主要代码：
main.cpp
// Std. Includes
#include
#include
// GLEW
#define GLEW_STATIC
#include
// GLFW
#include
// GL includes
#include "Shader.h"
#include "Camera.h"
#include "Mesh.h"
#include "Model.h"
// GLM Mathemtics
#include
#include
#include
#include
// Other Libs
#include
#pragma comment(lib,"glew32s.lib")
#pragma comment(lib,"glfw3.lib")
#pragma comment(lib,"SOIL.lib")
// Properties
GLuint screenWidth = 800, screenHeight = 600;
// Function prototypes
void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void Do_Movement();
// Camera
Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
bool keys[1024];
GLfloat lastX = 400, lastY = 300;
bool firstMouse = true;
GLfloat deltaTime = 0.0f;
GLfloat lastFrame = 0.0f;
// The MAIN function, from here we start our application and run our Game loop
int main()
{
// Init GLFW
glfwInit();
glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
GLFWwindow* window = glfwCreateWindow(screenWidth, screenHeight, "LearnOpenGL", nullptr, nullptr); // Windowed
glfwMakeContextCurrent(window);
// Set the required callback functions
glfwSetKeyCallback(window, key_callback);
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
// Options
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
// Initialize GLEW to setup the OpenGL Function pointers
glewExperimental = GL_TRUE;
glewInit();
// Define the viewport dimensions
glViewport(0, 0, screenWidth, screenHeight);
// Setup some OpenGL options
glEnable(GL_DEPTH_TEST);
// Setup and compile our shaders
Shader shader("load_model.vs", "load_model.frag");
// Load models
Model ourModel((GLchar*)("nanosuit/nanosuit.obj"));
// Draw in wireframe
//glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
// Game loop
while (!glfwWindowShouldClose(window))
{
// Set frame time
GLfloat currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
// Check and call events
glfwPollEvents();
Do_Movement();
// Clear the colorbuffer
glClearColor(0.05f, 0.05f, 0.05f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
shader.Use(); //
WorldUp = glm::vec3(upX, upY, upZ);this->Yaw = yaw;
this->Pitch = pitch;
this->updateCameraVectors();
}
// Returns the view matrix calculated using Eular Angles and the LookAt Matrix
glm::mat4 GetViewMatrix()
{
return glm::lookAt(this->Position, this->Position + this->Front, this->Up);
}
// Processes input received from any keyboard-like input system. Accepts input parameter in the form of camera defined ENUM (to abstract it from windowing systems)
void ProcessKeyboard(Camera_Movement direction, GLfloat deltaTime)
{
GLfloat velocity = this->MovementSpeed * deltaTime;
if (direction == FORWARD)
this->Position += this->Front * velocity;
if (direction == BACKWARD)
this->Position -= this->Front * velocity;
if (direction == LEFT)
this->Position -= this->Right * velocity;
if (direction == RIGHT)
this->Position += this->Right * velocity;
}
// Processes input received from a mouse input system. Expects the offset value in both the x and y direction.
void ProcessMouseMovement(GLfloat xoffset, GLfloat yoffset, GLboolean constrainPitch = true)
{
xoffset *= this->MouseSensitivity;
yoffset *= this->MouseSensitivity;
this->Yaw += xoffset;
this->Pitch += yoffset;
// Make sure that when pitch is out of bounds, screen doesn't get flipped
if (constrainPitch)
{
if (this->Pitch > 89.0f)
this->Pitch = 89.0f;
if (this->Pitch < -89.0f)
this->Pitch = -89.0f;
}
// Update Front, Right and Up Vectors using the updated Eular angles
this->updateCameraVectors();
}
// Processes input received from a mouse scroll-wheel event. Only requires input on the vertical wheel-axis
void ProcessMouseScroll(GLfloat yoffset)
{
if (this->Zoom >= 1.0f && this->Zoom Zoom -= yoffset;
if (this->Zoom Zoom = 1.0f;
if (this->Zoom >= 45.0f)
this->Zoom = 45.0f;
}
private:
// Calculates the front vector from the Camera's (updated) Eular Angles
void updateCameraVectors()
{
// Calculate the new Front vector
glm::vec3 front;
front.x = cos(glm::radians(this->Yaw)) * cos(glm::radians(this->Pitch));
front.y = sin(glm::radians(this->Pitch));
front.z = sin(glm::radians(this->Yaw)) * cos(glm::radians(this->Pitch));
this->Front = glm::normalize(front);
// Also re-calculate the Right and Up vector
this->Right = glm::normalize(glm::cross(this->Front, this->WorldUp)); // Normalize the vectors, because their length gets closer to 0 the more you look up or down which results in slower movement.
this->Up = glm::normalize(glm::cross(this->Right, this->Front));
}
};
Model.h
#pragma once
// Std. Includes
#include
#include
#include
#include
#include
#include
using namespace std;
// GL Includes
#include // Contains all the necessery OpenGL includes
#include
#include
#include
#include
#include
#include
#include
#pragma comment(lib,"assimpd.lib")
#include "Mesh.h"
GLint TextureFromFile(const char* path, string directory);
class Model
{
public:
/* Functions */
// Constructor, expects a filepath to a 3D model.
