#include "stdafx.h"

GLfloat colors[][3] = { { 0.33,0.33,0.33 },{ 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 } },

shadowMat[16],
vLuz[4] = {2., 3.5, 0, 1.},
vPizo[4] = { 0.0f, 1.0f /*-1?*/, 0.0f, /*-*/3.5 /* 3.5 ?*/};


#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 = -300.0f;
GLfloat delta = 0.01f;
GLfloat deltaR = 0.01f;

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 lineas() {
	glColor3f(0.0, 0., 0.);
	glBegin(GL_LINES);
	for (int i = 0; i < 10; i++)
	{
		glVertex2f(-1. + i*2. / 9., 1.);
		glVertex2f(-1. + i*2. / 9., -1.);

		glVertex2f(1, -1. + i*2. / 9.);
		glVertex2f(-1., -1. + i*2. / 9.);
	}
	glEnd();
}


void cuadrado() {
	glBegin(GL_POLYGON);
	glVertex2f(1., 1.);
	glVertex2f(1., -1.);
	glVertex2f(-1., -1.);
	glVertex2f(-1., 1.);
	glEnd();
}


void uncolored_cube(void)
{ /* map vertices to faces */
  /*cara 1*/	
	glPushMatrix();
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 2*/	
	glPushMatrix();
	glRotatef(90., 0., 1., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 3*/
	glPushMatrix();
	glRotatef(180., 0., 1., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 4*/
	glPushMatrix();
	glRotatef(270., 0., 1., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 5*/
	glPushMatrix();
	glRotatef(90., 1., 0., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 6*/
	glPushMatrix();
	glRotatef(-90., 1., 0., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();
}

void colorcube(void)
{ /* map vertices to faces */
  /*cara 1*/
	glColor3fv(colors[0]);
	glPushMatrix();
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 2*/
	glColor3fv(colors[1]);
	glPushMatrix();
	glRotatef(90., 0., 1., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 3*/
	glColor3fv(colors[2]);
	glPushMatrix();
	glRotatef(180., 0., 1., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 4*/
	glColor3fv(colors[3]);
	glPushMatrix();
	glRotatef(270., 0., 1., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();

	/*cara 5*/
	glColor3fv(colors[4]);
	glPushMatrix();
	glRotatef(90., 1., 0., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();
	
	/*cara 6*/
	glColor3fv(colors[5]);
	glPushMatrix();
	glRotatef(-90., 1., 0., 0);
	glTranslatef(0, 0, 1.);
	cuadrado();
	glPopMatrix();
}


void SombradeMiMundo(GLfloat datosdeLuz[], GLfloat datosdePlano[]) {
	glColor3f(0.33, 0.33, 0.33);
	//glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
	glPushMatrix();
		gltMakeShadowMatrix(datosdePlano, datosdeLuz, shadowMat);
		glMultMatrixf(shadowMat);
		uncolored_cube(); // Objetos_de_MiMundo();
	glPopMatrix();
}


///////////////////////////////////////////////////////////


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

	// Set drawing color to green
	glColor3f(0.0f, 1.0f, 0.0f);

	// 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);
}


// Called to draw scene
void piso() {
	glColor3f(.66, .66, .66);
	glPushMatrix();
	glTranslatef(0, /*-3.5*/ /*vPizo[3]?*/ -vPizo[3] , 0);
	glRotatef(-90., 1., 0, 0);
	glScalef(5., 5, 5.);
	cuadrado();
	glDisable(GL_DEPTH_TEST);
	lineas();
	if (bDepth)  glEnable(GL_DEPTH_TEST);	
	glPopMatrix();
}


void luz() {
	glColor3f(1., 1., 0.);
	glPushMatrix();
	glTranslatef(vLuz[0], vLuz[1], vLuz[2]);
	glutSolidSphere(.1, 20., 20.);
	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);
	glScalef(25., 25, 25.);

	piso();
	colorcube();
	glDisable(GL_DEPTH_TEST);
	SombradeMiMundo(vLuz, vPizo);
	if (bDepth)  glEnable(GL_DEPTH_TEST);
	luz();

	// 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, 1500.0);
	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);
	}

	// 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;
}