Add Skybox

.gitignore

@@ -2,3 +2,4 @@ build
 .directory
 lib/assimp/libassimp.so.5.0.0
 res/models
+res/textures

imgui.ini

@@ -9,7 +9,7 @@ Size=894,195
 Collapsed=0
 
 [Window][Debug Utils]
-Pos=14,16
+Pos=39,30
 Size=908,204
 Collapsed=0
 

res/shaders/skybox.frag

@@ -0,0 +1,13 @@
+#version 330 core
+
+layout(location = 0) out vec4 f_color;
+
+in vec3 v_texCoord;
+
+uniform samplerCube u_skybox;
+
+void main() {
+
+    f_color = texture(u_skybox, v_texCoord);
+
+}  

res/shaders/skybox.vert

@@ -0,0 +1,17 @@
+#version 330 core
+
+layout(location = 0) in vec3 a_position;
+
+out vec3 v_texCoord;
+
+uniform mat4 projection;
+uniform mat4 view;
+uniform mat4 u_viewProjectionMatrix;
+
+void main() {
+    
+    gl_Position = u_viewProjectionMatrix * vec4(a_position, 1.0);
+
+    v_texCoord = a_position;
+
+}  

src/Camera.h

@@ -20,6 +20,8 @@ public:
     void lookAtTarget(glm::vec3 target);
     void lookForward();
     
+    glm::mat4 getView() { return viewMatrix; }
+    glm::mat4 getProj() { return projectionMatrix; }
     glm::mat4 getViewProj() { return viewProjectionMatrix; }
     glm::vec3 getPosition() { return position; }
     glm::vec3 getDirection() { return frontVec; }

src/Controller.cpp

@@ -78,6 +78,7 @@ void Controller::run() {
 
     ShaderProgram shaderProgram("res/shaders/basic.vert", "res/shaders/basic.frag");
     ShaderProgram lightProgram("res/shaders/light.vert", "res/shaders/light.frag");
+    ShaderProgram skyboxProgram("res/shaders/skybox.vert", "res/shaders/skybox.frag");
 
     //Model model_backpack("res/models/backpack.ffo");
     //Model model_plant("res/models/plant.ffo");
@@ -104,6 +105,8 @@ void Controller::run() {
     lightSource.setRotation(glm::vec3(0.f));
     lightSource.setPosition(glm::vec3(-2.f, 1.5f, 2.f));
 
+    Skybox skybox(&model_cube, &skyboxProgram, "res/textures/skybox/");
+
     World world(&shaderProgram);
     world.addEntity(dragon);
     world.addEntity(lightSource);
@@ -137,6 +140,8 @@ void Controller::run() {
         camera->lookForward();
         camera->updateVPM();
 
+        skybox.draw(camera->getView(), camera->getProj());
+
         world.draw(camera->getViewProj(), camera->getPosition());
 
         #ifdef _DEBUG

src/Entity.cpp

@@ -80,3 +80,44 @@ void Entity::updateModelMatrix() {
     modelMatrix = translationMatrix * rotationMatrix * scaleMatrix;
 
 }
+
+
+
+Skybox::Skybox(Model *cubeModel, ShaderProgram *shaderProgram, const char *texturePseudoPath) 
+    :   cubeModel(cubeModel),
+        shaderProgram(shaderProgram),
+        cubeMap(texturePseudoPath),
+        vertexArray(cubeModel->getMesh(0)->getVertexArray()) {
+
+    // Empty
+
+}
+
+void Skybox::draw(glm::mat4 viewMatrix, glm::mat4 projectionMatrix) {
+
+    // To disable face culling first get current state
+    GLboolean active;
+    glGetBooleanv(GL_CULL_FACE_MODE, &active);
+    glDisable(GL_CULL_FACE);
+
+    glDepthMask(GL_FALSE);
+    shaderProgram->bind();
+
+    glm::mat4 viewProjectionMatrix = projectionMatrix * glm::mat4(glm::mat3(viewMatrix));
+
+    shaderProgram->setUniform("u_viewProjectionMatrix", viewProjectionMatrix);
+
+    cubeMap.bind(shaderProgram);
+    cubeModel->getMesh(0)->drawWithoutTextures(shaderProgram);
+    cubeMap.unbind();
+
+    shaderProgram->unbind();
+    glDepthMask(GL_TRUE);
+
+    // Restore face culling
+    if(active)
+        glEnable(GL_CULL_FACE);
+    else
+        glDisable(GL_CULL_FACE);
+
+}

src/Entity.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "Model.h"
+#include "Texture.h"
 #include "ShaderProgram.h"
 
 #include <glm/glm.hpp>
@@ -46,6 +47,26 @@ private:
 
     glm::mat4 modelMatrix = glm::mat4(1.0f);
 
-    ShaderProgram* shaderProgram;
+    ShaderProgram *shaderProgram;
+
+};
+
+class Skybox {
+
+public:
+
+    Skybox(Model *cubeModel, ShaderProgram *shaderProgram, const char *texturePseudoPath);
+    ~Skybox() = default;
+
+    void draw(glm::mat4 viewMatrix, glm::mat4 projectionMatrix);
+
+private:
+
+    Model *cubeModel;
+    ShaderProgram *shaderProgram;
+
+    CubeMap cubeMap;
+
+    VertexArray *vertexArray;
 
 };

src/Mesh.cpp

@@ -34,5 +34,12 @@ void Mesh::draw(ShaderProgram *shaderProgram) {
         (*it)->unbind();
     }
     
