OpenGL基础代码整理

3-1：画点，连成线

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

void init(void)
{
	glClearColor(1.0, 1.0, 0.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	gluOrtho2D(-10.0, 10.0, -10.0, 10.0);
}

void lineSegment(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(0.0, 0.4, 0.2);
	glBegin(GL_LINES);
		glVertex2i(10,10);
		glVertex2i(-10,-10);
		glVertex2i(-10, 0);
		glVertex2i(10, 0);
		glVertex2i(0, -10);
		glVertex2i(0, 10);
	glEnd();

	glFlush();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(100,100);
    glutInitWindowSize(800, 400);
    glutCreateWindow("第一个OpenGL程序");

	init();//设置背景，坐标系
    glutDisplayFunc(lineSegment);//
    glutMainLoop();
    return 0;
}

4-1

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-200.0, 200.0, -200.0, 200.0);
}

//rho = a(1-sint(theta))
//x = a(1 - sin(t))*cos(t)
//y = a(1 - sin(t))*sin(t)
void circleDisplay(void)
{
	float t;
	glClear(GL_COLOR_BUFFER_BIT);

	srand((unsigned)time(NULL));

	glColor3f(1.0, 0.0, 0.0);
	glLineWidth(10.0);
	glBegin(GL_LINE_LOOP);
	    for (int i = 0; i < 1000; i++)
	    {
		    t = -1 * Pi / 2+ 2 * i * Pi / 1000;
		    glVertex2f(100*(1 - sin(t))*cos(t), 100*(1 - sin(t))*sin(t));
	    }	
	glEnd();

	glFlush();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(50,100);
    glutInitWindowSize(800, 800);
    glutCreateWindow("第一个OpenGL程序");

	glClearColor(1.0, 1.0, 1.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-200.0, 200.0, -200.0, 200.0);

	glutDisplayFunc(circleDisplay);
    glutMainLoop();

    return 0;
}

4-2

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

float a = 60.0;

void circleDisplay(void)
{
	double rr, gg, bb;
	float x, y;
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(1.0, 0.0, 0.0);
	glLineWidth(5.0);
	//cout << "a=" << a << endl;
	glBegin(GL_LINE_STRIP);
	for (int i = 0; i <= 10000; i++)
	{
		x = -5 + 10.0 * i / 10000;
		glVertex2f(x, pow(x * x, 1.0 / 3.0) + 0.9 * sqrt(3.3 - x * x) * sin(a * Pi * x));
		//glVertex2f(x, x * x);
	}
	glEnd();

	glFlush();
}

void SpecialKeys(int key, int x, int y)
{
	if (key == GLUT_KEY_UP)
		a = a + 0.25;

	glutPostRedisplay();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(50,100);
    glutInitWindowSize(800, 800);
    glutCreateWindow("第一个OpenGL程序");

	glClearColor(1.0, 1.0, 1.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-3.0, 3.0, -3.0, 3.0);

	glutDisplayFunc(circleDisplay);
	//glutSpecialFunc(SpecialKeys);
    glutMainLoop();

    return 0;
}

4-3:point

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-200.0, 200.0, -200.0, 200.0);
}

void circleDisplay(void)
{
	double rr, gg, bb;
	float x, y;
	glClear(GL_COLOR_BUFFER_BIT);

	srand((unsigned)time(NULL));

	glPointSize(10.0);
	glBegin(GL_POINTS);
	for (int i = 0; i < 1000; i++)
	{
		rr = rand() / double(RAND_MAX);
		gg = rand() / double(RAND_MAX);
		bb = rand() / double(RAND_MAX);

		x = (rand() % (400 + 1)) - 200;
		y = (rand() % (400 + 1)) - 200;

		glColor3d(rr, gg, bb);
		glVertex2f(x, y);
	}
	glEnd();

	glFlush();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(50,100);
    glutInitWindowSize(800, 800);
    glutCreateWindow("第一个OpenGL程序");

	glClearColor(1.0, 1.0, 1.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-200.0, 200.0, -200.0, 200.0);

	glutDisplayFunc(circleDisplay);
    glutMainLoop();

    return 0;
}

5-1:bitmap显示字体

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 0.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-200.0, 200.0, -200.0, 200.0);
}

void circleDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(0.0, 0.0, 1.0);

	glRasterPos2i(0,0);
	glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, 'A');
	glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, 'B');
	glutBitmapCharacter(GLUT_BITMAP_HELVETICA_18, 'C');
	glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24, 'D');


	glFlush();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowPosition(50,100);
    glutInitWindowSize(800, 800);
    glutCreateWindow("第一个OpenGL程序");

	init();
	glutDisplayFunc(circleDisplay);
    glutMainLoop();

    return 0;
}

6-1:blending

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

int windowWidth = 600, windowHeight = 600;

