OpenGL/GLUT 使骑行顺畅的简单问题
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【中文标题】OpenGL/GLUT 使骑行顺畅的简单问题【英文标题】:OpenGL/GLUT Simple issue in making ride to be smooth 【发布时间】:2014-11-07 05:02:52 【问题描述】:我几乎完成了我被要求执行的程序,但我陷入了一个非常简单的逻辑问题,那就是:
通过鼠标左键单击来提高骑行速度,直到达到最大速度或鼠标右键单击被击中。
右击鼠标平稳降低骑行速度,直到达到零速度或鼠标左击被击中。
我正在使用信号和速度int
变量来实现我的目标,但我有两个问题:
-
如果我使用
Sleep()
函数来减慢有限的while 循环,程序只会冻结,并且没有任何效果。如果我不使用Sleep()
函数,运动就会变成瞬间跳跃,根本感觉不到任何东西在运动。
另外鼠标的左右点击只能用2次,之后就不能用了。
Screenshot of the program
任何提示都会很棒。
我的鼠标切换语句:
switch (button)
case GLUT_LEFT_BUTTON:
signal = 0;
smothIncrease();
break;
case GLUT_MIDDLE_BUTTON:
case GLUT_RIGHT_BUTTON:
signal = 1;
smothDecrease();
break;
default:
break;
辅助函数:
void smothIncrease()
while (true)
if (signal == 0)
if (speed == 15)
break;
angle++;
speed++;
Sleep(15);
glutPostRedisplay();
else if (signal == 1)
break;
void smothDecrease()
while (true)
if (signal == 1)
if (speed == 0)
break;
angle--;
speed--;
Sleep(15);
glutPostRedisplay();
else if (signal == 0)
break;
这里是完整的源代码:
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#define PI 3.14159265
static GLfloat lpos[] = 0.0, 5.0, 4.0, 1.0 ;
static GLfloat black[] = 0.0, 0.0, 0.0, 1.0 ;
static GLfloat white[] = 1.0, 1.0, 1.0, 1.0 ;
static GLfloat red[] = 1.0, 0.0, 0.0, 1.0 ;
static GLfloat lightgreen[] = 0.5, 1.0, 0.5, 1.0 ;
static float alpha = 0.0;
static float beta = PI / 6.0;
static float zoom = 25.0;
static bool lightSource = true;
float numberOfTriangles = 1;
static GLdouble cpos[3];
static double fenceHeight = -0.5;
static int angle = 0;
static int angle__IN_RANGE = 0.0;
static double radian__IN_RANGE = 0.0;
static int arrayOfAnglesInRange[181];
static int id = 0;
static int speed = 0;
static int signal = 0;
void writemessage()
void processAngle()
angle__IN_RANGE = arrayOfAnglesInRange[abs(angle) % 181];
void setRadian_IN_RANGE()
radian__IN_RANGE = ((float)angle__IN_RANGE / 180) * PI;
void fillArray()
int j = -45;
for (int i = 0; i < 181; i++)
if (i < 90)
arrayOfAnglesInRange[i] = j++;
else
arrayOfAnglesInRange[i] = j--;
//for (int i = 0; i < 182; i++)
//
// printf("%d\n", arrayOfAnglesInRange[i]);
//
void keepTrackOfID()
int tempAngle = angle;
//if (id % 4 == 0)
// angle += 0;
//else if (id % 4 == 1)
// angle += 60;
//else if (id % 4 == 2)
// angle += 120;
//else if (id % 4 == 3)
// angle += 180;
//if (id % 4 == 0)
// angle += 0;
//else if (id % 4 == 1)
// angle += 45;
//else if (id % 4 == 2)
// angle += 90;
//else if (id % 4 == 3)
// angle += 135;
if (id % 4 == 0)
angle += 0;
else if (id % 4 == 1)
angle += 30;
else if (id % 4 == 2)
angle += 60;
else if (id % 4 == 3)
angle += 90;
processAngle();
setRadian_IN_RANGE();
angle = tempAngle;
void smothIncrease()
while (true)
if (signal == 0)
if (speed == 15)
break;
angle++;
speed++;
Sleep(15);
glutPostRedisplay();
else if (signal == 1)
break;
void smothDecrease()
while (true)
if (signal == 1)
if (speed == 0)
break;
angle--;
speed--;
