effect: Add ShaderEffect

The ShaderEffect class is an abstract base type for shader-based
effects. GLSL-based effects should be implemented by sub-classing
ShaderEffect and overriding ActorMeta::set_actor() to set the source
code of the shader, and Effect::pre_paint() to update the uniform
values, if any.

The ShaderEffect has a generic API for sub-classes to set the values
of the uniforms defined by their shaders, and it uses the shader
types we defined for ClutterShader, to avoid re-inventing the wheel
every time.

clutter/clutter-shader-effect.h

@@ -0,0 +1,101 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Copyright (C) 2010  Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Author:
+ *   Emmanuele Bassi <ebassi@linux.intel.com>
+ */
+
+#if !defined(__CLUTTER_H_INSIDE__) && !defined(CLUTTER_COMPILATION)
+#error "Only <clutter/clutter.h> can be included directly."
+#endif
+
+#ifndef __CLUTTER_SHADER_EFFECT_H__
+#define __CLUTTER_SHADER_EFFECT_H__
+
+#include <clutter/clutter-offscreen-effect.h>
+
+G_BEGIN_DECLS
+
+#define CLUTTER_TYPE_SHADER_EFFECT              (clutter_shader_effect_get_type ())
+#define CLUTTER_SHADER_EFFECT(obj)              (G_TYPE_CHECK_INSTANCE_CAST ((obj), CLUTTER_TYPE_SHADER_EFFECT, ClutterShaderEffect))
+#define CLUTTER_IS_SHADER_EFFECT(obj)           (G_TYPE_CHECK_INSTANCE_TYPE ((obj), CLUTTER_TYPE_SHADER_EFFECT))
+#define CLUTTER_SHADER_EFFECT_CLASS(klass)      (G_TYPE_CHECK_CLASS_CAST ((klass), CLUTTER_TYPE_SHADER_EFFECT, ClutterShaderEffectClass))
+#define CLUTTER_IS_SHADER_EFFECT_CLASS(klass)   (G_TYPE_CHECK_CLASS_TYPE ((klass), CLUTTER_TYPE_SHADER_EFFECT))
+#define CLUTTER_SHADER_EFFECT_GET_CLASS(obj)    (G_TYPE_INSTANCE_GET_CLASS ((obj), CLUTTER_TYPE_SHADER_EFFECT, ClutterShaderEffectClass))
+
+typedef struct _ClutterShaderEffect             ClutterShaderEffect;
+typedef struct _ClutterShaderEffectPrivate      ClutterShaderEffectPrivate;
+typedef struct _ClutterShaderEffectClass        ClutterShaderEffectClass;
+
+/**
+ * ClutterShaderEffect:
+ *
+ * The <structname>ClutterShaderEffect</structname> structure contains
+ * only private data and should be accessed using the provided API
+ *
+ * Since: 1.4
+ */
+struct _ClutterShaderEffect
+{
+  /*< private >*/
+  ClutterOffscreenEffect parent_instance;
+
+  ClutterShaderEffectPrivate *priv;
+};
+
+/**
+ * ClutterShaderEffectClass:
+ *
+ * The <structname>ClutterShaderEffectClass</structname> structure contains
+ * only private data
+ *
+ * Since: 1.4
+ */
+struct _ClutterShaderEffectClass
+{
+  /*< private >*/
+  ClutterOffscreenEffectClass parent_class;
+
+  /* padding */
+  void (*_clutter_shader1) (void);
+  void (*_clutter_shader2) (void);
+  void (*_clutter_shader3) (void);
+  void (*_clutter_shader4) (void);
+  void (*_clutter_shader5) (void);
+  void (*_clutter_shader6) (void);
+};
+
+GType clutter_shader_effect_get_type (void) G_GNUC_CONST;
+
+void clutter_shader_effect_set_uniform       (ClutterShaderEffect *effect,
+                                              const gchar         *name,
+                                              GType                gtype,
+                                              gsize                size,
+                                              ...);
+void clutter_shader_effect_set_uniform_value (ClutterShaderEffect *effect,
+                                              const gchar         *name,
+                                              const GValue        *value);
+
+CoglHandle clutter_shader_effect_get_shader  (ClutterShaderEffect *effect);
+CoglHandle clutter_shader_effect_get_program (ClutterShaderEffect *effect);
+
+G_END_DECLS
+
+#endif /* __CLUTTER_SHADER_EFFECT_H__ */