Merge pull request #4 from FOSSEE/develop

merging dev into master

1 files changed, 210 insertions, 0 deletions

diff --git a/include/gal/opengl/shader.h b/include/gal/opengl/shader.h
new file mode 100644
index 0000000..a83de84
--- /dev/null
+++ b/include/gal/opengl/shader.h
@@ -0,0 +1,210 @@
+/*
+ * This program source code file is part of KICAD, a free EDA CAD application.
+ *
+ * Copyright (C) 2012 Torsten Hueter, torstenhtr <at> gmx.de
+ * Copyright (C) 2012 Kicad Developers, see change_log.txt for contributors.
+ *
+ * Graphics Abstraction Layer (GAL) for OpenGL
+ *
+ * Shader class
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+#ifndef SHADER_H_
+#define SHADER_H_
+
+#include <GL/glew.h>
+
+#include <string>
+#include <deque>
+
+namespace KIGFX
+{
+class OPENGL_GAL;
+
+/// Type definition for the shader
+enum SHADER_TYPE
+{
+    SHADER_TYPE_VERTEX	 = GL_VERTEX_SHADER,    ///< Vertex shader
+    SHADER_TYPE_FRAGMENT = GL_FRAGMENT_SHADER,  ///< Fragment shader
+    SHADER_TYPE_GEOMETRY = GL_GEOMETRY_SHADER   ///< Geometry shader
+};
+
+/**
+ * @brief Class SHADER provides the access to the OpenGL shaders.
+ *
+ * The purpose of this class is advanced drawing with OpenGL. One example is using the pixel
+ * shader for drawing exact circles or for anti-aliasing. This class supports vertex, geometry
+ * and fragment shaders.
+ * <br>
+ * Make sure that the hardware supports these features. This can be identified with the "GLEW"
+ * library.
+ */
+class SHADER
+{
+public:
+
+    /**
+     * @brief Constructor
+     */
+    SHADER();
+
+    /**
+     * @brief Destructor
+     */
+    virtual ~SHADER();
+
+    /**
+     * @brief Loads one of the built-in shaders and compiles it.
+     *
+     * @param aShaderNumber is the shader number (indexing from 0).
+     * @param aShaderType is the type of the shader.
+     * @return True in case of success, false otherwise.
+     */
+    bool LoadBuiltinShader( unsigned int aShaderNumber, SHADER_TYPE aShaderType );
+
+    /**
+     * @brief Loads one of the built-in shaders and compiles it.
+     *
+     * @param aShaderSourceName is the shader source file name.
+     * @param aShaderType is the type of the shader.
+     * @return True in case of success, false otherwise.
+     */
+    bool LoadShaderFromFile( const std::string& aShaderSourceName, SHADER_TYPE aShaderType );
+
+    /**
+     * @brief Link the shaders.
+     *
+     * @return true in case of success, false otherwise.
+     */
+    bool Link();
+
+    /**
+     * @brief Use the shader.
+     */
+    inline void Use()
+    {
+        glUseProgram( programNumber );
+        active = true;
+    }
+
+    /**
+     * @brief Deactivate the shader and use the default OpenGL program.
+     */
+    inline void Deactivate()
+    {
+        glUseProgram( 0 );
+        active = false;
+    }
+
+    /**
+     * @brief Returns the current state of the shader.
+     *
+     * @return True if any of shaders is enabled.
+     */
+    inline bool IsActive() const
+    {
+        return active;
+    }
+
+    /**
+     * @brief Configure the geometry shader - has to be done before linking!
+     *
+     * @param maxVertices is the maximum of vertices to be generated.
+     * @param geometryInputType is the input type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]
+     * @param geometryOutputType is the output type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]
+     */
+    void ConfigureGeometryShader( GLuint maxVertices, GLuint geometryInputType,
+                                  GLuint geometryOutputType );
+
+    /**
+     * @brief Add a parameter to the parameter queue.
+     *
+     * To communicate with the shader use this function to set up the names for the uniform
+     * variables. These are queued in a list and can be assigned with the SetParameter(..)
+     * method using the queue position.
+     *
+     * @param aParameterName is the name of the parameter.
+     * @return the added parameter location.
+     */
+    int AddParameter( const std::string& aParameterName );
+
+    /**
+     * @brief Set a parameter of the shader.
+     *
+     * @param aParameterNumber is the number of the parameter.
+     * @param aValue is the value of the parameter.
+     */
+    void SetParameter( int aParameterNumber, float aValue ) const;
+    void SetParameter( int aParameterNumber, int aValue ) const;
+
+    /**
+     * @brief Gets an attribute location.
+     *
+     * @param aAttributeName is the name of the attribute.
+     * @return the location.
+     */
+    int GetAttribute( std::string aAttributeName ) const;
+
+private:
+
+    /**
+     * @brief Get the shader program information.
+     *
+     * @param aProgram is the program number.
+     */
+    void programInfo( GLuint aProgram );
+
+    /**
+     * @brief Get the shader information.
+     *
+     * @param aShader is the shader number.
+     */
+    void shaderInfo( GLuint aShader );
+
+    /**
+     * @brief Read the shader source file
+     *
+     * @param aShaderSourceName is the shader source file name.
+     * @return the source as string
+     */
+    std::string readSource( std::string aShaderSourceName );
+
+    /**
+     * @brief Add a shader and compile the shader sources.
+     *
+     * @param aShaderSource is the shader source content.
+     * @param aShaderType is the type of the shader.
+     * @return True in case of success, false otherwise.
+     */
+    bool addSource( const std::string& aShaderSource, SHADER_TYPE aShaderType );
+
+    std::deque<GLuint>  shaderNumbers;      ///< Shader number list
+    GLuint              programNumber;      ///< Shader program number
+    bool                isProgramCreated;   ///< Flag for program creation
+    bool                isShaderLinked;     ///< Is the shader linked?
+    bool                active;             ///< Is any of shaders used?
+    GLuint              maximumVertices;    ///< The maximum of vertices to be generated
+    GLuint              geomInputType;      ///< Input type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]
+    GLuint              geomOutputType;     ///< Output type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]
+    std::deque<GLint>   parameterLocation;  ///< Location of the parameter
+};
+} // namespace KIGFX
+
+#endif /* SHADER_H_ */