// OPEN_GL_test.cpp : Defines the entry point for the console application.
//
// OPEN_GL_test.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

GLfloat colors[][3] = { { .3,.30,0.30 },{ 1.0,0.0,0.0 },
{ 1.0,1.0,0.0 },{ 0.0,1.0,0.0 },{ 0.0,0.0,1.0 },
{ 1.0,0.0,1.0 },{ 1.0,1.0,1.0 },{ 0.0,1.0,1.0 } };

#define GL_PI 3.1415f

GLfloat xRot = 0.45f;
GLfloat yRot = 0.35f;
GLboolean bCull = glIsEnabled(GL_CULL_FACE);
GLboolean bDepth = glIsEnabled(GL_DEPTH_TEST);
GLboolean bOutline = (GLboolean)true;

GLenum shademode = GL_FLAT;

GLfloat ex = 0.0f;
GLfloat ey = 50.0f;
GLfloat ez = -120.0f;
GLfloat delta = 0.01f;
GLfloat deltaR = 0.01f;
GLfloat ALFA = 0.25f;


GLfloat foc[] = { 15., 55., 0., 1. };
GLfloat pis[] = { 0.,1.,0., 50. /*?-50*/ };
GLfloat MatrizSombra[16];

void SetupRC()
{
	// Black background
	glClearColor(0.0f, 0.0f, .0f, 1.0f);

	// Set color shading model to flat
	glShadeModel(shademode);

	// Clockwise-wound polygons are front facing; this is reversed
	// because we are using triangle fans
	glFrontFace(GL_CW);
}

void cuadrado_unitario() {
	glBegin(GL_POLYGON);
	glVertex3f(-1., -1., 0);
	glVertex3f(-1., 1., 0);
	glVertex3f(1., 1., 0);
	glVertex3f(1., -1., 0);
	glEnd();
}
#define NUMLIN 10
void lineas_piso() {
	glColor4f(1., 1., 1., ALFA);
	glBegin(GL_LINES);
		for (int i = 0; i < NUMLIN; i++)
		{
			glVertex3f(-1. + i * 2. / (NUMLIN-1.), -1., 0);
			glVertex3f(-1. + i * 2. / (NUMLIN - 1.), 1., 0);

			glVertex3f(-1. , 1.- i * 2. / (NUMLIN - 1.), 0);
			glVertex3f(1. ,  1.- i * 2. / (NUMLIN - 1.), 0);
		}	
	glEnd();
}

void colorcube2sincolor() //para la sombra
{
	/* map vertices to faces */
	glPushMatrix();
		glScalef(10., 10., 10.);
		//cara1	
		glPushMatrix();
		glTranslatef(0., 0, 1.);
		cuadrado_unitario();
		glPopMatrix();

		//cara2	
		glPushMatrix();
		glRotatef(90., 0., 1., 0.);
		glTranslatef(0., 0, 1.);
		cuadrado_unitario();
		glPopMatrix();
	
		//cara3	
		glPushMatrix();
		glRotatef(180., 0., 1., 0.);
		glTranslatef(0., 0, 1.);
		cuadrado_unitario();
		glPopMatrix();

		//cara4	
		glPushMatrix();
		glRotatef(270., 0., 1., 0.);
		glTranslatef(0., 0, 1.);
		cuadrado_unitario();
		glPopMatrix();

		//cara5
		glPushMatrix();
		glRotatef(90., 0., 0., 1.);
		glRotatef(270., 0., 1., 0.);
		glTranslatef(0., 0, 1.);
		cuadrado_unitario();
		glPopMatrix();

		//cara6	
		glPushMatrix();
		glRotatef(-90., 0., 0., 1.);
		glRotatef(270., 0., 1., 0.);
		glTranslatef(0., 0, 1.);
		cuadrado_unitario();
		glPopMatrix();

	glPopMatrix();
}

void colorcube2(void)
{
	/* map vertices to faces */
	glPushMatrix();
	glScalef(10., 10., 10.);
	//cara1
	glColor4f(colors[0][0], colors[0][1], colors[0][2], ALFA);
	//glColor3fv(colors[0]);
	glPushMatrix();
	glTranslatef(0., 0, 1.);
	cuadrado_unitario();
	glPopMatrix();
	//cara2
	glColor4f(colors[1][0], colors[1][1], colors[1][2], ALFA);
	glColor3fv(colors[1]);
	glPushMatrix();
	glRotatef(90., 0., 1., 0.);
	glTranslatef(0., 0, 1.);
	cuadrado_unitario();
	glPopMatrix();
	//cara3
	glColor4f(colors[2][0], colors[2][1], colors[2][2], ALFA); 
	//glColor3fv(colors[2]);
	glPushMatrix();
	glRotatef(180., 0., 1., 0.);
	glTranslatef(0., 0, 1.);
	cuadrado_unitario();
	glPopMatrix();

