Merge lp:~smspillaz/unity/unity.fix_1016789 into lp:unity

[Sam Spilsbury]

Scale the generated fbo tex by the screen dimentions as its screen size
and ensure nux sets the reference viewport back to output size.

(LP: #1016789)

== Problem ==
See (LP: #1016789)

Output from the scratch fbo is scaled incorrectly in the multimonitor case when the items in question are above the shell - in this case, by a factor of screen size / output size. And also incorrectly in the blurs too, by the inverse. (built using USE_MODERN_COMPIZ_GL)

== Solution ==
Scale the generated fbo tex by the screen dimentions as its screen size
and ensure nux sets the reference viewport back to output size.

== Test ==
There is ongoing work to get the paint code under unit test (see lp:~smspillaz/unity/unity.less-paint-insanity). Until that's done, duplicating that here would effectively be redundant and as such there are no unit tests.

This work can be verified simply through manual testing the branch and ensuring blur and windows are "normally" scaled.

== Errata ==
When building lp:unity, I noticed that there are tons of very unrelated linker errors generated when turning USE_MODERN_COMPIZ_GL on. For some reason, when replacing those with the appropriate #if 1 / #if 0, they all went away. This needs to be looked into.

[jenkins (martin-mrazik+qa)]

PASSED: Continuous integration, rev:2439
http://s-jenkins:8080/job/unity-ci/5/

review: Approve (continuous-integration)

[Sam Spilsbury (smspillaz)]

review: Abstain

[Daniel van Vugt (vanvugt)]

Why is the first part for the whole screen (all outputs) but the second part for a single output (oGeo)? Looks like one of the chunks might be wrong.

review: Needs Information

[Sam Spilsbury (smspillaz)]

> Why is the first part for the whole screen (all outputs) but the second part
> for a single output (oGeo)? Looks like one of the chunks might be wrong.

The second argument to SetReferenceFramebuffer is the viewport dimentions. The viewport dimentions need to be reset to the size of the output.

[Daniel van Vugt (vanvugt)]

So long as it's not a mistake then all good.

review: Approve

=== modified file 'plugins/unityshell/src/unityshell.cpp'
--- plugins/unityshell/src/unityshell.cpp	2012-06-15 02:03:31 +0000
+++ plugins/unityshell/src/unityshell.cpp	2012-06-23 02:27:19 +0000
@@ -799,7 +799,7 @@
 #else
   nux::ObjectPtr<nux::IOpenGLTexture2D> device_texture =
     nux::GetGraphicsDisplay()->GetGpuDevice()->CreateTexture2DFromID(gScreen->fbo ()->tex ()->name (),
-      output->width(), output->height(), 1, nux::BITFMT_R8G8B8A8);
+      screen->width(), screen->height(), 1, nux::BITFMT_R8G8B8A8);
 #endif
 
   nux::GetGraphicsDisplay()->GetGpuDevice()->backup_texture0_ = device_texture;
@@ -812,7 +812,7 @@
   GLint fboID;
   // Nux renders to the referenceFramebuffer when it's embedded.
   glGetIntegerv(GL_FRAMEBUFFER_BINDING, &fboID);
-  wt->GetWindowCompositor().SetReferenceFramebuffer(fboID, geo);
+  wt->GetWindowCompositor().SetReferenceFramebuffer(fboID, oGeo);
 #endif
 
   nuxPrologue();