[PATCH v1 6/7] ui/console-gl: Add a helper to create a texture with linear memory layout

[Vivek Kasireddy]

There are cases where we do not want the memory layout of a texture to
be tiled as the component processing the texture memory would not know
how to de-tile either via software or hardware. Therefore, ensuring
that the memory backing the texture has a linear layout is absolutely
necessary in these situations.

Note that, requesting GL implementation to create a texture with
linear memory layout can only be done using memory objects. And, a
memory object can be created by importing a dmabuf fd.

Cc: Gerd Hoffmann <kra...@redhat.com>
Cc: Marc-André Lureau <marcandre.lur...@redhat.com>
Cc: Frediano Ziglio <fredd...@gmail.com>
Cc: Dongwon Kim <dongwon....@intel.com>
Signed-off-by: Vivek Kasireddy <vivek.kasire...@intel.com>
---
 include/ui/console.h |  2 ++
 ui/console-gl.c      | 26 ++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/ui/console.h b/include/ui/console.h
index a4a49ffc64..e53e3ce03e 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -444,6 +444,8 @@ bool console_gl_check_format(DisplayChangeListener *dcl,
                              pixman_format_code_t format);
 void surface_gl_create_texture(QemuGLShader *gls,
                                DisplaySurface *surface);
+void surface_gl_create_texture_from_fd(DisplaySurface *surface,
+                                       int fd, GLuint *texture);
 void surface_gl_update_texture(QemuGLShader *gls,
                                DisplaySurface *surface,
                                int x, int y, int w, int h);
diff --git a/ui/console-gl.c b/ui/console-gl.c
index dee317f42c..2c1b2ae377 100644
--- a/ui/console-gl.c
+++ b/ui/console-gl.c
@@ -102,6 +102,32 @@ void surface_gl_create_texture(QemuGLShader *gls,
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 }
 
+void surface_gl_create_texture_from_fd(DisplaySurface *surface,
+                                       int fd, GLuint *texture)
+{
+    unsigned long size = surface_stride(surface) * surface_height(surface);
+    GLuint mem_obj;
+
+    if (!epoxy_has_gl_extension("GL_EXT_memory_object") ||
+        !epoxy_has_gl_extension("GL_EXT_memory_object_fd")) {
+        return;
+    }
+
+#ifdef GL_EXT_memory_object_fd
+    glCreateMemoryObjectsEXT(1, &mem_obj);
+    glImportMemoryFdEXT(mem_obj, size, GL_HANDLE_TYPE_OPAQUE_FD_EXT, fd);
+    if (!glIsMemoryObjectEXT(mem_obj)) {
+        return;
+    }
+
+    glGenTextures(1, texture);
+    glBindTexture(GL_TEXTURE_2D, *texture);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_TILING_EXT, 
GL_LINEAR_TILING_EXT);
+    glTexStorageMem2DEXT(GL_TEXTURE_2D, 1, GL_RGBA8, surface_width(surface),
+                         surface_height(surface), mem_obj, 0);
+#endif
+}
+
 void surface_gl_update_texture(QemuGLShader *gls,
                                DisplaySurface *surface,
                                int x, int y, int w, int h)
-- 
2.39.2