opengl中怎么让一个图形移动然后停止,接着让另一个图形移动

[pyz3008208216]

我画了个长方体，用 glutTimerFunc来使长方体不断沿z轴拉长，做简单动画。
现在是想让第一个长方体停止拉长，然后让第二个长方体开始拉长，需要怎么办

[river80]

定时器控制好，更新显示内容就好了。

[pyz3008208216]

#include <GL/glut.h> #include <stdlib.h> int iCull = 0; int iOutline = 0; int iDepth = 0; void RenderScene(void) { static GLfloat z = 0.0f; static GLfloat z1 = 0.0f; glClear(GL_COLOR_BUFFER_BIT); if(iCull) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE); if(iDepth) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST); if(iOutline) glPolygonMode(GL_BACK,GL_LINE); else glPolygonMode(GL_BACK,GL_FILL); glPushMatrix(); gluLookAt( 4.0f,15.0f,5.0f,0.0f,0.0f,0.0f,0.0f,1.0f,0.0f); // 画第一个长方形 { glColor3f(1.0f, 0.0f, 0.0f); glPushMatrix(); glScalef(1.0f,1.0f,z); glBegin(GL_QUADS); glVertex3f(-2.0f,0.0f,0.0f); glVertex3f(2.0f,0.0f,0.0f); glVertex3f(2.0f,0.0f,-1.0f); glVertex3f(-2.0f,0.0f,-1.0f); glEnd(); glPopMatrix(); if(z<100.0f) z+=1; else z=100.0f;// 第一个长方形拉伸停止 } // 画第二个长方形 if(z=100.0f) { glPushMatrix(); glColor3f(0.0f, 1.0f, 0.0f); glScalef(1.0f,1.0f,z1); glBegin(GL_QUADS); glVertex3f(2.0f,0.0f,0.0f); glVertex3f(2.0f,0.0f,-1.0f); glVertex3f(-4.0f,5.0f,-1.0f); glVertex3f(-4.0f,5.0f,0.0f); glEnd(); glPopMatrix(); if(z1<100.0f) {z1+=1;} else z1= 100.0f;// 第二个长方形拉伸停止 } glFlush(); glPopMatrix(); } void TimerFunc(int value) { glutPostRedisplay(); glutTimerFunc(100, TimerFunc, 1); } void SetupRC(void) { glClearColor(0.0f, 0.0f, 1.0f, 1.0f); } void ChangeSize(int w, int h) { GLfloat aspectRatio; if(h == 0) h = 1; glViewport(0, 0, w, h); glMatrixMode(GL_PROJECTION); glLoadIdentity(); aspectRatio = (GLfloat)w / (GLfloat)h; if (w <= h) glOrtho (-100.0, 100.0, -100 / aspectRatio, 100.0 / aspectRatio, 100.0, -100.0); else glOrtho (-100.0 * aspectRatio, 100.0 * aspectRatio, -100.0, 100.0, 100.0, -100.0); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); } int main(int argc, char* argv[]) { glutInit(&argc, argv); glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); glutInitWindowSize(800, 600); glutCreateWindow("GLRect"); glutDisplayFunc(RenderScene); glutReshapeFunc(ChangeSize); glutTimerFunc(100, TimerFunc, 1); SetupRC(); glutMainLoop(); return 0; } 我没弄明白，问一下这个代码怎么修改啊

[victor_woo]

OpenGL Animation的基本思路： RenderScene 函数 display 里面显示模型(模型的某些参数可能是全局变量)，这个函数里面不要去修改任何数据！ 定时函数中修改全局变量(e.g.长方体的长度) 初始长度为1-->定时器函数(长度+1)-->显示(长度为2)-->定时器函数（长度+1）-->...........-->结束条件(或者下一段Animation启动)

void TimerFunc(int value)
    {
    glutPostRedisplay();
    glutTimerFunc(100, TimerFunc, 1);   //应该把改变模型的代码及逻辑处理(第一个，第二个)放在这里面
    }

[victor_woo]

把每次改变量和刷新间隔控制好，即可做出连续顺滑的animation

[victor_woo]

if(iCull)
glEnable(GL_CULL_FACE);
else
glDisable(GL_CULL_FACE);
if(iDepth)
glEnable(GL_DEPTH_TEST);
else
glDisable(GL_DEPTH_TEST);
if(iOutline)
glPolygonMode(GL_BACK,GL_LINE);
else
glPolygonMode(GL_BACK,GL_FILL);

这些GL属性设置应该放在初始化方法中按预设方案执行一次，以后每次改变相关属性直接执行一次即可，无需设置额外的BOOL变量来管理