Ubuntu下OpenGL編程基礎解析

本文重點介紹在Ubuntu下怎麼進行OpenGL基礎編程，其主要步驟如下：

1：首先當然需要安裝一些基本的編譯庫和OpenGL庫文件，主要安裝以下兩個就ok了

基本編譯庫：build-essential

sudo apt-get install build-essential

OpenGL工具庫：freeglut3-dev

sudo apt-get install freeglut3-dev

以上是本人在虛擬機上安裝的提示，可以看到除了freeglut3外 還安裝了其他額外的軟件包。

2：第二步，當然是編寫代碼了，這個就不用講了，自己貼一個，有時間可以研究下。

/* Rotating cube with color interpolation */

#include <stdlib.h>
#include <GL/glut.h>

GLfloat vertices[][3] = {{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},
{1.0,1.0,-1.0}, {-1.0,1.0,-1.0}, {-1.0,-1.0,1.0},
{1.0,-1.0,1.0}, {1.0,1.0,1.0}, {-1.0,1.0,1.0}};

GLfloat normals[][3] = {{-1.0,-1.0,-1.0},{1.0,-1.0,-1.0},
{1.0,1.0,-1.0}, {-1.0,1.0,-1.0}, {-1.0,-1.0,1.0},
{1.0,-1.0,1.0}, {1.0,1.0,1.0}, {-1.0,1.0,1.0}};

GLfloat colors[][3] = {{0.0,0.0,0.0},{1.0,0.0,0.0},
{1.0,1.0,0.0}, {0.0,1.0,0.0}, {0.0,0.0,1.0},
{1.0,0.0,1.0}, {1.0,1.0,1.0}, {0.0,1.0,1.0}};

void polygon(int a, int b, int c , int d)
{
glBegin(GL_POLYGON);
glColor3fv(colors[a]);
glNormal3fv(normals[a]);
glVertex3fv(vertices[a]);
glColor3fv(colors[b]);
glNormal3fv(normals[b]);
glVertex3fv(vertices[b]);
glColor3fv(colors[c]);
glNormal3fv(normals[c]);
glVertex3fv(vertices[c]);
glColor3fv(colors[d]);
glNormal3fv(normals[d]);
glVertex3fv(vertices[d]);
glEnd();
}



void colorcube(void)
{
/* map vertices to faces */

polygon(0,3,2,1);
polygon(2,3,7,6);
polygon(0,4,7,3);
polygon(1,2,6,5);
polygon(4,5,6,7);
polygon(0,1,5,4);
}

static GLfloat theta[] = {0.0,0.0,0.0};
static GLint axis = 2;

void display(void)
{
/* display callback, clear frame buffer and z buffer,
rotate cube and draw, swap buffers */

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glRotatef(theta[0], 1.0, 0.0, 0.0);
glRotatef(theta[1], 0.0, 1.0, 0.0);
glRotatef(theta[2], 0.0, 0.0, 1.0);
colorcube();
glFlush();
glutSwapBuffers();
}

void spinCube()
{
/* Idle callback, spin cube 2 degrees about selected axis */
theta[axis] += 2.0;
if( theta[axis] > 360.0 ) theta[axis] -= 360.0;
display();
}



void mouse(int btn, int state, int x, int y)
{
/* mouse callback, selects an axis about which to rotate */
if(btn==GLUT_LEFT_BUTTON && state == GLUT_DOWN) axis = 0;
if(btn==GLUT_MIDDLE_BUTTON && state == GLUT_DOWN) axis = 1;
if(btn==GLUT_RIGHT_BUTTON && state == GLUT_DOWN) axis = 2;
}

void myReshape(int w, int h)
{
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
{
glOrtho(-2.0, 2.0, -2.0 * (GLfloat) h / (GLfloat) w,
2.0 * (GLfloat) h / (GLfloat) w, -10.0, 10.0);
}
else
{
glOrtho(-2.0 * (GLfloat) w / (GLfloat) h,
2.0 * (GLfloat) w / (GLfloat) h, -2.0, 2.0, -10.0, 10.0);
}

glMatrixMode(GL_MODELVIEW);
}

main(int argc, char **argv)
{
glutInit(&argc, argv);
/* need both double buffering and z buffer */

glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutCreateWindow("colorcube");
glutReshapeFunc(myReshape);
glutDisplayFunc(display);
glutIdleFunc(spinCube);
glutMouseFunc(mouse);
glEnable(GL_DEPTH_TEST); /* Enable hidden--surface--removal */
glutMainLoop();

return 0;

}