Merge branch '69-partikelsystem' into 'develop'

Resolve "Partikelsystem"

Closes #69

See merge request !56

include/vkcv/DrawcallRecording.hpp

@@ -37,11 +37,12 @@ namespace vkcv {
     };
 
     struct DrawcallInfo {
-        inline DrawcallInfo(const Mesh& mesh, const std::vector<DescriptorSetUsage>& descriptorSets)
-            : mesh(mesh), descriptorSets(descriptorSets) {}
+        inline DrawcallInfo(const Mesh& mesh, const std::vector<DescriptorSetUsage>& descriptorSets, const uint32_t instanceCount = 1)
+            : mesh(mesh), descriptorSets(descriptorSets), instanceCount(instanceCount){}
 
         Mesh                            mesh;
         std::vector<DescriptorSetUsage> descriptorSets;
+        uint32_t                        instanceCount;
     };
 
     void recordDrawcall(

include/vkcv/PipelineConfig.hpp

@@ -18,16 +18,21 @@ namespace vkcv {
 	enum class CullMode{ None, Front, Back };
     enum class DepthTest { None, Less, LessEqual, Greater, GreatherEqual, Equal };
 
+    // add more as needed
+    // alternatively we could expose the blend factors directly
+    enum class BlendMode{ None, Additive };
+
     struct PipelineConfig {
-        ShaderProgram                           m_ShaderProgram;
-        uint32_t                                m_Width;
-		uint32_t                                m_Height;
-        PassHandle                              m_PassHandle;
-        VertexLayout                            m_VertexLayout;
-        std::vector<vk::DescriptorSetLayout>    m_DescriptorLayouts;
-        bool                                    m_UseDynamicViewport;
-        bool                                    m_UseConservativeRasterization  = false;
-        PrimitiveTopology                       m_PrimitiveTopology             = PrimitiveTopology::TriangleList;
+        ShaderProgram                         	m_ShaderProgram;
+        uint32_t                              	m_Width;
+		uint32_t                              	m_Height;
+        PassHandle                            	m_PassHandle;
+        VertexLayout                          	m_VertexLayout;
+        std::vector<vk::DescriptorSetLayout>  	m_DescriptorLayouts;
+        bool                                  	m_UseDynamicViewport;
+        bool                                  	m_UseConservativeRasterization 	= false;
+        PrimitiveTopology                     	m_PrimitiveTopology 			= PrimitiveTopology::TriangleList;
+		BlendMode                             	m_blendMode 					= BlendMode::None;
         bool                                    m_EnableDepthClamping           = false;
         Multisampling                           m_multisampling                 = Multisampling::None;
         CullMode                                m_culling                       = CullMode::None;

modules/camera/include/vkcv/camera/Camera.hpp

@@ -75,7 +75,7 @@ namespace vkcv::camera {
          * @brief Gets the current projection of the camera
          * @return The current projection matrix
          */
-        const glm::mat4& getProjection() const;
+        glm::mat4 getProjection() const;
 
         /**
          * @brief Gets the model-view-projection matrix of the camera with y-axis-correction applied

modules/camera/src/vkcv/camera/Camera.cpp

@@ -37,22 +37,22 @@ namespace vkcv::camera {
 		m_view = view;
 	}
 
-    const glm::mat4& Camera::getProjection() const {
-        return m_projection;
+    const glm::mat4 y_correction(
+        1.0f, 0.0f, 0.0f, 0.0f,
+        0.0f, -1.0f, 0.0f, 0.0f,
+        0.0f, 0.0f, 1.0f, 0.0f,
+        0.0f, 0.0f, 0.0f, 1.0f
+    );
+
+    glm::mat4 Camera::getProjection() const {
+        return y_correction * m_projection;
     }
 
     void Camera::setProjection(const glm::mat4& projection) {
-        m_projection =  projection;
+        m_projection = glm::inverse(y_correction) * projection;
     }
 
     glm::mat4 Camera::getMVP() const {
-		const glm::mat4 y_correction (
-				1.0f,  0.0f,  0.0f,  0.0f,
-				0.0f, -1.0f,  0.0f,  0.0f,
-				0.0f,  0.0f,  1.0f,  0.0f,
-				0.0f,  0.0f,  0.0f,  1.0f
-		);
-    	
         return y_correction * m_projection * m_view;
     }
 

projects/CMakeLists.txt

@@ -3,5 +3,6 @@
 add_subdirectory(bloom)
 add_subdirectory(first_triangle)
 add_subdirectory(first_mesh)
+add_subdirectory(particle_simulation)
 add_subdirectory(first_scene)
-add_subdirectory(voxelization)
\ No newline at end of file
+add_subdirectory(voxelization)

