#include "stdafx.h"
#define	checkImageWidth 256
#define	checkImageHeight 256
#define subImageWidth 64
#define subImageHeight 64

#define YGROUND       0.0f
#define EX				0.0f
#define EY				1.0f
#define EZ				8.0f
#define CX				0.0f
#define CY				YGROUND
#define CZ				0.0f
#define DELTA			0.01f
#define DELTA_R			0.01f

static GLubyte checkImage[checkImageHeight][checkImageWidth][4];
static GLubyte otherImage[checkImageHeight][checkImageWidth][4];

static GLubyte subImage[subImageHeight][subImageWidth][4];

static GLuint texName[2];

GLfloat ctrlpoints[4][4][3] = {
   { {-1.5, -1.5, 4.0},     {-0.5, -1.5, 2.0},     {0.5, -1.5, -1.0},     {1.5, -1.5, 2.0}},   
   { {-1.5, -0.5, 1.0},     {-0.5, -0.5, 3.0},     {0.5, -0.5, 0.0},     {1.5, -0.5, -1.0}},
   { {-1.5, 0.5, 4.0},     {-0.5, 0.5, 0.0},     {0.5, 0.5, 3.0},     {1.5, 0.5, 4.0}},
   { {-1.5, 1.5, -2.0},     {-0.5, 1.5, -2.0},     {0.5, 1.5, 0.0},     {1.5, 1.5, -1.0}}
};

GLboolean	bCull = (GLboolean)true, bDepth= (GLboolean)true,	bOutline=(GLboolean)true,
            bShade= (GLboolean)true;

GLfloat  ambientLight[] = { 0.3f, 0.3f, 0.3f, 1.0f },	 diffuseLight[] = { 0.7f, 0.7f, 0.7f, 1.0f },
         specular[] = { 1.0f, 1.0f, 1.0f, 1.0f},		 specref[] =  { 1.0f, 1.0f, 1.0f, 1.0f },
         mat_shininess[] = {50.0},

		 	ex=EX, ey=EY,  ez=EZ, 		cx=CX,  cy=CY, cz=CZ, 
		yground = YGROUND, delta= DELTA, 	 deltaR= DELTA_R, 
// The light is positioned by this code, located in the ChangeSize function:
		 lightPos[] = { -75.0f, 150.0f, -50.0f, 1.0f }; //{ -30.f, 4.0f, 15.0f, 1.0f };

void makeCheckImages(void)
{
   int i, j, c;
    
   for (i = 0; i < checkImageHeight; i++) {
      for (j = 0; j < checkImageWidth; j++) {
         c = ((((i&0x8)==0)^((j&0x8))==0))*255;
         checkImage[i][j][0] = (GLubyte) c;    checkImage[i][j][1] = (GLubyte) c;
         checkImage[i][j][2] = (GLubyte) c;    checkImage[i][j][3] = (GLubyte) 255;
         
		 c = ((((i&0x10)==0)^((j&0x10))==0))*255;
         otherImage[i][j][0] = (GLubyte) 0;    otherImage[i][j][1] = (GLubyte) 0;
         otherImage[i][j][2] = (GLubyte) c;    otherImage[i][j][3] = (GLubyte) 255;
      }
   }

   for (i = 0; i < subImageHeight; i++) {
		for (j = 0; j < subImageWidth; j++) {
		c = ((((i&0x4)==0)^((j&0x4))==0))*255;
		subImage[i][j][0] = (GLubyte) c;	subImage[i][j][1] = (GLubyte) 0;
		subImage[i][j][2] = (GLubyte) 0;	subImage[i][j][3] = (GLubyte) 255;
		}
	}
}


void SetupRC()
    {   
    // Set color shading model to flat
	glClearColor (0.0, 0.0, 0.0, 0.0);
    glShadeModel(GL_SMOOTH);
	glEnable(GL_DEPTH_TEST);

   makeCheckImages();
   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

   glGenTextures(2, texName);
   glBindTexture(GL_TEXTURE_2D, texName[0]);

   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth, checkImageHeight, 
                0, GL_RGBA, GL_UNSIGNED_BYTE, checkImage);

   glTexSubImage2D(GL_TEXTURE_2D, 0, 48, 170, subImageWidth, 
	   subImageHeight, GL_RGBA,	GL_UNSIGNED_BYTE, subImage);
   
   glTexSubImage2D(GL_TEXTURE_2D, 0, 48, 48, subImageWidth, 
	   subImageHeight, GL_RGBA,	GL_UNSIGNED_BYTE, subImage);
   
   glTexSubImage2D(GL_TEXTURE_2D, 0,  170, 48, subImageWidth, 
	   subImageHeight, GL_RGBA,	GL_UNSIGNED_BYTE, subImage);
   
  glTexSubImage2D(GL_TEXTURE_2D, 0,  170, 170, subImageWidth, 
	   subImageHeight, GL_RGBA,	GL_UNSIGNED_BYTE, subImage);

   glBindTexture(GL_TEXTURE_2D, texName[1]);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, checkImageWidth, 
                checkImageHeight, 0, GL_RGBA, GL_UNSIGNED_BYTE, 
                otherImage);
   glEnable(GL_TEXTURE_2D);

