[RQt-devel] one-sided glyph?

[Yihui Xie]

I see. Thanks a lot! I just wanted to use it to draw axis tick marks,
because its size is fixed on the screen. It is not a big problem.

Regards,
Yihui
--
Yihui Xie <xieyihui at gmail.com>
Phone: 515-294-2465 Web: http://yihui.name
Department of Statistics, Iowa State University
2215 Snedecor Hall, Ames, IA



On Fri, May 27, 2011 at 3:50 AM, Michael Lawrence
<lawrence.michael at gene.com> wrote:
> QPainterPath unfortunately does not allow "empty space" within its bounding
> rectangle. For now, it's probably best to just get the painter transform and
> figure out the necessary offset in pixels.  If this turns out to be a common
> problem, we could think about glyph anchor points.
>
> Michael
>
> On Thu, May 26, 2011 at 8:09 PM, Yihui Xie <xieyihui at gmail.com> wrote:
>>
>> Hi,
>>
>> Is it possible to create a "one-sided" glyph? For example, a segment
>> glyph that goes from (0, 0) to (1, 0) and when we draw it with
>> qdrawGlyph(..., x, y), (0, 0) in the glyph corresponds to (x, y) in
>> the plot. Currently it seems the glyphs are always centered around (x,
>> y).
>>
>> The example below uses qglyphSegment() in:
>> https://github.com/ggobi/qtpaint/blob/master/R/paintUtils.R#L45
>>
>> library(qtbase)
>> library(qtpaint)
>> s = qscene()
>> r = qlayer(s)
>> r[1, 1] = qlayer(paintFun = function(layer, painter) {
>>    qdrawCircle(painter, .3, .3, r = 2)
>>    qdrawGlyph(painter, qglyphSegment(x = 20, symm = FALSE), .3, .3)
>>    qdrawCircle(painter, .5, .5, r = 2)
>>    qdrawGlyph(painter, qglyphSegment(x = 30, d = pi/2, symm = FALSE), .5,
>> .5)
>> }, limits = qrect(matrix(c(0, 1, 0, 1), 2)))
>> print(qplotView(scene = s))
>>
>>
>> Thanks!
>>
>> Regards,
>> Yihui
>> --
>> Yihui Xie <xieyihui at gmail.com>
>> Phone: 515-294-2465 Web: http://yihui.name
>> Department of Statistics, Iowa State University
>> 2215 Snedecor Hall, Ames, IA
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>