projects/cmd_sync_test/src/main.cpp

@@ -175,8 +175,8 @@ int main(int argc, const char** argv) {
 	std::vector<vkcv::DrawcallInfo> shadowDrawcalls;
 	for (const auto& position : instancePositions) {
 		modelMatrices.push_back(glm::translate(glm::mat4(1.f), position));
-		drawcalls.push_back(vkcv::DrawcallInfo(loadedMesh, { descriptorUsage }));
-		shadowDrawcalls.push_back(vkcv::DrawcallInfo(loadedMesh, {}));
+		drawcalls.push_back(vkcv::DrawcallInfo(loadedMesh, { descriptorUsage },1));
+		shadowDrawcalls.push_back(vkcv::DrawcallInfo(loadedMesh, {},1));
 	}
 
 	modelMatrices.back() *= glm::scale(glm::mat4(1.f), glm::vec3(10.f, 1.f, 10.f));

projects/first_mesh/src/main.cpp

@@ -83,6 +83,7 @@ int main(int argc, const char** argv) {
     firstMeshProgram.addShader(vkcv::ShaderStage::FRAGMENT, std::filesystem::path("resources/shaders/frag.spv"));
 	
 	auto& attributes = mesh.vertexGroups[0].vertexBuffer.attributes;
+
 	
 	std::sort(attributes.begin(), attributes.end(), [](const vkcv::asset::VertexAttribute& x, const vkcv::asset::VertexAttribute& y) {
 		return static_cast<uint32_t>(x.type) < static_cast<uint32_t>(y.type);
@@ -149,7 +150,7 @@ int main(int argc, const char** argv) {
 	const vkcv::Mesh renderMesh(vertexBufferBindings, indexBuffer.getVulkanHandle(), mesh.vertexGroups[0].numIndices);
 
 	vkcv::DescriptorSetUsage    descriptorUsage(0, core.getDescriptorSet(descriptorSet).vulkanHandle);
-	vkcv::DrawcallInfo          drawcall(renderMesh, { descriptorUsage });
+	vkcv::DrawcallInfo          drawcall(renderMesh, { descriptorUsage },1);
 
     vkcv::camera::CameraManager cameraManager(window);
     uint32_t camIndex0 = cameraManager.addCamera(vkcv::camera::ControllerType::PILOT);

projects/first_scene/src/main.cpp

@@ -199,7 +199,7 @@ int main(int argc, const char** argv) {
 
         vkcv::DescriptorSetUsage descriptorUsage(0, core.getDescriptorSet(descriptorSets[i]).vulkanHandle);
 
-	    drawcalls.push_back(vkcv::DrawcallInfo(renderMesh, {descriptorUsage}));
+	    drawcalls.push_back(vkcv::DrawcallInfo(renderMesh, {descriptorUsage},1));
 	}
 
 	std::vector<glm::mat4> modelMatrices;

projects/first_triangle/src/main.cpp

@@ -167,7 +167,7 @@ int main(int argc, const char** argv) {
 	vkcv::ImageHandle swapchainImageHandle = vkcv::ImageHandle::createSwapchainImageHandle();
 
 	const vkcv::Mesh renderMesh({}, triangleIndexBuffer.getVulkanHandle(), 3);
-	vkcv::DrawcallInfo drawcall(renderMesh, {});
+	vkcv::DrawcallInfo drawcall(renderMesh, {},1);
 
 	const vkcv::ImageHandle swapchainInput = vkcv::ImageHandle::createSwapchainImageHandle();
 

projects/particle_simulation/.gitignore

+particle_simulation
\ No newline at end of file

projects/particle_simulation/CMakeLists.txt

+cmake_minimum_required(VERSION 3.16)
+project(particle_simulation)
+
+# setting c++ standard for the project
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+# this should fix the execution path to load local files from the project
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR})
+
+# adding source files to the project
+add_executable(particle_simulation 
+		src/main.cpp
+		src/ParticleSystem.hpp 
+		src/ParticleSystem.cpp
+		src/Particle.hpp 
+		src/Particle.cpp
+		src/BloomAndFlares.hpp
+		src/BloomAndFlares.cpp)
+
+# this should fix the execution path to load local files from the project (for MSVC)
+if(MSVC)
+	set_target_properties(particle_simulation PROPERTIES RUNTIME_OUTPUT_DIRECTORY_DEBUG ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
+	set_target_properties(particle_simulation PROPERTIES RUNTIME_OUTPUT_DIRECTORY_RELEASE ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
+
+	# in addition to setting the output directory, the working directory has to be set
+	# by default visual studio sets the working directory to the build directory, when using the debugger
+	set_target_properties(particle_simulation PROPERTIES VS_DEBUGGER_WORKING_DIRECTORY ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
+endif()
+
+# including headers of dependencies and the VkCV framework
+target_include_directories(particle_simulation SYSTEM BEFORE PRIVATE ${vkcv_include} ${vkcv_includes} ${vkcv_testing_include} ${vkcv_camera_include} ${vkcv_shader_compiler_include})
+
+# linking with libraries from all dependencies and the VkCV framework
+target_link_libraries(particle_simulation vkcv vkcv_testing vkcv_camera vkcv_shader_compiler)

