Merge lp:~albaguirre/mir/add-mirroring-support into lp:mir

[Alberto Aguirre]

Add support for vertical/horizontal mirroring.

Will be useful to screencasting clients on android platforms, where a screencast buffers can be read directly by the client; currently android-platform screencasting clients have to read bottom-up to unflip rendering.

[Mir CI Bot (mir-ci-bot)]

FAILED: Continuous integration, rev:3423
https://mir-jenkins.ubuntu.com/job/mir-ci/676/
Executed test runs:
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-mir/628/console
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/665
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/657
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/657
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/638
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/638/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/638
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/638/artifact/output/*zip*/output.zip
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/638/console
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/638/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/638
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/638/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/638
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/638/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/676/rebuild

review: Needs Fixing (continuous-integration)

[Mir CI Bot (mir-ci-bot)]

FAILED: Continuous integration, rev:3423
https://mir-jenkins.ubuntu.com/job/mir-ci/678/
Executed test runs:
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-mir/630/console
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/667
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/659
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/659
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/640
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/640/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/640
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/640/artifact/output/*zip*/output.zip
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/640/console
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/640/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/640
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/640/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/640
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/640/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/678/rebuild

review: Needs Fixing (continuous-integration)

[Alberto Aguirre (albaguirre)]

"01:32:26 Slave went offline during the build
01:32:26 ERROR: Connection was broken: java.io.EOFException
01:32:26 at org.jenkinsci.remoting.nio.NioChannelHub$3.run(NioChannelHub.java:613)
01:32:26 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
01:32:26 at java.util.concurrent.FutureTask.run(FutureTask.java:262)
01:32:26 at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:112)
01:32:26 at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
01:32:26 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
01:32:26 at java.util.concurrent.FutureTask.run(FutureTask.java:262)
01:32:26 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
01:32:26 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
01:32:26 at java.lang.Thread.run(Thread.java:745)"

Umm what's going on with the devices?

[Mir CI Bot (mir-ci-bot)]

PASSED: Continuous integration, rev:3423
https://mir-jenkins.ubuntu.com/job/mir-ci/680/
Executed test runs:
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-mir/632
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/669
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/661
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/661
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/642
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/642/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/642
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/642/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/642
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/642/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/642
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/642/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/642
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/642/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/680/rebuild

review: Approve (continuous-integration)

[Cemil Azizoglu (cemil-azizoglu)]

Ok.

Nit:

s/appplied/applied
83 + // Mirroring should be appplied after orientation

review: Approve

[Brandon Schaefer (brandontschaefer)]

+#include <iostream> :)

Also the set_rotation is public, even though the comment state it *shouldnt* be used else where. We are sure this doesnt break ABI for some random reason u8 is using it?

[Alberto Aguirre (albaguirre)]

The headers for the renderer are not published. But in any case the server ABI has been bumped already.

"+#include <iostream> :)"

Fixed :)

[Brandon Schaefer (brandontschaefer)]

LGTM

review: Approve

[Mir CI Bot (mir-ci-bot)]

PASSED: Continuous integration, rev:3425
https://mir-jenkins.ubuntu.com/job/mir-ci/693/
Executed test runs:
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-mir/648
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/685
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/677
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/677
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/658
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/658/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/658
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/658/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/658
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/658/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/658
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/658/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/658
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/658/artifact/output/*zip*/output.zip

Click here to trigger a rebuild:
https://mir-jenkins.ubuntu.com/job/mir-ci/693/rebuild

review: Approve (continuous-integration)

[Mir CI Bot (mir-ci-bot)]

FAILED: Autolanding.
More details in the following jenkins job:
https://mir-jenkins.ubuntu.com/job/mir-autolanding/147/
Executed test runs:
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-mir/651/console
    None: https://mir-jenkins.ubuntu.com/job/generic-land-mp/159/console
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-0-fetch/688
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=vivid+overlay/680
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-1-sourcepkg/release=xenial/680
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/661
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=clang,platform=mesa,release=vivid+overlay/661/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/661
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=amd64,compiler=gcc,platform=mesa,release=xenial/661/artifact/output/*zip*/output.zip
    FAILURE: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/661/console
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=cross-armhf,compiler=gcc,platform=android,release=vivid+overlay/661/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/661
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=android,release=vivid+overlay/661/artifact/output/*zip*/output.zip
    SUCCESS: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/661
        deb: https://mir-jenkins.ubuntu.com/job/build-2-binpkg-mir/arch=i386,compiler=gcc,platform=mesa,release=xenial/661/artifact/output/*zip*/output.zip

review: Needs Fixing (continuous-integration)

