OpenGL de プログラミング

#include <GL/glut.h>

//--------- 各種外部変数 --------------//
const int WindowNum = 2; //ウィンドウの数
int WinID[WindowNum]; //ウィンドウID
const char *WindowName[]={"Window 1", "Window 2"};


//-------- 各種プロトタイプ宣言 ----------//
void display();
void reshape(int w, int h);
void display2();
void reshape2(int w, int h);
void idle();
void DRAW_XYZ();
void DRAW_TRI();


//------------ OpenGLの初期設定 ------------//
void GLUT_INIT(int &ID,const char* name)
{
	glutInitDisplayMode(GLUT_RGBA| GLUT_DOUBLE|GLUT_DEPTH);
	glutInitWindowSize(640,480);
	ID = glutCreateWindow(name);
}

void GLUT_INIT2(int &ID,const char* name)
{
	glutInitDisplayMode(GLUT_RGBA| GLUT_DOUBLE|GLUT_DEPTH);
	glutInitWindowSize(320,240);
	ID = glutCreateWindow(name);
}


void GLUT_CALL_FUNC()
{
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
}

void GLUT_CALL_FUNC2()
{
	glutDisplayFunc(display2);
	glutReshapeFunc(reshape2);
}


void MY_INIT()
{
	glClearColor(1.0, 1.0, 1.0, 1.0);
	glEnable(GL_DEPTH_TEST);
}

void MY_INIT2()
{
	glClearColor(0.0, 0.0, 0.0, 1.0);
	glEnable(GL_DEPTH_TEST);
}


//関数ポインタの宣言
void (*GLUT_INIT_Ary[])(int &ID,const char* name) = {GLUT_INIT,GLUT_INIT2};
void (*GLUT_CALL_FUNC_Ary[])() = {GLUT_CALL_FUNC,GLUT_CALL_FUNC2};
void (*MY_INIT_Ary[])() = {MY_INIT,MY_INIT2};

//-------- ここからメイン関数 ------------//
int main(int argc, char **argv)
{
	glutInit(&argc,argv);

	for(int loop = 0; loop < WindowNum; ++loop)
	{
		( *GLUT_INIT_Ary[loop])( WinID[loop],WindowName[loop]);//関数ポインタを呼ぶ
		( *GLUT_CALL_FUNC_Ary[loop])();
		( *MY_INIT_Ary[loop])() ;
	}

	glutIdleFunc(idle);
    
	glutMainLoop();

	return 0;
}


//--------- ここから各種コールバック -----------//

void display()
{

	static int r =0;
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glLoadIdentity();
	gluLookAt(3.0, 4.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

	DRAW_XYZ();

	glPushMatrix();
		glRotatef(static_cast<float>(r),0,1,0);
		DRAW_TRI();
	glPopMatrix();


	glutSwapBuffers();

	if (++r > 360 ) r = 0;
}

void reshape(int w, int h)
{
	glViewport(0, 0, w, h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(30.0, (double)w / (double)h, 1.0, 100.0);
	glMatrixMode(GL_MODELVIEW);    
}


void display2()
{

	static int r =0;
	glClear(GL_COLOR_BUFFER_BIT| GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	gluLookAt(3.0, 4.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

	DRAW_XYZ();
	
	glPushMatrix();
		glRotatef(static_cast<float>(r),0,-1,0);
		DRAW_TRI();
	glPopMatrix();


	glutSwapBuffers();

	if (++r > 360 ) r = 0;
}

void reshape2(int w, int h)
{
	glViewport(0, 0, w, h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(30.0, (double)w / (double)h, 1.0, 100.0);
	glMatrixMode(GL_MODELVIEW);    
}

void idle(void)
{
	for(int loop = 0; loop < WindowNum; ++loop){
		glutSetWindow(WinID[loop]);
		glutPostRedisplay(); //再描画 (※display()関数を呼び出す関数 )
	}
}

//---------- ここから各種関数 ------------//
void DRAW_XYZ()
{
	glBegin(GL_LINES);

	glColor3d(0,1,0);//x
	glVertex2d(-100,0);
	glVertex2d(100, 0);

	glColor3d(1,0,0);//y
	glVertex2d(0,0);
	glVertex2d(0,100);

	glColor3d(0,0,1);//z
	glVertex3d(0,0,-100);
	glVertex3d(0,0, 100);
	glEnd();
}


void DRAW_TRI()
{
	glBegin(GL_TRIANGLES);
	glColor3d(1,1,0);
	glVertex2d(0,1);
	glVertex2d(-0.5, 0);
	glVertex2d(0.5, 0);
	glEnd();
}