OpenGL Shader 绘制天空盒_基础 2

参考:

http://learnopengl-cn.readthedocs.io/zh/latest/04%20Advanced%20OpenGL/06%20Cubemaps/

源码:

http://download.csdn.net/detail/yulinxx/9719755

main.cpp

#define GLEW_STATIC  #include <GL/glew.h>  #include <GLFW/glfw3.h>  #include "Shader.h"  #include "Camera.h"  #include <glm/glm.hpp>  #include <glm/gtc/matrix_transform.hpp>  #include <glm/gtc/type_ptr.hpp>  #include <SOIL/SOIL.h>  #include <vector>  #pragma comment (lib, "opengl32.lib")  #pragma comment (lib, "glew32s.lib")  #pragma comment (lib, "glfw3.lib")   #pragma comment (lib, "glfw3dll.lib")   #pragma comment (lib, "glew32mxs.lib")  #pragma comment (lib, "assimp.lib")  #pragma comment(lib, "SOIL.lib")  GLuint WIDTH = 800, HEIGHT = 600;void key_callback(GLFWwindow* pWnd, int key, int scancode, int action, int mode);void mouse_callback(GLFWwindow* pWnd, double xpos, double ypos);void Do_Movement();GLuint loadTexture(GLchar* path, GLboolean alpha = false);GLuint loadCubemapTexture(std::vector<const GLchar *> vecSkyfaces);Camera camera(glm::vec3(0.0f, 0.0f, 3.0f));bool keys[1024];GLfloat lastX = 400, lastY = 300;bool firstMouse = true;GLfloat deltaTime = 0.0f;GLfloat lastFrame = 0.0f;// ******************************************************int main(){glfwInit();glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3);glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);GLFWwindow* pWnd = glfwCreateWindow(WIDTH, HEIGHT, "LearnOpenGL", nullptr, nullptr); // Windowed  glfwMakeContextCurrent(pWnd);glfwSetKeyCallback(pWnd, key_callback);glfwSetCursorPosCallback(pWnd, mouse_callback);//glfwSetInputMode(pWnd, GLFW_CURSOR, GLFW_CURSOR_DISABLED);  glewExperimental = GL_TRUE;glewInit();glViewport(0, 0, WIDTH, HEIGHT);// 立方体  GLfloat cubeVertices[] = {-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};// 地面  GLfloat floorVertices[] = {5.0f,  -0.5f,  5.0f,  2.0f, 0.0f,-5.0f, -0.5f,  5.0f,  0.0f, 0.0f,-5.0f, -0.5f, -5.0f,  0.0f, 2.0f,5.0f,  -0.5f,  5.0f,  2.0f, 0.0f,-5.0f, -0.5f, -5.0f,  0.0f, 2.0f,5.0f,  -0.5f, -5.0f,  2.0f, 2.0f};// 天空盒GLfloat skyboxVertices[] = {-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, -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,  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};// 数据处理// 地面  GLuint floorVAO, floorVBO;glGenVertexArrays(1, &floorVAO);glBindVertexArray(floorVAO);{glGenBuffers(1, &floorVBO);glBindBuffer(GL_ARRAY_BUFFER, floorVBO);glBufferData(GL_ARRAY_BUFFER, sizeof(floorVertices), floorVertices, GL_STATIC_DRAW);glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (void*)0);glEnableVertexAttribArray(0);glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (void*)(3 * sizeof(GLfloat)));glEnableVertexAttribArray(1);}glBindVertexArray(0);// 盒子GLuint cubeVAO, cubeVBO;glGenVertexArrays(1, &cubeVAO);{glGenBuffers(1, &cubeVBO);glBindVertexArray(cubeVAO);glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVertices), &cubeVertices, GL_STATIC_DRAW);glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)0);glEnableVertexAttribArray(0);glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(GLfloat), (GLvoid*)(3 * sizeof(GLfloat)));glEnableVertexAttribArray(1);}glBindVertexArray(0);// 天空GLuint skyboxVAO, skyboxVBO;glGenVertexArrays(1, &skyboxVAO);glBindVertexArray(skyboxVAO);{glGenBuffers(1, &skyboxVBO);glBindBuffer(GL_ARRAY_BUFFER, skyboxVBO);glBufferData(GL_ARRAY_BUFFER, sizeof(skyboxVertices), skyboxVertices, GL_STATIC_DRAW);glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GL_FLOAT), (void*)0);glEnableVertexAttribArray(0);glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(GL_FLOAT), (void*)(2 * sizeof(GL_FLOAT)));glEnableVertexAttribArray(1);}glBindVertexArray(0);// Shader  Shader shaderCube("./Shader/cube_vertex", "./Shader/cube_fragement");Shader shaderFloor("./Shader/floor_vertex", "./Shader/floor_fragement");Shader shaderSkybox("./Shader/skybox_vertex", "./Shader/skybox_fragement");// 纹理  GLuint textCube = loadTexture("./Img/cube.jpg");GLuint textFloor = loadTexture("./Img/floor.jpg");std::vector<const GLchar*> vecSkyfaces;vecSkyfaces.push_back("./img/skybox/right.jpg");vecSkyfaces.push_back("./img/skybox/left.jpg");vecSkyfaces.push_back("./img/skybox/top.jpg");vecSkyfaces.push_back("./img/skybox/bottom.jpg");vecSkyfaces.push_back("./img/skybox/back.jpg");vecSkyfaces.push_back("./img/skybox/front.jpg");GLuint textureCubemap = loadCubemapTexture(vecSkyfaces);// 视图设置glm::mat4 model = glm::mat4();glm::mat4 view = camera.GetViewMatrix();glm::mat4 projection = glm::perspective(camera.Zoom, (float)WIDTH / (float)HEIGHT, 0.0f, 100.0f);// 主循环while (!glfwWindowShouldClose(pWnd)){GLfloat currentFrame = glfwGetTime();deltaTime = currentFrame - lastFrame;lastFrame = currentFrame;glfwPollEvents();Do_Movement();glClearColor(0.1f, 0.2f, 0.3f, 