[Mir CI Bot (mir-ci-bot)]

review: Approve (continuous-integration)

=== modified file 'include/common/mir_toolkit/common.h'
--- include/common/mir_toolkit/common.h	2016-01-29 08:18:22 +0000
+++ include/common/mir_toolkit/common.h	2016-03-29 17:48:29 +0000
@@ -169,6 +169,14 @@
     mir_orientation_right = 270
 } MirOrientation;
 
+/** Mirroring axis relative to the "natural" orientation of the display */
+typedef enum MirMirrorMode
+{
+    mir_mirror_mode_none,
+    mir_mirror_mode_vertical,
+    mir_mirror_mode_horizontal
+} MirMirrorMode;
+
 typedef enum MirOrientationMode
 {
     mir_orientation_mode_portrait = 1 << 0,

=== modified file 'include/platform/mir/graphics/display_buffer.h'
--- include/platform/mir/graphics/display_buffer.h	2016-01-29 08:18:22 +0000
+++ include/platform/mir/graphics/display_buffer.h	2016-03-29 17:48:29 +0000
@@ -79,6 +79,17 @@
      */
     virtual MirOrientation orientation() const = 0;
 
+    /** Returns the mirror mode of the display buffer relative to orientation
+     *
+     *  If your DisplayBuffer can do the mirroring itself then this will
+     *  always return mir_mirror_mode_none. If the DisplayBuffer does not
+     *  implement the mirroring itself then this function will return the
+     *  mirror mode the renderer must do after rotation to make things
+     *  "look right".
+     *
+     */
+    virtual MirMirrorMode mirror_mode() const = 0;
+
     /** Returns a pointer to the native display buffer object backing this
      *  display buffer.
      *

=== modified file 'include/test/mir/test/doubles/null_display_buffer.h'
--- include/test/mir/test/doubles/null_display_buffer.h	2016-01-29 08:18:22 +0000
+++ include/test/mir/test/doubles/null_display_buffer.h	2016-03-29 17:48:29 +0000
@@ -34,6 +34,7 @@
     geometry::Rectangle view_area() const override { return geometry::Rectangle(); }
     bool post_renderables_if_optimizable(graphics::RenderableList const&) override { return false; }
     MirOrientation orientation() const override { return mir_orientation_normal; }
+    MirMirrorMode mirror_mode() const override { return mir_mirror_mode_none; }
     NativeDisplayBuffer* native_display_buffer() override { return this; }
 };
 

=== modified file 'playground/demo-shell/demo_compositor.cpp'
--- playground/demo-shell/demo_compositor.cpp	2016-01-29 08:18:22 +0000
+++ playground/demo-shell/demo_compositor.cpp	2016-03-29 17:48:29 +0000
@@ -125,7 +125,7 @@
     }
     else
     {
-        renderer.set_rotation(display_buffer.orientation());
+        renderer.set_output_transform(display_buffer.orientation(), display_buffer.mirror_mode());
         renderer.set_viewport(viewport);
         renderer.begin(std::move(decorated));
         renderer.render(renderable_list);

=== modified file 'src/include/server/mir/compositor/renderer.h'
--- src/include/server/mir/compositor/renderer.h	2015-02-22 07:46:25 +0000
+++ src/include/server/mir/compositor/renderer.h	2016-03-29 17:48:29 +0000
@@ -21,6 +21,7 @@
 
 #include "mir/geometry/rectangle.h"
 #include "mir/graphics/renderable.h"
+#include <mir_toolkit/common.h>
 
 namespace mir
 {
@@ -35,7 +36,8 @@
     virtual ~Renderer() = default;
 
     virtual void set_viewport(geometry::Rectangle const& rect) = 0;
-    virtual void set_rotation(float degrees) = 0;
+    // Mirroring is to be applied after orientation
+    virtual void set_output_transform(MirOrientation orientation, MirMirrorMode mode) = 0;
     virtual void render(graphics::RenderableList const&) const = 0;
     virtual void suspend() = 0; // called when render() is skipped
 

