From dfb1b8d469cfd9c64282690bdf60a4dfe321692b Mon Sep 17 00:00:00 2001
From: Jakob Bornecrantz <jakob@collabora.com>
Date: Mon, 21 Feb 2022 20:31:46 +0000
Subject: [PATCH] c/render: Do not assume nullDescriptor is available

---
 src/xrt/compositor/render/comp_compute.c   | 30 ++++++++----------
 src/xrt/compositor/render/comp_render.h    | 10 ++++++
 src/xrt/compositor/render/comp_resources.c | 37 ++++++++++++++++++++++
 3 files changed, 61 insertions(+), 16 deletions(-)

diff --git a/src/xrt/compositor/render/comp_compute.c b/src/xrt/compositor/render/comp_compute.c
index 5a21f6ae8..fb95083c3 100644
--- a/src/xrt/compositor/render/comp_compute.c
+++ b/src/xrt/compositor/render/comp_compute.c
@@ -618,25 +618,23 @@ comp_rendering_compute_clear(struct comp_rendering_compute *crc,       //
 
 	VkSampler sampler = r->compute.default_sampler;
 	VkSampler src_samplers[2] = {sampler, sampler};
-	VkImageView src_image_views[2] = {VK_NULL_HANDLE, VK_NULL_HANDLE};
+	VkImageView src_image_views[2] = {r->dummy.color.image_view, r->dummy.color.image_view};
 	VkSampler distortion_samplers[6] = {sampler, sampler, sampler, sampler, sampler, sampler};
-	VkImageView distortion_image_views[6] = {VK_NULL_HANDLE, VK_NULL_HANDLE, VK_NULL_HANDLE,
-	                                         VK_NULL_HANDLE, VK_NULL_HANDLE, VK_NULL_HANDLE};
 
 	update_compute_discriptor_set(     //
-	    vk,                            //
-	    r->compute.src_binding,        //
-	    src_samplers,                  //
-	    src_image_views,               //
-	    r->compute.distortion_binding, //
-	    distortion_samplers,           //
-	    distortion_image_views,        //
-	    r->compute.target_binding,     //
-	    target_image_view,             //
-	    r->compute.ubo_binding,        //
-	    r->compute.ubo.buffer,         //
-	    VK_WHOLE_SIZE,                 //
-	    crc->descriptor_set);          //
+	    vk,                            // vk_bundle
+	    r->compute.src_binding,        // src_binding
+	    src_samplers,                  // src_samplers[2]
+	    src_image_views,               // src_image_views[2]
+	    r->compute.distortion_binding, // distortion_binding
+	    distortion_samplers,           // distortion_samplers[6]
+	    r->distortion.image_views,     // distortion_image_views[6]
+	    r->compute.target_binding,     // target_binding
+	    target_image_view,             // target_image_view
+	    r->compute.ubo_binding,        // ubo_binding
+	    r->compute.ubo.buffer,         // ubo_buffer
+	    VK_WHOLE_SIZE,                 // ubo_size
+	    crc->descriptor_set);          // descriptor_set
 
 	vk->vkCmdBindPipeline(              //
 	    crc->cmd,                       // commandBuffer
diff --git a/src/xrt/compositor/render/comp_render.h b/src/xrt/compositor/render/comp_render.h
index e65e303ae..cfefb7c16 100644
--- a/src/xrt/compositor/render/comp_render.h
+++ b/src/xrt/compositor/render/comp_render.h
@@ -238,6 +238,16 @@ struct comp_resources
 		struct comp_buffer ubos[2];
 	} mesh;
 
+	struct
+	{
+		struct
+		{
+			VkImage image;
+			VkImageView image_view;
+			VkDeviceMemory memory;
+		} color;
+	} dummy;
+
 	struct
 	{
 		//! Descriptor pool for compute work.
diff --git a/src/xrt/compositor/render/comp_resources.c b/src/xrt/compositor/render/comp_resources.c
index b3753616b..d544d0a21 100644
--- a/src/xrt/compositor/render/comp_resources.c
+++ b/src/xrt/compositor/render/comp_resources.c
@@ -507,6 +507,40 @@ comp_resources_init(struct comp_resources *r,
 	r->compute.ubo_binding = 3;
 
 
+	/*
+	 * Dummy
+	 */
+
+	{
+		VkFormat format = VK_FORMAT_R8G8B8A8_UNORM;
+		VkImageUsageFlags usage = VK_IMAGE_USAGE_SAMPLED_BIT;
+		VkExtent2D extent = {1, 1};
+
+		VkImageSubresourceRange subresource_range = {
+		    .aspectMask = VK_IMAGE_ASPECT_COLOR_BIT,
+		    .baseMipLevel = 0,
+		    .levelCount = 1,
+		    .baseArrayLayer = 0,
+		    .layerCount = 1,
+		};
+
+		C(vk_create_image_simple(    //
+		    vk,                      // vk_bundle
+		    extent,                  // extent
+		    format,                  // format
+		    usage,                   // usage
+		    &r->dummy.color.memory,  // out_mem
+		    &r->dummy.color.image)); // out_image
+
+		C(vk_create_view(                 //
+		    vk,                           // vk_bundle
+		    r->dummy.color.image,         // image
+		    format,                       // format
+		    subresource_range,            // subresource_range
+		    &r->dummy.color.image_view)); // out_view
+	}
+
+
 	/*
 	 * Shared
 	 */
@@ -687,6 +721,9 @@ comp_resources_close(struct comp_resources *r)
 
 	struct vk_bundle *vk = r->vk;
 
+	D(ImageView, r->dummy.color.image_view);
+	D(Image, r->dummy.color.image);
+	DF(Memory, r->dummy.color.memory);
 	D(DescriptorSetLayout, r->mesh.descriptor_set_layout);
 	D(PipelineLayout, r->mesh.pipeline_layout);
 	D(PipelineCache, r->pipeline_cache);