[PATCH v5 5/7] 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 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.

Cc: Gerd Hoffmann <kra...@redhat.com>
Cc: Marc-André Lureau <marcandre.lur...@redhat.com>
Cc: Dmitry Osipenko <dmitry.osipe...@collabora.com>
Cc: Frediano Ziglio <fredd...@gmail.com>
Cc: Dongwon Kim <dongwon....@intel.com>
Co-developed-by: Michael Scherle <michael.sche...@rz.uni-freiburg.de>
Signed-off-by: Vivek Kasireddy <vivek.kasire...@intel.com>
---
 include/ui/console.h |  3 +++
 ui/console-gl.c      | 48 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/include/ui/console.h b/include/ui/console.h
index 46b3128185..98feaa58bd 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -422,6 +422,9 @@ bool console_gl_check_format(DisplayChangeListener *dcl,
                              pixman_format_code_t format);
 void surface_gl_create_texture(QemuGLShader *gls,
                                DisplaySurface *surface);
+bool surface_gl_create_texture_from_fd(DisplaySurface *surface,
+                                       int fd, GLuint *texture,
+                                       GLuint *mem_obj);
 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 103b954017..afb36dba64 100644
--- a/ui/console-gl.c
+++ b/ui/console-gl.c
@@ -25,6 +25,7 @@
  * THE SOFTWARE.
  */
 #include "qemu/osdep.h"
+#include "qemu/error-report.h"
 #include "ui/console.h"
 #include "ui/shader.h"
 
@@ -96,6 +97,53 @@ void surface_gl_create_texture(QemuGLShader *gls,
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 }
 
+bool surface_gl_create_texture_from_fd(DisplaySurface *surface,
+                                       int fd, GLuint *texture,
+                                       GLuint *mem_obj)
+{
+    unsigned long size = surface_stride(surface) * surface_height(surface);
+    GLenum err = glGetError();
+    *texture = 0;
+    *mem_obj = 0;
+
+    if (!epoxy_has_gl_extension("GL_EXT_memory_object") ||
+        !epoxy_has_gl_extension("GL_EXT_memory_object_fd")) {
+        error_report("spice: required OpenGL extensions not supported: "
+                     "GL_EXT_memory_object and GL_EXT_memory_object_fd");
+        return false;
+    }
+
+#ifdef GL_EXT_memory_object_fd
+    glCreateMemoryObjectsEXT(1, mem_obj);
+    glImportMemoryFdEXT(*mem_obj, size, GL_HANDLE_TYPE_OPAQUE_FD_EXT, fd);
+
+    err = glGetError();
+    if (err != GL_NO_ERROR) {
+        error_report("spice: cannot import memory object from fd");
+        goto cleanup_mem;
+    }
+
+    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);
+    err = glGetError();
+    if (err != GL_NO_ERROR) {
+        error_report("spice: cannot create texture from memory object");
+        goto cleanup_tex_and_mem;
+    }
+    return true;
+
+cleanup_tex_and_mem:
+    glDeleteTextures(1, texture);
+cleanup_mem:
+    glDeleteMemoryObjectsEXT(1, mem_obj);
+
+#endif
+    return false;
+}
+
 void surface_gl_update_texture(QemuGLShader *gls,
                                DisplaySurface *surface,
                                int x, int y, int w, int h)
-- 
2.49.0