Sleep(15);
glutPostRedisplay();
else if (signal == 0)
break;
void reshape(int w, int h)
glViewport(0, 0, (GLsizei)w, (GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45.0, (GLfloat)w / (GLfloat)h, 0.01, 50.0);
glMatrixMode(GL_MODELVIEW);
void DrawSticksArroundYard()
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
glMaterialfv(GL_BACK, GL_AMBIENT_AND_DIFFUSE, black);
GLUquadricObj *quadObj;
// Right-Line
glPushMatrix();
glTranslatef(6.8, 1.0 + fenceHeight, -7.0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.1, 0.1, 14.0, 10, 10);
glPopMatrix();
// Left-Line
glPushMatrix();
glTranslatef(-6.8, 1.0 + fenceHeight, -7.0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.1, 0.1, 14.0, 10, 10);
glPopMatrix();
// Back-Line
glPushMatrix();
glTranslatef(-6.8, 1.0 + fenceHeight, -7.0);
glRotatef(90, 0, 1, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.1, 0.1, 13.7, 10, 10);
glRotatef(-90, 0, 1, 0);
glPopMatrix();
// Front-Line
glPushMatrix();
glTranslatef(6.8, 1.0 + fenceHeight, 7.0);
glRotatef(-90, 0, 1, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.1, 0.1, 13.7, 10, 10);
glRotatef(90, 0, 1, 0);
glPopMatrix();
// Pin-Front-Right
glPushMatrix();
glTranslatef(6.8, 0, 7.0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Front-Left
glPushMatrix();
glTranslatef(-6.8, 0, 7.0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Back-Left
glPushMatrix();
glTranslatef(-6.8, 0, -7.0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Back-Right
glPushMatrix();
glTranslatef(6.8, 0, -7.0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Back-Center
glPushMatrix();
glTranslatef(0, 0, -7.0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Front-Center
glPushMatrix();
glTranslatef(0, 0, 7.0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Right-Center
glPushMatrix();
glTranslatef(6.8, 0, 0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
// Pin-Left-Center
glPushMatrix();
glTranslatef(-6.8, 0, 0);
glRotatef(-90, 1, 0, 0);
quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.1, 1.3 + fenceHeight, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
void DrawYardFloor()
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, lightgreen);
glMaterialfv(GL_BACK, GL_AMBIENT_AND_DIFFUSE, lightgreen);
glBegin(GL_POLYGON);
glNormal3f(0, 1, 0);
glVertex3f(-7.3, -0.005, -7.3);
glVertex3f(-7.3, -0.005, 7.3);
glVertex3f(7.3, -0.005, 7.3);
glVertex3f(7.3, -0.005, -7.3);
glEnd();
void DrawCenterPin()
glRotatef(-90, 1, 0, 0);
GLUquadricObj *quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.2, 7, 10, 10);
glRotatef(90, 1, 0, 0);
void DrawBase()
glRotatef(-90, 1, 0, 0);
GLUquadricObj *quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.5, 0.1, 2, 10, 10);
glRotatef(90, 1, 0, 0);
void DrawTop()
glPushMatrix();
glTranslatef(0, 7, 0);
glRotatef(-90, 1, 0, 0);
GLUquadricObj *quadObj = gluNewQuadric();
gluCylinder(quadObj, 0.2, 0.0, 0.5, 10, 10);
