EFFECT TRANSPARENT ( TOUJOURS AVEC CAMERA ET SPIN )

#include <windows.h>
#include <GL\glut.h>
#include <stdio.h>

// variable pour distance de camera
static float Distance = -30.0f;

// variable pour le spin du cube
static float Spin = 0.0f;

typedef unsigned char uchar;

void RenderScene ( void )
{

	// angle de spin pour le cube
	static float fElect1 = 0.0f;

	// clear l'ecran
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

	// Retourner a (0,0,0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	// Controle la distance de camera
	glTranslatef(0.0f, 0.0f, Distance);

	// Controle le spin des cubes
	glRotatef(Spin, 1.0f, 0.0f, 0.0f);

	// "Enregistre" le current-matrix
	glPushMatrix();

	// spin le cube sur l'axe x
	glRotatef(fElect1, 1.0f, 0.0f, 0.0f);

	//spin le cube sur l'axe y
	glRotatef(fElect1, 0.0f, 1.0f, 0.0f);


	// Dessine le petit cube 
	glBegin (GL_QUADS);

		// Front Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(2.0f, 2.0f, 2.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(2.0f, -2.0f, 2.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(-2.0f, -2.0f, 2.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-2.0f, 2.0f, 2.0f);

		// Back Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(2.0f, 2.0f, -2.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(2.0f, -2.0f, -2.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(-2.0f, -2.0f, -2.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-2.0f, 2.0f, -2.0f);

		// Right Side
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(2.0f, 2.0f, 2.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(2.0f, 2.0f, -2.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(2.0f, -2.0f, -2.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(2.0f, -2.0f, 2.0f);

		// Left Side
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-2.0f, 2.0f, 2.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(-2.0f, 2.0f, -2.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(-2.0f, -2.0f, -2.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-2.0f, -2.0f, 2.0f);

		// Top Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-2.0f, 2.0f, -2.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(2.0f, 2.0f, -2.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(2.0f, 2.0f, 2.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-2.0f, 2.0f, 2.0f);

		// Bottom Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-2.0f, -2.0f, -2.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(2.0f, -2.0f, -2.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(2.0f, -2.0f, 2.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-2.0f, -2.0f, 2.0f);

		glEnd();

		
		glPopMatrix();

		// Ce qui donne l'effet transparent
		glEnable(GL_BLEND);

		// Meme rotation que le cube precedent
		glRotatef(fElect1, 1.0f, 0.0f, 0.0f);
		glRotatef(fElect1, 0.0f, 1.0f, 0.0f);

		// Dessine le grand cube
		glBegin (GL_QUADS);

		// Front Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(5.0f, 5.0f, 5.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(5.0f, -5.0f, 5.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(-5.0f, -5.0f, 5.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-5.0f, 5.0f, 5.0f);

		// Back Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(5.0f, 5.0f, -5.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(5.0f, -5.0f, -5.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(-5.0f, -5.0f, -5.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-5.0f, 5.0f, -5.0f);

		// Right Side
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(5.0f, 5.0f, 5.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(5.0f, 5.0f, -5.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(5.0f, -5.0f, -5.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(5.0f, -5.0f, 5.0f);

		// Left Side
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-5.0f, 5.0f, 5.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(-5.0f, 5.0f, -5.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(-5.0f, -5.0f, -5.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-5.0f, -5.0f, 5.0f);

		// Top Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-5.0f, 5.0f, -5.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(5.0f, 5.0f, -5.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(5.0f, 5.0f, 5.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-5.0f, 5.0f, 5.0f);

		// Bottom Face
		glColor3f(1.0f, 0.0f, 0.0f);
		glVertex3f(-5.0f, -5.0f, -5.0f);

		glColor3f(0.0f, 1.0f, 0.0f);
		glVertex3f(5.0f, -5.0f, -5.0f);

		glColor3f(0.0f, 0.0f, 1.0f);
		glVertex3f(5.0f, -5.0f, 5.0f);

		glColor3f(0.0f, 1.0f, 1.0f);
		glVertex3f(-5.0f, -5.0f, 5.0f);

		glEnd();

		// Rapport 1:1
		glBlendFunc(GL_ONE, GL_ONE);

		// Disable !! apres avoir dessiner tout object
		glDisable(GL_BLEND);

		// augment angle de rotation
		fElect1 += 1.0f;

		// swap les buffers
		glutSwapBuffers();

		// "update" notre scene
		glutPostRedisplay();

}


void SetupRC ( void )
{
	// Couleur noir pour le font d'ecran
	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);

	// enable le depth test
	glEnable(GL_DEPTH_TEST);
}

void ReSize ( GLsizei w, GLsizei h )
{
	// rapport fovy
	GLfloat fAspect;

	// au cas ou la window est resizer a une hauteur < 0
	if ( h == 0 )
		h = 1;

	// Viewport
	glViewport(0, 0, w, h);

	// rapport fove calculer
	fAspect = (GLfloat)w / (GLfloat)h;


	glMatrixMode(GL_PROJECTION);

	// La vue que l'on a choisi
	gluPerspective(60.0f, fAspect, 1.0, 400.0);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

}

void OnKey ( uchar Key, int X, int Y)
{
	switch (Key)
	{
		// au cas ou on tape 'i' ou 'I' zoom In
	case 'i': case 'I':
		Distance += 1.0f;
		break;

	case'o':case'O': // au cas ou on tape 'o' ou 'O' zoom Out
		Distance -= 1.0f;
		break;

	case 's':case'S':// si on tape 's' ou 'S' augment le taux de spin
		Spin += 5.0f;

		if ( Spin > 360.0f)
		{
			Spin = 0.0f;
		}
		break;
	}
}

void main ( void )
{
	// notre display mode
	glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGB);

	// créer notre fenêtre
	glutCreateWindow("Transparency");

	// Dessine note Scene
	glutDisplayFunc(RenderScene);

	// notre Resize function
	glutReshapeFunc(ReSize);

	// prends en charge l'input du user
	glutKeyboardFunc(OnKey);

	// font d'ecran
	SetupRC();

	// loop
	glutMainLoop();
}