Remove the legacy backends

src/common.h

@@ -57,7 +57,6 @@
 #include "config.h"
 #include "list.h"
 #include "region.h"
-#include "render.h"
 #include "statistics.h"
 #include "types.h"
 #include "utils.h"
@@ -183,8 +182,6 @@ typedef struct session {
 	xcb_window_t debug_window;
 	/// Whether the root tile is filled by us.
 	bool root_tile_fill;
-	/// Picture of the root window background.
-	paint_t root_tile_paint;
 	/// The backend data the root pixmap bound to
 	image_handle root_image;
 	/// A region of the size of the screen.
@@ -194,8 +191,6 @@ typedef struct session {
 	xcb_render_picture_t root_picture;
 	/// A Picture acting as the painting target.
 	xcb_render_picture_t tgt_picture;
-	/// Temporary buffer to paint to before sending to display.
-	paint_t tgt_buffer;
 	/// Window ID of the window we register as a symbol.
 	xcb_window_t reg_win;
 #ifdef CONFIG_OPENGL

src/config.c

@@ -811,7 +811,6 @@ char *parse_config(options_t *opt, const char *config_file, bool *shadow_enable,
 	// clang-format off
 	*opt = (struct options){
 	    .backend = BKEND_XRENDER,
-	    .legacy_backends = false,
 	    .glx_no_stencil = false,
 	    .mark_wmwin_focused = false,
 	    .mark_ovredir_focused = false,

src/config.h

@@ -102,8 +102,6 @@ typedef struct options {
 	/// Render to a separate window instead of taking over the screen
 	bool debug_mode;
 	// === General ===
-	/// Use the legacy backends?
-	bool legacy_backends;
 	/// Path to write PID to.
 	char *write_pid_path;
 	/// The backend in use.

src/meson.build

@@ -7,8 +7,8 @@ base_deps = [
 	libev
 ]
 
-srcs = [ files('picom.c', 'win.c', 'c2.c', 'x.c', 'config.c', 'vsync.c', 'utils.c',
-               'diagnostic.c', 'string_utils.c', 'render.c', 'kernel.c', 'log.c',
+srcs = [ files('picom.c', 'win.c', 'c2.c', 'x.c', 'config.c', 'utils.c',
+               'diagnostic.c', 'string_utils.c', 'kernel.c', 'log.c',
                'options.c', 'event.c', 'cache.c', 'atom.c', 'file_watch.c', 'statistics.c',
                'vblank.c') ]
 picom_inc = include_directories('.')
@@ -63,7 +63,6 @@ if get_option('opengl')
 		dependency('epoxy', required: true),
 		dependency('threads', required:true)
 	]
-	srcs += [ 'opengl.c' ]
 endif
 
 if get_option('dbus')