第一个3D程序！

 运行效果

CPP

#include <iostream>
#include <fstream>
#include <string>
#include <cmath>#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include <glm/glm.hpp>
#include <glm/gtc/type_ptr.hpp>
#include <glm/gtc/matrix_transform.hpp>
#include <soil2/SOIL2.h>#define PI 3.14159f#define numVAOs 1
#define numVBOs 128#define SPEED 0.1f
#define ANGLE 0.01fusing namespace std;GLuint rendering_program;
GLuint vao[numVAOs];
GLuint vbo[numVBOs];
GLuint vbo_count = 0;
GLuint mvloc, ploc, nloc;
GLuint clr_loc;
GLuint global_amb_loc, dirlight_amb_loc, dirlight_dif_loc, dirlight_dir_loc;int HEIGHT = 724, WIDTH = 1024;
float aspect = (float)WIDTH / (float)HEIGHT;glm::vec4 GlobalAmbient = { 0.5f, 0.5f, 0.5f, 1.0f };		//全局环境光
glm::vec4 DirLightAmbient = { 0.2f, 0.2f, 0.2f, 1.0f };		//定向光:环境特征
glm::vec4 DirLightDiffuse = { 0.35f, 0.35f, 0.35f, 1.0f };	//定向光:漫反射
glm::vec3 DirLightDirection = { -0.5f, -0.866f, 0.0f };glm::mat4 tmat;												//平移
glm::mat4 rmat;												//旋转
glm::mat4 vmat;												//t_mat * r_mat
glm::mat4 pmat;												//透视
glm::mat4 mvmat;
glm::mat4 invmat;											//mv矩阵的逆
glm::vec4 texture_color;struct Camera {float x, y, z;float theta, fine;
}camera;struct Plane {GLuint vbo_index[2] = { 0 };glm::vec3 position = { 0.0f, 0.0f, 0.0f };float vertex_positions[18] = {0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, 1.0f, 0.0f, 1.0f,1.0f, 0.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f};float vertex_normal[18] = {0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f,0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f, 0.0f, 1.0f, 0.0f};void init(float x, float y, float z) {vbo_index[0] = vbo_count++;vbo_index[1] = vbo_count++;position = { x, y, z };glBindBuffer(GL_ARRAY_BUFFER, vbo[vbo_index[0]]);glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_positions), vertex_positions, GL_STATIC_DRAW);glBindBuffer(GL_ARRAY_BUFFER, vbo[vbo_index[1]]);glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_normal), vertex_normal, GL_STATIC_DRAW);}void draw() {glUniformMatrix4fv(mvloc, 1, GL_FALSE, glm::value_ptr(mvmat));glUniformMatrix4fv(ploc, 1, GL_FALSE, glm::value_ptr(pmat));glUniformMatrix4fv(nloc, 1, GL_FALSE, glm::value_ptr(invmat));glUniform4fv(clr_loc, 1, glm::value_ptr(texture_color));glBindBuffer(GL_ARRAY_BUFFER, vbo[plane.vbo_index[0]]);glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(0);glBindBuffer(GL_ARRAY_BUFFER, vbo[plane.vbo_index[1]]);glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(1);glEnable(GL_DEPTH_TEST);glDepthFunc(GL_LEQUAL);glDrawArrays(GL_TRIANGLES, 0, 6);}
}plane;
