main.cpp
#define GLEW_STATIC
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <iostream>
#include "shader.h"
#include "stb_image.h"
#include <glm.hpp>
#include <gtc/matrix_transform.hpp>
#include <gtc/type_ptr.hpp>
#include "Camera.h"
GLfloat 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)
};
Camera* myCamera = new Camera(glm::vec3(0.0f, 0.0f, 3.0f), glm::vec3(0.0f, 0.0f, -1.0f), glm::vec3(0.0f, 1.0f, 0.0f));
void mouse_callback(GLFWwindow* window, double xpos, double ypos) {
myCamera->mouseCb(xpos, ypos);
};
void scroll_callback(GLFWwindow* window, double xoffset, double yoffset)
{
myCamera->scrollCb(xoffset, yoffset);
}
GLfloat deltaTime = 0.0f;
GLfloat lastFrame = 0.0f;
void processInput(GLFWwindow* window) {
GLfloat currentFrame = glfwGetTime();
deltaTime = currentFrame - lastFrame;
lastFrame = currentFrame;
if (glfwGetKey(window, GLFW_KEY_ESCAPE) == GLFW_PRESS)
glfwSetWindowShouldClose(window, true);
if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) {
myCamera->pressKeyW(deltaTime);
}
if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) {
myCamera->pressKeyS(deltaTime);
}
if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) {
myCamera->pressKeyA(deltaTime);
}
if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) {
myCamera->pressKeyD(deltaTime);
}
}
glm::vec3 lightPos(1.2f, 1.0f, 2.0f);//声明全局变量表示光源在场景的坐标
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(800, 600, "test", nullptr, nullptr);
if (window == nullptr)
{
std::cout << "Failed to create GLFW window" << std::endl;
glfwTerminate();
return -1;
}
glfwMakeContextCurrent(window);
glfwSetInputMode(window, GLFW_CURSOR, GLFW_CURSOR_DISABLED);
glfwSetCursorPosCallback(window, mouse_callback);
glfwSetScrollCallback(window, scroll_callback);
glewExperimental = GL_TRUE;
if (glewInit() != GLEW_OK)
{
std::cout << "Failed to initialize GLEW" << std::endl;
glfwTerminate();
return -1;
}
glViewport(0, 0, 800, 600);
GLuint VAO;
glGenVertexArrays(1, &VAO);
glBindVertexArray(VAO);
GLuint VBO;
glGenBuffers(1, &VBO);
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(0);
GLuint lightVAO;
glGenVertexArrays(1, &lightVAO);
glBindVertexArray(lightVAO);
// 只需要绑定VBO不用再次设置VBO的数据，因为容器(物体)的VBO数据中已经包含了正确的立方体顶点数据
glBindBuffer(GL_ARRAY_BUFFER, VBO);
glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);
glEnableVertexAttribArray(0);
glBindVertexArray(0);
glm::mat4 model;
glm::mat4 view;
glm::mat4 projection;
glEnable(GL_DEPTH_TEST);
Shader* testShader = new Shader("test.vert", "test.frag");
//glm::vec3 lightColor(1.0f, 1.0f, 1.0f);//定义一个白色光源
//glm::vec3 toyColor(1.0f, 0.5f, 0.31f);//定义一个珊瑚色物体，吸收除珊瑚色以外的所有颜色，反射珊瑚色
//glm::vec3 result = lightColor * toyColor; // = (1.0f, 0.5f, 0.31f);
可以定义物体的颜色为这个物体从一个光源反射各个颜色分量的多少
//glm::vec3 lightColor(0.0f, 1.0f, 0.0f);//定义绿光
//glm::vec3 toyColor(1.0f, 0.5f, 0.31f);
//glm::vec3 result = lightColor * toyColor;
= (0.0f, 0.5f, 0.0f);没有红蓝色光吸收，只吸收了光线中一半的绿色，反射一半的绿光。呈暗绿色
glm::vec3 lightColor(0.33f, 0.42f, 0.18f);
glm::vec3 toyColor(1.0f, 0.5f, 0.31f);
glm::vec3 result = lightColor * toyColor; // = (0.33f, 0.21f, 0.06f);
//保持灯不受其他光照影响一直明亮，创建另外一套着色器。
Shader* lightShader = new Shader("test.vert", "light.frag");
while (!glfwWindowShouldClose(window))
{
processInput(window);
glfwPollEvents();
glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);
testShader->Use();
glUniform3f(glGetUniformLocation(testShader->getProgram(), "objectColor"), 1.0f, 0.5f, 0.31f);// 设置物体颜色珊瑚红
glUniform3f(glGetUniformLocation(testShader->getProgram(), "lightColor"), 1.0f, 1.0f, 1.0f); // 把光源设置为白色
model = glm::mat4();
glUniformMatrix4fv(glGetUniformLocation(testShader->getProgram(), "model"), 1, GL_FALSE, glm::value_ptr(model));
view = myCamera->getViewMat4();
glUniformMatrix4fv(glGetUniformLocation(testShader->getProgram(), "view"), 1, GL_FALSE, glm::value_ptr(view));
projection = glm::perspective(glm::radians(myCamera->getFov()), 800.0f / 600.0f, 0.1f, 100.0f);
glUniformMatrix4fv(glGetUniformLocation(testShader->getProgram(), "projection"), 1, GL_FALSE, glm::value_ptr(projection));
glBindVertexArray(VAO);
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(lightVAO);
//平移灯源位置到lightPos
model = glm::mat4();
model = glm::translate(model, lightPos);
model = glm::scale(model, glm::vec3(0.2f));
lightShader->Use();
glUniformMatrix4fv(glGetUniformLocation(lightShader->getProgram(), "model"), 1, GL_FALSE, glm::value_ptr(model));
glUniformMatrix4fv(glGetUniformLocation(lightShader->getProgram(), "view"), 1, GL_FALSE, glm::value_ptr(view));
glUniformMatrix4fv(glGetUniformLocation(lightShader->getProgram(), "projection"), 1, GL_FALSE, glm::value_ptr(projection));
// 绘制灯立方体对象
glDrawArrays(GL_TRIANGLES, 0, 36);
glBindVertexArray(0);
glfwSwapBuffers(window);
}
glfwTerminate();
return 0;
}
顶点着色器
#version 330 core
layout (location = 0) in vec3 position;
out vec2 TextCoord;
uniform mat4 model;
uniform mat4 view;
uniform mat4 projection;
void main()
{
gl_Position = projection * view * model * vec4(position, 1.0);
}
物体片段着色器
#version 330 core
out vec4 color;
uniform vec3 objectColor;
uniform vec3 lightColor;
void main()
{
color = vec4(lightColor * objectColor, 1.0f);
}
灯源着色器
#version 330 core
out vec4 color;
void main()
{
color = vec4(1.0f); //设置四维向量的所有元素为 1.0f
}