/* 
   view.cc
   This file is part of the Osirion project and is distributed under 
   the terms and conditions of the GNU General Public License version 2 
*/

#include "client/client.h"
#include "client/shipdrawer.h"
#include "client/stardrawer.h"
#include "game/game.h"
#include "gl/gllib.h"
#include "sys/sys.h"
#include "math/mathlib.h"

#include <SDL/SDL.h>

namespace client
{

ShipDrawer *shipdrawer = 0;
StarDrawer *stardrawer = 0;

game::Ship *target =0; // the view's target

void View::init() {
	// draw scene
	if (!shipdrawer) {
		stardrawer = new StarDrawer(&game::star);
		shipdrawer = new ShipDrawer(&game::ship);	
		target = &game::ship;
	}
	
}

void View::shutdown() 
{
	delete stardrawer;
	stardrawer = 0;
	delete shipdrawer;
	shipdrawer = 0;
}

void View::reset() {
	// Change to the projection matrix and set our viewing volume.
	gl::matrixmode( GL_PROJECTION );
	gl::loadidentity();

	//glu::perspective( 64.0, video::ratio, 1.0, 1024.0 );
	const float frustumsize=0.5f;
	gl::frustum( -frustumsize * video.ratio, frustumsize * video.ratio, -frustumsize, frustumsize, 1.0f, 1024.0f);
	/* 
		map world coordinates to GL coordinates
	 
		The world coordinates are identical to GL coordinates, 
		but the default viewing pitch (0 degrees)
		is the positive X-axis
	*/
	gl::rotate(90.0f, 0, 1.0, 0);
}

void View::draw_background(float elapsed)
{
	using namespace gl;

// // 	// enable Alpha blending
	gl::enable(GL_BLEND); 
	
	// galactic axis
	begin(Lines);
	color(0.9f, 0.5f, 0.0f);
	vertex(-2,0,0);
	color(1.0f, 1.0f, 0.0f);
	vertex(2,0,0);

	vertex(0,0,-0.5);
	vertex(0,0,0.5);

	vertex(0,1.0f,0);
	vertex(0,-1, 0);
	end();

	int gridsize = 32;
	float s = 1.0f / gridsize;
	float y = -4.0f;

	float dx =  target->location.x - floorf(target->location.x);
	float dz =  target->location.z - floorf(target->location.z);

    	color(0,0, 1.0f); 
    	begin(Lines);
    	for (int i=-gridsize; i <= gridsize; i++) {
		color(0,0, 0, 0);
		vertex(i-dx, y, -gridsize-dz);
		color(0,0, (gridsize-abs(i))*s, (gridsize-abs(i))*s);
		vertex(i-dx, y, -dz);
		vertex(i-dx, y, -dz);
		color(0,0, 0, 0);
		vertex(i-dx, y, gridsize-dz);
	
		vertex(-gridsize-dx, y, i-dz);
		color(0,0, (gridsize-abs(i))*s, (gridsize-abs(i))*s);
		vertex(-dx, y, i-dz);
		vertex(-dx, y, i-dz);
		color(0,0, 0, 0);
		vertex(gridsize-dx, y, i-dz);
	}	
	end();

	gl::disable(GL_BLEND); 
}

void View::draw_world(float elapsed)  
{
	// draw the world
	gl::push();

	gl::translate(game::ship.location - target->location);
	gl::scale(0.2f,  0.2f,  0.2f);
	shipdrawer->draw(elapsed);
	gl::pop();

	gl::push();
	gl::translate(game::star.location - target->location);	
	stardrawer->draw(elapsed);
	gl::pop();

}

void View::draw(float elapsed) 
{
	// Clear the color and depth buffers.
	gl::clear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
	
	// We don't want to modify the projection matrix.
	gl::matrixmode( GL_MODELVIEW );
	gl::loadidentity();

	// Camera transformation
	camera.draw(elapsed);

	// draw the world
	draw_world(elapsed);
	
	// draw the semi-static background
	draw_background(elapsed);

	SDL_GL_SwapBuffers();
}

} // namespace view