struct Tetrahedron {GLuint vbo_index[2] = { 0 };glm::vec3 position = { 0.0f, 0.0f, 0.0f };float vertex_positions[36] = {0.0f, -0.408f, 1.155f, -1.0f, -0.408f, -0.577f, 1.0f, -0.408f, -0.577f,0.0f, -0.408f, 1.155f, 0.0f, 1.225f, 0.0f, -1.0f, -0.408f, -0.577f,0.0f, -0.408f, 1.155f, 1.0f, -0.408f, -0.577f, 0.0f, 1.225f, 0.0f,-1.0f, -0.408f, -0.577f, 0.0f, 1.225f, 0.0f, 1.0f, -0.408f, -0.577f};float vertex_normal[36] = {0.0f, -1.225f, -0.0f, 0.0f, -1.225f, 0.0f, 0.0f, -1.225f, 0.0f,-1.0f, 0.408f,-0.577f, -1.0f, 0.408f, 0.577f, -1.0f, 0.408f, 0.577f,1.0f, 0.408f, 0.577f, 1.0f, 0.408f, 0.577f, 1.0f, 0.408f, 0.577f,0.0f, 0.408f, -1.155f, 0.0f, 0.408f, -1.155f, 0.0f, 0.408f, -1.155f};void init(float x, float y, float z) {vbo_index[0] = vbo_count++;vbo_index[1] = vbo_count++;position = { x, y, z };glBindBuffer(GL_ARRAY_BUFFER, vbo[vbo_index[0]]);glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_positions), vertex_positions, GL_STATIC_DRAW);glBindBuffer(GL_ARRAY_BUFFER, vbo[vbo_index[1]]);glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_normal), vertex_normal, GL_STATIC_DRAW);}void draw() {glUniformMatrix4fv(mvloc, 1, GL_FALSE, glm::value_ptr(mvmat));glUniformMatrix4fv(ploc, 1, GL_FALSE, glm::value_ptr(pmat));glUniformMatrix4fv(nloc, 1, GL_FALSE, glm::value_ptr(invmat));glUniform4fv(clr_loc, 1, glm::value_ptr(glm::vec4(1.0f, 0.0f, 0.0f, 1.0f)));glBindBuffer(GL_ARRAY_BUFFER, vbo[tetrahedron.vbo_index[0]]);glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(0);glBindBuffer(GL_ARRAY_BUFFER, vbo[tetrahedron.vbo_index[1]]);glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(1);glEnable(GL_DEPTH_TEST);glDepthFunc(GL_LEQUAL);glDrawArrays(GL_TRIANGLES, 0, 12);}
}tetrahedron;
struct Icosahedron {GLuint vbo_index[2] = { 0 };glm::vec3 position = { 0.0f, 0.0f, 0.0f };float vertex_positions[180] = {-0.618f, 1.0f, 0.0f, 0.618f, 1.0f, 0.0f, 0.0f, 0.618f, -1.0f,0.618f, -1.0f, 0.0f, -0.618f, -1.0f, 0.0f, 0.0f, -0.618f, -1.0f,0.0f, 0.618f, -1.0f, -1.0f, 0.0f, -0.618f, -0.618f, 1.0f, 0.0f,-1.0f, 0.0f, -0.618f, 0.0f, -0.618f, -1.0f, -0.618f, -1.0f, 0.0f,0.618f, 1.0f, 0.0f, 1.0f, 0.0f, -0.618f, 0.0f, 0.618f, -1.0f,1.0f, 0.0f, -0.618f, 0.618f, -1.0f, 0.0f, 0.0f, -0.618f, -1.0f,-1.0f, 0.0f, -0.618f, 0.0f, 0.618f, -1.0f, 0.0f, -0.618f, -1.0f,0.0f, -0.618f, -1.0f, 0.0f, 0.618f, -1.0f, 1.0f, 0.0f, -0.618f,0.618f, 1.0f, 0.0f, -0.618f, 1.0f, 0.0f, 0.0f, 0.618f, 1.0f,-0.618f, -1.0f, 0.0f, 0.618f, -1.0f, 0.0f, 0.0f, -0.618f, 1.0f,-1.0f, 0.0f, 0.618f, 0.0f, 0.618f, 1.0f, -0.618f, 1.0f, 0.0f,-1.0f, 0.0f, 0.618f, -0.618f, -1.0f, 0.0f, 0.0f, -0.618f, 1.0f,0.618f, 1.0f, 0.0f, 0.0f, 0.618f, 1.0f, 1.0f, 0.0f, 0.618f,0.0f, -0.618f, 1.0f, 0.618f, -1.0f, 0.0f, 1.0f, 0.0f, 0.618f,0.0f, -0.618f, 1.0f, 0.0f, 0.618f, 1.0f, -1.0f, 0.0f, 0.618f,0.0f, 0.618f, 1.0f, 0.0f, -0.618f, 1.0f, 1.0f, 0.0f, 0.618f,-1.0f, 0.0f, 0.618f, -0.618f, 1.0f, 0.0f, -1.0f, 0.0f, -0.618f,-1.0f, 0.0f, 0.618f, -1.0f, 