comp: remove useless pano ubo from mesh distortion

It was left in as a debug measure, but is more confusing than useful,
especially with northstar directly generating a mesh and vive with its own shader.

src/xrt/compositor/main/comp_distortion.c

@@ -234,7 +234,9 @@ comp_distortion_destroy(struct comp_distortion *d)
 	vk->vkDestroyDescriptorSetLayout(vk->device, d->descriptor_set_layout,
 	                                 NULL);
 
-	_buffer_destroy(vk, &d->ubo_handle);
+	if (d->has_fragment_shader_ubo) {
+		_buffer_destroy(vk, &d->ubo_handle);
+	}
 	_buffer_destroy(vk, &d->vbo_handle);
 	_buffer_destroy(vk, &d->index_handle);
 	_buffer_destroy(vk, &d->ubo_viewport_handles[0]);
@@ -512,19 +514,35 @@ comp_distortion_update_descriptor_set(struct comp_distortion *d,
 	    .imageLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL,
 	};
 
-	VkWriteDescriptorSet write_descriptor_sets[3] = {
+	if (d->has_fragment_shader_ubo) {
-	    // Binding 0 : Render texture target
+		VkWriteDescriptorSet write_descriptor_sets[3] = {
-	    comp_distortion_get_image_write_descriptor_set(
+		    // Binding 0 : Render texture target
-	        d->descriptor_sets[eye], &image_info, 0),
+		    comp_distortion_get_image_write_descriptor_set(
-	    // Binding 1 : Fragment shader uniform buffer
+		        d->descriptor_sets[eye], &image_info, 0),
-	    comp_distortion_get_uniform_write_descriptor_set(d, 1, eye),
+		    // Binding 1 : Fragment shader uniform buffer
-	    // Binding 2 : view uniform buffer
+		    comp_distortion_get_uniform_write_descriptor_set(d, 1, eye),
-	    comp_distortion_get_uniform_write_descriptor_set_vp(d, 2, eye),
+		    // Binding 2 : view uniform buffer
-	};
+		    comp_distortion_get_uniform_write_descriptor_set_vp(d, 2,
+		                                                        eye),
+		};
 
-	vk->vkUpdateDescriptorSets(vk->device,
+		vk->vkUpdateDescriptorSets(vk->device,
-	                           ARRAY_SIZE(write_descriptor_sets),
+		                           ARRAY_SIZE(write_descriptor_sets),
-	                           write_descriptor_sets, 0, NULL);
+		                           write_descriptor_sets, 0, NULL);
+	} else {
+		VkWriteDescriptorSet write_descriptor_sets[2] = {
+		    // Binding 0 : Render texture target
+		    comp_distortion_get_image_write_descriptor_set(
+		        d->descriptor_sets[eye], &image_info, 0),
+		    // Binding 2 : view uniform buffer
+		    comp_distortion_get_uniform_write_descriptor_set_vp(d, 2,
+		                                                        eye),
+		};
+
+		vk->vkUpdateDescriptorSets(vk->device,
+		                           ARRAY_SIZE(write_descriptor_sets),
+		                           write_descriptor_sets, 0, NULL);
+	}
 
 	d->ubo_vp_data[eye].flip_y = flip_y;
 	memcpy(d->ubo_viewport_handles[eye].mapped, &d->ubo_vp_data[eye],
@@ -682,8 +700,9 @@ comp_distortion_update_uniform_buffer_warp(struct comp_distortion *d,
 
 		memcpy(d->ubo_handle.mapped, &d->ubo_vive, sizeof(d->ubo_vive));
 		break;
-	case XRT_DISTORTION_MODEL_PANOTOOLS:
 	case XRT_DISTORTION_MODEL_MESHUV:
+		break;
+	case XRT_DISTORTION_MODEL_PANOTOOLS:
 	default:
 		/*
 		 * Pano vision fragment shader
@@ -836,12 +855,15 @@ comp_distortion_init_buffers(struct comp_distortion *d,
 	VkDeviceSize vbo_size = 0;
 	VkDeviceSize index_size = 0;
 
+	// overridden for mesh distortion in switch below
+	d->has_fragment_shader_ubo = true;
+
 	switch (d->distortion_model) {
 	case XRT_DISTORTION_MODEL_PANOTOOLS:
 		ubo_size = sizeof(d->ubo_pano);
 		break;
 	case XRT_DISTORTION_MODEL_MESHUV:
-		ubo_size = sizeof(d->ubo_pano);
+		d->has_fragment_shader_ubo = false;
 		vbo_size = d->mesh.stride * d->mesh.num_vertices;
 		index_size = sizeof(int) * d->mesh.total_num_indices;
 		break;
@@ -855,15 +877,17 @@ comp_distortion_init_buffers(struct comp_distortion *d,
 		break;
 	}
 
-	// fp ubo
+	if (d->has_fragment_shader_ubo) {
-	ret = _create_buffer(vk, ubo_usage_flags, memory_property_flags,
+		// fp ubo
-	                     &d->ubo_handle, ubo_size, NULL);
+		ret = _create_buffer(vk, ubo_usage_flags, memory_property_flags,
-	if (ret != VK_SUCCESS) {
+		                     &d->ubo_handle, ubo_size, NULL);
-		VK_DEBUG(vk, "Failed to create warp ubo buffer!");
+		if (ret != VK_SUCCESS) {
-	}
+			VK_DEBUG(vk, "Failed to create warp ubo buffer!");
-	ret = _buffer_map(vk, &d->ubo_handle, VK_WHOLE_SIZE, 0);
+		}
-	if (ret != VK_SUCCESS) {
+		ret = _buffer_map(vk, &d->ubo_handle, VK_WHOLE_SIZE, 0);
-		VK_DEBUG(vk, "Failed to map warp ubo buffer!");
+		if (ret != VK_SUCCESS) {
+			VK_DEBUG(vk, "Failed to map warp ubo buffer!");
+		}
 	}
 
 	// vp ubo[0]

src/xrt/compositor/main/comp_distortion.h

@@ -54,6 +54,7 @@ struct comp_distortion
 	// Holds all of the needed common Vulkan things.
 	struct vk_bundle *vk;
 
+	bool has_fragment_shader_ubo;
 	struct comp_uniform_buffer ubo_handle;
 	struct comp_uniform_buffer vbo_handle;
 	struct comp_uniform_buffer index_handle;

src/xrt/compositor/shaders/mesh.frag

@@ -11,24 +11,6 @@
 
 layout (binding = 0) uniform sampler2D tex_sampler;
 
-layout (binding = 1, std140) uniform UBO
-{
-	// Distoriton coefficients (PanoTools model) [a,b,c,d]
-	vec4 hmd_warp_param;
-
-	// chromatic distortion post scaling
-	vec4 aberr;
-
-	// Position of lens center in m (usually eye_w/2, eye_h/2)
-	vec2 lens_center[2];
-
-	// Scale from texture co-ords to m (usually eye_w, eye_h)
-	vec2 viewport_scale;
-
-	// Distortion overall scale in m (usually ~eye_w/2)
-	float warp_scale;
-} ubo;
-
 layout (location = 0)  in vec2 in_ruv;
 layout (location = 1)  in vec2 in_guv;
 layout (location = 2)  in vec2 in_buv;