/* Relevant data structures. */
struct GPoint_st
{
	float x, y, z;
	float nx, ny, nz;
	float s0, t0;
};

typedef struct GSolid_st
{
	GPoint*			grid;
	int			size;
	int			gridmode;
	GColor*			color;
	struct GSolid_st* 	next;
} GSolid;

//A 4x4 matrix is represented by a 16 cell float array.
typedef float GOperator;

/* Some very relevant code concerning the VBO usage:
*/
void	
gscreen_init(int* argc, char* argv[], void (*render)(void))
{
	glutInit(argc, argv);
	glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(win_width, win_height);
	glutCreateWindow("Pub");
	
	glutReshapeFunc(&gscreen_reshape);
	glutDisplayFunc(render);
	glutIdleFunc(render);
	
	glutPassiveMotionFunc(&gmouse_passivemov);
	glutKeyboardFunc(&gkeyboard_keypress);
	glutKeyboardUpFunc(&gkeyboard_keyrelease);
	glutSetKeyRepeat(GLUT_KEY_REPEAT_OFF);
	
	//TODO: allow camera to be initialized anywhere else.
	gcamera_init(3);
	CAM->cam_eye[0] = 0; CAM->cam_eye[1] = 0; CAM->cam_eye[2] = 0;
	CAM->cam_dir[0] = 0; CAM->cam_dir[1] = 0; CAM->cam_dir[2] = 1;
	
	if (glewInit() != GLEW_OK)
	{
		fprintf(stderr, "err: glewInit();\n");
		exit(__LINE__);
	}
	
	glEnableClientState(GL_VERTEX_ARRAY);
	glEnableClientState(GL_NORMAL_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	
	glGenBuffers(1, buffer);
}

static void
gscreen_default_render()
{	
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	//Let's clear our matrix
	glLoadIdentity();
	
	//Firstly, we should apply our camera transformations,
	gcamera_apply();
	
	glClearColor(0.0f,0.0f,0.0f,0.0f);
	
	// draw the base's front
	glCullFace(GL_BACK);
	
	// set filling mode
	glPolygonMode(GL_FRONT, GL_FILL);
	
	//Now, we should render all objects
	//gscreen_object_renderer();
	glutWireTeapot(3.0f);
	//and swap buffers.
	glutSwapBuffers();
}

static void	
gscreen_display_solid(GSolid* s, GOperator* op)
{
	if (!s)
		return;
		
	glBindBuffer(GL_ARRAY_BUFFER, *buffer);
	glBufferData(GL_ARRAY_BUFFER, s->size*sizeof(GPoint), s->grid, GL_STATIC_DRAW);
	for (int i = 0; i < s->size; i++)
		printf("%.1f %.1f %.1f\n", s->grid[i].x, s->grid[i].y, s->grid[i].z);
	glVertexPointer(3, GL_FLOAT, sizeof(GPoint), 0);
	//glNormalPointer(GL_FLOAT, 8*sizeof(float), (float*)(sizeof(GLfloat)*3));
	
	if (op)
	{
		glPushMatrix();
		glMultMatrixf(op);
	}
	
	glDrawArrays(s->gridmode, 0, s->size);
	
	if (op)
		glPopMatrix();
		
	gscreen_display_solid(s->next, op);
}

void 
gscreen_object_renderer()
{
vector<triple<GSolid*, GOperator*, int> >::iterator i;

	for (i=screen_objs.begin(); i < screen_objs.end(); i++)
	{
		if ((*i).c == GSCREEN_OBJECT_DISPLAY)
			gscreen_display_solid((*i).a, (*i).b);
	}
}