我正在使用openGL在太阳系上做一个迷你项目。我正在尝试创建两个窗口，第一个显示我的名字，大学名称和其他细节，第二个将显示太阳系。我的第二个屏幕正在工作完全没问题，但是我无法在我的第一个屏幕上打印任何文字。下面是代码，任何人都可以检查我的代码并告诉我错误的位置。
#include<GL/glut.h>
#include<stdio.h>
#include<string.h>
#include<math.h>
static int m=0,M=0,v=0,V=0,E=0,e=0,r=0,R=0,j=0,J=0,s=0,S=0,U=0,u=0,n=0,N=0,X=0,z=0,B=0,b=0,c=0;
static GLint axis=2;
int isMainScreen=1;
GLfloat diffuseMaterial[4]={0.5,0.5,0.5,1.0};
/*initialize material property,light soure,lighting model,and depth buffer*/
void drawString1(float x, float y, float z, char * string) {
char * c;
glRasterPos3f(x, y, z);
for (c = string; * c != '\0'; c++) {
glutBitmapCharacter(GLUT_BITMAP_9_BY_15, * c);
}
}
void myinit(void)
{
glClearColor(0.0,0.0,0.0,0.0);
glShadeModel(GL_SMOOTH);
glEnable(GL_DEPTH_TEST);
GLfloat mat_specular[]={1.0,1.0,1.0,1.0};
GLfloat light_position[]={1.0,1.0,1.0,0.0};
glMaterialfv(GL_FRONT,GL_DIFFUSE,diffuseMaterial);
glMaterialfv(GL_FRONT,GL_SPECULAR,mat_specular);
glMaterialf(GL_FRONT,GL_SHININESS,25.0);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glLightfv(GL_LIGHT0,GL_POSITION,light_position);
glColorMaterial(GL_FRONT,GL_DIFFUSE);
glEnable(GL_COLOR_MATERIAL);
}
void display(void)
{
GLfloat position[]={0.0,0.0,1.5,1.0};
glColor3f(1.0,0.5,0.0);
glPushMatrix();
glRotatef((GLfloat)z,1.0,1.0,1.0);
glLightfv(GL_LIGHT0,GL_POSITION,position);
glDisable(GL_LIGHTING);
glutSolidSphere(0.8,40,16); /*draw sun*/
glPopMatrix();
glPushMatrix();
glLightfv(GL_LIGHT0,GL_POSITION,position);
glDisable(GL_LIGHTING);
glEnable(GL_LIGHTING);
glColor3f(1.5,0.5,0.0);
glutSolidTorus(0.2,0.9,6,20);
glPopMatrix();
glPushMatrix();
glRotatef((GLfloat)M,0.0,1.0,0.0);
glTranslatef(1.5,0.0,0.0);
glRotatef((GLfloat)m,0.0,1.0,0.0);
glColor3f(1.0,0.0,0.0);
glutSolidSphere(0.2,20,8); /*draw smaller planet mercury*/
glPopMatrix();
glPushMatrix();
glRotatef((GLfloat)V,0.0,1.0,0.0);
glTranslatef(2.0,0.0,1.0);
glRotatef((GLfloat)v,0.0,1.0,0.0);
glColor3f(7.5,9.5,1.0);
glutSolidSphere(0.2,20,8); /*draw smaller plant venus*/
glPopMatrix();
glPushMatrix();
glRotatef((GLfloat)E,0.0,1.0,0.0);
glTranslatef(3.5,0.0,0.0);
glRotatef((GLfloat)e,0.0,1.0,0.0);
glColor3f(0.1,6.5,2.0);
glutSolidSphere(0.2,20,8); /*draw smaller plant earth*/
glRotatef((GLfloat)X,0.0,1.0,0.0);
glTranslatef(0.3,0.2,0.0);
glColor3f(4.3,3.5,8.0);
glutSolidSphere(0.1,20,14); /*draw moon*/
glPopMatrix();
glPushMatrix();
glRotatef((GLfloat)R,0.0,1.0,0.0);
glTranslatef(5.0,0.0,3.0);
glRotatef((GLfloat)r,0.0,1.0,0.0);
glColor3f(1.0,0.2,0.0);
