Merge lp:~aacid/qtmir/glyph_workaround_speedup into lp:qtmir

[Albert Astals Cid]

Enable workaround_brokenFBOReadBack on various chipsets

Gives for impressive improvements in QSGDefaultDistanceFieldGlyphCache::storeGlyphs
impressive = 788ms -> 6ms

Copied from qtubuntu

 * Are there any related MPs required for this MP to build/function as expected?
No

 * Did you perform an exploratory manual test run of your code change and any related functionality?
Yes

 * If you changed the packaging (debian), did you subscribe the ubuntu-unity team to this MP?
N/A

[Unity8 CI Bot (unity8-ci-bot)]

PASSED: Continuous integration, rev:487
https://unity8-jenkins.ubuntu.com/job/lp-qtmir-ci/219/
Executed test runs:
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-0-fetch/1644
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/1597
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial+overlay/1597
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=amd64,release=vivid+overlay/1590
        deb: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=amd64,release=vivid+overlay/1590/artifact/output/*zip*/output.zip
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=amd64,release=xenial+overlay/1590
        deb: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=amd64,release=xenial+overlay/1590/artifact/output/*zip*/output.zip
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=armhf,release=vivid+overlay/1590
        deb: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=armhf,release=vivid+overlay/1590/artifact/output/*zip*/output.zip
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=armhf,release=xenial+overlay/1590
        deb: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=armhf,release=xenial+overlay/1590/artifact/output/*zip*/output.zip
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=i386,release=vivid+overlay/1590
        deb: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=i386,release=vivid+overlay/1590/artifact/output/*zip*/output.zip
    SUCCESS: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=i386,release=xenial+overlay/1590
        deb: https://unity8-jenkins.ubuntu.com/job/build-2-binpkg/arch=i386,release=xenial+overlay/1590/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://unity8-jenkins.ubuntu.com/job/lp-qtmir-ci/219/rebuild

review: Approve (continuous-integration)

[Gerry Boland (gerboland)]

LGTM

review: Approve

[lp:~aacid/qtmir/glyph_workaround_speedup]

488. By Albert Astals Cid on 2016-05-25

Make it detect the M10 GPU too (a 720)

Since it also gives 100ms -> 5ms improvements

=== modified file 'src/platforms/mirserver/miropenglcontext.cpp'
--- src/platforms/mirserver/miropenglcontext.cpp	2016-05-06 08:31:13 +0000
+++ src/platforms/mirserver/miropenglcontext.cpp	2016-05-25 13:52:29 +0000
@@ -25,6 +25,7 @@
 #include <QOpenGLFramebufferObject>
 #include <QSurfaceFormat>
 #include <QtPlatformSupport/private/qeglconvenience_p.h>
+#include <QtGui/private/qopenglcontext_p.h>
 
 // Mir
 #include <mir/graphics/display.h>
@@ -118,6 +119,23 @@
     }
 }
 
+static bool needsFBOReadBackWorkaround()
+{
+    static bool set = false;
+    static bool needsWorkaround = false;
+
+    if (!set) {
+        const char *rendererString = reinterpret_cast<const char *>(glGetString(GL_RENDERER));
+        // Keep in sync with qtubuntu
+        needsWorkaround = qstrncmp(rendererString, "Mali-400", 8) == 0
+                          || qstrncmp(rendererString, "Mali-T7", 7) == 0
+                          || qstrncmp(rendererString, "PowerVR Rogue G6200", 19) == 0;
+        set = true;
+    }
+
+    return needsWorkaround;
+}
+
 bool MirOpenGLContext::makeCurrent(QPlatformSurface *surface)
 {
     if (surface->surface()->surfaceClass() == QSurface::Offscreen) {
@@ -142,6 +160,10 @@
         }
 #endif
 
+        QOpenGLContextPrivate *ctx_d = QOpenGLContextPrivate::get(context());
+        if (!ctx_d->workaround_brokenFBOReadBack && needsFBOReadBackWorkaround())
+            ctx_d->workaround_brokenFBOReadBack = true;
+
         return true;
     }