1 files changed, 155 insertions, 0 deletions
diff --git a/apps/openmb/renderer/Skybox.cpp b/apps/openmb/renderer/Skybox.cpp
new file mode 100644
index 0000000..fea0021
--- /dev/null
+++ b/apps/openmb/renderer/Skybox.cpp
@@ -0,0 +1,155 @@
+#include "Skybox.hpp"
+
+#include "Shader.hpp"
+#include <stb_image.h>
+
+#include <algorithm>
+#include <filesystem>
+#include <iostream>
+
+namespace Fs = std::filesystem;
+
+namespace renderer {
+Skybox::Skybox () : mTexID( 0 ), mVAO( 0 ), mVBO( 0 ), mInitialized( false ) {}
+
+Skybox::~Skybox () {
+    if( mVBO )
+        glDeleteBuffers( 1, &mVBO );
+    if( mVAO )
+        glDeleteVertexArrays( 1, &mVAO );
+    if( mTexID )
+        glDeleteTextures( 1, &mTexID );
+}
+
+static std::string toLower ( const std::string& s ) {
+    std::string out = s;
+    std::transform( out.begin(), out.end(), out.begin(), [] ( unsigned char c ) { return std::tolower( c ); } );
+    return out;
+}
+
+bool Skybox::loadFromDirectory ( const std::string& dirPath ) {
+
+    std::vector<std::string> faceTokens = { "right", "left", "top", "bottom", "front", "back" };
+    std::vector<std::string> faces( 6 );
+
+    if( !Fs::exists( dirPath ) || !Fs::is_directory( dirPath ) ) {
+        std::cerr << "Skybox directory does not exist: " << dirPath << std::endl;
+        return false;
+    }
+
+    for( auto& entry : Fs::directory_iterator( dirPath ) ) {
+        if( !entry.is_regular_file() )
+            continue;
+        auto        name  = entry.path().filename().string();
+        std::string lname = toLower( name );
+        for( size_t i = 0; i < faceTokens.size(); ++i ) {
+            if( lname.find( faceTokens[i] ) != std::string::npos ) {
+                faces[i] = entry.path().string();
+            }
+        }
+    }
+
+    for( size_t i = 0; i < faces.size(); ++i ) {
+        if( faces[i].empty() ) {
+            std::cerr << "Missing skybox face for token: " << faceTokens[i] << std::endl;
+            return false;
+        }
+    }
+
+    return loadFaces( faces );
+}
+
+bool Skybox::loadFaces ( const std::vector<std::string>& faces ) {
+    glGenTextures( 1, &mTexID );
+    glBindTexture( GL_TEXTURE_CUBE_MAP, mTexID );
+
+    stbi_set_flip_vertically_on_load( false );
+    for( unsigned i = 0; i < faces.size(); ++i ) {
+        int            w, h, ch;
+        unsigned char* data = stbi_load( faces[i].c_str(), &w, &h, &ch, 0 );
+        if( !data ) {
+            std::cerr << "Failed to load skybox face: " << faces[i] << std::endl;
+            glBindTexture( GL_TEXTURE_CUBE_MAP, 0 );
+            return false;
+        }
+        GLenum format = ( ch == 4 ) ? GL_RGBA : GL_RGB;
+        glTexImage2D( GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, format, w, h, 0, format, GL_UNSIGNED_BYTE, data );
+        stbi_image_free( data );
+    }
+
+    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 );
+
+    initMesh();
+    mInitialized = true;
+    return true;
+}
+
+void Skybox::initMesh () {
+
+    float 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 };
+
+    glGenVertexArrays( 1, &mVAO );
+    glGenBuffers( 1, &mVBO );
+    glBindVertexArray( mVAO );
+    glBindBuffer( GL_ARRAY_BUFFER, mVBO );
+    glBufferData( GL_ARRAY_BUFFER, sizeof( skyboxVertices ), &skyboxVertices, GL_STATIC_DRAW );
+    glEnableVertexAttribArray( 0 );
+    glVertexAttribPointer( 0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof( float ), (void*)0 );
+    glBindVertexArray( 0 );
+}
+
+void Skybox::draw ( const glm::mat4& view, const glm::mat4& proj ) {
+    if( !mInitialized )
+        return;
+
+    static Shader s;
+    static bool   shaderLoaded = false;
+    if( !shaderLoaded ) {
+        s.fromFiles( "apps/openmb/resources/shaders/skybox.vert", "apps/openmb/resources/shaders/skybox.frag" );
+        shaderLoaded = true;
+    }
+
+    glDepthFunc( GL_LEQUAL );
+    glDepthMask( GL_FALSE );
+
+    s.use();
+
+    glm::mat4 viewNoTrans = glm::mat4( glm::mat3( view ) );
+    s.setMat4( "view", viewNoTrans );
+    s.setMat4( "proj", proj );
+
+    glActiveTexture( GL_TEXTURE0 );
+    glBindTexture( GL_TEXTURE_CUBE_MAP, mTexID );
+    s.setInt( "skybox", 0 );
+
+    glBindVertexArray( mVAO );
+    glDrawArrays( GL_TRIANGLES, 0, 36 );
+    glBindVertexArray( 0 );
+
+    glDepthMask( GL_TRUE );
+    glDepthFunc( GL_LESS );
+}
+
+}   // namespace renderer