=== modified file 'src/platforms/android/server/display_buffer.cpp'
--- src/platforms/android/server/display_buffer.cpp	2016-03-23 06:39:56 +0000
+++ src/platforms/android/server/display_buffer.cpp	2016-03-29 17:48:29 +0000
@@ -114,6 +114,11 @@
     return orientation_;
 }
 
+MirMirrorMode mga::DisplayBuffer::mirror_mode() const
+{
+    return mir_mirror_mode_none;
+}
+
 void mga::DisplayBuffer::configure(MirPowerMode power_mode, MirOrientation orientation, geom::Displacement offset)
 {
     power_mode_ = power_mode;

=== modified file 'src/platforms/android/server/display_buffer.h'
--- src/platforms/android/server/display_buffer.h	2016-01-29 08:18:22 +0000
+++ src/platforms/android/server/display_buffer.h	2016-03-29 17:48:29 +0000
@@ -66,6 +66,7 @@
     bool post_renderables_if_optimizable(RenderableList const& renderlist) override;
 
     MirOrientation orientation() const override;
+    MirMirrorMode mirror_mode() const override;
     NativeDisplayBuffer* native_display_buffer() override;
 
     void configure(MirPowerMode power_mode, MirOrientation orientation, geometry::Displacement) override;

=== modified file 'src/platforms/mesa/server/kms/display_buffer.cpp'
--- src/platforms/mesa/server/kms/display_buffer.cpp	2016-01-29 08:18:22 +0000
+++ src/platforms/mesa/server/kms/display_buffer.cpp	2016-03-29 17:48:29 +0000
@@ -186,6 +186,11 @@
     return rotation;
 }
 
+MirMirrorMode mgm::DisplayBuffer::mirror_mode() const
+{
+    return mir_mirror_mode_none;
+}
+
 void mgm::DisplayBuffer::set_orientation(MirOrientation const rot, geometry::Rectangle const& a)
 {
     rotation = rot;

=== modified file 'src/platforms/mesa/server/kms/display_buffer.h'
--- src/platforms/mesa/server/kms/display_buffer.h	2016-01-29 08:18:22 +0000
+++ src/platforms/mesa/server/kms/display_buffer.h	2016-03-29 17:48:29 +0000
@@ -74,6 +74,7 @@
     std::chrono::milliseconds recommended_sleep() const override;
 
     MirOrientation orientation() const override;
+    MirMirrorMode mirror_mode() const override;
     NativeDisplayBuffer* native_display_buffer() override;
 
     void set_orientation(MirOrientation const rot, geometry::Rectangle const& a);

=== modified file 'src/platforms/mesa/server/x11/graphics/display_buffer.cpp'
--- src/platforms/mesa/server/x11/graphics/display_buffer.cpp	2016-01-29 08:18:22 +0000
+++ src/platforms/mesa/server/x11/graphics/display_buffer.cpp	2016-03-29 17:48:29 +0000
@@ -72,6 +72,11 @@
     return orientation_;
 }
 
+MirMirrorMode mgx::DisplayBuffer::mirror_mode() const
+{
+    return mir_mirror_mode_none;
+}
+
 void mgx::DisplayBuffer::set_orientation(MirOrientation const new_orientation)
 {
     orientation_ = new_orientation;

=== modified file 'src/platforms/mesa/server/x11/graphics/display_buffer.h'
--- src/platforms/mesa/server/x11/graphics/display_buffer.h	2016-01-29 08:18:22 +0000
+++ src/platforms/mesa/server/x11/graphics/display_buffer.h	2016-03-29 17:48:29 +0000
@@ -53,6 +53,7 @@
     void set_orientation(MirOrientation const new_orientation);
 
     MirOrientation orientation() const override;
+    MirMirrorMode mirror_mode() const override;
     NativeDisplayBuffer* native_display_buffer() override;
 
 private:

=== modified file 'src/renderers/gl/renderer.cpp'
--- src/renderers/gl/renderer.cpp	2016-01-29 08:18:22 +0000
+++ src/renderers/gl/renderer.cpp	2016-03-29 17:48:29 +0000
@@ -43,6 +43,40 @@
 namespace mrg = mir::renderer::gl;
 namespace geom = mir::geometry;
 
