[weston,2/4] pixman: make shadow buffer optional

Submitted by Fabien Lahoudere on April 23, 2018, 9:44 a.m.

Details

Message ID 1524476699-10530-3-git-send-email-fabien.lahoudere@collabora.com
State Accepted
Headers show
Series "Optimize pixman renderer" ( rev: 2 ) in Wayland

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Commit Message

Fabien Lahoudere April 23, 2018, 9:44 a.m.
From: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

Add a flag to pixman-renderer for initializing the output with a shadow
framebuffer. All backends were getting the shadow implcitly, so all
backends are modified to ask for the shadow explicitly.

Using a shadow buffer is usually beneficial, because read-modify-write
cycles (blending) into a scanout-capable buffer may be very slow. The
scanout framebuffer may also have reduced color depth, making blending
and read-back produce inferior results.

In some use cases though the shadow buffer might be just an extra copy
hurting more than it helps. Whether it helps or hurts depends on the
platform and the workload. Therefore let the backends control whether
pixman-renderer uses a shadow buffer for an output or not.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Signed-off-by: Fabien Lahoudere <fabien.lahoudere@collabora.com>
---
 libweston/compositor-drm.c      |  3 +-
 libweston/compositor-fbdev.c    |  3 +-
 libweston/compositor-headless.c |  3 +-
 libweston/compositor-rdp.c      |  5 +--
 libweston/compositor-wayland.c  |  3 +-
 libweston/compositor-x11.c      |  6 ++--
 libweston/pixman-renderer.c     | 68 ++++++++++++++++++++++++-----------------
 libweston/pixman-renderer.h     |  6 +++-
 8 files changed, 60 insertions(+), 37 deletions(-)

Patch hide | download patch | download mbox

diff --git a/libweston/compositor-drm.c b/libweston/compositor-drm.c
index fa650c3..ce33905 100644
--- a/libweston/compositor-drm.c
+++ b/libweston/compositor-drm.c
@@ -4151,7 +4151,8 @@  drm_output_init_pixman(struct drm_output *output, struct drm_backend *b)
 			goto err;
 	}
 
-	if (pixman_renderer_output_create(&output->base) < 0)
+	if (pixman_renderer_output_create(&output->base,
+					  PIXMAN_RENDERER_OUTPUT_USE_SHADOW) < 0)
 		goto err;
 
 	pixman_region32_init_rect(&output->previous_damage,
diff --git a/libweston/compositor-fbdev.c b/libweston/compositor-fbdev.c
index de40c21..a78f6fa 100644
--- a/libweston/compositor-fbdev.c
+++ b/libweston/compositor-fbdev.c
@@ -511,7 +511,8 @@  fbdev_output_enable(struct weston_output *base)
 	output->base.start_repaint_loop = fbdev_output_start_repaint_loop;
 	output->base.repaint = fbdev_output_repaint;
 
-	if (pixman_renderer_output_create(&output->base) < 0)
+	if (pixman_renderer_output_create(&output->base,
+					PIXMAN_RENDERER_OUTPUT_USE_SHADOW) < 0)
 		goto out_hw_surface;
 
 	loop = wl_display_get_event_loop(backend->compositor->wl_display);
diff --git a/libweston/compositor-headless.c b/libweston/compositor-headless.c
index 6cb4f20..61a5bd9 100644
--- a/libweston/compositor-headless.c
+++ b/libweston/compositor-headless.c
@@ -172,7 +172,8 @@  headless_output_enable(struct weston_output *base)
 							 output->image_buf,
 							 output->base.current_mode->width * 4);
 
-		if (pixman_renderer_output_create(&output->base) < 0)
+		if (pixman_renderer_output_create(&output->base,
+					PIXMAN_RENDERER_OUTPUT_USE_SHADOW) < 0)
 			goto err_renderer;
 
 		pixman_renderer_output_set_buffer(&output->base,
diff --git a/libweston/compositor-rdp.c b/libweston/compositor-rdp.c
index 693f136..fd0651a 100644
--- a/libweston/compositor-rdp.c
+++ b/libweston/compositor-rdp.c
@@ -460,7 +460,7 @@  rdp_switch_mode(struct weston_output *output, struct weston_mode *target_mode)
 	output->current_mode->flags |= WL_OUTPUT_MODE_CURRENT;
 
 	pixman_renderer_output_destroy(output);
-	pixman_renderer_output_create(output);
+	pixman_renderer_output_create(output, PIXMAN_RENDERER_OUTPUT_USE_SHADOW);
 
 	new_shadow_buffer = pixman_image_create_bits(PIXMAN_x8r8g8b8, target_mode->width,
 			target_mode->height, 0, target_mode->width * 4);
@@ -546,7 +546,8 @@  rdp_output_enable(struct weston_output *base)
 		return -1;
 	}
 
