#include <GL/glut.h>
#pragma comment(linker,"/subsystem:\"windows\" /entry:\"mainCRTStartup\"") 
/*
三角形
GL_TRIANGLES(三个点成一个三角形)
GL_TRIANGLE_STRIP(相邻三点成一个三角形)
GL_TRIANGLE_FAN(同第二个，后2个和第一个成三角形)
四边形
GL_QUADS(四点一个)
GL_QUAD_STRIP(相邻四点一个)
多边形
GL_POLYGON
glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
*/
void drawPoint(void)
{
int i;
glColor3f (0.0, 0.0, 1.0);
glPointSize(5);
glBegin(GL_POINTS);
for (i = 0; i < 7; i++)
glVertex2f (0.2 + ((GLfloat) i * 0.1), 0.6);
glEnd ();
}
void drawLines(void)
{
glColor3f(0.0,0.0,1.0);
glLineWidth(5);
glBegin(GL_LINES);
glVertex2f(0.0, 0.0);
glVertex2f(0.25,0.25);
glVertex2f(0.75,0.25);
glVertex2f(0.0,0.0);
glEnd();
}
void drawOneLine(GLfloat a,GLfloat b,GLfloat c,GLfloat d)
{
glBegin(GL_LINES);
glVertex2f(a,b);
glVertex2f(c,d);
glEnd();
}
void drawLineStripple(void)
{
glEnable (GL_LINE_STIPPLE);
glColor3f (0.0, 0.0, 1.0);
glLineStipple (1, 0x0101);  /*  dotted  */
drawOneLine (-0.25, 0.8, -0.75, 0.8);
glLineStipple (1, 0x00FF);  /*  dashed  */
drawOneLine (-0.25, 0.6, -0.75, 0.6);
glLineStipple (1, 0x1C47);  /*  dash/dot/dash  */
drawOneLine (-0.25, 0.4, -0.75, 0.4);
///* in 2nd row, 3 wide lines, each with different stipple */
glLineWidth (5.0);
glLineStipple (1, 0x0101);  /*  dotted  */
drawOneLine (-0.25, 0.2, -0.75, 0.2);
glLineStipple (1, 0x00FF);  /*  dashed  */
drawOneLine (-0.25, 0.0, -0.75, 0.0);
glLineStipple (1, 0x1C47);  /*  dash/dot/dash  */
drawOneLine (-0.25, -0.2, -0.75, -0.2);
glLineWidth (1.0);
///* in 4th row, 6 independent lines with same stipple  */
int i;
for (i = 0; i < 6; i++) {
drawOneLine (0.05 + ((GLfloat) i * 0.01), 0.5,
0.05 + ((GLfloat)(i+1) * 0.01), 0.5);
}
//
///* in 5th row, 1 line, with dash/dot/dash stipple    */
///* and a stipple repeat factor of 5                  */
glLineStipple (5, 0x1C47);  /*  dash/dot/dash  */
drawOneLine (50.0, 25.0, 350.0, 25.0);
glDisable (GL_LINE_STIPPLE);
}
void drawLineStrip()
{
glColor3f (0.0, 0.0, 1.0);
glPointSize(5);
// glBegin(GL_LINE_STRIP);
glBegin(GL_LINE_LOOP);
glVertex2f(0.0,0.0);
glVertex2f(-0.3,-0.5);
glVertex2f(0.3,-0.5);
glEnd ();
}
void myDisplay(void)
{
glClear(GL_COLOR_BUFFER_BIT);
// glRectf(-0.5f, -0.5f, 0.5f, 0.5f);
//设置颜色
glColor3f(1.0,1.0,0.0);
//画出矩形
glBegin(GL_POLYGON);
glVertex3f(0.25,0.25,0.25);
glVertex3f(0.75,0.25,0.0);
glVertex3f(0.75,0.75,0.0);
glVertex3f(0.25,0.75,0.0);
//glVertex3f(0.0,0.5,0.0);
glEnd();
drawPoint();
drawLines();
drawLineStripple();
drawLineStrip();
glFlush();
}
void reshape (int w, int h)
{
// glViewport (0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
//gluOrtho2D (0.0, (GLdouble) w, 0.0, (GLdouble) h);
// glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0);
//glOrtho(left, right, bottom, top, near, far)
}
int main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowPosition(100, 100);
glutInitWindowSize(400, 400);
glutCreateWindow("第一个OpenGL程序");
//glClearColor (0.0, 1.0, 1.0, 0.0);
glutDisplayFunc(myDisplay);
glutReshapeFunc(reshape);
glutMainLoop();
return 0;
}

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