+namespace
+{
+float cos_for(MirOrientation orientation)
+{
+    switch(orientation)
+    {
+    case mir_orientation_normal:
+        return 1.0f;
+    case mir_orientation_inverted:
+        return -1.0f;
+    case mir_orientation_left:
+    case mir_orientation_right:
+        return 0.0f;
+    default:
+        BOOST_THROW_EXCEPTION(std::logic_error("Invalid orientation"));
+    }
+}
+
+float sine_for(MirOrientation orientation)
+{
+    switch(orientation)
+    {
+    case mir_orientation_left:
+        return 1.0f;
+    case mir_orientation_right:
+        return -1.0f;
+    case mir_orientation_normal:
+    case mir_orientation_inverted:
+        return 0.0f;
+    default:
+        BOOST_THROW_EXCEPTION(std::logic_error("Invalid orientation"));
+    }
+}
+}
 mrg::CurrentRenderTarget::CurrentRenderTarget(mg::DisplayBuffer* display_buffer)
     : render_target{
         dynamic_cast<renderer::gl::RenderTarget*>(display_buffer->native_display_buffer())}
@@ -126,7 +160,8 @@
       default_program(family.add_program(vshader, default_fshader)),
       alpha_program(family.add_program(vshader, alpha_fshader)),
       texture_cache(mgl::DefaultProgramFactory().create_texture_cache()),
-      rotation(NAN) // ensure the first set_rotation succeeds
+      orientation(mir_orientation_normal),
+      mirror_mode(mir_mirror_mode_none)
 {
     EGLDisplay disp = eglGetCurrentDisplay();
     if (disp != EGL_NO_DISPLAY)
@@ -177,7 +212,6 @@
     glBindBuffer(GL_ARRAY_BUFFER, 0);
 
     set_viewport(display_buffer.view_area());
-    set_rotation(0.0f);
 }
 
 mrg::Renderer::~Renderer()
@@ -218,7 +252,7 @@
         prog.last_used_frameno = frameno;
         glUniform1i(prog.tex_uniform, 0);
         glUniformMatrix4fv(prog.display_transform_uniform, 1, GL_FALSE,
-                           glm::value_ptr(screen_rotation));
+                           glm::value_ptr(display_transform));
         glUniformMatrix4fv(prog.screen_to_gl_coords_uniform, 1, GL_FALSE,
                            glm::value_ptr(screen_to_gl_coords));
     }
@@ -356,27 +390,28 @@
     viewport = rect;
 }
 
-void mrg::Renderer::set_rotation(float degrees)
+void mrg::Renderer::set_output_transform(MirOrientation new_orientation, MirMirrorMode new_mirror_mode)
 {
-    if (degrees == rotation)
+    if (new_orientation == orientation && new_mirror_mode == mirror_mode)
         return;
 
-    float rad = degrees * M_PI / 180.0f;
-    GLfloat cos = cosf(rad);
-    GLfloat sin = sinf(rad);
-
-    /*
-     * Transposed rotation matrix. You're reading it as transposed just
-     * because the C language is row-major. OpenGL however will load it as
-     * column-major. This is necessary because glUniformMatrix4fv in ES
-     * does not support the 'transpose' parameter, requiring it be GL_FALSE.
-     */
-    screen_rotation = {cos,  sin,  0.0f, 0.0f,
-                       -sin, cos,  0.0f, 0.0f,
-                       0.0f, 0.0f, 1.0f, 0.0f,
-                       0.0f, 0.0f, 0.0f, 1.0f};
-
-    rotation = degrees;
+    GLfloat const cos = cos_for(new_orientation);
+    GLfloat const sin = sine_for(new_orientation);
+
+    glm::mat2 rotation_matrix(cos, sin, -sin, cos);
+    glm::mat2 mirror_matrix;
+    if (new_mirror_mode == mir_mirror_mode_horizontal)
+    {
+        mirror_matrix[0][0] = -1.0f;
+    }
+    else if (new_mirror_mode == mir_mirror_mode_vertical)
+    {
+        mirror_matrix[1][1] = -1.0f;
+    }
+
+    display_transform = glm::mat4(mirror_matrix*rotation_matrix);
+    orientation = new_orientation;
+    mirror_mode = new_mirror_mode;
 }
 
 void mrg::Renderer::suspend()

=== modified file 'src/renderers/gl/renderer.h'
--- src/renderers/gl/renderer.h	2016-01-29 08:18:22 +0000
+++ src/renderers/gl/renderer.h	2016-03-29 17:48:29 +0000
@@ -63,7 +63,7 @@
 
