X11 mouse cursor alpha blending on OpenGL application broken
Submitted by Steven Noonan
Assigned to Xorg Project Team
Description
Created attachment 76203 Intel HD 4000 showing the issue
I'm encountering a rendering issue with a alpha-blended X11 cursor (created with libxcursor and set with XDefineCursor) on top of an OpenGL application. The application in question is TOME4 (Tales of Maj'Eyal). It uses SDL 2.x to interact with the X11 cursor API and set up an OpenGL rendering context.
I've reproduced this on both a ThinkPad X230 (Ivy Bridge, Intel HD 4000 graphics) and on a Westmere desktop system with a Radeon HD 6850. Both are using open source drivers. I have not however been able to reproduce it on a system with an NVIDIA card using the proprietary NVIDIA driver. I think the common component between the two affected systems is mesa, but I'm not sure what components of the graphics stack could be implicated in this issue.
I have also attempted using mesa from git (728240b64d) as well as the mesa 9.1 release.
I'm attaching photos of the screens on both systems. Screenshots are unable to capture the issue, as the image is rendered correctly there (screenshot also attached for comparison).
Attachment 76203, "Intel HD 4000 showing the issue":