	//cara4
	glColor4f(colors[3][0], colors[3][1], colors[3][2], ALFA); 
	//glColor3fv(colors[3]);
	glPushMatrix();
	glRotatef(270., 0., 1., 0.);
	glTranslatef(0., 0, 1.);
	cuadrado_unitario();
	glPopMatrix();

	//cara5
	glColor4f(colors[4][0], colors[4][1], colors[4][2], ALFA); 
	//glColor3fv(colors[4]);
	glPushMatrix();
	glRotatef(90., 0., 0., 1.);
	glRotatef(270., 0., 1., 0.);
	glTranslatef(0., 0, 1.);
	cuadrado_unitario();
	glPopMatrix();

	//cara6
	glColor4f(colors[5][0], colors[5][1], colors[5][2], ALFA); 
	//glColor3fv(colors[5]);
	glPushMatrix();
	glRotatef(-90., 0., 0., 1.);
	glRotatef(270., 0., 1., 0.);
	glTranslatef(0., 0, 1.);
	cuadrado_unitario();
	glPopMatrix();

	glPopMatrix();
}

// Called to draw scene
void piso() {
	glColor4f(0.5, 0.5, 0.5, ALFA);
	glPushMatrix();
	glTranslatef(0.,-pis[3], 0.);
	glRotatef(-90., 1., 0, 0);
	glScalef(50., 50., 50.);
	cuadrado_unitario();
	lineas_piso(); //para checar "Blending"
	glPopMatrix();
}

void foquito() {
	glColor4f(1., 1., 0, ALFA);
	glPushMatrix();
	glTranslatef(foc[0], foc[1], foc[2]);
	glutSolidSphere(1.5, 20, 20);
	glPopMatrix();
}

void gltMakeShadowMatrix(GLfloat vPlaneEquation[], 
	GLfloat vLightPos[], GLfloat destMat[])
{
	GLfloat dot;

	// Dot product of plane and light position
	dot = vPlaneEquation[0] * vLightPos[0] + vPlaneEquation[1] * vLightPos[1] +
		vPlaneEquation[2] * vLightPos[2] + vPlaneEquation[3] * vLightPos[3];

	// Now do the projection
	// First column
	destMat[0] = dot - vLightPos[0] * vPlaneEquation[0];
	destMat[4] = 0.0f - vLightPos[0] * vPlaneEquation[1];
	destMat[8] = 0.0f - vLightPos[0] * vPlaneEquation[2];
	destMat[12] = 0.0f - vLightPos[0] * vPlaneEquation[3];

	// Second column
	destMat[1] = 0.0f - vLightPos[1] * vPlaneEquation[0];
	destMat[5] = dot - vLightPos[1] * vPlaneEquation[1];
	destMat[9] = 0.0f - vLightPos[1] * vPlaneEquation[2];
	destMat[13] = 0.0f - vLightPos[1] * vPlaneEquation[3];

	// Third Column
	destMat[2] = 0.0f - vLightPos[2] * vPlaneEquation[0];
	destMat[6] = 0.0f - vLightPos[2] * vPlaneEquation[1];
	destMat[10] = dot - vLightPos[2] * vPlaneEquation[2];
	destMat[14] = 0.0f - vLightPos[2] * vPlaneEquation[3];

	// Fourth Column
	destMat[3] = 0.0f - vLightPos[3] * vPlaneEquation[0];
	destMat[7] = 0.0f - vLightPos[3] * vPlaneEquation[1];
	destMat[11] = 0.0f - vLightPos[3] * vPlaneEquation[2];
	destMat[15] = dot - vLightPos[3] * vPlaneEquation[3];
}

void SombradeMiMundo(GLfloat datosdeLuz[], GLfloat datosdePlano[]) {
	glColor3f(0.3, 0.3, 0.3);
	glPushMatrix();
	gltMakeShadowMatrix(datosdePlano, datosdeLuz, MatrizSombra);
	glMultMatrixf(MatrizSombra);
	colorcube2sincolor(); //en la plantilla <=>Objetos_de_MiMundo();
	glPopMatrix();
}


void RenderScene(void)
{
	// Reset coordinate system
	glLoadIdentity();
	gluLookAt(ex, ey, ez, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

	GLfloat x, y, angle;         // Storage for coordinates and angles
	int iPivot = 1;            // Used to flag alternating colors

