From: Mikko Rasa <tdb@tdb.fi>
Date: Tue, 30 Nov 2021 21:24:04 +0000 (+0200)
Subject: Don't create no-op barriers
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=d3337cbd2ec9fd06682c2cd9f52ff9f014f5f9db

Don't create no-op barriers
---

diff --git a/source/backends/vulkan/synchronizer.cpp b/source/backends/vulkan/synchronizer.cpp
index 7ce7c08a..c2c245a5 100644
--- a/source/backends/vulkan/synchronizer.cpp
+++ b/source/backends/vulkan/synchronizer.cpp
@@ -80,6 +80,9 @@ void Synchronizer::barrier(VkCommandBuffer command_buffer)
 	buffer_barriers.reserve(buffer_accesses.size());
 	for(BufferAccess &b: buffer_accesses)
 	{
+		if(b.pending_write==b.was_written)
+			continue;
+
 		buffer_barriers.emplace_back(VkBufferMemoryBarrier{ });
 		VkBufferMemoryBarrier &barrier = buffer_barriers.back();
 
@@ -105,6 +108,9 @@ void Synchronizer::barrier(VkCommandBuffer command_buffer)
 	image_barriers.reserve(image_accesses.size());
 	for(const ImageAccess &i: image_accesses)
 	{
+		if(i.pending_layout==i.current_layout)
+			continue;
+
 		image_barriers.emplace_back(VkImageMemoryBarrier{ });
 		VkImageMemoryBarrier &barrier = image_barriers.back();
 
@@ -135,6 +141,9 @@ void Synchronizer::barrier(VkCommandBuffer command_buffer)
 		dst_stage |= (is_write_layout(i.pending_layout) ? image_write_stages : image_read_stages);
 	}
 
+	if(buffer_barriers.empty() && image_barriers.empty())
+		return;
+
 	if(!src_stage)
 		src_stage = VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT;
 	if(!dst_stage)