/*
 Copyright (C) 2001-2006, William Joseph.
 All Rights Reserved.

 This file is part of GtkRadiant.

 GtkRadiant 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.

 GtkRadiant 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 GtkRadiant; if not, write to the Free Software
 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined(INCLUDED_VIEW_H)
#define INCLUDED_VIEW_H

#include "cullable.h"
#include "math/frustum.h"

extern int g_count_dots;
extern int g_count_planes;
extern int g_count_oriented_planes;
extern int g_count_bboxs;
extern int g_count_oriented_bboxs;

static inline void debug_count_dot ()
{
	++g_count_dots;
}

static inline void debug_count_plane ()
{
	++g_count_planes;
}

static inline void debug_count_oriented_plane ()
{
	++g_count_oriented_planes;
}

static inline void debug_count_bbox ()
{
	++g_count_bboxs;
}

static inline void debug_count_oriented_bbox ()
{
	++g_count_oriented_bboxs;
}

/// \brief View-volume culling and transformations.
class View : public VolumeTest {
	/// modelview matrix
	Matrix4 m_modelview;
	/// projection matrix
	Matrix4 m_projection;
	/// device-to-screen transform
	Matrix4 m_viewport;

	Matrix4 m_scissor;

	/// combined modelview and projection matrix
	Matrix4 m_viewproj;
	/// camera position in world space
	Vector4 m_viewer;
	/// view frustum in world space
	Frustum m_frustum;

	bool m_fill;

	void construct() {
		m_viewproj = matrix4_multiplied_by_matrix4(matrix4_multiplied_by_matrix4(m_scissor, m_projection), m_modelview);

		m_frustum = frustum_from_viewproj(m_viewproj);
		m_viewer = viewer_from_viewproj(m_viewproj);
	}
	public:
	View(bool fill = false) :
	m_modelview(Matrix4::getIdentity()),
	m_projection(Matrix4::getIdentity()),
	m_scissor(Matrix4::getIdentity()),
	m_fill(fill) {
	}
	void Construct(const Matrix4& projection, const Matrix4& modelview, std::size_t width, std::size_t height) {
		// modelview
		m_modelview = modelview;

		// projection
		m_projection = projection;

		// viewport
		m_viewport = Matrix4::getIdentity();
		m_viewport[0] = float(width / 2);
		m_viewport[5] = float(height / 2);
		if (fabs(m_projection[11])> 0.0000001)
		m_viewport[10] = m_projection[0] * m_viewport[0];
		else
		m_viewport[10] = 1 / m_projection[10];

		construct();
	}
	void EnableScissor(float min_x, float max_x, float min_y, float max_y) {
		m_scissor = Matrix4::getIdentity();
		m_scissor[0] = static_cast<float>((max_x - min_x) * 0.5);
		m_scissor[5] = static_cast<float>((max_y - min_y) * 0.5);
		m_scissor[12] = static_cast<float>((min_x + max_x) * 0.5);
		m_scissor[13] = static_cast<float>((min_y + max_y) * 0.5);
		matrix4_full_invert(m_scissor);

		construct();
	}
	void DisableScissor() {
		m_scissor = Matrix4::getIdentity();

		construct();
	}

	bool TestPoint(const Vector3& point) const {
		return viewproj_test_point(m_viewproj, point);
	}
	bool TestLine(const Segment& segment) const {
		return frustum_test_line(m_frustum, segment);
	}
	bool TestPlane(const Plane3& plane) const {
		debug_count_plane();
		return viewer_test_plane(m_viewer, plane);
	}
	bool TestPlane(const Plane3& plane, const Matrix4& localToWorld) const {
		debug_count_oriented_plane();
		return viewer_test_transformed_plane(m_viewer, plane, localToWorld);
	}
	VolumeIntersectionValue TestAABB(const AABB& aabb) const {
		debug_count_bbox();
		return frustum_test_aabb(m_frustum, aabb);
	}
	VolumeIntersectionValue TestAABB(const AABB& aabb, const Matrix4& localToWorld) const {
		debug_count_oriented_bbox();
		return frustum_intersects_transformed_aabb(m_frustum, aabb, localToWorld);
	}

	const Matrix4& GetViewMatrix() const {
		return m_viewproj;
	}
	const Matrix4& GetViewport() const {
		return m_viewport;
	}
	const Matrix4& GetModelview() const {
		return m_modelview;
	}
	const Matrix4& GetProjection() const {
		return m_projection;
	}

	bool fill() const {
		return m_fill;
	}
	const Vector3& getViewer() const {
		return m_viewer.getVector3();
	}
};

#endif
