Set VkAccelerationStructureGeometryTrianglesDataKHR::maxVertex to be …

…maximum vertex index (KhronosGroup#1097)

VkAccelerationStructureGeometryTrianglesDataKHR::maxVertex is the maximum vertex index in the VkAccelerationStructureGeometryTrianglesDataKHR::vertexData buffer i.e. the spec states "maxVertex is the number of vertices in vertexData minus one".

Currently the maxVertex value in the ray_queries and ray_tracing_extended is being set to the number of vertices, so this patch fixes them.  It's not caused any problems so far as both examples use an index buffer - but it's better to be technically correct!

samples/extensions/ray_queries/ray_queries.cpp

@@ -278,7 +278,7 @@ void RayQueries::create_bottom_level_acceleration_structure()
 		    index_buffer,
 		    transform_matrix_buffer,
 		    static_cast<uint32_t>(model.indices.size()),
-		    static_cast<uint32_t>(model.vertices.size()),
+		    static_cast<uint32_t>(model.vertices.size()) - 1,
 		    sizeof(Vertex),
 		    0, VK_FORMAT_R32G32B32_SFLOAT, VK_GEOMETRY_OPAQUE_BIT_KHR,
 		    get_buffer_device_address(vertex_buffer->get_handle()),

samples/extensions/ray_tracing_extended/ray_tracing_extended.cpp

@@ -385,7 +385,7 @@ void RaytracingExtended::create_bottom_level_acceleration_structure(bool is_upda
 			    model_buffer.is_static ? index_buffer : dynamic_index_buffer,
 			    model_buffer.transform_matrix_buffer,
 			    static_cast<uint32_t>(model_buffer.num_triangles),
-			    static_cast<uint32_t>(model_buffer.num_vertices),
+			    static_cast<uint32_t>(model_buffer.num_vertices) - 1,
 			    sizeof(NewVertex),
 			    0, VK_FORMAT_R32G32B32_SFLOAT, VK_GEOMETRY_OPAQUE_BIT_KHR,
 			    model_buffer.vertex_offset + (model_buffer.is_static ? static_vertex_handle : dynamic_vertex_handle),
@@ -399,7 +399,7 @@ void RaytracingExtended::create_bottom_level_acceleration_structure(bool is_upda
 			    dynamic_index_buffer,
 			    model_buffer.transform_matrix_buffer,
 			    static_cast<uint32_t>(model_buffer.num_triangles),
-			    static_cast<uint32_t>(model_buffer.num_vertices),
+			    static_cast<uint32_t>(model_buffer.num_vertices) - 1,
 			    sizeof(NewVertex),
 			    0, VK_FORMAT_R32G32B32_SFLOAT, VK_GEOMETRY_OPAQUE_BIT_KHR,
 			    model_buffer.vertex_offset + (model_buffer.is_static ? static_vertex_handle : dynamic_vertex_handle),