Добавление MeshLoader, он умеет загружать геометрию и нормали из .obj файлов

lab2/CMakeLists.txt

@@ -22,7 +22,7 @@ add_executable(
         src/graphics/Mesh.cpp
         src/graphics/Shader.h
         src/graphics/Shader.cpp
-)
+        src/graphics/MeshLoader.cpp src/graphics/MeshLoader.h)
 
 target_link_libraries(${PROJECT_NAME} glfw)
 target_link_libraries(${PROJECT_NAME} GLEW::GLEW)

lab2/res/cube.mtl

@@ -0,0 +1,12 @@
+# Blender MTL File: 'cube.blend'
+# Material Count: 1
+
+newmtl Material
+Ns 250.000000
+Ka 1.000000 1.000000 1.000000
+Kd 0.800000 0.800000 0.800000
+Ks 0.500000 0.500000 0.500000
+Ke 0.000000 0.000000 0.000000
+Ni 1.000000
+d 1.000000
+illum 2

lab2/res/cube.obj

@@ -0,0 +1,32 @@
+# Blender v3.4.1 OBJ File: 'cube.blend'
+# www.blender.org
+mtllib cube.mtl
+o Cube
+v 1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 1.000000
+v -1.000000 1.000000 -1.000000
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 1.000000
+v -1.000000 -1.000000 1.000000
+vn 0.0000 1.0000 0.0000
+vn 0.0000 0.0000 1.0000
+vn -1.0000 0.0000 0.0000
+vn 0.0000 -1.0000 0.0000
+vn 1.0000 0.0000 0.0000
+vn 0.0000 0.0000 -1.0000
+usemtl Material
+s off
+f 5//1 3//1 1//1
+f 3//2 8//2 4//2
+f 7//3 6//3 8//3
+f 2//4 8//4 6//4
+f 1//5 4//5 2//5
+f 5//6 2//6 6//6
+f 5//1 7//1 3//1
+f 3//2 7//2 8//2
+f 7//3 5//3 6//3
+f 2//4 4//4 8//4
+f 1//5 3//5 4//5
+f 5//6 1//6 2//6

lab2/res/main.vsh

@@ -1,7 +1,7 @@
 #version 330 core
 
 layout (location = 0) in vec3 v_position;
-layout (location = 1) in float light;
+layout (location = 1) in vec3 v_normal;
 
 out vec4 a_color;
 uniform mat4 projview;
@@ -9,6 +9,6 @@ uniform mat4 projview;
 void main(){
 //	gl_Position = vec4(v_position, 1) * projview;
 	gl_Position = projview * vec4(v_position, 1);
-	a_color = vec4(0.5, 0, 1, 1) * light;
+	a_color = vec4(0.5, 0, 1, 1);
 }
 

lab2/src/graphics/Mesh.cpp

@@ -43,7 +43,7 @@ void Mesh::reload(const float* buffer, size_t vertices){
 	this->vertices = vertices;
 }
 
-void Mesh::draw(){
+void Mesh::draw() const{
 	glBindVertexArray(vao);
 	glDrawArrays(GL_TRIANGLES, 0, vertices);
 	glBindVertexArray(0);

lab2/src/graphics/Mesh.h

@@ -13,7 +13,7 @@ public:
 	~Mesh();
 
 	void reload(const float* buffer, size_t vertices);
-	void draw();
+	void draw() const;
 };
 