0.0f, -0.618f, -0.618f, -1.0f, 0.0f,1.0f, 0.0f, 0.618f, 1.0f, 0.0f, -0.618f, 0.618f, 1.0f, 0.0f,1.0f, 0.0f, -0.618f, 1.0f, 0.0f, 0.618f, 0.618f, -1.0f, 0.0f};float vertex_normal[180] = {0.0f, 2.618f, -1.0f, 0.0f, 2.618f, -1.0f, 0.0f, 2.618f, -1.0f,0.0f, -2.618f, -1.0f, 0.0f, -2.618f, -1.0f, 0.0f, -2.618f, -1.0f,-1.0f, 1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, -1.0f,-1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f, -1.0f,1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f,1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f,-1.0f, 0.0f, -2.618f, -1.0f, 0.0f, -2.618f, -1.0f, 0.0f, -2.618f,1.0f, 0.0f, -2.618f, 1.0f, 0.0f, -2.618f, 1.0f, 0.0f, -2.618f,0.0f, 2.618f, 1.0f, 0.0f, 2.618f, 1.0f, 0.0f, 2.618f, 1.0f,0.0f, -2.618f, 1.0f, 0.0f, -2.618f, 1.0f, 0.0f, -2.618f, 1.0f,-1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f,-1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f, -1.0f, -1.0f, 1.0f,1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f,1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f, 1.0f, -1.0f, 1.0f,-1.0f, 0.0f, 2.618f, -1.0f, 0.0f, 2.618f, -1.0f, 0.0f, 2.618f,1.0f, 0.0f, 2.618f, 1.0f, 0.0f, 2.618f, 1.0f, 0.0f, 2.618f,-2.618f, 1.0f, 0.0f, -2.618f, 1.0f, 0.0f, -2.618f, 1.0f, 0.0f,-2.618f, -1.0f, 0.0f, -2.618f, -1.0f, 0.0f, -2.618f, -1.0f, 0.0f,2.618f, 1.0f, 0.0f, 2.618f, 1.0f, 0.0f, 2.618f, 1.0f, 0.0f,2.618f, -1.0f, 0.0f, 2.618f, -1.0f, 0.0f, 2.618f, -1.0f, 0.0f};void init(float x, float y, float z) {vbo_index[0] = vbo_count++;vbo_index[1] = vbo_count++;position = { x, y, z };glBindBuffer(GL_ARRAY_BUFFER, vbo[vbo_index[0]]);glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_positions), vertex_positions, GL_STATIC_DRAW);glBindBuffer(GL_ARRAY_BUFFER, vbo[vbo_index[1]]);glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_normal), vertex_normal, GL_STATIC_DRAW);}void draw() {glUniformMatrix4fv(mvloc, 1, GL_FALSE, glm::value_ptr(mvmat));glUniformMatrix4fv(ploc, 1, GL_FALSE, glm::value_ptr(pmat));glUniformMatrix4fv(nloc, 1, GL_FALSE, glm::value_ptr(invmat));glUniform4fv(clr_loc, 1, glm::value_ptr(glm::vec4(1.0f, 0.0f, 0.0f, 1.0f)));glBindBuffer(GL_ARRAY_BUFFER, vbo[icosahedron.vbo_index[0]]);glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(0);glBindBuffer(GL_ARRAY_BUFFER, vbo[icosahedron.vbo_index[1]]);glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 0, 0);glEnableVertexAttribArray(1);glEnable(GL_DEPTH_TEST);glDepthFunc(GL_LEQUAL);glDrawArrays(GL_TRIANGLES, 0, 60);}
}icosahedron;string ReadShaderSource(const char* file_path) {string content;string line = "";ifstream file_stream(file_path, ios::in);while (!file_stream.eof()) {getline(file_stream, line);content.append(line + "\n");}file_stream.close();return content;
}