							   // Clear the window and the depth buffer
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	// Turn culling on if flag is set
	if (bCull)   glEnable(GL_CULL_FACE);
	else        glDisable(GL_CULL_FACE);

	// Enable depth testing if flag is set
	if (bDepth)  glEnable(GL_DEPTH_TEST);
	else        glDisable(GL_DEPTH_TEST);

	// Draw the back side as a wireframe only, if flag is set
	if (bOutline)glPolygonMode(GL_BACK, GL_LINE);
	else        glPolygonMode(GL_BACK, GL_FILL);

	// Save matrix state and do the rotation
	glPushMatrix();
	glRotatef(xRot, 1.0f, 0.0f, 0.0f);
	glRotatef(yRot, 0.0f, 1.0f, 0.0f);
	/*reflejo*/
	piso();

	/*blending*/
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	glFrontFace(GL_CCW);
	glPushMatrix();	
	    glTranslatef(0., -pis[3], 0.);
		glScalef(1., -1., 1.);
	    glTranslatef(0., pis[3], 0.);
		foquito();
		colorcube2();
	glPopMatrix();
	glFrontFace(GL_CW);
	/*terminar reflejo*/	
	
	glDisable(GL_BLEND);
	/*terminar blending*/
	foquito();		
	/*sombra*/
	glDisable(GL_DEPTH_TEST); //para evitar los errores de redondeo
	SombradeMiMundo(foc, pis);
	if (bDepth)  glEnable(GL_DEPTH_TEST);

	colorcube2();
	// Restore transformations
	glPopMatrix();

	// Flush drawing commands
	glFlush(); // glutSwapBuffers();
}


// Called by GLUT library when the window has changed size
void ChangeSize(GLsizei w, GLsizei h)
{    // Set Viewport to window dimensions
	glViewport(0, 0, (GLsizei)w, (GLsizei)h);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	//glOrtho (-100.0, 100.0, -100, 100, -270.0, 270.0);
	//glFrustum (-1.0, 1.0, -1.0, 1.0, 1.5, 20.0);
	gluPerspective(60.0, 1.0, 1.5, 500.0);
	glMatrixMode(GL_MODELVIEW);
}

void SpecialKeys(int key, int x, int y)
{
	GLfloat dx, dz;

	if (key == GLUT_KEY_UP)
	{//increase distance from camera to origin
		ex *= (1.0f + deltaR);  ey *= (1.0f + deltaR); ez *= (1.0f + deltaR);
	}

	if (key == GLUT_KEY_DOWN)
	{//reduce distance from camera to origin (close up)
		ex *= (1.0f - deltaR); ey *= (1.0f - deltaR); ez *= (1.0f - deltaR);
	}

	if (key == GLUT_KEY_LEFT)
		//Rotate camera around origin in Oxz plane
	{
		dx = -ez;     dz = ex;
		GLfloat s = sqrtf(ex*ex + ey*ey + ez*ez);
		ex += delta*dx;       ez += delta*dz;
		GLfloat s1 = sqrtf(ex*ex + ey*ey + ez*ez) / s;
		ex /= s1; ey /= s1; ey /= s1;
	}

	if (key == GLUT_KEY_RIGHT)
		//Rotate camera around origin in Oxz plane
	{
		dx = -ez;     dz = ex;
		GLfloat s = sqrtf(ex*ex + ey*ey + ez*ez);
		ex -= delta*dx;      ez -= delta*dz;
		GLfloat s1 = sqrtf(ex*ex + ey*ey + ez*ez) / s;
		ex /= s1; ey /= s1; ey /= s1;
	}

	if (key == GLUT_KEY_F1) bCull = !bCull;
	if (key == GLUT_KEY_F2)bDepth = !bDepth;
	if (key == GLUT_KEY_F3)bOutline = !bOutline;
	if (key == GLUT_KEY_F4)
	{
		if (shademode == GL_FLAT) { shademode = GL_SMOOTH; }
		else { if (shademode == GL_SMOOTH) { shademode = GL_FLAT; } };
		glShadeModel(shademode);
	}

	if (key == GLUT_KEY_F11) {
		foc[1] *= (1. + delta);
	}
	if (key == GLUT_KEY_F12)
	    foc[1] /= (1. + delta);
	// Refresh the Window
	glutPostRedisplay();
}

int main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(/*GLUT_DOUBLE*/GLUT_SINGLE | GLUT_RGB);
	glutInitWindowSize(200, 200);
	glutInitWindowPosition(100, 100);
	glutCreateWindow(argv[0]);
	glutDisplayFunc(RenderScene);
	glutReshapeFunc(ChangeSize);
	glutSpecialFunc(SpecialKeys);

	SetupRC();
	glutMainLoop();
	return 0;
}