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 1.0);

	glEnable(GL_BLEND);
	//glBlendFunc(GL_ONE, GL_ZERO);// sFactor, dFactor
	//glBlendFunc(GL_ZERO, GL_ONE);// sFactor, dFactor
	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	//glBlendFunc(GL_ONE, GL_ONE);
}

void myDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glColor4f(1.0, 0.0, 0.0, 0.9);
	glRecti(-50, -50, 100, 100);

	glColor4f(0.0, 1.0, 0.0, 0.9);
	glRecti(-100, -100, 50, 50);

	glFlush();
}

void windowReshape(int w, int h)
{
	float aspectRatio;

	windowWidth = w;
	windowHeight = h;

	if (windowHeight == 0) windowHeight = 1;
	aspectRatio = (float)windowWidth / (float)windowHeight;

	glViewport(0, 0, windowWidth, windowHeight);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	if (windowWidth >= windowHeight)
		gluOrtho2D(-100.0*aspectRatio, 100.0*aspectRatio, -100.0, 100.0);
	else gluOrtho2D(-100.0, 100.0, -100.0 / aspectRatio, 100.0 / aspectRatio);
}

int main(int argc, char *argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(windowWidth, windowHeight);
	glutCreateWindow("第一个OpenGL程序");

	init();
	glutReshapeFunc(windowReshape);
	glutDisplayFunc(myDisplay);
	glutMainLoop();

	return 0;
}

6-2:reshape

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

int windowWidth = 600, windowHeight = 600;

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 1.0);
}

void myDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(1.0, 0.0, 0.0);
	glRectf(-50.0,-50.0, 50.0, 50.0);

	glFlush();
}

void windowReshape(int w, int h)
{
	float aspectRatio;

	windowWidth = w;
	windowHeight = h;

	aspectRatio = (float)windowWidth / (float)windowHeight;
	
	//if (windowHeight == 0) windowHeight = 1;
	//aspectRatio = (float)windowWidth / (float)windowHeight;

	glViewport(0, 0, windowWidth, windowHeight);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	if (windowWidth >= windowHeight)
		gluOrtho2D(-100.0*aspectRatio, 100.0*aspectRatio, -100.0, 100.0);
	else gluOrtho2D(-100.0, 100.0, -100.0 / aspectRatio, 100.0/aspectRatio);
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
    glutInitWindowPosition(100,100);
	glutInitWindowSize(windowWidth, windowHeight);
    glutCreateWindow("第一个OpenGL程序");

	init();
	glutReshapeFunc(windowReshape);
	glutDisplayFunc(myDisplay);
    glutMainLoop();

    return 0;
}

6-3:smooth

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

int windowWidth = 600, windowHeight = 600;

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 1.0);

	//glEnable(GL_BLEND);
	//glBlendFunc(GL_ONE, GL_ZERO);// sFactor, dFactor
	//glBlendFunc(GL_ZERO, GL_ONE);// sFactor, dFactor
	//glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
	//glBlendFunc(GL_ONE, GL_ONE);
}

void myDisplay(void)
{
	double rr, gg, bb;
	float t, x, y;

	srand((unsigned)time(NULL));

	glClear(GL_COLOR_BUFFER_BIT);

	glShadeModel(GL_SMOOTH);
	glBegin(GL_POLYGON);
	glVertex2f(0.0, 0.0);
	for (int i = 0; i <= 20; i++)
	{
		rr = rand() / double(RAND_MAX);
		gg = rand() / double(RAND_MAX);
		bb = rand() / double(RAND_MAX);

		t = Pi *i / 20;

		x = 60.0*cos(t);
		y = 60.0*sin(t);

		glColor3d(rr, gg, bb);
		glVertex2f(x, y);
	}
	glEnd();

	glFlush();
}

void windowReshape(int w, int h)
{
	float aspectRatio;

	windowWidth = w;
	windowHeight = h;

	if (windowHeight == 0) windowHeight = 1;
	aspectRatio = (float)windowWidth / (float)windowHeight;

	glViewport(0, 0, windowWidth, windowHeight);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	if (windowWidth >= windowHeight)
		gluOrtho2D(-100.0*aspectRatio, 100.0*aspectRatio, -100.0, 100.0);
	else gluOrtho2D(-100.0, 100.0, -100.0 / aspectRatio, 100.0 / aspectRatio);
}

int main(int argc, char *argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(windowWidth, windowHeight);
	glutCreateWindow("第一个OpenGL程序");

	init();
	glutReshapeFunc(windowReshape);
	glutDisplayFunc(myDisplay);
	glutMainLoop();

	return 0;
}

7-1:antialiasing 消除锯齿

#include "stdafx.h"
#define Pi 3.1415926

int windowWidth = 600, windowHeight = 600;