void PrintShaderLog(GLuint shader) {int len = 0;int ch_writtn = 0;char* log;glGetShaderiv(shader, GL_INFO_LOG_LENGTH, &len);if (len > 0) {log = (char*)malloc(len);glGetShaderInfoLog(shader, len, &ch_writtn, log);cout << "Shader Info Log:" << log << endl;free(log);}
}
void PrintProgramLog(GLuint program) {int len = 0;int ch_writtn = 0;char* log;glGetProgramiv(program, GL_INFO_LOG_LENGTH, &len);if (len > 0) {log = (char*)malloc(len);glGetProgramInfoLog(program, len, &ch_writtn, log);cout << "Program Info Log:" << log << endl;free(log);}
}
bool CheckOpenGLError() {bool found_error = false;int glerr = glGetError();while (glerr != GL_NO_ERROR) {cout << "GL ERROR:" << glerr << endl;found_error = true;glerr = glGetError();}return found_error;
}
GLuint CreateShaderProgram() {GLuint vshader = glCreateShader(GL_VERTEX_SHADER);GLuint fshader = glCreateShader(GL_FRAGMENT_SHADER);GLint vert_compiled;GLint frag_compiled;GLint linked;string vert_shader_string = ReadShaderSource("vert_shader.glsl");string frag_shader_string = ReadShaderSource("frag_shader.glsl");const char* vert_shader_source = vert_shader_string.c_str();const char* frag_shader_source = frag_shader_string.c_str();glShaderSource(vshader, 1, &vert_shader_source, NULL);glShaderSource(fshader, 1, &frag_shader_source, NULL);glCompileShader(vshader);CheckOpenGLError();glGetShaderiv(vshader, GL_COMPILE_STATUS, &vert_compiled);if (vert_compiled != 1) {cout << "vertex compilation failed" << endl;PrintShaderLog(vshader);}glCompileShader(fshader);CheckOpenGLError();glGetShaderiv(fshader, GL_COMPILE_STATUS, &frag_compiled);if (frag_compiled != 1) {cout << "fragment compilation failed" << endl;PrintShaderLog(fshader);}GLuint program = glCreateProgram();glAttachShader(program, vshader);glAttachShader(program, fshader);glLinkProgram(program);CheckOpenGLError();glGetProgramiv(program, GL_LINK_STATUS, &linked);if (linked != 1) {cout << "linking failed" << endl;PrintProgramLog(program);}return program;
}
GLuint LoadTexture(const char* ImagePath) {GLuint textureID;textureID = SOIL_load_OGL_texture(ImagePath, SOIL_LOAD_AUTO, SOIL_CREATE_NEW_ID, SOIL_FLAG_INVERT_Y);if (textureID == 0) cout << "could not find texture file:" << ImagePath << endl;return textureID;
}
void init(GLFWwindow* window) {vmat = glm::mat4(1.0f);rmat = glm::mat4(1.0f);pmat = glm::perspective(1.3f, aspect, 0.1f, 1000.0f);rendering_program = CreateShaderProgram();glGenVertexArrays(numVAOs, vao);glBindVertexArray(vao[0]);glGenBuffers(numVBOs, vbo);tetrahedron.init(4.0f, 4.0f, 0.0f);icosahedron.init(0.0f, 4.0f, 4.0f);plane.init(0.0f, 0.0f, 0.0f);
}
