gEDA project

gtk: Thin drawn polygons hide "clearline" lines, arcs, text

Bug #1072500 reported by Robert Fitzsimons on 2012-10-28

This bug affects 2 people

Affects		Status	Importance	Assigned to	Milestone
	gEDA project	Fix Committed	High	Chad Parker
	pcb	Fix Released	Medium	Chad Parker	pcb pcb-4.3.0

Bug Description

With the gtk hid. In the latest git revision, it's also been present for a while.

When the "clearline" attribute is set on a line/arc/text, if it then intersects with a polygon on the same layer, the intersecting part isn't visible in "Thin draw/Thin draw poly" modes.

To reproduce:
- Open pcb.
- Draw a rectangle/polygon.
- Deselect "New lines, arcs clear polygons", in the settings menu.
- Draw a new line which starts outside and then enters and ends in the polygon.
- Select "Thin draw ploy", in the settings menu.

The part of the line that enters the polygon has been clipped, is invisible. Though with a bit of care you can find end point with the mouse cursor.

Tags:

Revision history for this message

Robert Fitzsimons (robfitz273k) wrote on 2012-10-28:

Example pcb file. Edit (31.0 KiB, text/plain)

Revision history for this message

Robert Fitzsimons (robfitz273k) wrote on 2012-10-28:

Possible fix delaying the rendering of polygons. Edit (1.4 KiB, text/plain)

For transparent objects to work in OpenGL the opaque objects need to rendered first.
http://www.opengl.org/archives/resources/faq/technical/transparency.htm#blen0020

Note: This might have an effect on the lesstif hid?

Revision history for this message

Robert Fitzsimons (robfitz273k) wrote on 2012-10-29:

Example pcb file showing problem with polygons. Edit (33.5 KiB, text/plain)

A similar problem also exists with overlapping polygons in the same layer.

Revision history for this message

Robert Fitzsimons (robfitz273k) wrote on 2012-10-29:

Improved fix for rendering of polygons. Edit (4.9 KiB, text/plain)

This patch replaces the previous version. It splits the rendering of polygons into two parts for thin drawn mode, first the polygons contour and then later the transperent filling.

Tested with gtk and lesstif hids.

Traumflug (mah-jump-ing) on 2015-09-27

Changed in geda-project:
importance:	Undecided → High

Bert Timmerman (bert-timmerman) on 2015-12-27

tags:

added: gtk-gui

Bert Timmerman (bert-timmerman) on 2016-02-29

tags:

added: polygons

Chad Parker (parker-charles) on 2021-01-31

Changed in pcb:
status:	New → Confirmed
importance:	Undecided → Medium
milestone:	none → future-bug-fix-release

Revision history for this message

Chad Parker (parker-charles) wrote on 2021-02-07:

Branch LP1072500 implements a fix for this.

It more or less takes the same approach as the original patches, but the code base has diverged somewhat since they were submitted, and have they have bit-rotten.

Changed in pcb:
assignee:	nobody → Chad Parker (parker-charles)

Revision history for this message

Chad Parker (parker-charles) wrote on 2021-02-07:

Please test branch LP1072500 and report back.

It will be merged into master next weekend if I don't hear back from anyone.

Revision history for this message

Chad Parker (parker-charles) wrote on 2021-02-07:

transparency_check.pcb Edit (32.4 KiB, text/plain)

Used for observing polygon transparency in thindraw mode.

Chad Parker (parker-charles) on 2021-02-14

Changed in pcb:
status:	Confirmed → Fix Committed
Changed in geda-project:
status:	New → Fix Committed
assignee:	nobody → Chad Parker (parker-charles)