     // These are called with a valid GL context:
     void set_viewport(geometry::Rectangle const& rect) override;
-    void set_rotation(float degrees) override;
+    void set_output_transform(MirOrientation orientation, MirMirrorMode mode) override;
     void render(graphics::RenderableList const&) const override;
 
     // This is called _without_ a GL context:
@@ -123,10 +123,11 @@
 
 private:
     std::unique_ptr<mir::gl::TextureCache> const texture_cache;
-    float rotation;
+    MirOrientation orientation;
+    MirMirrorMode mirror_mode;
     geometry::Rectangle viewport;
-    glm::mat4 screen_to_gl_coords, screen_rotation;
-
+    glm::mat4 screen_to_gl_coords;
+    glm::mat4 display_transform;
     std::vector<mir::gl::Primitive> mutable primitives;
 };
 

=== modified file 'src/server/compositor/default_display_buffer_compositor.cpp'
--- src/server/compositor/default_display_buffer_compositor.cpp	2016-03-23 06:39:56 +0000
+++ src/server/compositor/default_display_buffer_compositor.cpp	2016-03-29 17:48:29 +0000
@@ -79,7 +79,7 @@
     }
     else
     {
-        renderer->set_rotation(display_buffer.orientation());
+        renderer->set_output_transform(display_buffer.orientation(), display_buffer.mirror_mode());
         renderer->render(renderable_list);
 
         report->renderables_in_frame(this, renderable_list);

=== modified file 'src/server/compositor/screencast_display_buffer.cpp'
--- src/server/compositor/screencast_display_buffer.cpp	2016-01-29 08:18:22 +0000
+++ src/server/compositor/screencast_display_buffer.cpp	2016-03-29 17:48:29 +0000
@@ -107,6 +107,11 @@
     return mir_orientation_normal;
 }
 
+MirMirrorMode mc::ScreencastDisplayBuffer::mirror_mode() const
+{
+    return mir_mirror_mode_none;
+}
+
 mg::NativeDisplayBuffer* mc::ScreencastDisplayBuffer::native_display_buffer()
 {
     return this;

=== modified file 'src/server/compositor/screencast_display_buffer.h'
--- src/server/compositor/screencast_display_buffer.h	2016-01-29 08:18:22 +0000
+++ src/server/compositor/screencast_display_buffer.h	2016-03-29 17:48:29 +0000
@@ -69,6 +69,8 @@
 
     MirOrientation orientation() const override;
 
+    MirMirrorMode mirror_mode() const override;
+
     NativeDisplayBuffer* native_display_buffer() override;
 
 private:

=== modified file 'src/server/graphics/nested/display_buffer.cpp'
--- src/server/graphics/nested/display_buffer.cpp	2016-01-29 08:18:22 +0000
+++ src/server/graphics/nested/display_buffer.cpp	2016-03-29 17:48:29 +0000
@@ -87,6 +87,11 @@
     return mir_orientation_normal;
 }
 
+MirMirrorMode mgn::detail::DisplayBuffer::mirror_mode() const
+{
+    return mir_mirror_mode_none;
+}
+
 mgn::detail::DisplayBuffer::~DisplayBuffer() noexcept
 {
 }

=== modified file 'src/server/graphics/nested/display_buffer.h'
--- src/server/graphics/nested/display_buffer.h	2016-01-29 08:18:22 +0000
+++ src/server/graphics/nested/display_buffer.h	2016-03-29 17:48:29 +0000
@@ -61,6 +61,7 @@
     void release_current() override;
     void swap_buffers() override;
     MirOrientation orientation() const override;
+    MirMirrorMode mirror_mode() const override;
 
     bool post_renderables_if_optimizable(RenderableList const& renderlist) override;
 

=== modified file 'src/server/graphics/offscreen/display_buffer.cpp'
--- src/server/graphics/offscreen/display_buffer.cpp	2016-01-29 08:18:22 +0000
+++ src/server/graphics/offscreen/display_buffer.cpp	2016-03-29 17:48:29 +0000
@@ -158,6 +158,11 @@
     return mir_orientation_normal;
 }
 
+MirMirrorMode mgo::DisplayBuffer::mirror_mode() const
+{
+    return mir_mirror_mode_none;
+}
+
 mg::NativeDisplayBuffer* mgo::DisplayBuffer::native_display_buffer()
 {
     return this;

