grouped = false);
void draw_obj();
void draw_obj_smooth();
void draw_obj_group_smooth(); // TODO
};
5 changes: 0 additions & 5 deletions src/Game.cpp
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Expand Up @@ -5,14 +5,12 @@
#include "OBJ.hpp"

#include <vector>
#include <iostream>

struct Game::Private { // P-IMPL pattern
glm::mat4x4 viewMat;
glm::mat4x4 projMat;

std::vector<OBJ> ocvLogo;
OBJ monkey;
};

Game::Game() : m_private(std::make_unique<Private>()), m_window(nullptr) {}
Expand Down Expand Up @@ -76,9 +74,6 @@ void Game::initialize() {
}
}

//m_private->monkey.load_obj(OPENGLTUTOR_HOME "assets/monkey.obj");
//m_private->monkey.load_obj(OPENGLTUTOR_HOME "assets/cube.obj");

CHECK_GL(glEnable(GL_DEPTH_TEST));
CHECK_GL(glEnable(GL_MULTISAMPLE));
CHECK_GL(glEnable(GL_BLEND));
Expand Down
82 changes: 42 additions & 40 deletions src/OBJ.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -5,17 +5,16 @@
#include <iostream>
#include <fstream>
#include <sstream>
#include <unordered_map>

void OBJ::load_obj(std::string path, bool enable_group) {
void OBJ::load_obj(std::string path, bool grouped) {
std::ifstream file(path);
if (!file.is_open()) {
std::cerr << "Failed to open file: " << path << '\n';
return;
}

std::string line;
int current_group = -1, grouped_face = 0;
unsigned int current_group = 0;

while (std::getline(file, line)) {
if (line.substr(0, 2) == "v ") {
Expand All @@ -37,21 +36,18 @@ void OBJ::load_obj(std::string path, bool enable_group) {
glm::uvec3 face = glm::uvec3(indices[0], indices[i - 1], indices[i]);
faces.push_back(face);

if (!enable_group && current_group >= 0) continue;
face_groups[current_group].push_back(faces.size() - 1);
grouped_face++;
smoothing_groups[current_group].push_back(faces.size() - 1);
}
} else if (line.substr(0, 7) == "#group ") {
std::istringstream s(line.substr(7));
unsigned int group;
s >> group;
current_group = group;
if (grouped) current_group = group;
}
}

file.close();
std::cout << "Loaded " << vertices.size() << " vertices, " << faces.size() << " faces.\n";
std::cout << grouped_face << " faces grouped.\n";
}

static glm::vec3 perspective_divide(glm::vec4 pos) {
Expand Down Expand Up @@ -79,13 +75,12 @@ static glm::vec3 compute_contrib_normal(glm::vec3 v0, glm::vec3 v1, glm::vec3 v2
return glm::normalize(norm) * contrib_w;
}

void OBJ::draw_obj() {
static void object_draw_flat_pass(OBJ const& obj) {
glBegin(GL_TRIANGLES);

for (auto face : faces) {
auto const &a = vertices.at(face[0]);
auto const &b = vertices.at(face[1]);
auto const &c = vertices.at(face[2]);
for (auto face : obj.faces) {
auto const& a = obj.vertices.at(face[0]);
auto const& b = obj.vertices.at(face[1]);
auto const& c = obj.vertices.at(face[2]);

glm::vec3 norm = compute_normal(a, b, c);
glNormal3fv(glm::value_ptr(norm));
Expand All @@ -94,38 +89,37 @@ void OBJ::draw_obj() {
glVertex3fv(glm::value_ptr(b));
glVertex3fv(glm::value_ptr(c));
}

CHECK_GL(glEnd());
}

void OBJ::draw_obj_smooth() {
std::vector<glm::vec3> vertexNormalBuffer(vertices.size());

// NormalComputePass
for (auto& face : faces) {
auto const& a = vertices.at(face[0]);
auto const& b = vertices.at(face[1]);
auto const& c = vertices.at(face[2]);

vertexNormalBuffer[face[0]] += compute_contrib_normal(a, b, c, 0);
vertexNormalBuffer[face[1]] += compute_contrib_normal(a, b, c, 1);
vertexNormalBuffer[face[2]] += compute_contrib_normal(a, b, c, 2);
static void normal_compute_pass(OBJ const& obj, std::vector<unsigned int> const& face_indices, std::vector<glm::vec3>& vertex_normal_buffer) {
for (auto const& index : face_indices) {
auto const& face = obj.faces.at(index);
auto const& a = obj.vertices.at(face[0]);
auto const& b = obj.vertices.at(face[1]);
auto const& c = obj.vertices.at(face[2]);

vertex_normal_buffer[face[0]] += compute_contrib_normal(a, b, c, 0);
vertex_normal_buffer[face[1]] += compute_contrib_normal(a, b, c, 1);
vertex_normal_buffer[face[2]] += compute_contrib_normal(a, b, c, 2);
}
for (auto& vn : vertexNormalBuffer) {
for (auto& vn : vertex_normal_buffer) {
vn = glm::normalize(vn);
}
}

// ObjectDrawPass
static void object_draw_smooth_pass(OBJ const& obj, std::vector<unsigned int> const& face_indices, std::vector<glm::vec3> const& vertex_normal_buffer) {
glBegin(GL_TRIANGLES);
for (auto const& face : faces) {
auto const& a = vertices.at(face[0]);
auto const& b = vertices.at(face[1]);
auto const& c = vertices.at(face[2]);

auto const& n0 = vertexNormalBuffer.at(face[0]);
auto const& n1 = vertexNormalBuffer.at(face[1]);
auto const& n2 = vertexNormalBuffer.at(face[2]);

for (auto const& index : face_indices) {
auto const& face = obj.faces.at(index);
auto const& a = obj.vertices.at(face[0]);
auto const& b = obj.vertices.at(face[1]);
auto const& c = obj.vertices.at(face[2]);

auto const& n0 = vertex_normal_buffer.at(face[0]);
auto const& n1 = vertex_normal_buffer.at(face[1]);
auto const& n2 = vertex_normal_buffer.at(face[2]);

glNormal3fv(glm::value_ptr(n0));
glVertex3fv(glm::value_ptr(a));
glNormal3fv(glm::value_ptr(n1));
Expand All @@ -136,6 +130,14 @@ void OBJ::draw_obj_smooth() {
CHECK_GL(glEnd());
}

void OBJ::draw_obj_group_smooth() {
// TODO
void OBJ::draw_obj() {
object_draw_flat_pass(*this);
}

void OBJ::draw_obj_smooth() {
for (auto const& [i, group] : smoothing_groups) {
std::vector<glm::vec3> vert_norm_buffer(vertices.size(), glm::vec3(0.0f));
normal_compute_pass(*this, group, vert_norm_buffer);
object_draw_smooth_pass(*this, group, vert_norm_buffer);
}
}

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