projects/particle_simulation/shaders/bloom/composite.comp

+#version 450
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(set=0, binding=0) uniform texture2D                          blurImage;
+layout(set=0, binding=1) uniform texture2D                          lensImage;
+layout(set=0, binding=2) uniform sampler                            linearSampler;
+layout(set=0, binding=3, r11f_g11f_b10f) uniform image2D            colorBuffer;
+
+layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
+
+
+void main()
+{
+    if(any(greaterThanEqual(gl_GlobalInvocationID.xy, imageSize(colorBuffer)))){
+        return;
+    }
+
+    ivec2 pixel_coord   = ivec2(gl_GlobalInvocationID.xy);
+    vec2  pixel_size    = vec2(1.0f) / textureSize(sampler2D(blurImage, linearSampler), 0);
+    vec2  UV            = pixel_coord.xy * pixel_size;
+
+    vec4 composite_color = vec4(0.0f);
+
+    vec3 blur_color   = texture(sampler2D(blurImage, linearSampler), UV).rgb;
+    vec3 lens_color   = texture(sampler2D(lensImage, linearSampler), UV).rgb;
+    vec3 main_color   = imageLoad(colorBuffer, pixel_coord).rgb;
+
+    // composite blur and lens features
+    float bloom_weight = 0.01f;
+    float lens_weight  = 0.f;
+    float main_weight = 1 - (bloom_weight + lens_weight);
+
+    composite_color.rgb = blur_color * bloom_weight +
+                          lens_color * lens_weight  +
+                          main_color * main_weight;
+
+    imageStore(colorBuffer, pixel_coord, composite_color);
+}
\ No newline at end of file

projects/particle_simulation/shaders/bloom/downsample.comp

+#version 450
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(set=0, binding=0) uniform texture2D                          inBlurImage;
+layout(set=0, binding=1) uniform sampler                            inImageSampler;
+layout(set=0, binding=2, r11f_g11f_b10f) uniform writeonly image2D  outBlurImage;
+
+layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
+
+
+void main()
+{
+    if(any(greaterThanEqual(gl_GlobalInvocationID.xy, imageSize(outBlurImage)))){
+        return;
+    }
+
+    ivec2 pixel_coord   = ivec2(gl_GlobalInvocationID.xy);
+    vec2  pixel_size    = vec2(1.0f) / imageSize(outBlurImage);
+    vec2  UV            = pixel_coord.xy * pixel_size;
+    vec2  UV_offset     = UV + 0.5f * pixel_size;
+
+    vec2 color_fetches[13] = {
+        // center neighbourhood (RED)
+        vec2(-1,  1), // LT
+        vec2(-1, -1), // LB
+        vec2( 1, -1), // RB
+        vec2( 1,  1), // RT
+
+        vec2(-2, 2), // LT
+        vec2( 0, 2), // CT
+        vec2( 2, 2), // RT
+
+        vec2(0 ,-2), // LC
+        vec2(0 , 0), // CC
+        vec2(2,  0), // CR
+
+        vec2(-2, -2), // LB
+        vec2(0 , -2), // CB
+        vec2(2 , -2)  // RB
+    };
+
+    float color_weights[13] = {
+        // 0.5f
+        1.f/8.f,
+        1.f/8.f,
+        1.f/8.f,
+        1.f/8.f,
+
+        // 0.125f
+        1.f/32.f,
+        1.f/16.f,
+        1.f/32.f,
+
+        // 0.25f
+        1.f/16.f,
+        1.f/8.f,
+        1.f/16.f,
+
+        // 0.125f
+        1.f/32.f,
+        1.f/16.f,
+        1.f/32.f
+    };
+
+    vec3 sampled_color = vec3(0.0f);
+
+    for(uint i = 0; i < 13; i++)
+    {
+        vec2 color_fetch = UV_offset + color_fetches[i] * pixel_size;
+        vec3 color = texture(sampler2D(inBlurImage, inImageSampler), color_fetch).rgb;
+        color *= color_weights[i];
+        sampled_color += color;
+    }
+
+    imageStore(outBlurImage, pixel_coord, vec4(sampled_color, 1.f));
+}
\ No newline at end of file