+}
+
+void Mesh::drawWithoutTextures(ShaderProgram *shaderProgram) {
+
+    vertexArray.bind();
+    glDrawElements(GL_TRIANGLES, numElements, GL_UNSIGNED_INT, 0);
+    vertexArray.unbind();
 
 }

src/Mesh.h

@@ -15,6 +15,9 @@ public:
     ~Mesh() = default;
 
     void draw(ShaderProgram *shaderProgram);
+    void drawWithoutTextures(ShaderProgram *shaderProgram);
+
+    VertexArray * getVertexArray() { return &vertexArray; }
 
 private:
 

src/Model.h

@@ -14,6 +14,8 @@ public:
 
     void draw(ShaderProgram *shaderProgram);
 
+    Mesh * getMesh(unsigned int index) { return meshes[index]; }
+
 
 private:
 

src/Texture.cpp

@@ -23,17 +23,14 @@ Texture::Texture(const char* texturePath, uint8_t textureType) {
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 
 
-    if(textureBuffer) {
+    if(!textureBuffer) {
+        std::cout << "[Warning] Texture " << texturePath << " not found!" << std::endl;
+        return;
+    }
 
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, textureWidth, textureHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureBuffer);
     //glGenerateMipmap(GL_TEXTURE_2D);
 
-    } else {
-
-        std::cout << "[Warning] Texture " << texturePath << " not found!" << std::endl;
-
-    }
-
     stbi_image_free(textureBuffer);
     glBindTexture(GL_TEXTURE_2D, 0);
 
@@ -76,3 +73,72 @@ void Texture::bind(uint8_t textureUnit, ShaderProgram* shaderProgram, uint8_t te
 void Texture::unbind() {
     glBindTexture(GL_TEXTURE_2D, 0);
 }
+
+
+
+CubeMap::CubeMap(const char* texturePseudoPath) {
+
+    // Reserve space in vector so that elements can be accessed explicitly.
+    texturePaths.resize(CUBEMAP_FACES_NUM_ITEMS);
+    fillTexturePathVector(texturePseudoPath);
+
+    stbi_set_flip_vertically_on_load(0);
+
+    glGenTextures(1, &textureId);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, textureId);
+
+    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);    
+
+    for(unsigned int i = 0; i < CUBEMAP_FACES_NUM_ITEMS; i++) {
+
+        auto *textureBuffer = stbi_load(texturePaths[i].c_str(), &textureWidth, &textureHeight, &bitsPerPixel, STBI_rgb_alpha);
+
+        if(!textureBuffer) {
+            std::cout << "[Warning] CubeMap Texture " << texturePaths[i].c_str() << " not found!" << std::endl;
+            return;
+        }
+
+        glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGBA8, textureWidth, textureHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, textureBuffer);
+        
+        stbi_image_free(textureBuffer);
+
+    }
+
+    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+
+}
+
+CubeMap::~CubeMap() {
+    glDeleteTextures(1, &textureId);
+}
+
+void CubeMap::bind(ShaderProgram *shaderProgram) {
+    std::string uniformName = "u_skybox";
+
+    shaderProgram->setUniform(uniformName.c_str(), 0);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_CUBE_MAP, textureId);
+}
+
+void CubeMap::unbind() {
+    glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+}
+
+void CubeMap::fillTexturePathVector(const char* texturePseudoPath) {
+
+    for(unsigned int i = 0; i < CUBEMAP_FACES_NUM_ITEMS; i++) {
+
+        texturePaths[cm_front]  = std::string(texturePseudoPath) + "front.png";
+        texturePaths[cm_back]   = std::string(texturePseudoPath) + "back.png";
+        texturePaths[cm_top]    = std::string(texturePseudoPath) + "top.png";
+        texturePaths[cm_bottom] = std::string(texturePseudoPath) + "bottom.png";
+        texturePaths[cm_left]   = std::string(texturePseudoPath) + "left.png";
+        texturePaths[cm_right]  = std::string(texturePseudoPath) + "right.png";
+
+    }
+
+}

src/Texture.h

@@ -3,9 +3,14 @@
 #include "ShaderProgram.h"
 
 #include "defines.h"
+
 #include <cstdint>
 #include <glad/glad.h>
 #include <string>
+#include <vector>
+
+// Order is important!
+enum cubeMapFaces{cm_right, cm_left, cm_top, cm_bottom, cm_back, cm_front, CUBEMAP_FACES_NUM_ITEMS};
 
 class Texture {
 
@@ -33,3 +38,27 @@ private:
     uint8_t textureType;
 
 };
+
+class CubeMap {
+
+public:
+
+    CubeMap(const char* texturePseudoPath);
+    ~CubeMap();
+
+    void bind(ShaderProgram *shaderProgram);
+    void unbind();
+
+private:
+
+    void fillTexturePathVector(const char* texturePseudoPath);
+
+    std::vector<std::string> texturePaths;
+
+    GLuint textureId;
+
+    int32_t textureWidth;
+    int32_t textureHeight;
+    int32_t bitsPerPixel;
+
+};

src/Window.cpp

@@ -9,7 +9,7 @@
 Window::Window() {
     width = INIT_WINDOW_WIDTH; height = INIT_WINDOW_HEIGHT;
 
-    window = glfwCreateWindow(width, height, "Fall-Fever", NULL, NULL);
+    window = glfwCreateWindow(width, height, "OpenGL", NULL, NULL);
     if(!window) {
         std::cout << "Failed to create window" << std::endl;
     }