Model(GLchar* path)
{
this->loadModel(path);
}
// Draws the model, and thus all its meshes
void Draw(Shader shader)
{
for (GLuint i = 0; i < this->meshes.size(); i++)
this->meshes[i].Draw(shader);
}
private:
/* Model Data */
vector meshes;
string directory;
vector textures_loaded; // Stores all the textures loaded so far, optimization to make sure textures aren't loaded more than once.
/* Functions */
// Loads a model with supported ASSIMP extensions from file and stores the resulting meshes in the meshes vector.
void loadModel(string path)
{
// Read file via ASSIMP
Assimp::Importer importer;
const aiScene* scene = importer.ReadFile(path, aiProcess_Triangulate | aiProcess_FlipUVs);
// Check for errors
if (!scene || scene->mFlags == AI_SCENE_FLAGS_INCOMPLETE || !scene->mRootNode) // if is Not Zero
{
cout mRootNode, scene);
}
// Processes a node in a recursive fashion. Processes each individual mesh located at the node and repeats this process on its children nodes (if any).
void processNode(aiNode* node, const aiScene* scene)
{
// Process each mesh located at the current node
for (GLuint i = 0; i < node->mNumMeshes; i++)
{
// The node object only contains indices to index the actual objects in the scene.
// The scene contains all the data, node is just to keep stuff organized (like relations between nodes).
aiMesh* mesh = scene->mMeshes[node->mMeshes[i]];
this->meshes.push_back(this->processMesh(mesh, scene));
}
// After we've processed all of the meshes (if any) we then recursively process each of the children nodes
for (GLuint i = 0; i < node->mNumChildren; i++)
{
this->processNode(node->mChildren[i], scene);
}
}
Mesh processMesh(aiMesh* mesh, const aiScene* scene)
{
// Data to fill
vector vertices;
vector indices;
vector textures;
// Walk through each of the mesh's vertices
for (GLuint i = 0; i < mesh->mNumVertices; i++)
{
Vertex vertex;
glm::vec3 vector; // We declare a placeholder vector since assimp uses its own vector class that doesn't directly convert to glm's vec3 class so we transfer the data to this placeholder glm::vec3 first.
// Positions
vector.x = mesh->mVertices[i].x;
vector.y = mesh->mVertices[i].y;
vector.z = mesh->mVertices[i].z;
vertex.Position = vector;
// Normals
vector.x = mesh->mNormals[i].x;
vector.y = mesh->mNormals[i].y;
vector.z = mesh->mNormals[i].z;
vertex.Normal = vector;
// Texture Coordinates
if (mesh->mTextureCoords[0]) // Does the mesh contain texture coordinates?
{
glm::vec2 vec;
// A vertex can contain up to 8 different texture coordinates. We thus make the assumption that we won't
// use models where a vertex can have multiple texture coordinates so we always take the first set (0).
vec.x = mesh->mTextureCoords[0][i].x;
vec.y = mesh->mTextureCoords[0][i].y;
vertex.TexCoords = vec;
}
else
vertex.TexCoords = glm::vec2(0.0f, 0.0f);
vertices.push_back(vertex);
}
// Now wak through each of the mesh's faces (a face is a mesh its triangle) and retrieve the corresponding vertex indices.
for (GLuint i = 0; i < mesh->mNumFaces; i++)
{
aiFace face = mesh->mFaces[i];
// Retrieve all indices of the face and store them in the indices vector
for (GLuint j = 0; j < face.mNumIndices; j++)
indices.push_back(face.mIndices[j]);
}
// Process materials
if (mesh->mMaterialIndex >= 0)
{
aiMaterial* material = scene->mMaterials[mesh->mMaterialIndex];
// We assume a convention for sampler names in the shaders. Each diffuse texture should be named
// as 'texture_diffuseN' where N is a sequential number ranging from 1 to MAX_SAMPLER_NUMBER.
// Same applies to other texture as the following list summarizes:
// Diffuse: texture_diffuseN
// Specular: texture_specularN
// Normal: texture_normalN
// 1. Diffuse maps
vector diffuseMaps = this->loadMaterialTextures(material, aiTextureType_DIFFUSE, "texture_diffuse");
textures.insert(textures.end(), diffuseMaps.begin(), diffuseMaps.end());
// 2. Specular maps
vector specularMaps = this->loadMaterialTextures(material, aiTextureType_SPECULAR, "texture_specular");
textures.insert(textures.end(), specularMaps.begin(), specularMaps.end());
}
// Return a mesh object created from the extracted mesh data
return Mesh(vertices, indices, textures);
}
// Checks all material textures of a given type and loads the textures if they're not loaded yet.
