古き良きteapot

3D的なことをしたくなったのでデバッグ用にいろいろOpenGLを調べていたのですが今はOpenGL3.1ごろやらで必須になったCore Profileとかいうのが主流らしいです。 ただデバッグ用に確認したいだけで高速化を求めなければGLUTで十分だなあと思った次第です。 teapotを回転するだけですが時代を感じてよいですね。

	#include <stdio.h>
	#include <stdlib.h>
	#ifdef __APPLE__
	#include <GLUT/glut.h>
	#else
	#include <GL/glut.h>
	#endif
	typedef struct {
	int width;
	int height;
	char* title;
	float field_of_view_angle;
	float z_near;
	float z_far;
	} glutWindow;
	typedef struct {
	int down;
	int pos[2];
	float angle[2];
	} glutMouse;
	glutWindow win;
	glutMouse m;
	float g_rotation = 0;
	float g_rotation_speed = 0.2f;
	void display() {
	// Clear Screen and Depth Buffer
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glLoadIdentity();
	// Define a viewing transformation
	gluLookAt(4, 2, 0, 0, 0, 0, 0, 1, 0);
	// Push and pop the current matrix stack.
	// This causes that translations and rotations on this matrix wont influence
	// others.
	glPushMatrix();
	glColor3f(1, 0, 0);
	// Rotate the teapot
	glRotated(90, 0.0, 1.0, 0.0);
	glRotated(m.angle[0], 0.0, 1.0, 0.0);
	glRotated(m.angle[1], 1.0, 0.0, 0.0);
	// Draw the teapot
	glutSolidTeapot(1);
	glPopMatrix();
	g_rotation += g_rotation_speed;
	glutSwapBuffers();
	}
	void initialize() {
	// select projection matrix
	glMatrixMode(GL_PROJECTION);
	// set the viewport
	glViewport(0, 0, win.width, win.height);
	// set matrix mode
	glMatrixMode(GL_PROJECTION);
	// reset projection matrix
	glLoadIdentity();
	GLfloat aspect = (GLfloat)win.width / win.height;
	// set up a perspective projection matrix
	gluPerspective(win.field_of_view_angle, aspect, win.z_near, win.z_far);
	// specify which matrix is the current matrix
	glMatrixMode(GL_MODELVIEW);
	glShadeModel(GL_SMOOTH);
	// specify the clear value for the depth buffer
	glClearDepth(1.0f);
	glDepthFunc(GL_LEQUAL);
	glEnable(GL_DEPTH_TEST);
	// specify implementation-specific hints
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
	GLfloat amb_light[] = {0.1, 0.1, 0.1, 1.0};
	GLfloat diffuse[] = {0.6, 0.6, 0.6, 1};
	GLfloat specular[] = {0.7, 0.7, 0.3, 1};
	glLightModelfv(GL_LIGHT_MODEL_AMBIENT, amb_light);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuse);
	glLightfv(GL_LIGHT0, GL_SPECULAR, specular);
	glEnable(GL_LIGHT0);
	glEnable(GL_COLOR_MATERIAL);
	glShadeModel(GL_SMOOTH);
	glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_FALSE);
	glEnable(GL_LIGHTING);
	glClearColor(0.0, 0.0, 0.0, 1.0);
	}
	void keyboard(unsigned char key, int mousePositionX, int mousePositionY) {
	switch (key) {
	case 'q':
	exit(0);
	break;
	default:
	break;
	}
	}
	void mouse(int button, int state, int x, int y) {
	if (button == GLUT_LEFT_BUTTON) {
	if (state == GLUT_DOWN) {
	m.pos[0] = x;
	m.pos[1] = y;
	m.down = 1;
	}
	if (state == GLUT_UP) {
	m.down = 0;
	}
	}
	}
	void motion(int x, int y) {
	int mx, my;
	if (m.down) {
	mx = (double)(x - m.pos[0]);
	my = (double)(y - m.pos[1]);
	m.pos[0] = x;
	m.pos[1] = y;
	m.angle[0] += mx;
	m.angle[1] += my;
	glutPostRedisplay();
	}
	}
	int main(int argc, char** argv) {
	// set window values
	win.width = 640;
	win.height = 480;
	win.title = "teapot";
	win.field_of_view_angle = 45;
	win.z_near = 1.0f;
	win.z_far = 500.0f;
	// set mouse values;
	m.down = 0;
	m.angle[0] = m.angle[1] = 0.0;
	// initialize and run program
	glutInit(&argc, argv); // GLUT initialization
	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); // Display Mode
	glutInitWindowSize(win.width, win.height); // set window size
	glutCreateWindow(win.title); // create Window
	glutDisplayFunc(display); // register Display Function
	glutIdleFunc(display); // register Idle Function
	glutKeyboardFunc(keyboard); // register Keyboard Handler
	glutMouseFunc(mouse);
	glutMotionFunc(motion);
	initialize();
	glutMainLoop(); // run GLUT mainloop
	return 0;
	}

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