LearnOpenGL-笔记5

有了games101的基础，光照这一部分看起来非常轻松。

颜色

把光源的颜色与物体的颜色值相乘，所得到的就是这个物体所反射的颜色（也就是我们所感知到的颜色）：

glm::vec3 lightColor(1.0f, 1.0f, 1.0f);
glm::vec3 toyColor(1.0f, 0.5f, 0.31f);
glm::vec3 result = lightColor * toyColor; // = (1.0f, 0.5f, 0.31f);

创建一个光照场景

1.光源
光源在光照场景中的样子没有任何作用，仅仅是在图像中表示光源的位置，方便观察也能够让图像显得更加真实。
光源的形状外貌不应该受到修改被光照物体着色器的影响，因此需要单独为光源写着色器。

light.vs:

#version 330 core
layout (location = 0) in vec3 aPos;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main()
{
   
	gl_Position = projection * view * model * vec4(aPos, 1.0);
}

light.fs:

#version 330 core
out vec4 Fragcolor;

void main()
{
   
	Fragcolor = vec4(1.0); 
	//注意，这样就可以把四个分量全部设置为1；
}

然后是物体的着色器：
color.vs:

#version 330 core
layout (location = 0) in vec3 aPos;

uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;

void main()
{
   
	gl_Position = projection * view * model * vec4(aPos, 1.0);
}

color.fs:

#version 330 core
out vec4 FragColor;

uniform vec3 objectColor;
uniform vec3 lightColor;

void main()
{
   
    FragColor = vec4(lightColor * objectColor, 1.0);
}

干净的场地.cpp:

#include <glad/glad.h>
#include <GLFW/glfw3.h>
#include <glm/glm.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <shader.h>
#include <camera.h>
#include <iostream>

void framebuffer_size_callback(GLFWwindow* window, int width, int height);
void mouse_callback(GLFWwindow* window, double xpos, double ypos);
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset);
void processInput(GLFWwindow* window);

const unsigned int SCR_WIDTH = 800;
const unsigned int SCR_HEIGHT = 600;

Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));
float lastX = SCR_WIDTH / 2.0f;
float lastY = SCR_HEIGHT / 2.0f;
bool firstMouse = true;
float deltaTime = 0.0f;
float lastFrame = 0.0f;
glm::vec3 lightPos(1.2f, 1.0f, 2.0f);

int main()
{
   
	glfwInit();
	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);
	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);

	GLFWwindow* window = glfwCreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", NULL, NULL);
	glfwMakeContextCurrent(window);
	glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
	glfwSetCursorPosCallback(window, mouse_callback);
	glfwSetScrollCallback(window, scroll_callback);
	glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED); //捕获并隐藏鼠标
	gladLoadGLLoader((GLADloadproc)glfwGetProcAddress);
	glEnable(GL_DEPTH_TEST);
	Shader objectShader("2.1color.vs", "2.1color.fs");
	Shader lightShader("2.1light.vs", "2.1light.fs");

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

    -0.5f, -0.5f,  0.5f,
     0.5f, -0.5f,  0.5f,
     0.5f,  0.5f,  0.5f,
     0.5f,  0.5f,  0.5f,
    -0.5f,  0.5f,  0.5f,
    -0.5f, -0.5f,  0.5f,

    -0.5f,  0.5f,  0.5f,
    -0.5f,  0.5f, -0.5f,
    -0.5f, -0.5f, -0.5f,
    -0.5f, -0.5f, -0.5f,
    -0.5f, -0.5f,  0.5f,
    -0.5f,  0.5f,  0.5f,

     0.5f,  0.5f,  0.5f,
     0.5f,  0.5f, -0.5f,
     0.5f, -0.5f, -0.5f,
     0.5f, -0.5f, -0.5f,
     0.5f, -0.5f,  0.5f,
     0.5f,  0.5f,  0.5f,

    -0.5f, -0.5f, -0.5f,
     0.5f, -0.5f, -0.5f,
     0.5f, -0.5f,  0.5f,
     0.5f, -0.5f,  0.5f,
    -0.5f, -0.5f,  0.5f,
    -0.5f, -0.5f, -0.5f,

    -0.5f,  0.5f, -0.5f,
     0.5f,  0.5f, -0.5f,
     0.5f,  0.5f,  0.5f,
     0.5f,  0.5f,  0.5f,
    -0.5f,  0.5f,  0.5f,
    -0.5f,  0.5f, -0.5f,
    };

    unsigned int VBO, lightVAO, objectVAO;
    glGenVertexArrays(1, &objectVAO);
    glGenVertexArrays(1, &lightVAO);
    glGenBuffers(1, &VBO);

    glBindBuffer(GL_ARRAY_BUFFER, VBO);
    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);

    glBindVertexArray(objectVAO);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    //glEnableVertexAttribArray应该在glVertexAttribPointer之前还是之后调用？
    //答案是都可以，只要在绘图调用（glDraw*系列函数）前调用即可。
    //使用glEnableVertexAttribArray，以顶点属性位置值作为参数，启用顶点属性

    glBindVertexArray(lightVAO);
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    while (!glfwWindowShouldClose(window))
    {
   
        float currentFrame = static_cast<float>(glfwGetTime());
        deltaTime = currentFrame - lastFrame;
        lastFrame = currentFrame;
        processInput(window);
        glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        objectShader.use();
        objectShader.setVec3("objectColor", 1.0f, 0.5f, 0.31f);
        objectShader.setVec3("lightColor", 1.0f, 1.0f, 1.0f);
        glm::mat4 projection = glm::perspective(glm::radians(camera.Zoom), (float)SCR_WIDTH / (float)SCR_HEIGHT, 0.1f, 100.0f);
        glm::mat4 view = camera.GetViewMatrix();
        glm::mat4 model = glm::mat4(1.0f);
        objectShader.setMat4("projection", projection);
        objectShader.setMat4("view", view);
        objectShader.setMat4("model"</