-	if (pixman_renderer_output_create(&output->base) < 0) {
+	if (pixman_renderer_output_create(&output->base,
+					  PIXMAN_RENDERER_OUTPUT_USE_SHADOW) < 0) {
 		pixman_image_unref(output->shadow_surface);
 		return -1;
 	}
diff --git a/libweston/compositor-wayland.c b/libweston/compositor-wayland.c
index 2473f08..56ed474 100644
--- a/libweston/compositor-wayland.c
+++ b/libweston/compositor-wayland.c
@@ -782,7 +782,8 @@  cleanup_window:
 static int
 wayland_output_init_pixman_renderer(struct wayland_output *output)
 {
-	return pixman_renderer_output_create(&output->base);
+	return pixman_renderer_output_create(&output->base,
+				     PIXMAN_RENDERER_OUTPUT_USE_SHADOW);
 }
 
 static void
diff --git a/libweston/compositor-x11.c b/libweston/compositor-x11.c
index 78b0d7c..4a9d068 100644
--- a/libweston/compositor-x11.c
+++ b/libweston/compositor-x11.c
@@ -849,7 +849,8 @@  x11_output_switch_mode(struct weston_output *base, struct weston_mode *mode)
 			return -1;
 		}
 
-		if (pixman_renderer_output_create(&output->base) < 0) {
+		if (pixman_renderer_output_create(&output->base,
+				PIXMAN_RENDERER_OUTPUT_USE_SHADOW) < 0) {
 			weston_log("Failed to create pixman renderer for output\n");
 			x11_output_deinit_shm(b, output);
 			return -1;
@@ -1021,7 +1022,8 @@  x11_output_enable(struct weston_output *base)
 			weston_log("Failed to initialize SHM for the X11 output\n");
 			goto err;
 		}
-		if (pixman_renderer_output_create(&output->base) < 0) {
+		if (pixman_renderer_output_create(&output->base,
+				PIXMAN_RENDERER_OUTPUT_USE_SHADOW) < 0) {
 			weston_log("Failed to create pixman renderer for output\n");
 			x11_output_deinit_shm(b, output);
 			goto err;
diff --git a/libweston/pixman-renderer.c b/libweston/pixman-renderer.c
index cf43b15..1ea275b 100644
--- a/libweston/pixman-renderer.c
+++ b/libweston/pixman-renderer.c
@@ -337,13 +337,19 @@  repaint_region(struct weston_view *ev, struct weston_output *output,
 	struct pixman_surface_state *ps = get_surface_state(ev->surface);
 	struct pixman_output_state *po = get_output_state(output);
 	struct weston_buffer_viewport *vp = &ev->surface->buffer_viewport;
+	pixman_image_t *target_image;
 	pixman_transform_t transform;
 	pixman_filter_t filter;
 	pixman_image_t *mask_image;
 	pixman_color_t mask = { 0, };
 
-	/* Clip rendering to the damaged output region */
-	pixman_image_set_clip_region32(po->shadow_image, repaint_output);
+	if (po->shadow_image)
+		target_image = po->shadow_image;
+	else
+		target_image = po->hw_buffer;
+
+ 	/* Clip rendering to the damaged output region */
+	pixman_image_set_clip_region32(target_image, repaint_output);
 
 	pixman_renderer_compute_transform(&transform, ev, output);
 
