skybox基本实现

实现了skybox类，添加了一个skybox着色器，能正常显示，目前的bug为贴图上下颠倒

FinalProject/FinalProject.vcxproj

@@ -114,6 +114,7 @@
     <ClCompile Include="renderable.cpp" />
     <ClCompile Include="sceneviewer.cpp" />
     <ClCompile Include="shader.cpp" />
+    <ClCompile Include="skybox.cpp" />
     <ClCompile Include="texture.cpp" />
     <ClCompile Include="vao.cpp" />
     <ClCompile Include="vbo.cpp" />

FinalProject/FinalProject.vcxproj.filters

@@ -100,6 +100,9 @@
     <ClCompile Include="logger.cpp">
       <Filter>Source Files\Utils</Filter>
     </ClCompile>
+    <ClCompile Include="skybox.cpp">
+      <Filter>Source Files\OpenGL Abstractions</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="camera.h">

FinalProject/sceneviewer.cpp

@@ -11,6 +11,7 @@
 #include "shader.h"
 #include "logger.h"
 #include "model.h"
+#include "skybox.h"
 
 using std::vector;
 
@@ -65,10 +66,22 @@ void SceneViewer::initializeGL() {
     vertexShader.dispose();
     fragmentShader.dispose();
 
+    skyShader.ensureInitialized();
+
+    VertexShader vertexShader_sky("./temp/shaders/skyboxShader.vs");
+    FragmentShader fragmentShader_sky("./temp/shaders/skyboxShader.fs");
+    skyShader.attachShader(vertexShader_sky);
+    skyShader.attachShader(fragmentShader_sky);
+    vertexShader_sky.dispose();
+    fragmentShader_sky.dispose();
+
+
     Model* backpackModel = new Model("D:\\ProgrammingFile\\SceneEditor\\Models\\backpack\\backpack.obj");
     Logger::info("Model loaded");
     Renderable backpack(backpackModel);
     _objects.push_back(backpack);
+
+    sky = new skybox("D:/ProgrammingFile/SceneEditor/skybox");
     
     _camera.setPosition(glm::vec3(0.0f, 0.0f, 5.0f));
 }
@@ -93,6 +106,13 @@ void SceneViewer::paintGL() {
     }
 
     _shaderProgram.unbind();
+
+    skyShader.bind();
+    view = glm::mat4(glm::mat3(view));
+    skyShader.setUniform("view", view);
+    skyShader.setUniform("projection", projection);
+    sky->render();
+    skyShader.unbind();
 }
 
 void SceneViewer::mousePressEvent(QMouseEvent* event) {

FinalProject/sceneviewer.h

@@ -12,6 +12,7 @@
 #include "renderable.h"
 #include "vao.h"
 #include "utils.h"
+#include "skybox.h"
 
 class SceneViewer : public QOpenGLWidget, protected QOpenGLFunctions
 {
@@ -23,6 +24,8 @@ private:
     std::vector<Renderable> _objects;
     // Shader program for objects
     ShaderProgram _shaderProgram = ShaderProgram::empty();
+    ShaderProgram skyShader = ShaderProgram::empty();
+    skybox* sky;
     // Main camera
     Camera _camera;
     float _cameraMovementSpeed = 0.02f;

FinalProject/skybox.cpp

@@ -0,0 +1,69 @@
+#include "utils.h"
+#include "skybox.h"
+#include "shader.h"
+#include "camera.h"
+
+#include <STBImage/stb_image.h>
+#include <vector>
+#include <string>
+
+skybox::skybox(std::string path){
+    faces.clear();
+    faces.push_back(path + "/right.jpg");
+    faces.push_back(path + "/left.jpg");
+    faces.push_back(path + "/top.jpg");
+    faces.push_back(path + "/bottom.jpg");
+    faces.push_back(path + "/front.jpg");
+    faces.push_back(path + "/back.jpg");
+
+    cubemapTexture = loadCubemap(faces);
+    
+    OPENGL_EXTRA_FUNCTIONS->glGenVertexArrays(1, &skyboxVAO);
+    OPENGL_EXTRA_FUNCTIONS->glGenBuffers(1, &skyboxVBO);
+    OPENGL_EXTRA_FUNCTIONS->glBindVertexArray(skyboxVAO);
+    OPENGL_EXTRA_FUNCTIONS->glBindBuffer(GL_ARRAY_BUFFER, skyboxVBO);
+    OPENGL_EXTRA_FUNCTIONS->glBufferData(GL_ARRAY_BUFFER, sizeof(skyboxVertices), &skyboxVertices, GL_STATIC_DRAW);
+    OPENGL_EXTRA_FUNCTIONS->glEnableVertexAttribArray(0);
+    OPENGL_EXTRA_FUNCTIONS->glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
+}
+
+void skybox::render() {
+    OPENGL_EXTRA_FUNCTIONS->glDepthFunc(GL_LEQUAL);  // change depth function so depth test passes when values are equal to depth buffer's content
+    // skybox cube
+    OPENGL_EXTRA_FUNCTIONS->glBindVertexArray(skyboxVAO);
+    OPENGL_EXTRA_FUNCTIONS->glActiveTexture(GL_TEXTURE0);
+    OPENGL_EXTRA_FUNCTIONS->glBindTexture(GL_TEXTURE_CUBE_MAP, cubemapTexture);
+    OPENGL_EXTRA_FUNCTIONS->glDrawArrays(GL_TRIANGLES, 0, 36);
+    OPENGL_EXTRA_FUNCTIONS->glBindVertexArray(0);
+    OPENGL_EXTRA_FUNCTIONS->glDepthFunc(GL_LESS); // set depth function back to default
+}
+
+unsigned int skybox::loadCubemap(std::vector<std::string> faces)
+{
+    unsigned int textureID;
+    OPENGL_FUNCTIONS->glGenTextures(1, &textureID);
+    OPENGL_FUNCTIONS->glBindTexture(GL_TEXTURE_CUBE_MAP, textureID);
+
+    int width, height, nrChannels;
+    for (unsigned int i = 0; i < faces.size(); i++)
+    {
+        unsigned char* data = stbi_load(faces[i].c_str(), &width, &height, &nrChannels, 0);
+        if (data)
+        {
+            OPENGL_FUNCTIONS->glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, width, height, 0, GL_RGB, GL_UNSIGNED_BYTE, data);
+            stbi_image_free(data);
+        }
+        else
+        {
+            std::cout << "Cubemap texture failed to load at path: " << faces[i] << std::endl;
+            stbi_image_free(data);
+        }
+    }
+    OPENGL_FUNCTIONS->glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    OPENGL_FUNCTIONS->glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    OPENGL_FUNCTIONS->glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    OPENGL_FUNCTIONS->glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    OPENGL_FUNCTIONS->glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+
+    return textureID;
+}