glRotatef(90, 1, 0, 0);
glPopMatrix();
void DrawHorizontalStick()
glLineWidth(15);
glColor3f(1.0, 0.0, 0.0);
glBegin(GL_LINES);
glVertex3f(0.0, 7.0, 0.0);
glVertex3f(4.0 * cos(radian__IN_RANGE), 7.0 + 3.0 * sin(radian__IN_RANGE), 0.0);
glEnd();
void DrawVerticalStick()
glLineWidth(5);
glColor3f(1.0, 0.0, 0.0);
glBegin(GL_LINES);
glVertex3f(4.0 * cos(radian__IN_RANGE), 7.0 + 3.0 * sin(radian__IN_RANGE), 0.0);
glVertex3f(4.0 * cos(radian__IN_RANGE), 7.0 + 3.0 * sin(radian__IN_RANGE) - 1, 0.0);
glEnd();
void DrawCabin()
// Back
glNormal3f(0.0, 0.0, -1.0);
glBegin(GL_POLYGON);
glVertex3f(0, 0, -1);
glVertex3f(0, 1, -1);
glVertex3f(2, 1, -1);
glVertex3f(2, 0, -1);
glEnd();
glNormal3f(0.0, 0.0, -1.0);
glBegin(GL_POLYGON);
glVertex3f(0, 1.7, -1);
glVertex3f(0, 2, -1);
glVertex3f(2, 2, -1);
glVertex3f(2, 1.7, -1);
glEnd();
glNormal3f(0.0, 0.0, -1.0);
glBegin(GL_POLYGON);
glVertex3f(0, 1, -1);
glVertex3f(0, 1.7, -1);
glVertex3f(0.2, 1.7, -1);
glVertex3f(0.2, 1, -1);
glEnd();
glNormal3f(0.0, 0.0, -1.0);
glBegin(GL_POLYGON);
glVertex3f(1.8, 1, -1);
glVertex3f(1.8, 1.7, -1);
glVertex3f(2, 1.7, -1);
glVertex3f(2, 1, -1);
glEnd();
// Front
glNormal3f(0.0, 0.0, 1.0);
glBegin(GL_POLYGON);
glVertex3f(2, 0, 1);
glVertex3f(2, 1, 1);
glVertex3f(0, 1, 1);
glVertex3f(0, 0, 1);
glEnd();
glNormal3f(0.0, 0.0, 1.0);
glBegin(GL_POLYGON);
glVertex3f(2, 1.7, 1);
glVertex3f(2, 2, 1);
glVertex3f(0, 2, 1);
glVertex3f(0, 1.7, 1);
glEnd();
glNormal3f(0.0, 0.0, 1.0);
glBegin(GL_POLYGON);
glVertex3f(0.2, 1, 1);
glVertex3f(0.2, 1.7, 1);
glVertex3f(0, 1.7, 1);
glVertex3f(0, 1, 1);
glEnd();
glNormal3f(0.0, 0.0, 1.0);
glBegin(GL_POLYGON);
glVertex3f(2, 1, 1);
glVertex3f(2, 1.7, 1);
glVertex3f(1.8, 1.7, 1);
glVertex3f(1.8, 1, 1);
glEnd();
// Floor
glNormal3f(0.0, -1.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(2, 0, -1);
glVertex3f(2, 0, 1);
glVertex3f(0, 0, 1);
glVertex3f(0, 0, -1);
glEnd();
// Top
glNormal3f(0.0, 1.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(2, 2, 1);
glVertex3f(2, 2, -1);
glVertex3f(0, 2, -1);
glVertex3f(0, 2, 1);
glEnd();
// Right
glNormal3f(1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(2, 0, -1);
glVertex3f(2, 1, -1);
glVertex3f(2, 1, 1);
glVertex3f(2, 0, 1);
glEnd();
glNormal3f(1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(2, 1.7, -1);
glVertex3f(2, 2, -1);
glVertex3f(2, 2, 1);
glVertex3f(2, 1.7, 1);
glEnd();
glNormal3f(1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(2, 1, -1);
glVertex3f(2, 1.7, -1);
glVertex3f(2, 1.7, -0.8);
glVertex3f(2, 1, -0.8);
glEnd();
glNormal3f(1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(2, 1, 0.8);
glVertex3f(2, 1.7, 0.8);
glVertex3f(2, 1.7, 1);
glVertex3f(2, 1, 1);
glEnd();
// Left
glNormal3f(-1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(0, 0, -1);
glVertex3f(0, 0, 1);
glVertex3f(0, 1, 1);
glVertex3f(0, 1, -1);
glEnd();
