如何重置开罗的当前点?
How to reset the current point in cairo?
从 cairo 文档中,我可以看到一些功能,例如 Text toy-API cairo_show_text()
需要设置当前点。
我们可以用 cairo_move_to()
设置当前点,然后调用 cairo_show_text()
它将光栅化所需位置的文本。
顺便说一句,这导致了一个错误,因为在光栅化文本之后,我正在抚摸一条路径,该路径(最初调用 cairo_move_to()
来设置文本的当前点)有错误的点。
我在调用 cairo_show_text()
后立即调用 cairo_stroke()
解决了这个错误,它似乎有效,因为它重置了当前点。
似乎调用 cairo_close_path()
而不是 cairo_stroke()
没有帮助。它没有重置当前点。我认为这很奇怪。为什么?
我的最后一个问题是:有没有正确的方法来重置当前点?我觉得应该有。
来自https://www.cairographics.org/manual/cairo-Paths.html#cairo-new-path
cairo_new_path ()
Clears the current path. After this call there will be no path and no current point.
完整性:还有这个函数不清除当前路径:
来自https://www.cairographics.org/manual/cairo-Paths.html#cairo-new-sub-path
cairo_new_sub_path ()
Begin a new sub-path. Note that the existing path is not affected. After this call there will be no current point.
In many cases, this call is not needed since new sub-paths are frequently started with cairo_move_to().
A call to cairo_new_sub_path()
is particularly useful when beginning a new sub-path with one of the cairo_arc()
calls. This makes things easier as it is no longer necessary to manually compute the arc's initial coordinates for a call to cairo_move_to()
.
从 cairo 文档中,我可以看到一些功能,例如 Text toy-API cairo_show_text()
需要设置当前点。
我们可以用 cairo_move_to()
设置当前点,然后调用 cairo_show_text()
它将光栅化所需位置的文本。
顺便说一句,这导致了一个错误,因为在光栅化文本之后,我正在抚摸一条路径,该路径(最初调用 cairo_move_to()
来设置文本的当前点)有错误的点。
我在调用 cairo_show_text()
后立即调用 cairo_stroke()
解决了这个错误,它似乎有效,因为它重置了当前点。
似乎调用 cairo_close_path()
而不是 cairo_stroke()
没有帮助。它没有重置当前点。我认为这很奇怪。为什么?
我的最后一个问题是:有没有正确的方法来重置当前点?我觉得应该有。
来自https://www.cairographics.org/manual/cairo-Paths.html#cairo-new-path
cairo_new_path ()
Clears the current path. After this call there will be no path and no current point.
完整性:还有这个函数不清除当前路径:
来自https://www.cairographics.org/manual/cairo-Paths.html#cairo-new-sub-path
cairo_new_sub_path ()
Begin a new sub-path. Note that the existing path is not affected. After this call there will be no current point.
In many cases, this call is not needed since new sub-paths are frequently started with cairo_move_to().
A call to
cairo_new_sub_path()
is particularly useful when beginning a new sub-path with one of thecairo_arc()
calls. This makes things easier as it is no longer necessary to manually compute the arc's initial coordinates for a call tocairo_move_to()
.