1.0f);glClear(GL_COLOR_BUFFER_BIT);// 绘制天空盒shaderSkybox.useShaderPrograme();view = glm::mat4(glm::mat3(camera.GetViewMatrix()));glUniformMatrix4fv(glGetUniformLocation(shaderSkybox.getPrograme(), "view"),1, GL_FALSE, glm::value_ptr(view));glUniformMatrix4fv(glGetUniformLocation(shaderSkybox.getPrograme(), "projection"),1, GL_FALSE, glm::value_ptr(projection));glBindVertexArray(cubeVAO);// 使用天空盒数据{glActiveTexture(GL_TEXTURE0);glUniform1i(glGetUniformLocation(shaderSkybox.getPrograme(), "skybox"), 0);glBindTexture(GL_TEXTURE_CUBE_MAP, textureCubemap); // 使用天空盒数据纹理{glDrawArrays(GL_TRIANGLES, 0, 36);}glBindTexture(GL_TEXTURE_CUBE_MAP, 0);}glBindVertexArray(0);view = camera.GetViewMatrix();// 绘制地面shaderFloor.useShaderPrograme();glBindVertexArray(floorVAO);{glUniformMatrix4fv(glGetUniformLocation(shaderFloor.getPrograme(), "model"),1, GL_FALSE, glm::value_ptr(model));glUniformMatrix4fv(glGetUniformLocation(shaderFloor.getPrograme(), "view"),1, GL_FALSE, glm::value_ptr(view));glUniformMatrix4fv(glGetUniformLocation(shaderFloor.getPrograme(), "projection"),1, GL_FALSE, glm::value_ptr(projection));glActiveTexture(GL_TEXTURE0);glBindTexture(GL_TEXTURE_2D, textFloor);{glDrawArrays(GL_TRIANGLES, 0, 6);}glBindTexture(GL_TEXTURE_2D, 0);}glBindVertexArray(0);// 绘制立方体shaderCube.useShaderPrograme();glBindVertexArray(cubeVAO);// 使用立方体数据{glUniformMatrix4fv(glGetUniformLocation(shaderCube.getPrograme(), "model"),1, GL_FALSE, glm::value_ptr(model));glUniformMatrix4fv(glGetUniformLocation(shaderCube.getPrograme(), "view"),1, GL_FALSE, glm::value_ptr(view));glUniformMatrix4fv(glGetUniformLocation(shaderCube.getPrograme(), "projection"),1, GL_FALSE, glm::value_ptr(projection));glUniform3f(glGetUniformLocation(shaderCube.getPrograme(), "cameraPos"), camera.Position.x, camera.Position.y, camera.Position.z);glActiveTexture(GL_TEXTURE0);glUniform1i(glGetUniformLocation(shaderCube.getPrograme(), "inTexture"), 0);glBindTexture(GL_TEXTURE_CUBE_MAP, skyboxVAO);// 使用天空盒的纹理{glDrawArrays(GL_TRIANGLES, 0, 36);}glBindTexture(GL_TEXTURE_2D, 0);}glBindVertexArray(0);glfwSwapBuffers(pWnd);}// While 循环之后  清理资源,退出程序  glDeleteVertexArrays(1, &cubeVAO);glDeleteVertexArrays(1, &floorVAO);glDeleteVertexArrays(1, &skyboxVAO);glDeleteBuffers(1, &cubeVBO);glDeleteBuffers(1, &floorVBO);glDeleteBuffers(1, &skyboxVBO);glfwTerminate();return 0;}// ******************************************************// 加载纹理  GLuint loadTexture(GLchar* path, GLboolean alpha /*= false*/){int nPicW = 0, nPicH = 0;unsigned char* pChImg =SOIL_load_image(path, &nPicW, &nPicH, 0, alpha ? SOIL_LOAD_RGBA : SOIL_LOAD_RGB);GLuint textureID = 0;glGenTextures(1, &textureID);glBindTexture(GL_TEXTURE_2D, textureID);{glTexImage2D(GL_TEXTURE_2D, 0, alpha ? GL_RGBA : GL_RGB, nPicW, nPicH, 0,alpha ? GL_RGBA : GL_RGB, GL_UNSIGNED_BYTE, pChImg);glGenerateMipmap(GL_TEXTURE_2D);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, alpha ? GL_CLAMP_TO_EDGE : GL_REPEAT);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, alpha ? GL_CLAMP_TO_EDGE : GL_REPEAT);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);}glBindTexture(GL_TEXTURE_2D, 0);SOIL_free_image_data(pChImg);return textureID;}// ******************************************************// 加载天空盒纹理GLuint loadCubemapTexture(std::vector<const GLchar *> vecSkyfaces){GLuint textureId = 0;glGenTextures(1, &textureId);glBindTexture(GL_TEXTURE_CUBE_MAP, textureId);{int nW = 0, nH = 0;unsigned char* pChImg = nullptr;for (int i = 0; i < vecSkyfaces.size(); i++){pChImg = SOIL_load_image(vecSkyfaces[i], &nW, &nH, 0, SOIL_LOAD_RGB);glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB,nW, nH, 0, GL_RGB, GL_UNSIGNED_BYTE, pChImg);SOIL_free_image_data(pChImg);}glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);}glBindTexture(GL_TEXTURE_CUBE_MAP, 0);return textureId;}// ******************************************************void Do_Movement(){if (keys[GLFW_KEY_W])camera.ProcessKeyboard(FORWARD, deltaTime);if (keys[GLFW_KEY_S])camera.ProcessKeyboard(BACKWARD, deltaTime);if (keys[GLFW_KEY_A])camera.ProcessKeyboard(LEFT, deltaTime);if (keys[GLFW_KEY_D])camera.ProcessKeyboard(RIGHT, deltaTime);}// ******************************************************void key_callback(GLFWwindow* window, int key, int scancode, int action, int mode){if (key == GLFW_KEY_ESCAPE && action == GLFW_PRESS)glfwSetWindowShouldClose(window, GL_TRUE);if (action == GLFW_PRESS)keys[key] = true;else if (action == GLFW_RELEASE)keys[key] = false;}// ******************************************************void mouse_callback(GLFWwindow* window, double xpos, double ypos){if (firstMouse){lastX = xpos;lastY = ypos;firstMouse = false;}GLfloat xoffset = xpos - lastX;GLfloat yoffset = lastY - ypos;lastX = xpos;lastY = ypos;camera.ProcessMouseMovement(xoffset, yoffset);}

