Add support for EGL, for YUV image formats

EGL support is still incomplete; stuff like scaling is missing.

* 12to11.c (PickVisual, XLMain): Remove function.  Initialize
renderers, and rely on that to initialize the visuals.
* 12to11.man: Document new environment variables.
* Imakefile (SRCS, OBJS): Add picture_renderer.c and renderer.c
and their associated objects.
(GENHEADERS): New variable for generated headers.
(EGL_SRCS, EGL_OBJS): New variables.
(LOCAL_LIBRARIES, SRCS, OBJS, DEFINES): [HaveEglSupport]: Add
EGL defines, libraries, and objects.:(shaders.h): New rule.
(depend, cleandir): Depend on generated headers and SRCs.
$($(OBJS)): Depend on $(GENHEADERS).
* README: Write how to build with EGL support and update content
descriptions.
* buffer.c (XLPictureFromBuffer): Delete function.
(XLRenderBufferFromBuffer): New function.
(XLPixmapFromBuffer): Delete function.
* compositor.h (enum _Operation, struct _SharedMemoryAttributes)
(struct _DmaBufAttributes, union _RenderTarget)
(union _RenderBuffer, struct _RenderFuncs, struct _DrmFormat)
(struct _ShmFormat, struct _BufferFuncs, struct
_ExtBufferFuncs): New structures.
(Fallthrough): New define.  Define to __attribute__
((fallthrough)) wherever supported.  Replace uses of Picture
with RenderBuffer.
* dmabuf.c (struct _DrmFormatInfo): Remove structures.
(struct _BufferParams): Remove link.
(struct _Buffer): Replace pixmap and picture with render buffer
object.
(dri3_opcode, all_formats, pending_success, next_roundtrip_id)
(round_trip_window): Delete.
(ReleaseBufferParams, HandleParamsResourceDestroy, ForceRoundTrip)
(DepthForFormat, XLHandleErrorForDmabuf, PictFormatForFormat)
(DestroyBacking, GetPictureFunc, GetPixmapFunc, GetBufferFunc)
(CreateBufferFor, ModifierHigh, FinishBufferCreation)
(XLHandleOneXEventForDmabuf, CreateHeader, Create, CreateImmed)
(FindFormatMatching, FindSupportedModifiers, FindSupportedFormats)
(SendSupportedFormats, HandleBind, InitDrmDevice, WriteFormatTable)
(ReallyInitDmabuf, ReadSupportedFormats, XLInitDmabuf): Remove
various functions and reimplement as a wrapper around the
renderer abstraction, instead of DRI3.
* fns.c (struct _Busfault): New structure.
(busfault_tree, bus_handler_installed): New variables.
(GetHeight, FixHeights, RotateLeft, RotateRight, RebalanceBusfault)
(RecordBusfault, DetectBusfault, DeleteMin, RemoveBusfault)
(HandleBusfault, MaybeInstallBusHandler, BlockSigbus)
(UnblockSigbus, XLRecordBusfault, XLRemoveBusfaults): New
functions to store non-overlapping regions of mapped memory in
an AVL tree, and to ignore SIGBUS events that trap within.
* icon_surface.c (struct _IconSurface): Replace picture with
rendering target.
(ReleaseBacking, XLGetIconSurface): Use rendering targets
instead of pictures.
* libraries.def: Add defines for EGL.
* run.c (HandleOneXEvent): Replace old dmabuf code with renderer
code.
* seat.c (CursorFromRole, PictureForCursor, ApplyCursor)
(UpdateCursorFromSubcompositor, Subframe, EndSubframe): Rewrite
cursor code to use rendering targets and not pictures.
* shm.c (Buffer, DereferencePool): Remove SIGBUS protection.
(DereferenceBuffer): Reimplement in terms of renderer functions.
(GetPictureFunc): Delete function.
(GetBufferFunc): New function.
(GetPixmapFunc): Delete function.
(PrintBuffer): Remove now-broken implementation.
(DepthForFormat, PictFormatForFormat): Delete functions, as they
are now part of the rendering backend.
(IsFormatSupported): New function.
(CreateBuffer): Reimplement in terms of renderer functions.
(ResizePool): Change SIGBUS protection for resize.
(CreatePool): Protect buffer data from SIGBUS should a client
truncate the file.
(PostFormats): Reimplement in terms of RenderGetShmFormats.
(XLInitShm): Stop initializing MIT-SHM.
* subcompositor.c (IsTargetAttached): New flag and associated
macros.
(struct _View): Remove useless field.
(struct _Subcompositor): Change target to RenderTarget.  Add
fields for prior damage.
(MakeSubcompositor): Initialize new fields.
(SubcompositorSetTarget): Accept RenderTarget, not picture, and
set target attached flag.
(ViewGetTransform): Delete function.
(ViewApplyTransform): New function.
(FillBoxesWithTransparency): Reimplement in terms of renderer
functions.
(StorePreviousDamage): New function.
(SubcompositorUpdate): Reimplement in terms of renderer
functions.  Also, learn to deal with situations where the buffer
reflects the state 1 to 2 swaps ago.
(SubcompositorExpose): Reimplement in terms of renderer
functions.
(SubcompositorFree): Free new fields.
(SubcompositorInit): Remove no longer required initialization of
identity matrix.
* xdata.c (ReceiveBody): Fix coding style.
* xdg_surface.c (struct _XdgRole, ReleaseBacking,
XLGetXdgSurface): Switch from pictures to RenderTargets.
* xerror.c (ErrorHandler): Handle errors for picture renderer
instead of dmabuf.c.