void MoveCamera(GLFWwindow* window) {bool translate = false;bool rotato = false;if (glfwGetKey(window, GLFW_KEY_W) == GLFW_PRESS) {camera.x -= (float)sin(camera.theta) * SPEED;camera.z -= (float)cos(camera.theta) * SPEED;translate = true;}if (glfwGetKey(window, GLFW_KEY_S) == GLFW_PRESS) {camera.x += (float)sin(camera.theta) * SPEED;camera.z += (float)cos(camera.theta) * SPEED;translate = true;}if (glfwGetKey(window, GLFW_KEY_A) == GLFW_PRESS) {camera.x -= (float)cos(camera.theta) * SPEED;camera.z += (float)sin(camera.theta) * SPEED;translate = true;}if (glfwGetKey(window, GLFW_KEY_D) == GLFW_PRESS) {camera.x += (float)cos(camera.theta) * SPEED;camera.z -= (float)sin(camera.theta) * SPEED;translate = true;}if (glfwGetKey(window, GLFW_KEY_SPACE) == GLFW_PRESS) {camera.y += SPEED;translate = true;}if (glfwGetKey(window, GLFW_KEY_R) == GLFW_PRESS) {camera.y -= SPEED;translate = true;}if (glfwGetKey(window, GLFW_KEY_UP) == GLFW_PRESS) {if (camera.fine < PI / 2.0) {camera.fine += ANGLE;rotato = true;}}if (glfwGetKey(window, GLFW_KEY_DOWN) == GLFW_PRESS) {if (camera.fine > -PI / 2.0) {camera.fine -= ANGLE;rotato = true;}}if (glfwGetKey(window, GLFW_KEY_LEFT) == GLFW_PRESS) {camera.theta += ANGLE;rotato = true;}if (glfwGetKey(window, GLFW_KEY_RIGHT) == GLFW_PRESS) {camera.theta -= ANGLE;rotato = true;}if (translate) tmat = glm::translate(glm::mat4(1.0f), glm::vec3(-camera.x, -camera.y, -camera.z));if (rotato) rmat = {{ cos(camera.theta)  , sin(camera.fine) * sin(camera.theta), cos(camera.fine) * sin(camera.theta), 0.0f },{ 0.0f				 , cos(camera.fine)					 , -sin(camera.fine)				   , 0.0f },{ -sin(camera.theta) , sin(camera.fine) * cos(camera.theta), cos(camera.fine) * cos(camera.theta), 0.0f },{ 0.0f				 , 0.0f								 , 0.0f								   , 1.0f }};if (translate || rotato) vmat = rmat * tmat;
}
void WindowReshapeCallback(GLFWwindow* window, int new_width, int new_height) {WIDTH = new_width;HEIGHT = new_height;aspect = (float)WIDTH / (float)HEIGHT;pmat = glm::perspective(1.3f, aspect, 0.1f, 1000.0f);glViewport(0, 0, WIDTH, HEIGHT);
}
void InstallLight() {global_amb_loc = glGetUniformLocation(rendering_program, "GlobalAmbient");dirlight_amb_loc = glGetUniformLocation(rendering_program, "DirLightAmbient");dirlight_dif_loc = glGetUniformLocation(rendering_program, "DirLightDiffuse");dirlight_dir_loc = glGetUniformLocation(rendering_program, "DirLightDirection");glProgramUniform4fv(rendering_program, global_amb_loc, 1, glm::value_ptr(GlobalAmbient));glProgramUniform4fv(rendering_program, dirlight_amb_loc, 1, glm::value_ptr(DirLightAmbient));glProgramUniform4fv(rendering_program, dirlight_dif_loc, 1, glm::value_ptr(DirLightDiffuse));glProgramUniform3fv(rendering_program, dirlight_dir_loc, 1, glm::value_ptr(DirLightDirection));
}