Camera.h   Shader.h 参考之前的文章

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Shader  GLSL 语言部分

地面  立方体   天空  绘制渲染方式不一样

所以分别给它们定义Shader

地面

floor_vertex

#version 330 core    layout (location = 0) in vec3 position;    layout (location = 1) in vec2 texCoords;        out vec2 TexCoords;        uniform mat4 model;    uniform mat4 view;    uniform mat4 projection;        void main()    {        gl_Position = projection * view * model * vec4(position, 1.0f);        TexCoords = texCoords;    }

floor_fragement

#version 330 core        in vec2 TexCoords;        out vec4 color;        uniform sampler2D inTexture;        void main()    {        color = texture(inTexture, TexCoords);    } 

立方体

cube_vertex

// ================  #version 330 core  layout (location = 0) in vec3 pos;  layout (location = 1) in vec3 normal;  //out vec2 TexCoords;  out vec3 Normal;out vec3 Pos; uniform mat4 model;  uniform mat4 view;  uniform mat4 projection;    void main()  {      gl_Position = projection * view * model * vec4(pos, 1.0f);      //TexCoords = texCoords;  Normal = mat3(transpose(inverse(model))) * normal;Pos = vec3(model * vec4(pos, 1.0f));}  

cube_fragement

// ================  #version 330 core  //in vec2 TexCoords;  in vec3 Normal;in vec3 Pos;out vec4 color;  uniform vec3 cameraPos;  uniform samplerCube skybox;//uniform sampler2D inTexture;    void main()  {      //color = texture(inTexture, TexCoords);  vec3 I = normalize(Pos - cameraPos);vec3 R = reflect(I, normalize(Normal));color = texture(skybox, R);}  

天空

skybox_vertex

#version 330 core  layout (location = 0) in vec3 position;out vec3 TexCoords;  uniform mat4 view;uniform mat4 projection;  void main()  {      gl_Position = projection * view * vec4(position, 1.0f);      TexCoords = position;}

skybox_fragement

// ================  #version 330 corein vec3 TexCoords;out vec4 color;uniform samplerCube skybox;void main(){    color = texture(skybox, TexCoords);}