我正在研究一个应用程序,在这个应用程序中,我绘制了一个循环的进度指示器,它慢慢变得“充满”,在这里您可以看到a couple of images。我正在使用中间模式,并且我只通过在每个帧更新时绘制顶点来绘制该圆形(请参阅下面的代码)。当圆圈填满白色和灰色之间的边界线时有点闪烁,我想知道如何让它更平滑。如何使用openGL获得真正流畅的移动对象
这是一个具体的例子,但总的来说,我想知道如何获得最平滑的运动,即使使用非常简单的lineair插值?当我在iphone上浏览页面时看到动作时,它非常平滑,这让我想知道如何在我的(快速)mac上实现这一点?
感谢
Roxlu
PhotoBoothCountdown::PhotoBoothCountdown(float fMillisDuration)
:duration(fMillisDuration)
,start_time(0)
{
setActionCommand("take_picture");
}
void PhotoBoothCountdown::update() {
if(start_time != 0) {
float cur = ofGetElapsedTimeMillis();
perc = (cur-start_time)/duration;
}
}
void PhotoBoothCountdown::draw() {
float resolution = 150;
int parts_filled = resolution * perc;
int parts_unfilled = (resolution - parts_filled);
float part_angle = TWO_PI/resolution;
//printf("filled: %i/%i/%i\n", parts_filled, parts_unfilled, (parts_filled+parts_unfilled));
float radius = 300.0f;
float width = 100;
float radius_inner = radius-width;
float center_x = ofGetWidth()/2;
float center_y = ofGetHeight()/2;
float angle = 0;
glBegin(GL_TRIANGLE_STRIP);
glColor4f(0.2f, 0.2f, 0.2f,0.9f);
for(int i = 0; i <= parts_filled; ++i) {
float cosa = cos(angle);
float sina = sin(angle);
glVertex2f(center_x + cosa * radius,center_y + sina * radius);
glVertex2f(center_x + cosa * radius_inner,center_y + sina * radius_inner);
angle += part_angle;
}
glEnd();
glBegin(GL_TRIANGLE_STRIP);
glColor4f(1.0f, 1.0f, 1.0f,0.9f);
angle -= part_angle;
for(int i = 0; i <= parts_unfilled; ++i) {
float cosa = cos(angle);
float sina = sin(angle);
glVertex2f(center_x + cosa * radius,center_y + sina * radius);
glVertex2f(center_x + cosa * radius_inner,center_y + sina * radius_inner);
angle += part_angle;
}
glEnd();
if(perc >= 1) {
printf("should fire");
fireEvent();
reset();
}
}
void PhotoBoothCountdown::start() {
start_time = ofGetElapsedTimeMillis();
end_time = start_time + duration;
}
void PhotoBoothCountdown::reset() {
start_time = 0;
end_time = 0;
perc = 0;
}
OpenGL默认为双缓冲 – doc 2010-08-03 16:37:11
@doc:OpenGL对单一缓冲区和双缓冲区的了解不多 - 这就是窗口系统接口的工作,比如wgl或glx。这就是为什么人们通常会调用'glutSwapBuffers',而不是神话般的'glSwapBuffers', – 2010-08-04 02:52:50
@doc:不是,它取决于你初始化它的方式。 @Eric:+1 – Calvin1602 2010-08-04 07:15:27