glutSolidSphere(0.2,20,8); /*draw smaller planet mars*/
glPopMatrix();
glPushMatrix();
glRotatef((GLfloat)J,0.0,1.0,0.0);
glTranslatef(-2.5,0.0,1.0);
glRotatef((GLfloat)j,0.0,1.0,0.0);
glColor3f(0.9,0.7,0.3);
glutSolidSphere(0.2,20,8);/*draw smaller planet Jupiter*/
glPopMatrix();
glPushMatrix();
glRotatef((GLfloat)S,0.0,1.0,0.0);
glTranslatef(-5.0,0.0,0.0);
gluLookAt(0.0,10.0,2.0,1.0,0.0,0.0,0.0,0.0,1.0);
glRotatef((GLfloat)s,0.0,0.0,5.0);
glColor3f(4.5,0.5,0.0);
glutSolidSphere(0.5,20,16); /*draw smaller plant Saturn*/
int i=0;
glBegin(GL_QUAD_STRIP);
for(i=0;i<=360;i++)
{
glVertex3f(sin(i*3.1416/180)*0.5,cos(i*3.1416/180)*0.5,0);
glVertex3f(sin(i*3.1416/180)*0.7,cos(i*3.1416/180)*0.7,0);
}
glEnd();
glPopMatrix();
glPushMatrix();
glRotatef ((GLfloat) U, 0.0, 1.0,0.0);
glTranslatef (-6.5, 0.0, 0.0);
gluLookAt (10.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 10.0, 1.0);
glRotatef((GLfloat) u, 0.0, 0.0, 5.0);
glColor3f( 1.2, 0.6,0.2);
glutSolidSphere (0.5, 20, 16); /* draw smaller planet Uranus*/
glBegin(GL_QUAD_STRIP);
for(i=0; i<=360; i++)
{
glVertex3f(sin(i*3.1416/180)*0.5,cos(i*3.1416/180)*0.5, 0);
glVertex3f(sin(i*3.1416/180)*0.7, cos(i*3.1416/180)*0.7,0);
}
glEnd();
glPopMatrix();
glPushMatrix();
glRotatef ((GLfloat) N,0.0, 1.0, 0.0);
glTranslatef (-8.0, 0.0, 0.0);
glRotatef ((GLfloat) n, 0.0, 1.0, 0.0);
glColor3f(1.0, 2.0, 0.0);
glutSolidSphere(0.4, 20, 8);
glPopMatrix();/* draw smaller planet Neptune */
glPushMatrix();
glRotatef ((GLfloat) c, 6.0, -14.0,-6.0);
glTranslatef (5.0,3.0,-1.0);
glScalef(0.60,0.0,2.5);
glColor3f (7.5, 9.5, 2.0);
glutSolidSphere (0.2, 12, 6);
glPopMatrix();/*draw comet*/
//to put the stars as a background
glPushMatrix();
glTranslatef(0.0,-2.0,0.0);
gluLookAt(0.0,10.0,0.0,1.0,0.0,0.0,0.0,0.0,3.0);
glRotatef((GLfloat)b,0.0,0.0,0.0);
glScalef(200.0,0.0,0.0);
glColor3f(4.3,3.5,1.0);
glutSolidSphere(0.04,20,8);
glPopMatrix();
glPushMatrix();
glTranslatef(0.0,2.0,0.0);
gluLookAt(0.0,10.0,2.0,1.0,0.0,0.0,0.0,0.0,1.0);
glRotatef((GLfloat)b,0.0,0.0,0.0);
glScalef(200.0,0.0,0.0);
glColor3f(4.3,3.5,1.0);
glutSolidSphere(0.04,20,8);
glPopMatrix();
glPushMatrix();
glTranslatef(8.7,9.0,0.0);
gluLookAt(0.0,10.0,2.0,1.0,0.0,0.0,0.0,0.0,1.0);
glRotatef((GLfloat)b,1.0,7.0,5.0);
glColor3f(4.3,3.5,1.0);
glutSolidSphere(0.04,20,8);
glPopMatrix();
glutSwapBuffers();
}
void reshape(int w,int h)
{
glViewport(0,0,(GLsizei)w,(GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(60.0,(GLfloat)w/(GLfloat)h,1.0,20.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0.0,0.0,5.0,0.0,0.0,0.0,0.0,1.0,0.0);