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

    // Enable lighting
    glEnable(GL_LIGHTING);		glEnable(GL_CULL_FACE);
	glEnable(GL_DEPTH_TEST);	glPolygonMode(GL_BACK,GL_FILL);

		// the light source GL_LIGHT0 is enabled:
	
	// Set up and enable light 0
	glLightfv(GL_LIGHT0,GL_AMBIENT,ambientLight);
	glLightfv(GL_LIGHT0,GL_DIFFUSE,diffuseLight);
	glLightfv(GL_LIGHT0,GL_SPECULAR,specular);
	glEnable(GL_LIGHT0);
	glLightfv(GL_LIGHT0,GL_POSITION,lightPos);

	// Enable color tracking
	glEnable(GL_COLOR_MATERIAL);
	// Front material ambient and diffuse colors track glColor
	glColorMaterial(GL_FRONT,GL_AMBIENT_AND_DIFFUSE);

	// All materials hereafter have full specular reflectivity
	// with a high shine
	glMaterialfv(GL_FRONT, GL_SPECULAR,specref);
    glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuseLight);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
	
	 // Light blue background
    glClearColor(0.0f, 0.0f, 1.0f, 1.0f );

	//setup evaluator
   glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4,
           0, 1, 12, 4, &ctrlpoints[0][0][0]);
   glEnable(GL_MAP2_VERTEX_3);
   glEnable(GL_AUTO_NORMAL);
   glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
    }

void DrawSurface(void)
{	
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   glEnable(GL_TEXTURE_2D);
   glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
   glBindTexture(GL_TEXTURE_2D, texName[0]);
   
   /* 
   void glMapGrid2{fd}(GLint nu, TYPEu1, TYPEu2,
GLint nv, TYPEv1, TYPEv2);

void glEvalMesh2(GLenum mode, GLint i1, GLint i2, GLint j1, GLint j2);

   (It's nearly
equivalent because when i is equal to nu or j to nv, the parameter 
is exactly equal to u2 or v2, not to u1+nu*(u2-u1)/nu, which might 
be slightly different due to round-off error.)
   
   glEvalMesh2(GL_FILL, 0, 20, 0, 20);

   for (i = nu1; i < nu2; i++) { // mode == GL_FILL 
glBegin(GL_QUAD_STRIP);
for (j = nv1; j <= nv2; j++) {
glEvalCoord2(u1 + i*(u2-u1)/nu, v1+j*(v2-v1)/nv);
glEvalCoord2(u1 + (i+1)*(u2-u1)/nu, v1+j*(v2-v1)/nv);
glEnd();
}*/
    glEvalMesh2(GL_FILL, 0, 20, 0, 20);
	glMapGrid2f(20, 0.0f, 1.0f,	20, 0.0f, 1.0f);

   glBegin(GL_QUADS);
for (int i = 0; i < 20; i++) { // mode == GL_FILL 

for (int j = 0; j <= 20; j++) {
glTexCoord2f((GLfloat) i /20.0f, (GLfloat) j/20.); 
                 glEvalCoord2f( (GLfloat) i /20.0f, (GLfloat) j/20.0);

glTexCoord2f((GLfloat) i /20.0f, (GLfloat) (j+1)/20.); 
                 glEvalCoord2f( (GLfloat) i /20.0f, (GLfloat) (j+1)/20.0);

glTexCoord2f((GLfloat)(i+1)/20.0f, (GLfloat) (j+1)/20.0f);  
                 glEvalCoord2f( (GLfloat)(i+1)/20.0f, (GLfloat) (j+1)/20.0f);

glTexCoord2f((GLfloat)(i+1)/20.0f, (GLfloat) j/20.0f);  
                 glEvalCoord2f( (GLfloat)(i+1)/20.0f, (GLfloat) j/20.0f);

}
}
glEnd();
//
//for (int i = 0; i < 20; i++) { // mode == GL_FILL 
//glBegin(GL_QUAD_STRIP);
//for (int j = 0; j <= 20; j++) {
//glTexCoord2f((GLfloat) i /20.0f, (GLfloat) j/20.); 
//                 glEvalCoord2f( (GLfloat) i /20.0f, (GLfloat) j/20.0);
//glTexCoord2f((GLfloat)(i+1)/20.0f, (GLfloat) j/20.0f);  
//                 glEvalCoord2f( (GLfloat)(i+1)/20.0f, (GLfloat) j/20.0f);
//glEnd();
//}
//}

