/*
    Raydium - CQFD Corp.
    http://raydium.org/
    License: GPL - GNU General Public License, see "gpl.txt" file.
*/

#ifndef DONT_INCLUDE_HEADERS
#include "index.h"
#else
#include "headers/sky.h"
#endif


void raydium_sky_box_cache(void)
{
raydium_texture_current_set_name("BOXfront.tga");
raydium_texture_current_set_name("BOXback.tga");
raydium_texture_current_set_name("BOXleft.tga");
raydium_texture_current_set_name("BOXright.tga");
raydium_texture_current_set_name("BOXbottom.tga");
raydium_texture_current_set_name("BOXtop.tga");

raydium_hdr_texture_name("BOXfront.tga",1);
raydium_hdr_texture_name("BOXback.tga",1);
raydium_hdr_texture_name("BOXleft.tga",1);
raydium_hdr_texture_name("BOXright.tga",1);
raydium_hdr_texture_name("BOXbottom.tga",1);
raydium_hdr_texture_name("BOXtop.tga",1);
}


void raydium_sky_box_render(GLfloat x, GLfloat y, GLfloat z)
{
//GLfloat one[]={1.,1.,1.,1.};
#define sizeb ((raydium_projection_far-raydium_projection_near)/2.f)
/*
GLfloat (x+size)=(x+5);
GLfloat sizey=(x+5);
GLfloat (z+size)=(x+5);
GLfloat minv=(x-5);
*/

if(raydium_fog_enabled_tag && !raydium_sky_force) return;

glDisable(GL_LIGHTING);
glDisable(GL_FOG);
//glColor4fv(raydium_background_color);
//glColor4fv(one);

raydium_texture_current_set_name("BOXfront.tga");
raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
//glBindTexture(GL_TEXTURE_2D,raydium_texture_current_set_name("BOXfront.tga"));
glColor4fv(raydium_background_color);
glDepthMask(GL_FALSE);
glBegin(GL_QUADS);
    glTexCoord2f(1.0f, 1.0f); glVertex3f((x+sizeb),(y-sizeb),(z-sizeb));
    glTexCoord2f(0.0f, 1.0f); glVertex3f((x+sizeb),(y+sizeb),(z-sizeb));
    glTexCoord2f(0.0f, 0.0f); glVertex3f((x+sizeb),(y+sizeb),(z+sizeb)); 
    glTexCoord2f(1.0f, 0.0f); glVertex3f((x+sizeb),(y-sizeb),(z+sizeb));
glEnd();

				
raydium_texture_current_set_name("BOXback.tga");
raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
//glBindTexture(GL_TEXTURE_2D,raydium_texture_current_set_name("BOXback.tga"));
glColor4fv(raydium_background_color);
glDepthMask(GL_FALSE);
glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 1.0f); glVertex3f((x-sizeb),(y-sizeb),(z-sizeb));
    glTexCoord2f(1.0f, 1.0f); glVertex3f((x-sizeb),(y+sizeb),(z-sizeb));
    glTexCoord2f(1.0f, 0.0f); glVertex3f((x-sizeb),(y+sizeb),(z+sizeb)); 
    glTexCoord2f(0.0f, 0.0f); glVertex3f((x-sizeb),(y-sizeb),(z+sizeb));
glEnd();


raydium_texture_current_set_name("BOXright.tga");
raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
//glBindTexture(GL_TEXTURE_2D,raydium_texture_current_set_name("BOXright.tga"));
glColor4fv(raydium_background_color);
glDepthMask(GL_FALSE);
glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 1.0f); glVertex3f((x-sizeb),(y+sizeb),(z-sizeb));
    glTexCoord2f(1.0f, 1.0f); glVertex3f((x+sizeb),(y+sizeb),(z-sizeb));
    glTexCoord2f(1.0f, 0.0f); glVertex3f((x+sizeb),(y+sizeb),(z+sizeb)); 
    glTexCoord2f(0.0f, 0.0f); glVertex3f((x-sizeb),(y+sizeb),(z+sizeb));
glEnd();