 #endif /* GRAPHICS_MESH_H_ */

lab2/src/graphics/MeshLoader.cpp

@@ -0,0 +1,162 @@
+//
+// Created by vlad on 23.03.23.
+//
+
+#include "MeshLoader.h"
+#include <vector>
+#include <glm/vec3.hpp>
+#include <fstream>
+#include <iostream>
+#include <glm/vec2.hpp>
+#include <sstream>
+
+
+enum ParserState {
+    IDLE,
+    COMMENT,
+    READ_STR
+};
+
+struct MeshPoint {
+    glm::vec3 point;
+    glm::vec3 normal;
+};
+
+Mesh *MeshLoader::loadMesh(const std::string &filename) {
+    std::vector<glm::vec3> points;
+    std::vector<glm::vec3> normals;
+    std::vector<MeshPoint> mesh_points;
+
+
+    std::ifstream file(filename + ".obj", std::ios::in);
+
+    ParserState state = IDLE;
+    int line = 1;
+
+    char tmp_buff[128];
+    int tmp_buff_index = 0;
+    while (true) {
+        char in;
+
+        file.read(&in, 1);
+
+        if (file.eof()) {
+            break;
+        }
+
+        if (tmp_buff_index >= 128) {
+            std::cerr << "[MeshLoader] Error: tmp buffer overflow"
+                         " (line " << line << " file: " << filename << ")" << std::endl;
+            return nullptr;
+        }
+
+        if (in == '\n') {
+            line++;
+        }
+
+        switch (state) {
+            case IDLE:
+                tmp_buff[0] = in;
+                tmp_buff_index = 1;
+
+                // нет состояния, возможно после пустой строки
+                if (in == '#' || in == 'o' || in == 's') {
+                    // коммент если это информация о имени объекта или о сглаживании
+                    state = COMMENT;
+                } else if (in == 'v' || in == 'f') {
+                    state = READ_STR;
+                }
+                break;
+
+            case COMMENT:
+                // строка коммента, читаем до конца линии
+                if (in == '\n') {
+                    state = IDLE;
+                }
+                break;
+
+            case READ_STR:
+                if (in == '\n') {
+                    state = IDLE;
+                    // парсим строку
+                    tmp_buff[tmp_buff_index] = 0; // делаем null-terminator
+                    tmp_buff_index = 0;
+                    std::string source(tmp_buff);
+
+                    if (source.find("v ") == 0) {
+                        // вершина
+                        char* end = nullptr;
+
+                        glm::vec3 tmp_point(0, 0, 0);
+                        tmp_point.x = std::strtof(tmp_buff + 2, &end);
+                        tmp_point.y = std::strtof(end, &end);
+                        tmp_point.z = std::strtof(end, &end);
+                        points.push_back(tmp_point);
+                    } else if (source.find("vn ") == 0) {
+                        // нормаль
+                        char* end = nullptr;
+
+                        glm::vec3 tmp_point(0, 0, 0);
+                        tmp_point.x = std::strtof(tmp_buff + 3, &end);
+                        tmp_point.y = std::strtof(end, &end);
+                        tmp_point.z = std::strtof(end, &end);
+                        normals.push_back(tmp_point);
+                    } else if (source.find("f ") == 0) {
+                        // фрагмент, он же треугольник
+                        std::istringstream source_stream(tmp_buff + 2);
+                        std::string point;
+                        while (getline(source_stream, point, ' ')) {
+                            std::istringstream point_stream(point);
+                            std::string vertex, texture, normal;
+                            getline(point_stream, vertex, '/');
+                            getline(point_stream, texture, '/');
+                            getline(point_stream, normal, '\0'); // до конца строки
+
+                            MeshPoint p{};
+                            // сначала точка
+                            int tmp = std::atoi(vertex.c_str());
+                            if (tmp > 0) {
+                                tmp -= 1;
+                                p.point = points[tmp];
+                            }
+
+                            tmp = std::atoi(normal.c_str());
+                            if (tmp > 0) {
+                                tmp -= 1;
+                                p.normal = normals[tmp];
+                            }
+
+                            mesh_points.push_back(p);
+                        }
+                    }
+                } else {
+                    tmp_buff[tmp_buff_index++] = in;
+                }
+                break;
+        }
+    }
+
+    // тут имеем готовый массив вершин
+    // размер меша = кол-во вершин * (3 + 3)
+    const int vertices = (int)mesh_points.size();
+    auto* out_mesh = new float[vertices * (3 + 3)];
+
+    int curr_index = 0;
+    for (const auto& p : mesh_points) {
+        // точка
+        out_mesh[curr_index++] = p.point.x;
+        out_mesh[curr_index++] = p.point.y;
+        out_mesh[curr_index++] = p.point.z;
+
+        // нормаль
+        out_mesh[curr_index++] = p.normal.x;
+        out_mesh[curr_index++] = p.normal.y;
+        out_mesh[curr_index++] = p.normal.z;
+    }
+
+    const int attrs[] = {3, 3, 0};
+    Mesh* m = new Mesh(out_mesh, vertices, attrs);
+
+    delete[] out_mesh;
+    return m;
+}

lab2/src/graphics/MeshLoader.h

@@ -0,0 +1,18 @@
+//
+// Created by vlad on 23.03.23.
+//
+
+#ifndef GRAPHICS_LABS_MESHLOADER_H
+#define GRAPHICS_LABS_MESHLOADER_H
+
+
+#include <string>
+#include "Mesh.h"
+
+class MeshLoader {
+public:
+    static Mesh *loadMesh(const std::string &filename);
+};
+
+
+#endif //GRAPHICS_LABS_MESHLOADER_H

lab2/src/main.cpp

@@ -18,6 +18,7 @@
 #include "window/Events.h"
 #include "graphics/Mesh.h"
 #include "graphics/Shader.h"
+#include "graphics/MeshLoader.h"
 
 
 #define SPEED_FACTOR 2.5f
@@ -78,6 +79,7 @@ static void updateCameraPosition(Camera& cam, float delta) {
 
 
 static Mesh* world;
+static Mesh* model_mesh;
 static Shader* shader;
 static void drawWorld(Camera& cam) {
     auto projview = cam.getProjection() * cam.getView();
@@ -96,7 +98,8 @@ static void drawWorld(Camera& cam) {
     angle += 0.001f;
 
     shader->uniformMatrix("projview", projview * model_scale * model_translate * model_rotate);
-    world->draw();
+//    world->draw();
+    model_mesh->draw();
 }
 
 
@@ -141,20 +144,22 @@ void mainloop(Camera& camera) {
 void loadResources() {
     const float buffer[] = {
             // треугольник
-            //  X   Y   Z Light
+            //  X   Y   Z  nX  nY  nZ
-            -1, -1, 0.5, 0.5,
+            -1, -1, 0.5, 0, 0, 1,
-            1, -1, 0.5, 0.1,
+            1, -1, 0.5, 0, 0, 1,
-            0, 1, 0.5, 0.9,
+            0, 1, 0.5, 0, 0, 1,
 
-            -1, -1, -0.5, 0.5,
+            -1, -1, -0.5, 0, 0, -1,
-            1, -1, -0.5, 0.1,
+            1, -1, -0.5, 0, 0, -1,
-            0, 1, -0.5, 0.9,
+            0, 1, -0.5, 0, 0, -1,
     };
     const int mesh_attrs[] {
-            3, 1, 0
+            3, 3, 0
     };
     world = new Mesh(buffer, 6, mesh_attrs);
 
+    model_mesh = MeshLoader::loadMesh("res/cube");
+
     shader = Shader::loadShader("res/main.vsh", "res/main.fsh");
 }