glNormal3f(-1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(0, 1.7, -1);
glVertex3f(0, 1.7, 1);
glVertex3f(0, 2, 1);
glVertex3f(0, 2, -1);
glEnd();
glNormal3f(-1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(0, 1, -1);
glVertex3f(0, 1, -0.8);
glVertex3f(0, 1.7, -0.8);
glVertex3f(0, 1.7, -1);
glEnd();
glNormal3f(-1.0, 0.0, 0.0);
glBegin(GL_POLYGON);
glVertex3f(0, 1, 0.8);
glVertex3f(0, 1, 1);
glVertex3f(0, 1.7, 1);
glVertex3f(0, 1.7, 0.8);
glEnd();
void darwCabin__FINAL()
glPushMatrix();
glTranslatef(4.0 * cos(radian__IN_RANGE), 7.0 + 3.0 * sin(radian__IN_RANGE) - 3, 0.0);
glRotatef(angle, 0, 1, 0);
glPushMatrix();
glTranslatef(-1, 0, 0);
DrawCabin();
glPopMatrix();
glRotatef(-angle, 0, 1, 0);
glPopMatrix();
void display(void)
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glLoadIdentity();
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 64);
cpos[0] = zoom * cos(beta) * sin(alpha);
cpos[1] = zoom * sin(beta);
cpos[2] = zoom * cos(beta) * cos(alpha);
gluLookAt(cpos[0], cpos[1], cpos[2], 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
if (lightSource == true)
glLightfv(GL_LIGHT0, GL_POSITION, lpos);
glMaterialfv(GL_FRONT, GL_EMISSION, white);
glPushMatrix();
glTranslatef(lpos[0], lpos[1], lpos[2]);
glutSolidSphere(0.1, 10, 8);
glPopMatrix();
glMaterialfv(GL_FRONT, GL_EMISSION, black);
DrawYardFloor();
DrawSticksArroundYard();
DrawCenterPin();
DrawBase();
DrawTop();
glRotatef(angle, 0, 1, 0);
for (int i = 0; i < 4; i++)
glPushMatrix();
glRotatef(i * 360 / 4, 0, 1, 0);
keepTrackOfID();
DrawHorizontalStick();
DrawVerticalStick();
darwCabin__FINAL();
id++;
glPopMatrix();
glRotatef(-angle, 0, 1, 0);
glutSwapBuffers();
glFlush();
void keyboard(unsigned char key, int x, int y)
static int polygonmode[2];
switch (key)
case 27:
exit(0);
break;
case 'x':
if (lightSource == true)
lpos[0] = lpos[0] + 0.2;
glutPostRedisplay();
break;
case 'X':
if (lightSource == true)
lpos[0] = lpos[0] - 0.2;
glutPostRedisplay();
break;
case 'y':
if (lightSource == true)
lpos[1] = lpos[1] + 0.2;
glutPostRedisplay();
break;
case 'Y':
if (lightSource == true)
lpos[1] = lpos[1] - 0.2;
glutPostRedisplay();
break;
case 'z':
if (lightSource == true)
lpos[2] = lpos[2] + 0.2;
glutPostRedisplay();
break;
case 'Z':
if (lightSource == true)
lpos[2] = lpos[2] - 0.2;
glutPostRedisplay();
break;
case '+':
if (zoom != 1.5)zoom = zoom - 0.5;
glutPostRedisplay();
break;
case '-':
if (zoom != 30)zoom = zoom + 0.5;
glutPostRedisplay();
break;
case '0':
if (lightSource == true)
glDisable(GL_LIGHT0);
lightSource = false;
else
glEnable(GL_LIGHT0);
lightSource = true;
glutPostRedisplay();
break;
case 'e':
if (fenceHeight < 2)
fenceHeight += 0.5;
glutPostRedisplay();
break;
case 'd':
if (fenceHeight > -0.5)
fenceHeight -= 0.5;
glutPostRedisplay();
break;
case 'w':
glGetIntegerv(GL_POLYGON_MODE, polygonmode);
if (polygonmode[0] == GL_FILL)
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
else glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glutPostRedisplay();
break;
case 'n':
angle++;
processAngle();
setRadian_IN_RANGE();
glutPostRedisplay();
break;
case 'm':
angle--;
processAngle();
setRadian_IN_RANGE();
glutPostRedisplay();
break;
default:
break;
void mouse(int button, int state, int x, int y)
switch (button)
case GLUT_LEFT_BUTTON:
signal = 0;
smothIncrease();
break;
case GLUT_MIDDLE_BUTTON:
case GLUT_RIGHT_BUTTON:
signal = 1;
smothDecrease();
break;
default:
break;
void specialkey(GLint key, int x, int y)
switch (key)
case GLUT_KEY_RIGHT:
alpha = alpha + PI / 180;
if (alpha > 2 * PI) alpha = alpha - 2 * PI;
glutPostRedisplay();
break;
case GLUT_KEY_LEFT:
alpha = alpha - PI / 180;
if (alpha < 0) alpha = alpha + 2 * PI;
glutPostRedisplay();
break;
case GLUT_KEY_UP:
if (beta < 0.45*PI) beta = beta + PI / 180;
glutPostRedisplay();
break;
case GLUT_KEY_DOWN:
if (beta > -0.05*PI) beta = beta - PI / 180;
glutPostRedisplay();
break;
default:
break;
int main(int argc, char** argv)
writemessage();
fillArray();
processAngle();
setRadian_IN_RANGE();
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(1200, 800);
glutInitWindowPosition(0, 0);
glutCreateWindow(argv[0]);
glClearColor(0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_SMOOTH);
/* initially GL_FILL mode (default), later GL_LINE to show wireframe */
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glEnable(GL_LIGHTING);
glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
glEnable(GL_LIGHT0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
gluLookAt(0.0, 5.0, 10.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0);
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutMouseFunc(mouse);
glutKeyboardFunc(keyboard);
glutSpecialFunc(specialkey);
glutMainLoop();
return 0;
【问题讨论】:
GLUTPostRedisplay
不显示您的框架。它所做的只是通知 GLUT 在下一个 GLUT-mainloop 中显示您的帧。摆脱 smoothXXX
函数中的循环,每次将速度更改一。
【参考方案1】:
您的代码有几个问题,我会在发现它们时进行解释。
第一件事是您对所有变量(例如速度和角度)使用int
数据类型,并且使用整数不会得到任何平滑,因此您应该将所有这些整数更改为float
.
glutPostRedisplay
只会标记你的帧被再次渲染。换句话说,该函数将立即返回,并且在下一个渲染帧事件之前不会发生任何事情。 Sleep
调用使您的进程冻结(它会中断您程序中的任何处理,包括 glut 渲染循环)。无需在此函数上放置 while
循环,因为您无法以这种方式控制渲染循环。
你应该有一个新的变量来控制速度的变化,并且在你的显示函数中你应该改变运动的速度。您的新 smothIncrease
可能如下所示:
float speedChange = 0.0f;
void smothIncrease()
speedChange += 1.0f; // you may want to have other increment factor
glutPostRedisplay();
在您的 display
函数中,您应该将速度更改为您刚刚增加的因子:
if (speed < 15.0f)
speed += speedChange;
但是这样我们如何在没有事件发生(鼠标点击,按键)时重绘框架?我知道的最好的方法是设置一个空闲函数,然后在这个空闲函数上调用glutPostRedisplay
。这将保证您的窗口始终处于更新状态。
看看那些链接
glutPostRedisplay reference glutIdleFunc reference【讨论】:
+1 以获得普遍的好答案。我仍然想指出,使用int
变量是没有问题的,只要它们的精度足以解决手头的问题。特别是在从 0 到 15 的离散范围内使用 int
与 float
几乎没有区别。
我认为他只是从 0 到 15 作为起点,最终会调整这些数字以达到他想要的速度。所以最好删除这些整数,因为它会在将来导致错误。例如:int speed += 0.5
将导致 C++ 将数字四舍五入到最接近的整数,从长远来看可能不会发生任何事情。过去这发生在我身上,即使过程中没有明确的浮点数。感谢您的意见。以上是关于OpenGL/GLUT 使骑行顺畅的简单问题的主要内容,如果未能解决你的问题,请参考以下文章