=== modified file 'src/server/graphics/offscreen/display_buffer.h'
--- src/server/graphics/offscreen/display_buffer.h	2016-01-29 08:18:22 +0000
+++ src/server/graphics/offscreen/display_buffer.h	2016-03-29 17:48:29 +0000
@@ -71,6 +71,7 @@
     void swap_buffers() override;
 
     MirOrientation orientation() const override;
+    MirMirrorMode mirror_mode() const override;
 
     bool post_renderables_if_optimizable(RenderableList const& renderlist) override; 
 

=== modified file 'src/server/server.cpp'
--- src/server/server.cpp	2016-01-29 08:18:22 +0000
+++ src/server/server.cpp	2016-03-29 17:48:29 +0000
@@ -177,8 +177,7 @@
     }
 
     void set_viewport(mir::geometry::Rectangle const&) override {}
-
-    void set_rotation(float) override {}
+    void set_output_transform(MirOrientation, MirMirrorMode) override {}
 
     void render(mir::graphics::RenderableList const& renderables) const override
     {

=== modified file 'src/server/symbols.map'
--- src/server/symbols.map	2016-03-26 00:19:29 +0000
+++ src/server/symbols.map	2016-03-29 17:48:29 +0000
@@ -642,7 +642,7 @@
     mir::renderer::gl::Renderer::Program::Program*;
     mir::renderer::gl::Renderer::draw*;
     mir::renderer::gl::Renderer::render*;
-    mir::renderer::gl::Renderer::set_rotation*;
+    mir::renderer::gl::Renderer::set_output_transform*;
     mir::renderer::gl::Renderer::set_viewport*;
     mir::renderer::gl::Renderer::suspend*;
     mir::renderer::gl::Renderer::tessellate*;

=== modified file 'tests/include/mir/test/doubles/mock_display_buffer.h'
--- tests/include/mir/test/doubles/mock_display_buffer.h	2016-01-29 08:18:22 +0000
+++ tests/include/mir/test/doubles/mock_display_buffer.h	2016-03-29 17:48:29 +0000
@@ -45,6 +45,7 @@
     MOCK_CONST_METHOD0(view_area, geometry::Rectangle());
     MOCK_METHOD1(post_renderables_if_optimizable, bool(graphics::RenderableList const&));
     MOCK_CONST_METHOD0(orientation, MirOrientation());
+    MOCK_CONST_METHOD0(mirror_mode, MirMirrorMode());
     MOCK_METHOD0(native_display_buffer, graphics::NativeDisplayBuffer*());
 };
 

=== modified file 'tests/include/mir/test/doubles/mock_renderer.h'
--- tests/include/mir/test/doubles/mock_renderer.h	2015-02-22 07:46:25 +0000
+++ tests/include/mir/test/doubles/mock_renderer.h	2016-03-29 17:48:29 +0000
@@ -32,7 +32,7 @@
 struct MockRenderer : public compositor::Renderer
 {
     MOCK_METHOD1(set_viewport, void(geometry::Rectangle const&));
-    MOCK_METHOD1(set_rotation, void(float));
+    MOCK_METHOD2(set_output_transform, void(MirOrientation, MirMirrorMode));
     MOCK_CONST_METHOD1(render, void(graphics::RenderableList const&));
     MOCK_METHOD0(suspend, void());
 

=== modified file 'tests/include/mir/test/doubles/stub_renderer.h'
--- tests/include/mir/test/doubles/stub_renderer.h	2015-06-18 02:46:16 +0000
+++ tests/include/mir/test/doubles/stub_renderer.h	2016-03-29 17:48:29 +0000
@@ -33,13 +33,9 @@
 class StubRenderer : public compositor::Renderer
 {
 public:
-    void set_viewport(geometry::Rectangle const&) override
-    {
-    }
-
-    void set_rotation(float) override
-    {
-    }
+    void set_viewport(geometry::Rectangle const&) override {}
+    void set_output_transform(MirOrientation, MirMirrorMode) override {}
+    void suspend() override {}
 
     void render(graphics::RenderableList const& renderables) const override
     {
@@ -48,10 +44,6 @@
         // Yield to reduce runtime under valgrind
         std::this_thread::yield();
     }
-
-    void suspend() override
-    {
-    }
 };
 