raydium_texture_current_set_name("BOXleft.tga");
raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
//glBindTexture(GL_TEXTURE_2D,raydium_texture_current_set_name("BOXleft.tga"));
glColor4fv(raydium_background_color);
glDepthMask(GL_FALSE);
glBegin(GL_QUADS);
    glTexCoord2f(1.0f, 1.0f); glVertex3f((x-sizeb),(y-sizeb),(z-sizeb));
    glTexCoord2f(0.0f, 1.0f); glVertex3f((x+sizeb),(y-sizeb),(z-sizeb));
    glTexCoord2f(0.0f, 0.0f); glVertex3f((x+sizeb),(y-sizeb),(z+sizeb)); 
    glTexCoord2f(1.0f, 0.0f); glVertex3f((x-sizeb),(y-sizeb),(z+sizeb));
glEnd();

raydium_texture_current_set_name("BOXtop.tga");
raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
//glBindTexture(GL_TEXTURE_2D,raydium_texture_current_set_name("BOXtop.tga"));
glColor4fv(raydium_background_color);
glDepthMask(GL_FALSE);
glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 0.0f); glVertex3f((x-sizeb),(y-sizeb),(z+sizeb));
    glTexCoord2f(1.0f, 0.0f); glVertex3f((x+sizeb),(y-sizeb),(z+sizeb));
    glTexCoord2f(1.0f, 1.0f); glVertex3f((x+sizeb),(y+sizeb),(z+sizeb)); 
    glTexCoord2f(0.0f, 1.0f); glVertex3f((x-sizeb),(y+sizeb),(z+sizeb));
glEnd();


raydium_texture_current_set_name("BOXbottom.tga");
raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
//glBindTexture(GL_TEXTURE_2D,raydium_texture_current_set_name("BOXbottom.tga"));
glColor4fv(raydium_background_color);
glDepthMask(GL_FALSE);
glBegin(GL_QUADS);
    glTexCoord2f(0.0f, 1.0f); glVertex3f((x-sizeb),(y-sizeb),(z-sizeb));
    glTexCoord2f(1.0f, 1.0f); glVertex3f((x+sizeb),(y-sizeb),(z-sizeb));
    glTexCoord2f(1.0f, 0.0f); glVertex3f((x+sizeb),(y+sizeb),(z-sizeb)); 
    glTexCoord2f(0.0f, 0.0f); glVertex3f((x-sizeb),(y+sizeb),(z-sizeb));
glEnd();


if(raydium_light_enabled_tag) glEnable(GL_LIGHTING);
if(raydium_fog_enabled_tag) glEnable(GL_FOG);
glDepthMask(GL_TRUE);

}

void raydium_sky_sphere_render(GLfloat x, GLfloat y, GLfloat z,int detail)
{	
	int i, j,co;
	GLfloat currentradious,z1,z2,ang1,dx,dy,h;
	//the next is static cause this will be used to store the vertices of the sphere.
	//i suppose that it could be external to this function.
	static GLfloat p[RAYDIUM_SKY_SPHERE_MAX_DETAIL][RAYDIUM_SKY_SPHERE_MAX_DETAIL][3];

	//keeping safe the current matrix
	glPushMatrix();
	
	//glPushAttrib(GL_COLOR_BUFFER_BIT); Gl attrib functions shoudn't be used

	//increasing angles to simulate orbit
	raydium_sky_sphere_angle_orbit_u += 10 * raydium_frame_time;
	raydium_sky_sphere_angle_orbit_v += 1 * raydium_frame_time;

	//test code.
	//the rotation speed should be changed with a function
	raydium_sky_sphere_y_vel=0.01;
	raydium_sky_sphere_x_vel=0.01;

