Fixed eglStream compositing

When creating the eglStream from the fd we also need to create
the texture and call stream_consumer_gltexture. Otherwise
the wayland client can't create the wayland client surface.

Fixed the qwindow-compositor example to use the texture associated
to the QWaylandBufferRef when compositing a EXTERNAL_OES target.

QML compositing only works when QSG_RENDER_LOOP is set to basic
as we need to generate a texture from the gui thread.

As the texture is created by the bufferintegration it might end up
in a different gl context than the quick item using it. The texture
is also deleted together with the buffer, which prevents the use
of the texture afterwards. Both problems need to be fixed in follow
up commits.

Task-number: QTBUG-50850
Change-Id: Ifec67bbe9e4b2a680c871dc4aced37b71b7b6f80
Reviewed-by: Louai Al-Khanji <louai.al-khanji@qt.io>
Reviewed-by: Giulio Camuffo <giulio.camuffo@kdab.com>

2 files changed, 48 insertions, 4 deletions

diff --git a/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.cpp b/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.cpp
index e6b68225b..1c009d342 100644
--- a/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.cpp
+++ b/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.cpp
@@ -117,6 +117,7 @@ struct BufferState
     EGLint egl_format;
     QVarLengthArray<EGLImageKHR, 3> egl_images;
     EGLStreamKHR egl_stream;
+    GLuint eglstream_texture;
 
     bool isYInverted;
     QSize size;
@@ -167,6 +168,7 @@ struct buffer_destroy_listener : wl_listener
 BufferState::BufferState()
     : egl_format(EGL_TEXTURE_RGBA)
     , egl_stream(EGL_NO_STREAM_KHR)
+    , eglstream_texture(0)
     , isYInverted(true)
 {}
 
@@ -269,7 +271,21 @@ void WaylandEglClientBufferIntegrationPrivate::attach_egl_fd_texture(struct ::wl
         return;
     }
 
+    if (!QOpenGLContext::currentContext())
+        qWarning("EglClientBufferIntegration: creating texture with no current context");
+
+    //TODO This texture might end up in a different context than the quick item which wants to use it, this needs to be fixed somehow.
+    glGenTextures(1, &state.eglstream_texture);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_EXTERNAL_OES, state.eglstream_texture);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_EXTERNAL_OES, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
     register_buffer(buffer, state);
+
+    bindBuffer(buffer);
 }
 
 void WaylandEglClientBufferIntegrationPrivate::register_buffer(struct ::wl_resource *buffer, BufferState state)
@@ -301,8 +317,12 @@ void WaylandEglClientBufferIntegrationPrivate::bindBuffer(struct ::wl_resource *
     const BufferState state = buffers.value(buffer);
 
     if (state.egl_stream != EGL_NO_STREAM_KHR) {
-        if (funcs->stream_consumer_gltexture(egl_display, state.egl_stream) != EGL_TRUE)
-            qWarning("%s:%d: eglStreamConsumerGLTextureExternalKHR failed: 0x%x", Q_FUNC_INFO, __LINE__, eglGetError());
+        EGLint stream_state;
+        funcs->query_stream(egl_display, state.egl_stream, EGL_STREAM_STATE_KHR, &stream_state);
+
+        if (stream_state == EGL_STREAM_STATE_CREATED_KHR)
+            if (funcs->stream_consumer_gltexture(egl_display, state.egl_stream) != EGL_TRUE)
+                qWarning("%s:%d: eglStreamConsumerGLTextureExternalKHR failed: 0x%x", Q_FUNC_INFO, __LINE__, eglGetError());
     } else {
         GLint previousTexture = GL_TEXTURE0;
         glGetIntegerv(GL_ACTIVE_TEXTURE, &previousTexture);
@@ -340,6 +360,11 @@ void WaylandEglClientBufferIntegrationPrivate::handle_buffer_destroy(wl_listener
 
     BufferState state = self->buffers.take(buffer);
 
+    /* TODO This texture shouldn't get deleted here as the compositor might want to show an transition. But at the same time we need to make sure
+            that the texture is deleted properly although if the compositor didn't use it (e.g. by creating a quick item)*/
+    if (state.eglstream_texture)
+        glDeleteTextures(1, &state.eglstream_texture);
+
     for (int i = 0; i < state.egl_images.size(); i++)
         self->egl_destroy_image(self->egl_display, state.egl_images[i]);
 
@@ -453,6 +478,17 @@ QWaylandBufferRef::BufferFormatEgl WaylandEglClientBufferIntegration::bufferForm
     return formatFromEglFormat(d->buffers.value(buffer).egl_format);
 }
 
+uint WaylandEglClientBufferIntegration::textureForBuffer(wl_resource *buffer, int plane)
+{
+    Q_UNUSED(plane)
+    Q_D(WaylandEglClientBufferIntegration);
+    if (!buffer)
+        return 0;
+
+    const BufferState state = d->buffers.value(buffer);
+    return state.eglstream_texture;
+}
+
 void WaylandEglClientBufferIntegration::bindTextureToBuffer(struct ::wl_resource *buffer)
 {
     Q_D(WaylandEglClientBufferIntegration);
@@ -475,8 +511,15 @@ void WaylandEglClientBufferIntegration::updateTextureForBuffer(struct ::wl_resou
 
     const BufferState state = d->buffers.value(buffer);
 
-    if (state.egl_stream != EGL_NO_STREAM_KHR)
-        d->funcs->stream_consumer_acquire(d->egl_display, state.egl_stream);
+    if (state.egl_stream != EGL_NO_STREAM_KHR) {
+        EGLint stream_state;
+        d->funcs->query_stream(d->egl_display, state.egl_stream, EGL_STREAM_STATE_KHR, &stream_state);
+
+        if (stream_state == EGL_STREAM_STATE_NEW_FRAME_AVAILABLE_KHR) {
+            if (d->funcs->stream_consumer_acquire(d->egl_display, state.egl_stream) != EGL_TRUE)
+                qWarning("%s:%d: eglStreamConsumerAcquireKHR failed: 0x%x", Q_FUNC_INFO, __LINE__, eglGetError());
+        }
+    }
 }
 
 QWaylandSurface::Origin WaylandEglClientBufferIntegration::origin(struct ::wl_resource *buffer) const
diff --git a/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.h b/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.h
index 57e83717a..74cad708d 100644
--- a/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.h
+++ b/src/hardwareintegration/compositor/wayland-egl/waylandeglclientbufferintegration.h
@@ -54,6 +54,7 @@ public:
 
     void initializeBuffer(struct ::wl_resource *buffer) Q_DECL_OVERRIDE;
     QWaylandBufferRef::BufferFormatEgl bufferFormat(struct ::wl_resource *buffer) Q_DECL_OVERRIDE;
+    uint textureForBuffer(struct ::wl_resource *buffer, int plane) Q_DECL_OVERRIDE;
     void bindTextureToBuffer(struct ::wl_resource *buffer) Q_DECL_OVERRIDE;
     void updateTextureForBuffer(struct ::wl_resource *buffer) Q_DECL_OVERRIDE;