Private function to tell if we have RENDER extension.

Private function to tell if we have RENDER extension.

Thu Jan  3 22:18:15 2002  Owen Taylor  <otaylor@redhat.com>

	* gdk/x11/gdkdrawable-x11.c gdk/x11/gdkprivate-x11.h
	(_gdk_x11_have_render): Private function to tell if we have RENDER
	extension.

	* gdk/x11/gdkgc-x11.c (_gdk_x11_gc_get_fg_picture): Return
	None if we don't have RENDER extension.

	* gdk/x11/gdkpango-x11.c (gdk_pango_context_get): Don't
	use Xft unless we have render extension.

	* gdk/x11/gdkdrawable-x11.c (gdk_x11_drawable_get_picture):
	Handle missing render extension.

	* gdk/gdkdraw.c gdk/gdkdrawable.h gdk/gdkpixmap.c gdk/gdkwindow.c
	gdk/gdkinternals.h: Add a private copy_to_image() virtual function
	to the GdkDrawable vtable that extends get_image() to allow
	copying onto existing images.  Make the default implementation of
	get_image() use this so that backends don't have to implement
	both. Add private wrapper _gdk_drawable_copy_to_image().

	* gdk/x11/gdkimage-x11.c gdk/x11/gdkprivate-x11.c
	gdk/x11/gdkdrawable-x11.c (_gdk_x11_copy_to_image): Implement
	copy_to_image() semantics, speed up by using ShmPixmaps and
	XCopyArea when possible, XFlush() after ungrabbing the server,
	generally redo the logic once again.

	* gdk/gdkinternals.h gdk/x11/gdkimage-x11.c
	_gdk_windowing_bits_per_depth(): Function to convert from depth to
	bits-per-pixel. (We assume only one bpp per depth - X requires
	this.)

	* gdk/gdkinternals.h gdk/gdkrgb.c gdk/gdkimage.c: Move the GdkRGB
	scratch image code into a generic _gdk_image_get_scratch() chunk
	of code that we can use other places we need scratch images.

	* gdk/gdkimage.c gdk/x11/gdkimage.c gdk/gdkinternals.h:
	Add _gdk_image_new_for_depth() as the backend
	to _gdk_image_new() to allowing creating images with
	a depth and no visual.

	* gdk/gdkpixbuf-drawable.c: Fix so that getting
	parts of images not at 0,0 actually works.

	* gdk/gdkdrawable.h gdk/gdkinternals.h gdk/gdkdraw.c
	gdk/gdkwindow.c gdk/gdkpixmap.c gdk/gdkpixbuf-render.c:
	 - Add a new GdkDrawableClass vfunc _draw_pixbuf, and
	  _gdk_draw_pixbuf() [ will be made public later ], to allow
	  backends to accelerate drawing pixbufs.
	 - Move the implementation of gdk_pixbuf_render_to_drawable_alpha()
	   to be the default implementation.
	 - Update docs for gdk_pixbuf_render_to_drawable_alpha().
	 - Optimize the default implementation by using
	   _gdk_image_copy_to_pixmap() and scratch shared images, and
	   special casing the compositing.

	* gdk/x11/gdkdrawable-x11.c: Accelerate _gdk_draw_pixbuf()
	with alpha using the RENDER extension.

        * gdk/gdkpixbuf-drawable.c (gdk_pixbuf_get_from_drawable):
	Optimize by _gdk_image_copy_to_pixmap() and scratch images.

	* tests/testrgb.c: Add test for speed of alpha composition,
	reduce the number of iterations since alpha composition
	can be a bit slow.

	* gdk/x11/gdkimage-x11.c gdk/gdkprivate-x11.h (_gdk_x11_image_get_shm_pixmap):
	Private function to get a ShmPixmap for an image, if possible.