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 1.0);

	glEnable(GL_LINE_SMOOTH);
	glEnable(GL_BLEND);
	glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
}

void myDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glColor3f(0.0, 0.0, 1.0);
	glLineWidth(200.0);
	glBegin(GL_LINES);
	glVertex2i(-5, -1); 
	glVertex2i(5, 1);
	glEnd();

	glFlush();
}

void windowReshape(int w, int h)
{
	float aspectRatio;

	windowWidth = w;
	windowHeight = h;

	aspectRatio = (float)windowWidth / (float)windowHeight;

	glViewport(0, 0, windowWidth, windowHeight);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	if (windowWidth >= windowHeight)
		gluOrtho2D(-10.0*aspectRatio, 10.0*aspectRatio, -10.0, 10.0);
	else gluOrtho2D(-10.0, 10.0, -10.0 / aspectRatio, 10.0 / aspectRatio);
}

int main(int argc, char *argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(windowWidth, windowHeight);
	glutCreateWindow("第一个OpenGL程序");

	init();
	glutReshapeFunc(windowReshape);
	glutDisplayFunc(myDisplay);
	glutMainLoop();

	return 0;
}

7-2:fill area

#include "stdafx.h"
#define Pi 3.1415926

int windowWidth = 600, windowHeight = 600;

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 1.0);
}

void myDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	//glColor3f(1.0, 0.0, 0.0);
	//glBegin(GL_TRIANGLES);
	//glVertex2i(-50, -50); 
	//glVertex2i(50, -50);
	//glVertex2i(0, 50);
	//glEnd();

	//glColor3f(1.0, 0.0, 0.0);
	//glBegin(GL_POLYGON);
	//glVertex2i(-50, 0); glVertex2i(-25, -50);
	//glVertex2i(25, -50); glVertex2i(50, 0);
	//glVertex2i(25, 50); glVertex2i(-25, 50);
	//glEnd();

	//glShadeModel(GL_SMOOTH);//GL_FLAT
	//glBegin(GL_TRIANGLES);
	//glColor3f(1.0, 0.0, 0.0); glVertex2i(-50, -50);
	//glColor3f(0.0, 1.0, 0.0); glVertex2i(50, -50);
	//glColor3f(0.0, 0.0, 1.0); glVertex2i(0, 50);
	//glEnd();

	//glShadeModel(GL_SMOOTH);//GL_FLAT
	//glBegin(GL_POLYGON);
	//glColor3ub(255, 0, 0); glVertex2i(-50, 0);
	//glColor3ub(255, 97, 0); glVertex2i(-25, -50);
	//glColor3ub(255, 255, 0); glVertex2i(25, -50);
	//glColor3ub(0, 255, 0); glVertex2i(50, 0);
	//glColor3ub(0, 255, 255); glVertex2i(25, 50);
	//glColor3ub(0, 0, 255); glVertex2i(-25, 50);
	//glEnd();

	//glShadeModel(GL_SMOOTH);//GL_FLAT
	//glBegin(GL_POLYGON);
	//glColor3ub(255, 0, 0); glVertex2i(-50, 0);
	//glColor3ub(255, 255, 0); glVertex2i(-25, -50);
	//glColor3ub(255, 255, 0); glVertex2i(25, -50);
	//glColor3ub(255, 0, 0); glVertex2i(50, 0);
	//glEnd();

	glFlush();
}

void windowReshape(int w, int h)
{
	float aspectRatio;

	windowWidth = w;
	windowHeight = h;

	aspectRatio = (float)windowWidth / (float)windowHeight;

	glViewport(0, 0, windowWidth, windowHeight);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	if (windowWidth >= windowHeight)
		gluOrtho2D(-100.0*aspectRatio, 100.0*aspectRatio, -100.0, 100.0);
	else gluOrtho2D(-100.0, 100.0, -100.0 / aspectRatio, 100.0 / aspectRatio);
}

int main(int argc, char *argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGBA | GLUT_SINGLE);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(windowWidth, windowHeight);
	glutCreateWindow("第一个OpenGL程序");

	init();
	glutReshapeFunc(windowReshape);
	glutDisplayFunc(myDisplay);
	glutMainLoop();

	return 0;
}

7-3:line-type

// OPENGL.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#define Pi 3.1415926

void init(void)
{
	glClearColor(1.0, 1.0, 1.0, 1.0);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluOrtho2D(-10.0, 10.0, -10.0, 10.0);
}

void circleDisplay(void)
{
	glClear(GL_COLOR_BUFFER_BIT);

	glEnable(GL_LINE_STIPPLE);
	
	glLineWidth(10.0f);
	glColor3f(0.0, 0.0, 0.0);
	glLineStipple(1, 0x0101);
	glBegin(GL_LINES);
	glVertex2f(-5.0,-5.0);
	glVertex2f(5.0, 5.0);
	glEnd();

	glFlush();
}

int main(int argc, char *argv[])
{
    glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_SINGLE | GLUT_RGBA);
    glutInitWindowPosition(50,100);
    glutInitWindowSize(800, 800);
    glutCreateWindow("第一个OpenGL程序");

	init();
	glutDisplayFunc(circleDisplay);
    glutMainLoop();

    return 0;
}