Load instead of Clear in ImGui pass

Author: karnkaul

guide/src/dear_imgui/imgui_integration.md

@@ -46,6 +46,9 @@ We use a separate render pass for Dear ImGui, again for isolation, and to enable
 
 ```cpp
 m_imgui->end_frame();
+// we don't want to clear the image again, instead load it intact after the
+// previous pass.
+color_attachment.setLoadOp(vk::AttachmentLoadOp::eLoad);
 rendering_info.setColorAttachments(color_attachment)
   .setPDepthAttachment(nullptr);
 command_buffer.beginRendering(rendering_info);

src/app.cpp

@@ -244,6 +244,9 @@ void App::render(vk::CommandBuffer const command_buffer) {
 	command_buffer.endRendering();
 
 	m_imgui->end_frame();
+	// we don't want to clear the image again, instead load it intact after the
+	// previous pass.
+	color_attachment.setLoadOp(vk::AttachmentLoadOp::eLoad);
 	rendering_info.setColorAttachments(color_attachment)
 		.setPDepthAttachment(nullptr);
 	command_buffer.beginRendering(rendering_info);