intel: Try using glCopyTexSubImage2D in _mesa_meta_BlitFramebuffer

In the case where glBlitFramebuffer is being used to copy to a texture
without scaling it is faster if we can use the hardware to do a blit
rather than having to do a texture render. In most of the drivers
glCopyTexSubImage2D will use a blit so this patch makes it check for
when glBlitFramebuffer is doing a simple copy and then divert to
glCopyTexSubImage2D.

This was originally proposed as an extension to the common meta-ops.
However, it was rejected as using the BLT is only advantageous for Intel
hardware.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=33934
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mesa/drivers/dri/intel/intel_tex.h b/src/mesa/drivers/dri/intel/intel_tex.h
index 6552ed0d33..52462f39d5 100644
--- a/src/mesa/drivers/dri/intel/intel_tex.h
+++ b/src/mesa/drivers/dri/intel/intel_tex.h
@@ -65,4 +65,12 @@ void intel_tex_unmap_images(struct intel_context *intel,
 
 int intel_compressed_num_bytes(GLuint mesaFormat);
 
+GLboolean intel_copy_texsubimage(struct intel_context *intel,
+                                 GLenum target,
+                                 struct intel_texture_image *intelImage,
+                                 GLenum internalFormat,
+                                 GLint dstx, GLint dsty,
+                                 GLint x, GLint y,
+                                 GLsizei width, GLsizei height);
+
 #endif