	//updating the x and y values according the speed and the framerate
	raydium_sky_sphere_x_pos+=raydium_sky_sphere_x_vel * raydium_frame_time;
	raydium_sky_sphere_y_pos+=raydium_sky_sphere_y_vel * raydium_frame_time;

	//using dx and dy to simplify the code
	dx=raydium_sky_sphere_x_pos;
	dy=raydium_sky_sphere_y_pos;

	//turning off "specials" for render
	glDisable(GL_LIGHTING);
	glDisable(GL_FOG);
	glEnable(GL_TEXTURE_2D);
	glColor4fv(raydium_background_color);
	glDepthMask(GL_FALSE);
	
	//glEnable(GL_BLEND);
	//glBlendFunc(GL_DST_COLOR,GL_SRC_COLOR);
	
	//MAKING THE SPHERE
	
	//check if the points are already calculated.
	//there is no reason to enter constantly.
	if(raydium_sky_sphere_generated!=1)
	{
		//getting the points of the sphere, but no drawing
		for(i=0;i<=detail;i++)
		{
			//getting the radius for each section of the sphere
			currentradious		=	raydium_trigo_sin(180*((float)i/(float)detail));
			//getting the heights for each section of the sphere
			z1	 		=	raydium_trigo_cos(180*((float)i/(float)detail));		
			for(j=0;j<=detail;j++)
			{
				ang1		=	360*((float)j/(float)detail);
				p[i][j][0]	=	currentradious * raydium_trigo_cos(ang1);
				p[i][j][1]	=	currentradious * raydium_trigo_sin(ang1);
				p[i][j][2]	=	z1;
			}
		}
		raydium_sky_sphere_generated	=	1;
	}

	//Postioning the modelview in the pos of the camera
	glTranslatef(x,y,z);

	//test code
	//the texture should be loaded with a different function
	if(!raydium_texture_exists("SKYCLOUDS.tga"))
	{
		raydium_texture_load("SKYCLOUDS.tga");
	}
	raydium_texture_current_set_name("SKYCLOUDS.tga");	
	
	//activating texture 
	raydium_rendering_internal_prepare_texture_render(raydium_texture_current_main);
	
	//shutdown the DEPTH writting
	glDepthMask(GL_FALSE);

	//activating and setting fog
	raydium_fog_enable();
	glFogf(GL_FOG_START,0.6);
	glFogf(GL_FOG_END,1);
	glFogi(GL_FOG_MODE,GL_EXP2);
	
	//setting h to the height of the vault
	h=raydium_sky_sphere_heigth;

	//activating the blending needed for the clouds
	glEnable(GL_BLEND);
	glBlendFunc(GL_DST_COLOR,GL_ONE_MINUS_SRC_ALPHA);

	//drawing the layers of clouds
	for(co=0;co<raydium_sky_sphere_quality;co++)
	{
		//drawing the upper vault		
		
		glBegin(GL_TRIANGLES);
		glColor4f(1,1,1,1*(co/raydium_sky_sphere_quality));
		glTexCoord2f(-1+dx,1+dy);
		glVertex3f(-1,1,0);
		glTexCoord2f(1+dx,1+dy);
		glVertex3f(1,1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);
	
		glTexCoord2f(1+dx,1+dy);
		glVertex3f(1,1,0);
		glTexCoord2f(1+dx,-1+dy);
		glVertex3f(1,-1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);
	
		glTexCoord2f(1+dx,-1+dy);
		glVertex3f(1,-1,0);
		glTexCoord2f(-1+dx,-1+dy);
		glVertex3f(-1,-1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);	
	
		glTexCoord2f(-1+dx,1+dy);
		glVertex3f(-1,1,0);
		glTexCoord2f(-1+dx,-1+dy);
		glVertex3f(-1,-1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);
		
		//drawing the botom vault, mirror of the upper one
		h=-h;
		
