#include <stdlib.h>
#include <math.h>
#include <GL/gl.h>
#include <GL/glext.h>
#include <neofx/math.h>
#include <zoom/level.h>
#include <zoom/light.h>
#include <zoom/player.h>
#include <zoom/render.h>


extern PLAYER player;
extern LEVEL *level;
extern GLuint sphere;
extern int nLights;
extern LIGHT *lights;
extern COLOR ambient;
extern GLuint lightmap;


static int SortByTex(const void *p1, const void *p2) {
	return ((POLYGON*)p1)->texture - ((POLYGON*)p2)->texture;
}

void Render() {
	//GLfloat std_emission[] ={{0.0, 0.0, 0.0, 1.0};
	MATRIX rotate = {.f = {
		player.rotycos, 0.0, -player.rotysin, 0.0,
		0.0, 1.0, 0.0, 0.0,
		player.rotysin, 0.0, player.rotycos, 0.0,
		0.0, 0.0, 0.0, 1.0
	}};
	POLYGON_LIST *room;
	int i, j, k;
	float d;
	VECTOR v, v1, v2;
	VERTEX p;
	COLOR c;
	GLint last_tex;
	
	
	glLoadIdentity();
	
	glRotatef(player.rotx, 1.0, 0.0, 0.0);
	glMultMatrixf(rotate.f);
	
	
	glTranslatef(-player.pos.x, -player.pos.y, -player.pos.z);
	
	room = DrawRoom(level, player.room);
	qsort(room->polygons, room->nPolygons, sizeof(POLYGON), SortByTex);
	
	glDepthMask(GL_TRUE);
	glDepthFunc(GL_LESS);
	
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	
	glBlendFunc(GL_ONE, GL_ZERO);
	
	glColor3fv((GLfloat*)&ambient);
	
	glActiveTexture(GL_TEXTURE1);
	glDisable(GL_TEXTURE_2D);
	glActiveTexture(GL_TEXTURE0);
	
	glBindTexture(GL_TEXTURE_2D, room->polygons[0].texture);
	last_tex = room->polygons[0].texture;
	glBegin(GL_TRIANGLES);
	
	for(i = 0; i < room->nPolygons; i++) {
		if(last_tex != room->polygons[i].texture) {
			glEnd();
			glBindTexture(GL_TEXTURE_2D, room->polygons[i].texture);
			last_tex = room->polygons[i].texture;
			glBegin(GL_TRIANGLES);
		}
		
		glMultiTexCoord2fv(0, (GLfloat*)&room->polygons[i].texcoords[0]);
		glVertex3fv((GLfloat*)&room->polygons[i].vertices[0]);
		glMultiTexCoord2fv(0, (GLfloat*)&room->polygons[i].texcoords[1]);
		glVertex3fv((GLfloat*)&room->polygons[i].vertices[1]);
		glMultiTexCoord2fv(0, (GLfloat*)&room->polygons[i].texcoords[2]);
		glVertex3fv((GLfloat*)&room->polygons[i].vertices[2]);
		
		
	}
	
	glEnd();
	
	glDepthFunc(GL_EQUAL);
	glDepthMask(GL_FALSE);
	
	glBlendFunc(GL_ONE, GL_ONE);
	
	glColor3f(1.0, 1.0, 1.0);
	
	glBindTexture(GL_TEXTURE_2D, lightmap);
	glActiveTexture(GL_TEXTURE1);
	
	for(i = 0; i < nLights; i++) {
	  if(room->polygons[0].texture) {
	    glEnable(GL_TEXTURE_2D);
	    glBindTexture(GL_TEXTURE_2D, room->polygons[0].texture);
	  }
		else
		  glDisable(GL_TEXTURE_2D);
		
		last_tex = room->polygons[0].texture;
		
		glBegin(GL_TRIANGLES);
		
		for(j = 0; j < room->nPolygons; j++) {
			if(last_tex != room->polygons[j].texture) {
				glEnd();
				glBindTexture(GL_TEXTURE_2D, room->polygons[j].texture);
				last_tex = room->polygons[j].texture;
				glBegin(GL_TRIANGLES);
			}
			
			d = VectorDot(room->polygons[j].normal, VectorSub(room->polygons[j].vertices[0], lights[i].pos));
			
			if(d < 0) {
				c = VectorMul(lights[i].diffuse, 1.0/(d*d));
				glColor3fv((GLfloat*)&c);
				
				v1 = VectorNormalize(VectorSub(room->polygons[j].vertices[0], room->polygons[j].vertices[1]));
				
				for(k = 0; k < 3; k++) {
          p = VectorAdd(lights[i].pos, VectorMul(room->polygons[j].normals[k], d));
					v = VectorSub(room->polygons[j].vertices[k], p);
					
          v2 = VectorCross(v1, room->polygons[j].normals[k]);
          
					glMultiTexCoord2f(0, VectorDot(v, v1)*0.04 / d + 0.5, VectorDot(v, v2)*0.04 / d + 0.5);
					glMultiTexCoord2fv(1, (GLfloat*)&room->polygons[j].texcoords[k]);
					glVertex3fv((GLfloat*)&room->polygons[j].vertices[k]);
				}
			}
		}
		
		glEnd();
	}
	
	free(room);
	
	/*glPushMatrix();
	glDisable(GL_TEXTURE_2D);
	glColor3f(1.0, 1.0, 1.0);
	glTranslatef(lights[0].pos.x, lights[0].pos.y, lights[0].pos.z);
	glScalef(0.1, 0.1, 0.1);
	glCallList(sphere);
	glEnable(GL_TEXTURE_2D);
	glPopMatrix();*/
	
	glFlush();
}