OpenGL模型加载之网格

Mesh.h

#pragma once
#ifndef MESH_H
#define MESH_H
#include <glad/glad.h>
#include <GLFW/glfw3.h>
#define STB_IMAGE_IMPLEMENTATION
#include <stb_image.h>

#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <iostream>
#include <vector>
#include <sstream>
#include <string>
#include "Shader.h"
using namespace std;
struct Vertex {
	glm::vec3 Position;
	glm::vec3 Normal;
	glm::vec2 TexCoords;
	/*glm::vec3 Tangent;
	glm::vec3 Bitanent;*/ //目前用不到的注释掉了
};
struct Texture {
	unsigned int id;
	string type;	//	是漫反射贴图或者是镜面光贴图
	string path;
};
class Mesh {
	public:
		/*网格数据*/
		vector<Vertex>vertices;
		vector<unsigned int>indices;
		vector<Texture>textures;
		/*函数*/
		Mesh(vector<Vertex>vertices, vector<unsigned int>indices, vector<Texture>textures)
		{
			this->vertices = vertices;
			this->indices = indices;
			this->textures = textures;
			setupMesh();
		}
		void Draw(Shader shader)
		{
			unsigned int diffuseNr = 1;
			unsigned int specularNr = 1;

			/*unsigned int normalNr = 1;
			unsigned int heightNr = 1;*/

			for (unsigned int i = 0; i < textures.size(); i++)
			{
				glActiveTexture(GL_TEXTURE0 + i);//在绑定之前**相应的纹理单元
				//获取纹理序号（diffuse_textureN 中的N）
				string number;
				string name = textures[i].type;
				if (name == "texture_diffuse")
					number = std::to_string(diffuseNr++);
				else if (name == "texture_specular")
					number = std::to_string(specularNr++);

				//else if (name == "texture_normal")			//目前不需要注释掉
				//	number = std::to_string(normalNr++);
				//else if (name == "texture_height")
				//	number = std::to_string(heightNr++);

				//shader.setInt(("material." + name + number).c_str(), i);
				glUniform1i(glGetUniformLocation(shader.ID, (name + number).c_str()), i);
				glBindTexture(GL_TEXTURE_2D, textures[i].id);
			}
			glActiveTexture(GL_TEXTURE0);

			//绘制网格
			glBindVertexArray(VAO);
			glDrawElements(GL_TRIANGLES, indices.size(), GL_UNSIGNED_INT, 0);
			glBindVertexArray(0);
		}
	private:
		/*渲染数据*/
		unsigned int VAO, VBO, EBO;
		/*函数*/
		void setupMesh()
		{
			glGenVertexArrays(1, &VAO);
			glGenBuffers(1, &VBO);
			glGenBuffers(1, &EBO);

			glBindVertexArray(VAO);
			glBindBuffer(GL_ARRAY_BUFFER, VBO);

			glBufferData(GL_ARRAY_BUFFER, vertices.size() * sizeof(Vertex), &vertices[0], GL_STATIC_DRAW);

			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, EBO);
			glBufferData(GL_ELEMENT_ARRAY_BUFFER, indices.size() * sizeof(unsigned int), &indices[0], GL_STATIC_DRAW);

			//顶点位置
			glEnableVertexAttribArray(0);
			glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)0);

			//顶点法线
			glEnableVertexAttribArray(1);
			glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void*)offsetof(Vertex, Normal));

			//顶点纹理坐标
			glEnableVertexAttribArray(2);
			glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (void *)offsetof(Vertex, TexCoords));
			glBindVertexArray(0);
		}
};
#endif