 

=== modified file 'tests/unit-tests/compositor/test_default_display_buffer_compositor.cpp'
--- tests/unit-tests/compositor/test_default_display_buffer_compositor.cpp	2016-01-29 08:18:22 +0000
+++ tests/unit-tests/compositor/test_default_display_buffer_compositor.cpp	2016-03-29 17:48:29 +0000
@@ -100,6 +100,8 @@
         using namespace testing;
         ON_CALL(display_buffer, orientation())
             .WillByDefault(Return(mir_orientation_normal));
+        ON_CALL(display_buffer, mirror_mode())
+            .WillByDefault(Return(mir_mirror_mode_none));
         ON_CALL(display_buffer, view_area())
             .WillByDefault(Return(screen));
         ON_CALL(display_buffer, post_renderables_if_optimizable(_))
@@ -195,9 +197,10 @@
     EXPECT_CALL(mock_renderer, suspend())
         .Times(0);
     EXPECT_CALL(display_buffer, orientation())
-        .InSequence(render_seq)
         .WillOnce(Return(mir_orientation_normal));
-    EXPECT_CALL(mock_renderer, set_rotation(_))
+    EXPECT_CALL(display_buffer, mirror_mode())
+        .WillOnce(Return(mir_mirror_mode_none));
+    EXPECT_CALL(mock_renderer, set_output_transform(mir_orientation_normal, mir_mirror_mode_none))
         .InSequence(render_seq);
     EXPECT_CALL(mock_renderer, render(ContainerEq(mg::RenderableList{big, small})))
         .InSequence(render_seq);
@@ -220,6 +223,8 @@
         .WillByDefault(Return(screen));
     ON_CALL(display_buffer, orientation())
         .WillByDefault(Return(mir_orientation_normal));
+    ON_CALL(display_buffer, mirror_mode())
+            .WillByDefault(Return(mir_mirror_mode_none));
 
     Sequence seq;
     EXPECT_CALL(display_buffer, post_renderables_if_optimizable(_))
@@ -228,7 +233,7 @@
 
     EXPECT_CALL(display_buffer, orientation())
         .InSequence(seq);
-    EXPECT_CALL(mock_renderer, set_rotation(mir_orientation_normal))
+    EXPECT_CALL(mock_renderer, set_output_transform(mir_orientation_normal, mir_mirror_mode_none))
         .InSequence(seq);
     EXPECT_CALL(mock_renderer, render(IsEmpty()))
         .InSequence(seq);
@@ -243,7 +248,7 @@
         .WillOnce(Return(false));
     EXPECT_CALL(display_buffer, orientation())
         .InSequence(seq);
-    EXPECT_CALL(mock_renderer, set_rotation(mir_orientation_normal))
+    EXPECT_CALL(mock_renderer, set_output_transform(mir_orientation_normal, mir_mirror_mode_none))
         .InSequence(seq);
     EXPECT_CALL(mock_renderer, render(IsEmpty()))
         .InSequence(seq);
@@ -267,6 +272,8 @@
         .WillRepeatedly(Return(screen));
     EXPECT_CALL(display_buffer, orientation())
         .WillOnce(Return(mir_orientation_normal));
+    EXPECT_CALL(display_buffer, mirror_mode())
+        .WillOnce(Return(mir_mirror_mode_none));
     EXPECT_CALL(display_buffer, post_renderables_if_optimizable(_))
         .WillRepeatedly(Return(false));
 

=== modified file 'tests/unit-tests/graphics/android/test_display_group.cpp'
--- tests/unit-tests/graphics/android/test_display_group.cpp	2016-01-29 08:18:22 +0000
+++ tests/unit-tests/graphics/android/test_display_group.cpp	2016-03-29 17:48:29 +0000
@@ -37,6 +37,7 @@
     mir::geometry::Rectangle view_area() const override { return {}; }
     bool post_renderables_if_optimizable(mg::RenderableList const&) override { return false; }
     MirOrientation orientation() const override { return mir_orientation_normal; }
+    MirMirrorMode mirror_mode() const override { return mir_mirror_mode_none; }
     mg::NativeDisplayBuffer* native_display_buffer() override { return this; }
     void configure(MirPowerMode, MirOrientation, mir::geometry::Displacement) override {}
     mga::DisplayContents contents() override