refactor abuffer and add msaa support. volumes temporarily disabled.

include/openspace/rendering/volume.h

@@ -0,0 +1,132 @@
+/*****************************************************************************************
+ *                                                                                       *
+ * OpenSpace                                                                             *
+ *                                                                                       *
+ * Copyright (c) 2014-2016                                                               *
+ *                                                                                       *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this  *
+ * software and associated documentation files (the "Software"), to deal in the Software *
+ * without restriction, including without limitation the rights to use, copy, modify,    *
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software, and to    *
+ * permit persons to whom the Software is furnished to do so, subject to the following   *
+ * conditions:                                                                           *
+ *                                                                                       *
+ * The above copyright notice and this permission notice shall be included in all copies *
+ * or substantial portions of the Software.                                              *
+ *                                                                                       *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,   *
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A         *
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT    *
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF  *
+ * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE  *
+ * OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                                         *
+ ****************************************************************************************/
+
+#ifndef __VOLUME_H__
+#define __VOLUME_H__
+
+#include <string>
+#include <vector>
+
+namespace ghoul {
+    namespace opengl {
+        class Texture;
+        class ProgramObject;
+    }
+}
+
+namespace openspace {
+
+class Volume {
+public:
+
+    /**
+     * Constructor
+     */
+    Volume() {};    
+
+    /**
+     * Destructor
+     */
+    virtual ~Volume() {};
+
+    /**
+     * Render the volume's entry points (front face of the bounding geometry)
+     */
+    //virtual void renderEntryPoints(const RenderData& data, ghoul::opengl::ProgramObject* program) = 0;
+
+    /**
+     * Render the volume's exit points (back face of the bounding geometry)
+     */
+    //virtual void renderExitPoints(const RenderData& data, ghoul::opengl::ProgramObject* program) = 0;
+    
+    /**
+     * Prepare the volume for the ABuffer's resolve step.
+     * Make sure textures are up to date, bind them to texture units, set program uniforms etc.
+     */
+    //virtual void preRayCast(ghoul::opengl::ProgramObject* program) {};
+
+    /**
+     * Clean up for the volume after the ABuffer's resolve step.
+     * Make sure texture units are deinitialized, etc.
+     */
+    //virtual void postRayCast(ghoul::opengl::ProgramObject* program) {};
+
+    /**
+     * Return a path to a file with the uniforms, per-vertex variables, functions etc
+     * required to transform the vertices of the bounding geometry to view space.
+     * It could also set other vertex out variables for the fragment shader to access.
+     *
+     * The shader preprocessor will have acceess to
+     *   A #{namespace} variable (unique per helper file)
+     * 
+     * Should define the function:
+     * vec4 getVertex()
+     */
+    //virtual std::string getBoundsVsPath() = 0;
+
+    /*
+     * Return a path to a file with the functions, uniforms and fragment shader in variables
+     * required to generate the fragment color and depth. 
+     *
+     * Should define the function:
+     * Fragment getFragment()
+     * 
+     * The shader preprocessor will have acceess to
+     *   A #{namespace} variable (unique per helper file)
+     */ 
+    //virtual std::string getBoundsFsPath() = 0;
+    
+    /**
+     * Return a path to a file with all the uniforms, functions etc
+     * required to perform ray casting through this volume.
+     *
+     * The header should define the following two functions:
+     *   vec4 sampler#{id}(vec3 samplePos, vec3 dir, float occludingAlpha, inout float maxStepSize)
+     *      (return color of sample)
+     *   float stepSize#{id}(vec3 samplePos, vec3 dir)
+     *      (return the preferred step size at this sample position)
+     *
+     * The shader preprocessor will have acceess to
+     *   An #{id} variable (unique per volume)
+     *   A #{namespace} variable (unique per helper file)
+     */
+    //virtual std::string getRayCastPath() = 0;
+
+    /**
+     * Return a path to a glsl file with helper functions required for the
+     * transformation and raycast steps.
+     * This file will be included once per shader program generated,
+     * regardless of how many volumes say they require the file.
+     * Ideal to avoid redefinitions of helper functions.
+     * 
+     * The shader preprocessor will have access to the #{namespace} variable (unique per helper file)
+     * which should be a prefix to all symbols defined by the helper
+     */
+    //virtual std::string getHelperPath() = 0;
+
+}; // Volume
+
+} // openspace
+
+#endif  // __VOLUME_H__