Measure tools should support rotation constraint

[Alexandre Prokoudine]

Measure tool should be able to use app's rotation constraint so that one could press Ctrl and have perfectly horizontal or vertical measurement line.

[Felipe "Juca" Sanches (felipe-sanches)]

implemented in bzr revision 10320

[su_v (suv-lp)]

With r10320, the measuring of gaps when using a (constrained) horizontal measuring path is wrong (see attachment).
Not reproduced with vertical measure path (constrained to 90°), nor when using an arbitrary angle.

[Alexandre Prokoudine (alexandre-prokoudine)]

@~suv, confirmed

[Felipe "Juca" Sanches (felipe-sanches)]

can you please check whether bzr revision 10328 properly addresses this issue?

[su_v (suv-lp)]

@Juca - it is better now (r10330), but I still see some flakiness when dragging the cursor while keeping 'Ctrl' pressed. In the attached file, measure the filled rectangles + path horizontally, and once you see the expected result (gaps between objects and between their path segments are all equal (100px)), keep 'Ctrl'+dragging the cursor some pixels to the left and right: for me, at some cursor positions, random gaps / intersections are missed, and the labels jump around.

BTW - I discovered a way to keep the measurement labels on-canvas even when switching tools:

1) switch to the measure tool ('M') and measure some objects (click-drag)
2) while the measure tool is active, do not click a second time (i.e. the labels are still visible)
2) press 'Esc', press 'S' (to switch to the select tool)

Result: the measure path and the labels stay on-canvas until the next time the measure tool is used.

[su_v (suv-lp)]

Reopening - measuring at 0° with r10365 still has randomly incorrect intersections/gaps measured and/or wrong label positions, depending on current cursor position while dragging the mouse slightly with 'Ctrl' still pressed. Results can vary depending on measuring across sub-paths of one object or across segments of different objects.

When measuring horizontally from right to left with 'Ctrl' pressed, the angle indicator displays 180.01° (other constrained angles are labeled without rounding/precision errors).

[ScislaC (scislac)]

~suv: Can you still reproduce the rounding/precision errors? It looks to me like this report should be closed since it does support constraints now. However, new bugs should be opened if they don't exist for the jumping labels and such and other issues.

[su_v (suv-lp)]

> When measuring horizontally from right to left with 'Ctrl' pressed, the angle
> indicator displays 180.01° (other constrained angles are labeled without
> rounding/precision errors).

No longer reproduced with current trunk r11533.