@@ -363,11 +369,11 @@  repaint_region(struct weston_view *ev, struct weston_output *output,
 	}
 
 	if (source_clip)
-		composite_clipped(ps->image, mask_image, po->shadow_image,
+		composite_clipped(ps->image, mask_image, target_image,
 				  &transform, filter, source_clip);
 	else
 		composite_whole(pixman_op, ps->image, mask_image,
-				po->shadow_image, &transform, filter);
+				target_image, &transform, filter);
 
 	if (mask_image)
 		pixman_image_unref(mask_image);
@@ -379,14 +385,14 @@  repaint_region(struct weston_view *ev, struct weston_output *output,
 		pixman_image_composite32(PIXMAN_OP_OVER,
 					 pr->debug_color, /* src */
 					 NULL /* mask */,
-					 po->shadow_image, /* dest */
+					 target_image, /* dest */
 					 0, 0, /* src_x, src_y */
 					 0, 0, /* mask_x, mask_y */
 					 0, 0, /* dest_x, dest_y */
-					 pixman_image_get_width (po->shadow_image), /* width */
-					 pixman_image_get_height (po->shadow_image) /* height */);
+					 pixman_image_get_width (target_image), /* width */
+					 pixman_image_get_height (target_image) /* height */);
 
-	pixman_image_set_clip_region32 (po->shadow_image, NULL);
+	pixman_image_set_clip_region32(target_image, NULL);
 }
 
 static void
@@ -575,9 +581,12 @@  pixman_renderer_repaint_output(struct weston_output *output,
 		pixman_region32_copy(&hw_damage, output_damage);
 	}
 
-	repaint_surfaces(output, output_damage);
-
-	copy_to_hw_buffer(output, &hw_damage);
+	if (po->shadow_image) {
+		repaint_surfaces(output, output_damage);
+		copy_to_hw_buffer(output, &hw_damage);
+	} else {
+		repaint_surfaces(output, &hw_damage);
+	}
 	pixman_region32_fini(&hw_damage);
 
 	pixman_region32_copy(&output->previous_damage, output_damage);
@@ -902,7 +911,7 @@  pixman_renderer_output_set_hw_extra_damage(struct weston_output *output,
 }
 
 WL_EXPORT int
-pixman_renderer_output_create(struct weston_output *output)
+pixman_renderer_output_create(struct weston_output *output, uint32_t flags)
 {
 	struct pixman_output_state *po;
 	int w, h;
@@ -911,25 +920,27 @@  pixman_renderer_output_create(struct weston_output *output)
 	if (po == NULL)
 		return -1;
 
-	/* set shadow image transformation */
-	w = output->current_mode->width;
-	h = output->current_mode->height;
+	if (flags & PIXMAN_RENDERER_OUTPUT_USE_SHADOW) {
+		/* set shadow image transformation */
+		w = output->current_mode->width;
+		h = output->current_mode->height;
 
-	po->shadow_buffer = malloc(w * h * 4);
+		po->shadow_buffer = malloc(w * h * 4);
 
-	if (!po->shadow_buffer) {
-		free(po);
-		return -1;
-	}
+		if (!po->shadow_buffer) {
+			free(po);
+			return -1;
+		}
 
-	po->shadow_image =
-		pixman_image_create_bits(PIXMAN_x8r8g8b8, w, h,
-					 po->shadow_buffer, w * 4);
+		po->shadow_image =
+			pixman_image_create_bits(PIXMAN_x8r8g8b8, w, h,
+						 po->shadow_buffer, w * 4);
 
-	if (!po->shadow_image) {
-		free(po->shadow_buffer);
-		free(po);
-		return -1;
+		if (!po->shadow_image) {
+			free(po->shadow_buffer);
+			free(po);
+			return -1;
+		}
 	}
 
 	output->renderer_state = po;
@@ -942,7 +953,8 @@  pixman_renderer_output_destroy(struct weston_output *output)
 {
 	struct pixman_output_state *po = get_output_state(output);
 
-	pixman_image_unref(po->shadow_image);
+	if (po->shadow_image)
+		pixman_image_unref(po->shadow_image);
 
 	if (po->hw_buffer)
 		pixman_image_unref(po->hw_buffer);
diff --git a/libweston/pixman-renderer.h b/libweston/pixman-renderer.h
index f19e147..7a5f729 100644
--- a/libweston/pixman-renderer.h
+++ b/libweston/pixman-renderer.h
@@ -30,8 +30,12 @@ 
 int
 pixman_renderer_init(struct weston_compositor *ec);
 
+enum pixman_renderer_output_flags {
+	PIXMAN_RENDERER_OUTPUT_USE_SHADOW = (1 << 0),
+};
+
 int
-pixman_renderer_output_create(struct weston_output *output);
+pixman_renderer_output_create(struct weston_output *output, uint32_t flags);
 
 void
 pixman_renderer_output_set_buffer(struct weston_output *output,