}
void keyboard(unsigned char key,int x,int y)
{
printf("%d", key);
switch(key)
{
case 'z':
z=(z+50)%360;
glutPostRedisplay();
break;
case 'm':
m=(m+3)%360;
glutPostRedisplay();
break;
case 'M':
M=(M+12)%360;
glutPostRedisplay();
break;
case 'v':
v=(v+2)%360;
glutPostRedisplay();
break;
case 'V':
V=(V+10)%360;
glutPostRedisplay();
break;
case 'e':
e=(e+5)%360;
glutPostRedisplay();
break;
case 'E':
E=(E+8)%360;
glutPostRedisplay();
break;
case 'r':
r=(r+6)%360;
glutPostRedisplay();
break;
case 'R':
R=(R+6)%360;
glutPostRedisplay();
break;
case 'j':
j=(j+10)%360;
glutPostRedisplay();
break;
case 'J':
J=(J+4)%360;
glutPostRedisplay();
break;
case 's':
s=(s+9)%360;
glutPostRedisplay();
break;
case 'S':
S=(S+3)%360;
glutPostRedisplay();
break;
case 'u':
u=(u+8)%360;
glutPostRedisplay();
break;
case 'U':
U=(U+2)%360;
glutPostRedisplay();
break;
case 'n':
n=(n+7)%360;
glutPostRedisplay();
break;
case 'N':
N=(N+1)%360;
glutPostRedisplay();
break;
case 'b':
b=(b+10)%360;
glutPostRedisplay();
break;
case 'c':
c=(c+1)%360;
b=(b+10)%360;
glutPostRedisplay();
break;
case 'X':
X=(X+5)%360;
glutPostRedisplay();
break;
case 'a':
z=(z+50)%360;
b=(b+10)%360;
m=(m+3)%360;
v=(v+2)%360;
e=(e+5)%360;
r=(r+6)%360;
j=(j+10)%360;
s=(s+9)%360;
u=(u+8)%360;
n=(n+7)%360;
c=(c+1)%360;
glutPostRedisplay();
break;
case 'A':
z=(z+50)%360;
b=(b+10)%360;
M=(M+12)%360;
V=(V+10)%360;
E=(E+8)%360;
R=(R+6)%360;
J=(J+4)%360;
S=(S+3)%360;
U=(U+2)%360;
N=(N+1)%360;
c=(c+1)%360;
glutPostRedisplay();
break;
case 'B':
z=(z+50)%360;
b=(b+10)%360;
c=(c+1)%360;
m=(m+3)%360;
M=(M+12)%360;
v=(v+2)%360;
V=(V+10)%360;
e=(e+5)%360;
E=(E+8)%360;
r=(r+6)%360;
R=(R+6)%360;
j=(j+10)%360;
J=(J+4)%360;
s=(s+9)%360;
S=(S+3)%360;
u=(u+8)%360;
U=(U+2)%360;
n=(n+7)%360;
N=(N+1)%360;
glutPostRedisplay();
break;
case 13:
isMainScreen = 0;
break;
case 27:
exit(0);
break;
default:
break;
}
}
void frontscreen(void)
{
glColor3f(0.0,0.0,1.0);
drawString1(0.5,0.5,0.0,"MVJ College of Engineering");
glColor3f(0.7,0,1);
drawString1(120,400,0.0,"DEPARTMENT OF COMPUTER SCIENCE AND ENGINEERING");
glColor3f(1,0.5,0);
drawString1(210.0, 300.0,0.0,"A MINI PROJECT ON");
glColor3f(1,0,0);
drawString1(220,270,0.0,"PROJECT TITLE");
glColor3f(1,0.5,0);
drawString1(20,50,0.0,"BY:");
glColor3f(0.5,0,0.5);
drawString1(10,40,0.0,"NAME FIRST (USN)");
drawString1(10,34,0.0,"NAME SECOND (USN)");
glColor3f(1,0.5,0);
drawString1(68,50,0.0,"GUIDES:");
glColor3f(0.5,0.2,0.2);
