/* 	gl.h
	This file is part of the Osirion project
*/

#ifndef __INCLUDED_OSIRIONGL_H__
#define __INCLUDED_OSIRIONGL_H__

// OpenGL headers
#include <GL/gl.h>

// project headers
#include "common/vector3f.h"
#include "common/color.h"

/// wrapper namespace for OpenGL operations
/*! The GL namespace provides a wrapper to the OpenGL library functions.
 *  All methods take floats or Vector3f and Color as parameters.
 */
namespace gl
{
	/// initialize the OpenGL subsystem
	void init();

	/// shutdown the OpenGL subsystem
	void shutdown();

	/// enum to denote Vertex drawing modes
	enum Primitive {
		Points=GL_POINTS,
		Lines=GL_LINES,
		LineStrip=GL_LINE_STRIP,
		LineLoop=GL_LINE_LOOP,
		Triangles=GL_TRIANGLES,
		TriangleStrip=GL_TRIANGLE_STRIP,
		TriangleFan=GL_TRIANGLE_FAN,
		Quads=GL_QUADS,
		QuadStrip=GL_QUAD_STRIP,
		Polygon=GL_POLYGON
	};


	/// glViewPort
	void viewport(GLint x, GLint y, GLsizei width, GLsizei height );

	/// set the color used to clear to buffer 
	void clearcolor(Color const &color);
	/// set the color used to clear to buffer 
	void clearcolor(const float r, const float g, const float b, const float a);

	/// clear buffers to preset values
	void clear (GLbitfield mask);

	/// glMatrixMode
	void matrixmode(GLenum mode);

	/// glEnable
	void enable(GLenum cap);

	/// glShadeModel
	void shademodel(GLenum mode);

	/// glCullFace
	void cullface(GLenum mode);

	/// glFrontFace
	void frontface(GLenum mode);


	/// glDepthMask
	void depthmask(GLenum mode);

	/// Delimite the start of a sequence of verteces describing a primitive or group of primitives
	/*!	@param primitive The type of drawing primitive
	 *  @see end()
	 */
	void begin(Primitive primitive);

	/// Delimit the end of a sequence of verteces describing a primitive or group of primitives
	/*! @see begin()
	 */
	void end();

	/// Add the next vertex the the current drawing operation
	/*! From the glVertex() description:
	 *  vertex() commands are used within begin()/end() pairs to specify point,
	 *	line, and polygon vertices.  The current color, normal, and texture
	 *	coordinates are associated with the vertex when vertex() is called.
	 */
	void vertex(const Vector3f& vector);
	
	void vertex(const float x, const float y, const float z);
	
	/// Multiply the current matrix by a general rotation matrix
	/*! @param angle The angle of the rotation, in degrees [0-360]
	 *  @param vector The rotation axes, relative to the origin (0,0,0)
	 */
	void rotate(const float angle, const Vector3f& vector);

	/// Multiply the current matrix by a general rotation matrix
	/*! @param angle The angle of the rotation, in degrees
	 *  @param x The x-coordinate of the rotation vector
	 *  @param y The y-coordinate of the rotation vector
	 *  @param z The z-coordinate of the rotation vector
	 */
	void rotate(const float angle, const float x, const float y, const float z);

	/// Multiply the current matrix by a general translation matrix
	/*! @param vector The translation vector, relative to the origin (0,0,0)
	 */
	void translate(const Vector3f& vector);

	/// Multiply the current matrix by a general translation matrix
	/*!
	 * @param x The x-coordinate of the translation vector
	 * @param y The y-coordinate of the translation vector
	 * @param z The z-coordinate of the translation vector
	 */
	void translate(const float x, const float y, const float z);

	/// Multiply the current matrix by a general scaling matrix
	/*! @param vector The scale factor for all 3 axes
	 */
	void scale(const Vector3f& vector);

	/// Multiply the current matrix by a general scaling matrix
	/*!
	 * @param x x-scaling factor
	 * @param y y-scaling factor
	 * @param z z-scaling factor
	 */
	void scale(const float x, const float y, const float z);

	/// Specify the drawing color for the next GL functions
	/*! @param color the new drawing color
	 */
	void color(Color const & color);
		
	/*! @param r red value of the new drawing color
	 *  @param g green value of the new drawing color
	 *  @param b blue value of the new drawing color
	 *  @param a alpha value of the new drawing color
	 */
	void color(const float r, const float g, const float b, const float a=1.0f);
	
	/// Push the current transformation matrix to the stack
	void push();
	
	/// Replace the transformation matrix with the top from the stack
	void pop();
	
	/// Replace the transformation matrix with the identity matrtix
	void loadidentity();

	/// Perspective matrix
	void frustum(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble znear, GLdouble zfar);
};

#endif // __INCLUDED_OSIRIONGL_H__