#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 Resize(GLsizei w,GLsizei h);
void CALLBACK Paint(void);

#define NMCOLORS    32
#define RAMPSTART   16

void Init(void)
{
	int i;
	glEnable(GL_DEPTH_TEST);
	glDepthFunc(GL_LESS);

	for(i=0;i<NMCOLORS;i++)
	{
		GLfloat shade;
		shade=(GLfloat)(NMCOLORS-i)/(GLfloat)NMCOLORS;
		auxSetOneColor(16+i,shade,shade,shade);
	}

	glEnable(GL_FOG);

	glFogi(GL_FOG_MODE,GL_LINEAR);
	glFogi(GL_FOG_INDEX,NMCOLORS);
	glFogf(GL_FOG_START,0.0);
	glFogf(GL_FOG_END,4.0);
	glHint(GL_FOG_HINT,GL_NICEST);
	glClearIndex((GLfloat)(NMCOLORS+RAMPSTART-1));
}

void CALLBACK Paint(void)
{
	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

	glPushMatrix();
	glTranslatef(-1.0,-1.0,-1.0);
	glRotatef(-90.0,1.0,0.0,0.0);
	glIndexi(RAMPSTART);
	auxSolidCone(1.0,2.0);
	glPopMatrix();

	glPushMatrix();
	glTranslatef(0.0,-1.0,-2.25);
	glRotatef(-90.0,1.0,0.0,0.0);
	glIndexi(RAMPSTART);
	auxSolidCone(1.0,2.0);
	glPopMatrix();

	glPushMatrix();
	glTranslatef(1.0,-1.0,-3.5);
	glRotatef(-90.0,1.0,0.0,0.0);
	glIndexi(RAMPSTART);
	auxSolidCone(1.0,2.0);
	glPopMatrix();

	glFlush();
}

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

	glViewport(0,0,w,h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	if(w<=h)
		glOrtho(-2.0,2.0,-2.0*(GLfloat)h/(GLfloat)w,
		2.0*(GLfloat)h/(GLfloat)w,0.0,10.0);
	else
		glOrtho(-2.0*(GLfloat)w/(GLfloat)h,
		2.0*(GLfloat)w/(GLfloat)h,-2.0,2.0,0.0,10.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

int main(int argc,char** argv)
{
	auxInitDisplayMode(AUX_SINGLE|AUX_INDEX|AUX_DEPTH16);
	auxInitPosition(0,0,200,200);
	auxInitWindow("霧(Color Index )");

	Init();

	auxReshapeFunc(Resize);
	auxMainLoop(Paint);

	return(0);
}