// The required info is returned as a Texture struct.
vector loadMaterialTextures(aiMaterial* mat, aiTextureType type, string typeName)
{
vector textures;
for (GLuint i = 0; i < mat->GetTextureCount(type); i++)
{
aiString str;
mat->GetTexture(type, i, &str);
// Check if texture was loaded before and if so, continue to next iteration: skip loading a new texture
GLboolean skip = false;
for (GLuint j = 0; j < textures_loaded.size(); j++)
{
if (std::strcmp(textures_loaded[j].path.c_str(), str.C_Str()) == 0)
{
textures.push_back(textures_loaded[j]);
skip = true; // A texture with the same filepath has already been loaded, continue to next one. (optimization)
break;
}
}
if (!skip)
{ // If texture hasn't been loaded already, load it
Texture texture;
texture.id = TextureFromFile(str.C_Str(), this->directory);
texture.type = typeName;
texture.path = str.C_Str();
textures.push_back(texture);
this->textures_loaded.push_back(texture); // Store it as texture loaded for entire model, to ensure we won't unnecesery load duplicate textures.
}
}
return textures;
}
};
GLint TextureFromFile(const char* path, string directory)
{
//Generate texture ID and load texture data
string filename = string(path);
filename = directory + '/' + filename;
GLuint textureID;
glGenTextures(1, &textureID);
int width, height;
unsigned char* image = SOIL_load_image(filename.c_str(), &width, &height, 0, SOIL_LOAD_RGB);
// Assign texture to ID
glBindTexture(GL_TEXTURE_2D, textureID);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, image);
glGenerateMipmap(GL_TEXTURE_2D);
// Parameters
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glBindTexture(GL_TEXTURE_2D, 0);
SOIL_free_image_data(image);
return textureID;
}
Mesh.h
#pragma once
// Std. Includes
#include "Shader.h"
#include
#include
#include
#include
#include
using namespace std;
// GL Includes
#include // Contains all the necessery OpenGL includes
#include
#include
struct Vertex {
// Position
glm::vec3 Position;
// Normal
glm::vec3 Normal;
// TexCoords
glm::vec2 TexCoords;
};
struct Texture {
GLuint id;
string type;
string path;
};
class Mesh {
public:
/* Mesh Data */
vector vertices;
vector indices;
vector textures;
/* Functions */
// Constructor
Mesh(vector vertices, vector indices, vector textures)
{
this->vertices = vertices;
this->indices = indices;
this->textures = textures;
// Now that we have all the required data, set the vertex buffers and its attribute pointers.
this->setupMesh();
}
// Render the mesh
void Draw(Shader shader)
{
// Bind appropriate textures
GLuint diffuseNr = 1;
GLuint specularNr = 1;
for (GLuint i = 0; i < this->textures.size(); i++)
{
glActiveTexture(GL_TEXTURE0 + i); // Active proper texture unit before binding
// Retrieve texture number (the N in diffuse_textureN)
stringstream ss;
string number;
string name = this->textures[i].type;
if (name == "texture_diffuse")
ss VAO);
glDrawElements(GL_TRIANGLES, this->indices.size(), GL_UNSIGNED_INT, 0);
glBindVertexArray(0);
// Always good practice to set everything back to defaults once configured.
for (GLuint i = 0; i < this->textures.size(); i++)
{
glActiveTexture(GL_TEXTURE0 + i);
glBindTexture(GL_TEXTURE_2D, 0);
}
}
private:
/* Render data */
GLuint VAO, VBO, EBO;
/* Functions */
// Initializes all the buffer objects/arrays
void setupMesh()
{
// Create buffers/arrays
glGenVertexArrays(1, &this->VAO);
glGenBuffers(1, &this->VBO);
glGenBuffers(1, &this->EBO);
glBindVertexArray(this->VAO);
// Load data into vertex buffers
glBindBuffer(GL_ARRAY_BUFFER, this->VBO);
// A great thing about structs is that their memory layout is sequential for all its items.
// The effect is that we can simply pass a pointer to the struct and it translates perfectly to a glm::vec3/2 array which
// again translates to 3/2 floats which translates to a byte array.
glBufferData(GL_ARRAY_BUFFER, this->vertices.size() * sizeof(Vertex), &this->vertices[0], GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, this->EBO);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, this->indices.size() * sizeof(GLuint), &this->indices[0], GL_STATIC_DRAW);
// Set the vertex attribute pointers
// Vertex Positions
glEnableVertexAttribArray(0);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)0);
// Vertex Normals
glEnableVertexAttribArray(1);
glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, Normal));
// Vertex Texture Coords
glEnableVertexAttribArray(2);
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (GLvoid*)offsetof(Vertex, TexCoords));
glBindVertexArray(0);
}
};
load_model.vs
#version 330 core
layout(location = 0) in vec3 position;
layout(location = 1) in vec3 normal;
layout(location = 2) in vec2 texCoords;
out vec2 TexCoords;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
gl_Position = projection * view * model * vec4(position, 1.0f);
TexCoords = texCoords;
}
load_model.frag
#version 330 core
in vec2 TexCoords;
out vec4 color;
uniform sampler2D texture_diffuse1;
void main()
{
color = vec4(texture(texture_diffuse1, TexCoords));
}
效果：
obj文件已上传至我的资源，需要的可以下载
