#include<windows.h>

#include<GL/gl.h>
#include<GL/glu.h>
#include<GL/glaux.h>

#pragma comment(lib,"opengl32")
#pragma comment(lib,"glu32")
#pragma comment(lib,"glaux")

void Init(void);
void CALLBACK ToggleEye(AUX_EVENTREC* event);
void CALLBACK Resize(GLsizei w,GLsizei h);
void CALLBACK Paint(void);

void Init(void)
{
	GLfloat mat_ambient[]={0.0,0.0,0.0,0.15};
	GLfloat mat_specular[]={1.0,1.0,1.0,0.15};
	GLfloat mat_shininess[]={15.0};

	glMaterialfv(GL_FRONT,GL_AMBIENT,mat_ambient);
	glMaterialfv(GL_FRONT,GL_SPECULAR,mat_specular);
	glMaterialfv(GL_FRONT,GL_SHININESS,mat_shininess);

	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);
	glDepthFunc(GL_LESS);
	glEnable(GL_DEPTH_TEST);
}

GLboolean eyePosition=GL_FALSE;

void CALLBACK ToggleEye(AUX_EVENTREC *event)
{
	if(eyePosition)
		eyePosition=GL_FALSE;
	else
		eyePosition=GL_TRUE;
}

void CALLBACK Paint(void)
{
	GLfloat position[]={0.0,0.0,1.0,1.0};
	GLfloat mat_torus[]={0.75,0.75,0.0,1.0};
	GLfloat mat_cylinder[]={0.0,0.75,0.75,0.15};

	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	glLightfv(GL_LIGHT0,GL_POSITION,position);
	glPushMatrix();

	if(eyePosition)
		gluLookAt(0.0,0.0,9.0,0.0,0.0,0.0,0.0,1.0,0.0);
	else
		gluLookAt(0.0,0.0,-9.0,0.0,0.0,0.0,0.0,1.0,0.0);

	glPushMatrix();
	glTranslatef(0.0,0.0,1.0);
	glMaterialfv(GL_FRONT,GL_DIFFUSE,mat_torus);
	auxSolidTorus(0.275,0.85);
	glPopMatrix();

	glEnable(GL_BLEND);
	glDepthMask(GL_FALSE);

	glBlendFunc(GL_SRC_ALPHA,GL_ONE);
	glMaterialfv(GL_FRONT,GL_DIFFUSE,mat_cylinder);
	glTranslatef(0.0,0.0,-1.0);
	auxSolidCylinder(1.0,2.0);
	glDepthMask(GL_TRUE);

	glDisable(GL_BLEND);
	glPopMatrix();

	glFlush();
}

void CALLBACK Resize(GLsizei w,GLsizei h)
{
	if(!h)return;

	glViewport(0,0,w,h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(30.0,(GLfloat)w/(GLfloat)h,1.0,20.0);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

int main(int argc,char** argv)
{
	auxInitDisplayMode(AUX_SINGLE|AUX_RGB|AUX_DEPTH16);
	auxInitPosition(0,0,500,500);
	auxInitWindow("融合與透明");
	auxMouseFunc(AUX_LEFTBUTTON,AUX_MOUSEDOWN,ToggleEye);

	Init();

	auxReshapeFunc(Resize);
	auxMainLoop(Paint);

	return(0);
}