Create and delete shaders and programs only on construction/destruction.

Also inlined some simple functions, updated documentation.

src/AbstractShaderProgram.cpp

@@ -24,14 +24,6 @@ using namespace Corrade::Utility;
 
 namespace Magnum {
 
-AbstractShaderProgram::AbstractShaderProgram(): state(Initialized) {
-    program = glCreateProgram();
-}
-
-AbstractShaderProgram::~AbstractShaderProgram() {
-    if(program) glDeleteProgram(program);
-}
-
 bool AbstractShaderProgram::use() {
     if(state != Linked) return false;
 
@@ -85,11 +77,7 @@ void AbstractShaderProgram::link() {
                 << message;
     }
 
-    if(status == GL_FALSE) {
-        glDeleteProgram(program);
-        program = 0;
-        state = Failed;
-    } else state = Linked;
+    state = status == GL_FALSE ? Failed : Linked;
 }
 
 GLint AbstractShaderProgram::uniformLocation(const std::string& name) {

src/AbstractShaderProgram.h

@@ -104,15 +104,21 @@ class MAGNUM_EXPORT AbstractShaderProgram {
             typedef T Type;                     /**< %Attribute type */
         };
 
-        /** @brief Default constructor */
-        AbstractShaderProgram();
+        /**
+         * @brief Constructor
+         *
+         * Creates one OpenGL shader program.
+         */
+        inline AbstractShaderProgram(): state(Initialized) {
+            program = glCreateProgram();
+        }
 
         /**
          * @brief Destructor
          *
-         * Deletes the shader program.
+         * Deletes associated OpenGL shader program.
          */
-        ~AbstractShaderProgram();
+        inline ~AbstractShaderProgram() { glDeleteProgram(program); }
 
         /**
          * @brief Use shader

src/Shader.cpp

@@ -29,7 +29,7 @@ Shader::Shader(Shader&& other): _type(other._type), _state(other._state), source
 }
 
 Shader& Shader::operator=(Shader&& other) {
-    if(shader) glDeleteShader(shader);
+    glDeleteShader(shader);
 
     _type = other._type;
     _state = other._state;
@@ -79,7 +79,6 @@ GLuint Shader::compile() {
         _sources[i] = static_cast<const GLchar*>(sources[i].c_str());
 
     /* Create shader and set its source */
-    shader = glCreateShader(_type);
     glShaderSource(shader, sources.size(), _sources, nullptr);
 
     /* Compile shader */
@@ -119,12 +118,12 @@ GLuint Shader::compile() {
     }
 
     if(status == GL_FALSE) {
-        glDeleteShader(shader);
-        shader = 0;
         _state = Failed;
-    } else _state = Compiled;
-
-    return shader;
+        return 0;
+    } else {
+        _state = Compiled;
+        return shader;
+    }
 }
 
 }

src/Shader.h

@@ -116,17 +116,13 @@ class MAGNUM_EXPORT Shader {
         /**
          * @brief Constructor
          *
-         * Creates empty OpenGL shader. Sources can be added with addData()
+         * Creates empty OpenGL shader. Sources can be added with addSource()
          * or addFile().
          * @see fromData(), fromFile()
          */
-        inline Shader(Type type): _type(type), _state(Initialized), shader(0) {}
-
-        /** @brief Move constructor */
-        Shader(Shader&& other);
-
-        /** @brief Move assignment operator */
-        Shader& operator=(Shader&& other);
+        inline Shader(Type type): _type(type), _state(Initialized), shader(0) {
+            shader = glCreateShader(_type);
+        }
 
         /**
          * @brief Destructor
@@ -135,6 +131,12 @@ class MAGNUM_EXPORT Shader {
          */
         inline ~Shader() { if(shader) glDeleteShader(shader); }
 
+        /** @brief Move constructor */
+        Shader(Shader&& other);
+
+        /** @brief Move assignment operator */
+        Shader& operator=(Shader&& other);
+
         /**
          * @brief %Shader type
          *