shader.hpp: add geometry shader support

include/shader.hpp

@@ -19,31 +19,38 @@ public:
     unsigned int ID;
     // constructor generates the shader on the fly
     // ------------------------------------------------------------------------
-    Shader(const char *vertexPath, const char *fragmentPath)
+    Shader(const char* geometryPath, const char *vertexPath, const char *fragmentPath)
     {
         // 1. retrieve the vertex/fragment source code from filePath
         std::string vertexCode;
         std::string fragmentCode;
+        std::string geometryCode;
         std::ifstream vShaderFile;
         std::ifstream fShaderFile;
+        std::ifstream gShaderFile;
         // ensure ifstream objects can throw exceptions:
         vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
         fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
+        gShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
         try
         {
             // open files
             vShaderFile.open(vertexPath);
             fShaderFile.open(fragmentPath);
-            std::stringstream vShaderStream, fShaderStream;
+            gShaderFile.open(geometryPath);
+            std::stringstream vShaderStream, fShaderStream, gShaderStream;
             // read file's buffer contents into streams
             vShaderStream << vShaderFile.rdbuf();
             fShaderStream << fShaderFile.rdbuf();
+            gShaderStream << gShaderFile.rdbuf();
             // close file handlers
             vShaderFile.close();
             fShaderFile.close();
+            gShaderFile.close();
             // convert stream into string
             vertexCode = vShaderStream.str();
             fragmentCode = fShaderStream.str();
+	    geometryCode = gShaderStream.str();
         }
         catch (std::ifstream::failure &e)
         {
@@ -51,8 +58,9 @@ public:
         }
         const char *vShaderCode = vertexCode.c_str();
         const char *fShaderCode = fragmentCode.c_str();
+        const char *gShaderCode = geometryCode.c_str();
         // 2. compile shaders
-        unsigned int vertex, fragment;
+        unsigned int vertex, fragment, geometry;
         // vertex shader
         vertex = glCreateShader(GL_VERTEX_SHADER);
         glShaderSource(vertex, 1, &vShaderCode, NULL);
@@ -63,15 +71,23 @@ public:
         glShaderSource(fragment, 1, &fShaderCode, NULL);
         glCompileShader(fragment);
         checkCompileErrors(fragment, "FRAGMENT");
+	// geometry shader
+	geometry = glCreateShader(GL_GEOMETRY_SHADER);
+	glShaderSource(geometry, 1, &gShaderCode, NULL);
+	glCompileShader(geometry);
+	checkCompileErrors(geometry, "GEOMETRY");
+    
         // shader Program
         ID = glCreateProgram();
         glAttachShader(ID, vertex);
         glAttachShader(ID, fragment);
+        glAttachShader(ID, geometry);
         glLinkProgram(ID);
         checkCompileErrors(ID, "PROGRAM");
         // delete the shaders as they're linked into our program now and no longer necessary
         glDeleteShader(vertex);
         glDeleteShader(fragment);
+        glDeleteShader(geometry);
     }
     // activate the shader
     // ------------------------------------------------------------------------