Imakefile

@@ -22,7 +22,8 @@ SRCS = 12to11.c run.c alloc.c fns.c output.c compositor.c       \
   frame_clock.c xerror.c ewmh.c timer.c subsurface.c seat.c     \
   data_device.c xdg_popup.c linux-dmabuf-unstable-v1.c dmabuf.c \
   buffer.c select.c xdata.c xsettings.c dnd.c icon_surface.c    \
-  primary-selection-unstable-v1.c primary_selection.c
+  primary-selection-unstable-v1.c primary_selection.c           \
+  renderer.c picture_renderer.c
 
 OBJS = 12to11.o run.o alloc.o fns.o output.o compositor.o       \
   xdg-shell.o surface.o region.o shm.o atoms.o subcompositor.o  \
@@ -30,7 +31,32 @@ OBJS = 12to11.o run.o alloc.o fns.o output.o compositor.o       \
   frame_clock.o xerror.o ewmh.o timer.o subsurface.o seat.o     \
   data_device.o xdg_popup.o linux-dmabuf-unstable-v1.o dmabuf.o \
   buffer.o select.o xdata.o xsettings.o dnd.o icon_surface.o    \
-  primary-selection-unstable-v1.o primary_selection.o
+  primary-selection-unstable-v1.o primary_selection.o           \
+  renderer.o picture_renderer.o
+
+GENHEADERS = transfer_atoms.h primary-selection-unstable-v1.h \
+  linux-dmabuf-unstable-v1.h xdg-shell.h
+
+#ifdef HaveEglSupport
+
+       EGL_SRCS   = egl.c
+       EGL_OBJS   = egl.o
+LOCAL_LIBRARIES ::= $(LOCAL_LIBRARIES) $(EGL) $(GLES)
+           SRCS ::= $(SRCS) $(EGL_SRCS)
+           OBJS ::= $(OBJS) $(EGL_OBJS)
+        DEFINES ::= $(DEFINES) -DHaveEglSupport
+
+shaders.h: shaders.txt shaders.awk
+	awk -f shaders.awk shaders.txt > $@
+
+depend:: shaders.h
+
+$(EGL_OBJS): shaders.h
+
+cleandir::
+	$(RM) shaders.h
+
+#endif
 
 OPTIMIZE = -O0
 ANALYZE  = -fanalyzer
@@ -68,8 +94,11 @@ transfer_atoms.h: short_types.txt mime0.awk mime1.awk mime2.awk mime3.awk \
 	awk -f mime3.awk short_types.txt >> $@
 	awk -f mime4.awk short_types.txt >> $@
 
-$(OBJS): transfer_atoms.h primary-selection-unstable-v1.h \
-	 linux-dmabuf-unstable-v1.h xdg-shell.h
+$(OBJS): $(GENHEADERS)
+
+/* depend somehow does not depend on SRCS, even though some of OBJS
+   are generated.  */
+depend:: $(GENHEADERS) $(SRCS)
 
 linux-dmabuf-unstable-v1.h: linux-dmabuf-unstable-v1.xml
 	$(WAYLAND_SCANNER) server-header $< $@