/* ex4-2.c */
/* compile: cc -o ex4-2 ex4-2.c -g -O2 -Wall -lglfw -lGLU -lGL -lX11 -lXrandr -lm */

#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <GL/glfw.h>

int main(void)
{
	glfwInit();
	glfwOpenWindow(640, 400, 0, 0, 0, 0, 0, 0, GLFW_WINDOW);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-0.2, 2 * M_PI + 0.2, -1.2, 1.2, -1.0, 1.0);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();

	for (;;)
	{

	int width, height;
	double rad;

	glfwWaitEvents();

	if (glfwGetKey(GLFW_KEY_ESC) || !glfwGetWindowParam(GLFW_OPENED))
	break;

	glfwGetWindowSize(&width, &height);
	glViewport(0, 0, width, height); 

	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
	glClear(GL_COLOR_BUFFER_BIT);

	/* x軸とy軸 */
	glColor3d(1.0, 1.0, 1.0);
	glBegin(GL_LINES);
		glVertex2d(0.0, 0.0);
		glVertex2d(2 * M_PI, 0.0);
		glVertex2d(0.0, -1.0);
		glVertex2d(0.0, 1.0);
	glEnd();

	/* 曲線 */
	glColor3d(0.5, 1.0, 0.5);
	glBegin(GL_LINE_STRIP);
		for (rad=0; rad<=2*M_PI; rad += M_PI / 36)
		{
		double s = sin(rad);
		printf("x:%f y:%f＼n", rad, s);
		glVertex2d(rad, s);
		}
	glEnd();

	glfwSwapBuffers();

	}

	glfwTerminate();
	return 0;
}