		//glColor4f(1,1,1,1);
		glTexCoord2f(-1+dx,1+dy);
		glVertex3f(-1,1,0);
		glTexCoord2f(1+dx,1+dy);
		glVertex3f(1,1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);
	
		glTexCoord2f(1+dx,1+dy);
		glVertex3f(1,1,0);
		glTexCoord2f(1+dx,-1+dy);
		glVertex3f(1,-1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);
	
		glTexCoord2f(1+dx,-1+dy);
		glVertex3f(1,-1,0);
		glTexCoord2f(-1+dx,-1+dy);
		glVertex3f(-1,-1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);	
	
		glTexCoord2f(-1+dx,1+dy);
		glVertex3f(-1,1,0);
		glTexCoord2f(-1+dx,-1+dy);
		glVertex3f(-1,-1,0);
		glTexCoord2f(0+dx,0+dy);
		glVertex3f(0,0,h);
		glEnd();
	
		//recalculating the new heigth of the vault(a new layer)
		h=-h*0.95;	
	}

	//deactivating the fog, unused
	raydium_fog_disable();
	//reactivating the previous blending
	glEnable(GL_BLEND);
	glBlendFunc(GL_ONE_MINUS_SRC_COLOR,GL_SRC_COLOR);

	//match the orientation of the camera with the universe
	//rotating according the orbit angles(ugly)
	glRotatef(raydium_sky_sphere_angle_orbit_v,0,0,1);
	glRotatef(raydium_sky_sphere_angle_orbit_u,1,0,0);

	//now drawing the sphere with the pre-obtained values
	for(i=0;i<detail;i++)
	{
		for(j=0;j<detail;j++)
		{
			//calculating colors
			z1 = 1-sin((float)2*i/detail);
			z2 = 1-sin((float)(2*i+2)/detail);
			
			glBegin(GL_TRIANGLES);
			
			glColor4f(z1,z1,z1,1);
			glVertex3f(p[i][j][0],p[i][j][1],p[i][j][2]);
			
			glColor4f(z1,z1,z1,1);
			glVertex3f(p[i][j+1][0],p[i][j+1][1],p[i][j+1][2]);
			
			glColor4f(z2,z2,z2,1);
			glVertex3f(p[i+1][j][0],p[i+1][j][1],p[i+1][j][2]);
			
			glColor4f(z2,z2,z2,1);
			glVertex3f(p[i+1][j][0],p[i+1][j][1],p[i+1][j][2]);
			
			glColor4f(z2,z2,z2,1);
			glVertex3f(p[i+1][j+1][0],p[i+1][j+1][1],p[i+1][j+1][2]);
			
			glColor4f(z1,z1,z1,1);
			glVertex3f(p[i][j+1][0],p[i][j+1][1],p[i][j+1][2]);
			
			glEnd();
		}
	}

	//restoring previus states
	glDisable(GL_BLEND);
	glEnable(GL_TEXTURE_2D);
	glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
	if(raydium_fog_enabled_tag) glEnable(GL_FOG);
	if(raydium_light_enabled_tag) glEnable(GL_LIGHTING);
	glDepthMask(GL_TRUE);
	//glPopAttrib();
	glPopMatrix();

}

void raydium_sky_atmosphere_enable(void)
{
	raydium_sky_atmosphere_enable_tag=1;
	raydium_sky_sphere_quality=20;
	raydium_sky_sphere_heigth=0.09;
	//this will force to recalculate the sphere once
	raydium_sky_sphere_generated=0;
	raydium_log("atmosphere created with quality 20");
}

void raydium_sky_atmosphere_disable(void)
{
	raydium_sky_atmosphere_enable_tag=0;
}

void raydium_sky_atmosphere_render( GLfloat x, GLfloat y, GLfloat z,int detail)
{
	if(raydium_sky_atmosphere_enable_tag)
	{	
		raydium_sky_sphere_render(x,y,z,detail);
	}
}

signed char raydium_sky_atmosphere_check(void)
{
	return raydium_sky_atmosphere_enable_tag;
}