FPS相机

LookAt

定义一个摄像机位置、目标位置和上向量

glm::mat4 view;
view = glm::lookAt(glm::vec3(0.0f, 0.0f, 3.0f), 
           glm::vec3(0.0f, 0.0f, 0.0f), 
           glm::vec3(0.0f, 1.0f, 0.0f));

随时间旋转

在最开始定义相机位置、朝向（不是方向向量了，是面向向量）、上方向

glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f);
glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f);
glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f);

在渲染循环里：（第二个参数用相机位置+朝向就可以加出目标位置）

unsigned int r = 5;
float x = sin(glfwGetTime()) * r, z = cos(glfwGetTime()) * r;
view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);

生成多个立方体

把vertices填充6个面的36个点（没有用indices，所以一个面六个点都写上了）

float vertices[] = {
		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
		 0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,

		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		 0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
		-0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,

		-0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		-0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		-0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,

		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		-0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f
	};

启用Z-Buffer
glEnable(GL_DEPTH_TEST);
然后在渲染循环里每次清空当前深度缓存
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
循环十次，画十个正方体，把每个立方体平移一个距离，定义在cubepositions里：

glm::vec3 cubePositions[] = {
	  glm::vec3(0.0f,  0.0f,  0.0f),
	  glm::vec3(2.0f,  5.0f, -15.0f),
	  glm::vec3(-1.5f, -2.2f, -2.5f),
	  glm::vec3(-3.8f, -2.0f, -12.3f),
	  glm::vec3(2.4f, -0.4f, -3.5f),
	  glm::vec3(-1.7f,  3.0f, -7.5f),
	  glm::vec3(1.3f, -2.0f, -2.5f),
	  glm::vec3(1.5f,  2.0f, -2.5f),
	  glm::vec3(1.5f,  0.2f, -1.5f),
	  glm::vec3(-1.3f,  1.0f, -1.5f)
	};

在model矩阵中进行变换，在渲染循环里进行十个绘制：

for (unsigned int i = 0; i < 10; i++)
		{
			glm::mat4 model = glm::mat4(1.0f);
			model = glm::translate(model, cubePositions[i]);
			model = glm::rotate(model, glm::radians(20.0f*i), glm::vec3(1.0f, 0.2f, 0.3f));
			unsigned int r = 5;
			float x = sin(glfwGetTime()) * r, z = cos(glfwGetTime()) * r;
			view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);
			projection = glm::perspective(glm::radians(45.0f), (float)800 / (float)600, 0.1f, 100.0f);
			glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
			glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
			glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, glm::value_ptr(projection));
			glDrawArrays(GL_TRIANGLES, 0, 36);
		}

用键盘WASD驱动

要在processInput中进行，cameraPos等的定义要在最开头：

void processInput(GLFWwindow* window)
{
	if (glfwGetKey(window, GLFW_KEY_KP_ENTER) == GLFW_PRESS or glfwGetKey(window, GLFW_KEY_ENTER) == GLFW_PRESS or glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
		glfwSetWindowShouldClose(window, true);
	float cameraSpeed = 0.05f;
	if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
		cameraPos += cameraSpeed * cameraFront;
	if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
		cameraPos -= cameraSpeed * cameraFront;
	if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
		cameraPos += cameraSpeed * glm::normalize(glm::cross(cameraUp, cameraFront));
	if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
		cameraPos -= cameraSpeed * glm::normalize(glm::cross(cameraUp, cameraFront));
}

到目前为止的程序

#include<glad/glad.h>
#include<GLFW/glfw3.h>
#include<iostream>
#include<Shader.cpp>
#define STB_IMAGE_IMPLEMENTATION
#include<stb_image.h>
#include<glm/glm.hpp>
#include<glm/gtc/matrix_transform.hpp>
#include<glm/gtc/type_ptr.hpp>
glm::vec3 cameraPos = glm::vec3(0.0f, 0.0f, 3.0f);
glm::vec3 cameraFront = glm::vec3(0.0f, 0.0f, -1.0f);
glm::vec3 cameraUp = glm::vec3(0.0f, 1.0f, 0.0f);
void framebuffer_size_callback(GLFWwindow* window, int width, int height) 
{
	glViewport(0, 0, width, height);
}
void processInput(GLFWwindow* window)
{
	if (glfwGetKey(window, GLFW_KEY_KP_ENTER) == GLFW_PRESS or glfwGetKey(window, GLFW_KEY_ENTER) == GLFW_PRESS or glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
		glfwSetWindowShouldClose(window, true);
	float cameraSpeed = 0.05f;
	if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS)
		cameraPos += cameraSpeed * cameraFront;
	if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS)
		cameraPos -= cameraSpeed * cameraFront;
	if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS)
		cameraPos += cameraSpeed * glm::normalize(glm::cross(cameraUp, cameraFront));
	if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS)
		cameraPos -= cameraSpeed * glm::normalize(glm::cross(cameraUp, cameraFront));
}
int main()
{
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
	//创建窗口对象
	GLFWwindow* window = glfwCreateWindow(800, 600, "LJHyyds", NULL, NULL);
	if (window == NULL)
	{
		std::cout << "Failed to create" << std::endl;
		glfwTerminate();
		return -1;
	}
	glfwMakeContextCurrent(window);
	//初始化GLAD管理指针，加载系统OpenGL函数指针
	if (!gladLoadGLLoader((GLADloadproc)glfwGetProcAddress))
	{
		std::cout << "Failed to init GLAD" << std::endl;
		return -1;
	}
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
	Shader myshader("shader.vs", "shader.fs");
	float vertices[] = {
		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,
		 0.5f, -0.5f, -0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 0.0f,