   //glTexCoord2f(0.0, 0.0);  glEvalCoord2f(0.0f, 0.0f);//glVertex3f( 400.0f, -150.0f, -700.0f); 
   //glTexCoord2f(0.0, 1.0); glEvalCoord2f(0.0f, 1.0f);// glVertex3f(-400.0f, -150.0f, -700.0f); 

   //glTexCoord2f(1.0, 1.0); glEvalCoord2f(1.0f, 1.0f);//  glVertex3f(-400.0f, -150.0f, 200.0f); 
   //glTexCoord2f(1.0, 0.0); glEvalCoord2f(1.0f, 0.0f);// glVertex3f(400.0f, -150.0f, 200.0f);

   //glEnd();
  // glFlush();
   glDisable(GL_TEXTURE_2D);
}

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

			// Reset coordinate system
    glLoadIdentity();
	
	gluLookAt (ex, ey, ez, cx,  cy, cz, 0.0, 1.0, 0.0);
 	//gluLookAt (ex, ey, ez, 0.0, -50.0, 0.0, 0.0, 1.0, 0.0);
 
	glPushMatrix();
   glRotatef(85.0, 1.0, 1.0, 1.0);
  
  
	DrawSurface();
   glPopMatrix();
    // Flush drawing commands
     glutSwapBuffers();

    }

void ChangeSize(GLsizei w, GLsizei h)
    {    // Set Viewport to window dimensions
    glViewport(0, 0, (GLsizei)w, (GLsizei)h);

	glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    
	gluPerspective(60.0, 1.0, 1.5, 700.0);
	glMatrixMode (GL_MODELVIEW);	
    }



void SpecialKeys(int key, int x, int y)
    {GLfloat dx, dy, dz;
    
	if(key == GLUT_KEY_UP)
	{//increase distance from camera to origin
		ex*=(1.0f+deltaR);  ey*=(1.0f+deltaR);	ez*=(1.0f+deltaR);
		
   // Refresh the Window
    glutPostRedisplay();
		return;
	}

    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);
   // Refresh the Window
    glutPostRedisplay();
	return;}

    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; 
   // Refresh the Window
    glutPostRedisplay();return;
	}

    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;
	
   // Refresh the Window
    glutPostRedisplay();return;}
 
	if(key ==  GLUT_KEY_F5)//Rotate camera around origin in Oyz plane
         {dy=-ez;     dz= ey;
     GLfloat s=sqrtf(ex*ex+ey*ey+ez*ez);
		ey-=delta*dy;      	ez-=delta*dz;
	GLfloat s1=sqrtf(ex*ex+ey*ey+ez*ez)/s;
	ex/=s1;	ey/=s1;	ey/=s1;
	
   // Refresh the Window
    glutPostRedisplay();return;}

	if(key ==  GLUT_KEY_F6)//Rotate camera around origin in Oyz plane
         {dy=-ez;     dz= ey;
     GLfloat s=sqrtf(ex*ex+ey*ey+ez*ez);
		ey+=delta*dy;      	ez+=delta*dz;
	GLfloat s1=sqrtf(ex*ex+ey*ey+ez*ez)/s;
	ex/=s1;	ey/=s1;	ey/=s1; 
	
   // Refresh the Window
    glutPostRedisplay();return;}

	if(key ==  GLUT_KEY_F1){ bCull=!bCull;
	  // Turn on/off culling on if flag is set
		if(bCull)   glEnable(GL_CULL_FACE);
		else        glDisable(GL_CULL_FACE);

   // Refresh the Window
    glutPostRedisplay();return;
		}
	if(key ==  GLUT_KEY_F2){bDepth=!bDepth;
		 if(bDepth)  glEnable(GL_DEPTH_TEST);
		else        glDisable(GL_DEPTH_TEST);
		
   // Refresh the Window
    glutPostRedisplay();return;
		}

	if(key ==  GLUT_KEY_F3){bOutline=!bOutline;

    // 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);
  // Refresh the Window
    glutPostRedisplay();
	return;
	}
	if(key ==  GLUT_KEY_F4)
		{bShade=!bShade;
		if(bShade){glShadeModel(GL_FLAT);}
		   else {glShadeModel(GL_SMOOTH);} 
		   // Refresh the Window
    glutPostRedisplay();
		   return;
		}
    }



void keyboard(unsigned char key, int x, int y)
{
   switch (key) {
      case 27:
         exit(0);
         break;
   }
}


int main(int argc, char** argv)
{
glutInit(&argc, argv);
 glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize (500, 500);
glutInitWindowPosition (100, 100);
 glutCreateWindow (argv[0]);
 glutDisplayFunc(RenderScene);
    glutReshapeFunc(ChangeSize);
	 glutSpecialFunc (SpecialKeys);
	 glutKeyboardFunc(keyboard);
    SetupRC();
    glutMainLoop();
return 0;
}