Drawing graphics and 3D enhancement techniques (ii)----Point drawing of straight line elements

A. Straight line point painting mode: That is, do not completely fill all the pixels to draw a straight line, but in the form of a point painting, spaced to draw a line

First enable PIP mode:

Glenable (gl_line_stipple);

Then customize to create your own PIP mode

Gllinestipple (gllint factor,glushort pattern);

Where the first parameter factor is a multiplication factor, the second parameter pattern is a custom PIP pattern: A 16-bit value, each bit indicating that part of a segment is open or closed, and 16-based, for example: 0x5555

Example of a straight-line pip:

//STIPPLE.cpp: Defines the entry point of the console application. //#include"stdafx.h"#include<GL\glut.h>voidInit () {Glclearcolor (0.0f,0.0f,0.0f,0.0f);}voidMydisplay () {glclear (gl_color_buffer_bit); Glint Factor=1; Glushort pattern=0x5555;    Glfloat y;            Glenable (gl_line_stipple); glcolor3f (0.0,1.0f,0.0f);  for(y =-80.0f; Y <80.0f; y+=20.0f) {gllinestipple (Factor,pattern);    Glbegin (Gl_lines); GLVERTEX2F (-80.0f, y); GLVERTEX2F (80.0, y); Factor++;        Glend (); } glutswapbuffers ();}voidChangesize (intWinth) {    if(h==0) {h=1; } glviewport (0,0, w,h);    Glmatrixmode (gl_projection);    Glloadidentity (); if(w<=h) {gluortho2d (-100.0,100.0,-100.0* (glfloat) h/(glfloat) W,100.0* (glfloat) h/(Glfloat) w); }    Else{gluortho2d (-100.0* (Glfloat) w/(glfloat) H,100.0* (Glfloat) w/(glfloat) h,-100.0,100.0);    } glmatrixmode (Gl_modelview);    Glloadidentity (); }intMainintargcChar**argv) {Glutinit (&argc,argv); Glutinitdisplaymode (Glut_rgb|glut_double); Glutinitwindowposition ( -, -); Glutinitwindowsize ( -, -); Glutcreatewindow ("Line_stipple");    Init ();    Glutdisplayfunc (Mydisplay);        Glutreshapefunc (changesize); Glutmainloop ();}

Drawing graphics and 3D enhancement techniques (ii)----Point drawing of straight line elements