		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		 0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 1.0f,
		-0.5f,  0.5f,  0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,

		-0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		-0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		-0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,

		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f, -0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f, -0.5f,  0.5f,  1.0f, 0.0f,
		-0.5f, -0.5f,  0.5f,  0.0f, 0.0f,
		-0.5f, -0.5f, -0.5f,  0.0f, 1.0f,

		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f,
		 0.5f,  0.5f, -0.5f,  1.0f, 1.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		 0.5f,  0.5f,  0.5f,  1.0f, 0.0f,
		-0.5f,  0.5f,  0.5f,  0.0f, 0.0f,
		-0.5f,  0.5f, -0.5f,  0.0f, 1.0f
	};
	glm::vec3 cubePositions[] = {
	  glm::vec3(0.0f,  0.0f,  0.0f),
	  glm::vec3(2.0f,  5.0f, -15.0f),
	  glm::vec3(-1.5f, -2.2f, -2.5f),
	  glm::vec3(-3.8f, -2.0f, -12.3f),
	  glm::vec3(2.4f, -0.4f, -3.5f),
	  glm::vec3(-1.7f,  3.0f, -7.5f),
	  glm::vec3(1.3f, -2.0f, -2.5f),
	  glm::vec3(1.5f,  2.0f, -2.5f),
	  glm::vec3(1.5f,  0.2f, -1.5f),
	  glm::vec3(-1.3f,  1.0f, -1.5f)
	};
	unsigned int VBO, VAO, texture;
	glGenBuffers(1, &VBO);
	glGenTextures(1, &texture);
	glGenVertexArrays(1, &VAO);
	glBindVertexArray(VAO);
	glBindTexture(GL_TEXTURE_2D, texture);
	glBindBuffer(GL_ARRAY_BUFFER, VBO);
	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);	//第一个是类型，第二个是大小，第三个是数据
	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
	glEnableVertexAttribArray(0);
	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
	glEnableVertexAttribArray(1);
	int width, height, nrChannels;
	unsigned char *data = stbi_load("container.jpg", &width, &height, &nrChannels, 0);
	if (data)
	{
		glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
		glGenerateMipmap(GL_TEXTURE_2D);
	}
	else
	{
		std::cout << "Failed to load texture" << std::endl;
	}
	stbi_image_free(data);
	unsigned int modelLoc = glGetUniformLocation(myshader.ID, "model");
	unsigned int viewLoc = glGetUniformLocation(myshader.ID, "view");
	unsigned int projectionLoc = glGetUniformLocation(myshader.ID, "projection");
	glEnable(GL_DEPTH_TEST);
	myshader.use();
	while (!glfwWindowShouldClose(window))
	{
		processInput(window);
		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
		glClearColor(0.0f, 0.5f, 1.0f, 1.0f);
		glClear(GL_COLOR_BUFFER_BIT);
		glm::mat4 view = glm::mat4(1.0f), projection = glm::mat4(1.0f);
		for (unsigned int i = 0; i < 10; i++)
		{
			glm::mat4 model = glm::mat4(1.0f);
			model = glm::translate(model, cubePositions[i]);
			model = glm::rotate(model, glm::radians(20.0f*i), glm::vec3(1.0f, 0.2f, 0.3f));
			unsigned int r = 5;
			float x = sin(glfwGetTime()) * r, z = cos(glfwGetTime()) * r;
			view = glm::lookAt(cameraPos, cameraPos + cameraFront, cameraUp);
			projection = glm::perspective(glm::radians(45.0f), (float)800 / (float)600, 0.1f, 100.0f);
			glUniformMatrix4fv(modelLoc, 1, GL_FALSE, glm::value_ptr(model));
			glUniformMatrix4fv(viewLoc, 1, GL_FALSE, glm::value_ptr(view));
			glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, glm::value_ptr(projection));
			glDrawArrays(GL_TRIANGLES, 0, 36);
		}
		glfwSwapBuffers(window);
		glfwPollEvents();
	}
	glDeleteVertexArrays(1, &VAO);
	glDeleteBuffers(1, &VBO);
	//关闭窗口
	glfwTerminate();
	return 0;
}