void display(GLFWwindow* window, double curretTime) {glClear(GL_DEPTH_BUFFER_BIT);glClear(GL_COLOR_BUFFER_BIT);glUseProgram(rendering_program);InstallLight();mvloc = glGetUniformLocation(rendering_program, "mvmat");ploc = glGetUniformLocation(rendering_program, "pmat");nloc = glGetUniformLocation(rendering_program, "nmat");clr_loc = glGetUniformLocation(rendering_program, "texture_color");glDisable(GL_CULL_FACE);for (int x = -32; x < 32; x++)for (int z = -32; z < 32; z++) {glm::mat4 mmat_p = glm::translate(glm::mat4(1.0f), glm::vec3((float)x, 0.0f, (float)z));if ((x + z) & 1)texture_color = { 0.0f, 1.0f, 0.0f, 1.0f };elsetexture_color = { 0.0f, 0.0f, 1.0f, 1.0f };mvmat = vmat * mmat_p;invmat = glm::transpose(glm::inverse(mvmat));plane.draw();}glEnable(GL_CULL_FACE);glm::mat4 mmat_t = glm::translate(glm::mat4(1.0f), tetrahedron.position);mvmat = vmat * mmat_t;invmat = glm::transpose(glm::inverse(mvmat));texture_color = { 1.0f, 0.0f, 0.0f, 1.0f };tetrahedron.draw();glm::mat4 mmat_i = glm::translate(glm::mat4(1.0f), icosahedron.position);mvmat = vmat * mmat_i;invmat = glm::transpose(glm::inverse(mvmat));texture_color = { 1.0f, 0.0f, 0.0f, 1.0f };icosahedron.draw();
}
int main() {if (!glfwInit()) { exit(EXIT_FAILURE); }glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 4);glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);GLFWwindow* window = glfwCreateWindow(WIDTH, HEIGHT, "HelloWorld", NULL, NULL);glfwMakeContextCurrent(window);if (glewInit() != GLEW_OK) { exit(EXIT_FAILURE); }glfwSwapInterval(1);glfwSetWindowSizeCallback(window, WindowReshapeCallback);init(window);while (!glfwWindowShouldClose(window)) {MoveCamera(window);display(window, glfwGetTime());glfwSwapBuffers(window);glfwPollEvents();}glfwDestroyWindow(window);glfwTerminate();exit(EXIT_SUCCESS);
}

顶点着色器

#version 430layout (location=0) in vec3 position;
layout (location=1) in vec3 normal;out vec3 varying_normal;
out vec3 varying_direction;uniform mat4 mvmat;
uniform mat4 pmat;
uniform mat4 nmat;
uniform vec4 texture_color;
h
uniform vec4 GlobalAmbient;
uniform vec4 DirLightAmbient;
uniform vec4 DirLightDiffuse;
uniform vec3 DirLightDirection;void main(void) {varying_normal = (nmat * vec4(normal, 1.0)).xyz;varying_direction = (nmat * vec4(DirLightDirection, 1.0)).xyz;gl_Position = pmat * mvmat * vec4(position, 1.0);
}

片段着色器

#version 430in vec3 varying_normal;
in vec3 varying_direction;out vec4 color;uniform mat4 mvmat;
uniform mat4 pmat;
uniform mat4 nmat;
uniform vec4 texture_color;uniform vec4 GlobalAmbient;
uniform vec4 DirLightAmbient;
uniform vec4 DirLightDiffuse;
uniform vec3 DirLightDirection;void main(void) {vec3 L = normalize(varying_direction);vec3 N = normalize(varying_normal);float cos_theta = dot(L, N);vec3 ambient = GlobalAmbient.xyz * texture_color.xyz + DirLightAmbient.xyz * texture_color.xyz;vec3 diffuse = texture_color.xyz * DirLightDiffuse.xyz * max(cos_theta, 0.0);color = vec4(ambient + diffuse, 1.0);
}