////////////////////////////////////////////////////////////////////////////////
//    Scorched3D (c) 2000-2011, 2025, 2026
//
//    This file is part of Scorched3D.
//
//    Scorched3D 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.
//
//    Scorched3D 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, write to the Free Software Foundation, Inc.,
//    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
////////////////////////////////////////////////////////////////////////////////

#include <GLEXT/GLState.hpp>
#include <GLW/GLWFlag.hpp>
#include <cmath>

REGISTER_CLASS_SOURCE(GLWFlag);

GLWFlag::GLWFlag(Vector &color, float x, float y, float w) :
	GLWidget(x, y, w, 20.0f),
	color_(color),
	offset_(0.0f)
{}

GLWFlag::~GLWFlag()
{}

void GLWFlag::simulate(float frameTime)
{
	offset_ -= 10.0f * frameTime;
}

void GLWFlag::draw()
{
	GLState currentState(GLState::TEXTURE_OFF);

	const float diff = 1.0f;
	const float rad = ( M_PIf * 4.0f ) / w_;

	glBegin(GL_QUADS);
		for (float a=0.0f; a<=w_-diff; a+=diff)
		{
			float mult  = std::sinf( std::fmaf( a, rad,  offset_ ) );
			float cmult = std::fmaf( mult, 0.25f, 0.75f );
			float hmult = mult * 2.0f;

			glColor3f(color_[0] * cmult, color_[1] * cmult, color_[2] * cmult);
			glVertex2f(x_ + a, y_  + hmult);
			glVertex2f(x_ + a + diff, y_ + hmult);
			glVertex2f(x_ + a + diff, y_ + h_ + hmult);
			glVertex2f(x_ + a, y_ + h_ + hmult);
		}
	glEnd();
}
