本文整理汇总了C++中Engine::ClearArea方法的典型用法代码示例。如果您正苦于以下问题：C++ Engine::ClearArea方法的具体用法？C++ Engine::ClearArea怎么用？C++ Engine::ClearArea使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类Engine的用法示例。
在下文中一共展示了Engine::ClearArea方法的1个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: GdBeginDr
int GdBeginDr(Drauing *drawing, GpBox *damage, int landscape)
{
int needToRedraw= 0;
Engine *eng;
if (damage) {
/* If drawing has incurred damage, report damage to ALL engines
interested in the drawing (not just active engines). */
for (eng=GpNextEngine(0) ; eng ; eng=GpNextEngine(eng))
if (eng->drawing==drawing) GpDamage(eng, drawing, damage);
}
/* Loop on active engines to alert them that drawing is coming. */
for (eng=GpNextActive(0) ; eng ; eng=GpNextActive(eng)) {
if (eng->drawing!=drawing) {
/* This engine is not marked as interested in this drawing.
Mark it, and reset damaged and lastDrawn flags so that no
elements will be inhibited. */
eng->drawing= drawing;
eng->lastDrawn= -1;
eng->damaged= 0;
if (landscape != eng->landscape) {
eng->landscape= landscape;
/* This change will be detected and acted upon by the first call
to the ChangeMap method (GpSetTrans). */
}
/* The semantics here are subtle --
After a ClearDrawing, GdDetach zeroes eng->drawing in order to
communicate that the drawing has been cleared. Thus, the code
gets here on a GdDraw after the drawing has been cleared, so
the time has come to carry out the deferred clearing of this
engine's plotting surface. */
GpClear(eng, CONDITIONALLY);
needToRedraw= 1;
} else if (eng->damaged) {
/* This engine was interested in the drawing, which has been
damaged. Clear damaged area in preparation for repair work.
(This is redundant if the damage was due to an X windows
expose event, but the resulting inefficiency is very small.) */
eng->ClearArea(eng, &eng->damage);
needToRedraw= 1;
} else if (eng->lastDrawn<drawing->nElements-1) {
needToRedraw= 1;
}
}
gdNowRendering= gdMaxRendered= -1;
return needToRedraw;
}