本文整理汇总了C++中geom::Rect::hasZeroArea方法的典型用法代码示例。如果您正苦于以下问题：C++ Rect::hasZeroArea方法的具体用法？C++ Rect::hasZeroArea怎么用？C++ Rect::hasZeroArea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geom::Rect的用法示例。
在下文中一共展示了Rect::hasZeroArea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: sp_export_png_file
ExportResult sp_export_png_file(SPDocument *doc, gchar const *filename,
Geom::Rect const &area,
unsigned long width, unsigned long height, double xdpi, double ydpi,
unsigned long bgcolor,
unsigned (*status)(float, void *),
void *data, bool force_overwrite,
GSList *items_only)
{
g_return_val_if_fail(doc != NULL, EXPORT_ERROR);
g_return_val_if_fail(filename != NULL, EXPORT_ERROR);
g_return_val_if_fail(width >= 1, EXPORT_ERROR);
g_return_val_if_fail(height >= 1, EXPORT_ERROR);
g_return_val_if_fail(!area.hasZeroArea(), EXPORT_ERROR);
if (!force_overwrite && !sp_ui_overwrite_file(filename)) {
// aborted overwrite
return EXPORT_ABORTED;
}
doc->ensureUpToDate();
/* Calculate translation by transforming to document coordinates (flipping Y)*/
Geom::Point translation = Geom::Point(-area[Geom::X][0], area[Geom::Y][1] - doc->getHeight().value("px"));
/* This calculation is only valid when assumed that (x0,y0)= area.corner(0) and (x1,y1) = area.corner(2)
* 1) a[0] * x0 + a[2] * y1 + a[4] = 0.0
* 2) a[1] * x0 + a[3] * y1 + a[5] = 0.0
* 3) a[0] * x1 + a[2] * y1 + a[4] = width
* 4) a[1] * x0 + a[3] * y0 + a[5] = height
* 5) a[1] = 0.0;
* 6) a[2] = 0.0;
*
* (1,3) a[0] * x1 - a[0] * x0 = width
* a[0] = width / (x1 - x0)
* (2,4) a[3] * y0 - a[3] * y1 = height
* a[3] = height / (y0 - y1)
* (1) a[4] = -a[0] * x0
* (2) a[5] = -a[3] * y1
*/
Geom::Affine const affine(Geom::Translate(translation)
* Geom::Scale(width / area.width(),
height / area.height()));
//SP_PRINT_MATRIX("SVG2PNG", &affine);
struct SPEBP ebp;
ebp.width = width;
ebp.height = height;
ebp.background = bgcolor;
/* Create new drawing */
Inkscape::Drawing drawing;
drawing.setExact(true); // export with maximum blur rendering quality
unsigned const dkey = SPItem::display_key_new(1);
// Create ArenaItems and set transform
drawing.setRoot(doc->getRoot()->invoke_show(drawing, dkey, SP_ITEM_SHOW_DISPLAY));
drawing.root()->setTransform(affine);
ebp.drawing = &drawing;
// We show all and then hide all items we don't want, instead of showing only requested items,
// because that would not work if the shown item references something in defs
if (items_only) {
hide_other_items_recursively(doc->getRoot(), items_only, dkey);
}
ebp.status = status;
ebp.data = data;
bool write_status = false;;
ebp.sheight = 64;
ebp.px = g_try_new(guchar, 4 * ebp.sheight * width);
if (ebp.px) {
write_status = sp_png_write_rgba_striped(doc, filename, width, height, xdpi, ydpi, sp_export_get_rows, &ebp);
g_free(ebp.px);
}
// Hide items, this releases arenaitem
doc->getRoot()->invoke_hide(dkey);
return write_status ? EXPORT_OK : EXPORT_ERROR;
}