drawString1(63,40,0.0,"GUIDE NAME FIRST");
drawString1(63,34,0.0,"GUIDE NAME SECOND");
glColor3f(1,0.1,1);
drawString1(32,10,0.0,"PRESS ENTER TO START");
glFlush();
glutPostRedisplay();
}
void mouse(int btn ,int state,int x,int y)
{
if(btn==GLUT_LEFT_BUTTON && state==GLUT_DOWN)
{
z=(z+50)%360;
b=(b+10)%360;
c=(c+1)%360;
m=(m+3)%360;M=(M+12)%360;
v=(v+2)%360;V=(V+10)%360;
e=(e+5)%360;E=(E+8)%360;
r=(r+6)%360;R=(R+6)%360;
j=(j+10)%360;J=(J+4)%360;
s=(s+9)%360;S=(S+3)%360;
u=(u+8)%360;U=(U+2)%360;
n=(n+7)%360;N=(N+1)%360;
glutPostRedisplay();
}
if(btn==GLUT_MIDDLE_BUTTON && state==GLUT_DOWN)
{
z=(z+50)%360;
b=(b+10)%360;
c=(c+1)%360;
m=(m+3)%360;M=(M+12)%360;
v=(v-2)%360;V=(V-10)%360;
e=(e+5)%360;E=(E+8)%360;
r=(r-6)%360;R=(R-6)%360;
j=(j+10)%360;J=(J+4)%360;
s=(s-9)%360;S=(S-3)%360;
u=(u+8)%360;U=(U+2)%360;
n=(n-7)%360;N=(N-1)%360;
glutPostRedisplay();
}
if(btn==GLUT_RIGHT_BUTTON && state==GLUT_DOWN)
{
z=(z-50)%360;
b=(b-10)%360;
c=(c+1)%360;
m=(m-3)%360;M=(M-12)%360;
v=(v-2)%360;V=(V-10)%360;
e=(e-5)%360;E=(E-8)%360;
r=(r-6)%360;R=(R-6)%360;
j=(j-10)%360;J=(J-4)%360;
s=(s-9)%360;S=(S-3)%360;
u=(u-8)%360;U=(U-2)%360;
n=(n-7)%360;N=(N-1)%360;
glutPostRedisplay();
}
}
void mydisplay() {
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
if (isMainScreen) {
frontscreen();
} else {
display();
}
}
int main(int argc,char **argv[])
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
glutInitWindowSize(1024, 600);
glutInitWindowPosition(100,100);
glutCreateWindow("planets amidst stars");
myinit();
glutDisplayFunc(mydisplay);
glutReshapeFunc(reshape);
glutKeyboardFunc(keyboard);
//glutKeyboardFunc(myKeyboardFunc);
glutMouseFunc(mouse);
glEnable(GL_DEPTH_TEST);
glutMainLoop();
return 0;
}
有人可以更正错误吗？
答案 0 :(得分：3)
正如您在glutInitDisplayMode中指定的那样，您正在使用双缓冲（GLUT_DOUBLE）：
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB|GLUT_DEPTH);
这导致你必须在渲染结束时调用glutSwapBuffers来交换当前窗口的缓冲区（glFlush是不够的。）
此外，我建议设置一个正交投影，将视图空间1：1映射到窗口坐标
使用glOrtho进行此操作，并使用glMatrixMode在投影矩阵堆栈和模型视图矩阵堆栈之间切换。
更改函数frontscreen中的代码，如下所示：
double vp_width = 1024.0; // update by reshape
double vp_height = 600.0; // update by reshape
void frontscreen(void)
{
glMatrixMode( GL_PROJECTION );
glPushMatrix();
glLoadIdentity();
glOrtho( 0, vp_width, vp_height, 0.0, -1.0, 1.0 );
glMatrixMode( GL_MODELVIEW );
glPushMatrix();
glLoadIdentity();
.....
glMatrixMode( GL_PROJECTION );
glPopMatrix();
glMatrixMode( GL_MODELVIEW );
glPopMatrix();
glutSwapBuffers(); // <----- glutSwapBuffers insted of glFlush
glutPostRedisplay();
}