projects/particle_simulation/shaders/bloom/lensFlares.comp

+#version 450
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(set=0, binding=0) uniform texture2D                          blurBuffer;
+layout(set=0, binding=1) uniform sampler                            linearSampler;
+layout(set=0, binding=2, r11f_g11f_b10f) uniform image2D            lensBuffer;
+
+layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
+
+vec3 sampleColorChromaticAberration(vec2 _uv)
+{
+    vec2 toCenter = (vec2(0.5) - _uv);
+
+    vec3    colorScales     = vec3(-1, 0, 1);
+    float   aberrationScale = 0.1;
+    vec3 scaleFactors = colorScales * aberrationScale;
+
+    float r = texture(sampler2D(blurBuffer, linearSampler), _uv + toCenter * scaleFactors.r).r;
+    float g = texture(sampler2D(blurBuffer, linearSampler), _uv + toCenter * scaleFactors.g).g;
+    float b = texture(sampler2D(blurBuffer, linearSampler), _uv + toCenter * scaleFactors.b).b;
+    return vec3(r, g, b);
+}
+
+// _uv assumed to be flipped UV coordinates!
+vec3 ghost_vectors(vec2 _uv)
+{
+    vec2 ghost_vec = (vec2(0.5f) - _uv);
+
+    const uint c_ghost_count = 64;
+    const float c_ghost_spacing = length(ghost_vec) / c_ghost_count;
+
+    ghost_vec *= c_ghost_spacing;
+
+    vec3 ret_color = vec3(0.0f);
+
+    for (uint i = 0; i < c_ghost_count; ++i)
+    {
+        // sample scene color
+        vec2 s_uv = fract(_uv + ghost_vec * vec2(i));
+        vec3 s = sampleColorChromaticAberration(s_uv);
+
+        // tint/weight
+        float d = distance(s_uv, vec2(0.5));
+        float weight = 1.0f - smoothstep(0.0f, 0.75f, d);
+        s *= weight;
+
+        ret_color += s;
+    }
+
+    ret_color /= c_ghost_count;
+    return ret_color;
+}
+
+vec3 halo(vec2 _uv)
+{
+    const float c_aspect_ratio = float(imageSize(lensBuffer).x) / float(imageSize(lensBuffer).y);
+    const float c_radius = 0.6f;
+    const float c_halo_thickness = 0.1f;
+
+    vec2 halo_vec = vec2(0.5) - _uv;
+    //halo_vec.x /= c_aspect_ratio;
+    halo_vec = normalize(halo_vec);
+    //halo_vec.x *= c_aspect_ratio;
+
+
+    //vec2 w_uv = (_uv - vec2(0.5, 0.0)) * vec2(c_aspect_ratio, 1.0) + vec2(0.5, 0.0);
+    vec2 w_uv = _uv;
+    float d = distance(w_uv, vec2(0.5)); // distance to center
+
+    float distance_to_halo = abs(d - c_radius);
+
+    float halo_weight = 0.0f;
+    if(abs(d - c_radius) <= c_halo_thickness)
+    {
+        float distance_to_border = c_halo_thickness - distance_to_halo;
+        halo_weight = distance_to_border / c_halo_thickness;
+
+        //halo_weight = clamp((halo_weight / 0.4f), 0.0f, 1.0f);
+        halo_weight = pow(halo_weight, 2.0f);
+
+
+        //halo_weight = 1.0f;
+    }
+
+    return sampleColorChromaticAberration(_uv + halo_vec) * halo_weight;
+}
+
+
+
+void main()
+{
+    if(any(greaterThanEqual(gl_GlobalInvocationID.xy, imageSize(lensBuffer)))){
+        return;
+    }
+
+    ivec2 pixel_coord   = ivec2(gl_GlobalInvocationID.xy);
+    vec2  pixel_size    = vec2(1.0f) / imageSize(lensBuffer);
+    vec2  UV            = pixel_coord.xy * pixel_size;
+
+    vec2 flipped_UV = vec2(1.0f) - UV;
+
+    vec3 color = vec3(0.0f);
+
+    color += ghost_vectors(flipped_UV);
+    color += halo(UV);
+    color  *= 0.5f;
+
+    imageStore(lensBuffer, pixel_coord, vec4(color, 0.0f));
+}
\ No newline at end of file

projects/particle_simulation/shaders/bloom/upsample.comp

+#version 450
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(set=0, binding=0) uniform texture2D                          inUpsampleImage;
+layout(set=0, binding=1) uniform sampler                            inImageSampler;
+layout(set=0, binding=2, r11f_g11f_b10f) uniform image2D  outUpsampleImage;
+
+layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
+
+void main()
+{
+    if(any(greaterThanEqual(gl_GlobalInvocationID.xy, imageSize(outUpsampleImage)))){
+        return;
+    }
+
+
+    ivec2 pixel_coord   = ivec2(gl_GlobalInvocationID.xy);
+    vec2  pixel_size    = vec2(1.0f) / imageSize(outUpsampleImage);
+    vec2  UV            = pixel_coord.xy * pixel_size;
+
+    const float gauss_kernel[3] = {1.f, 2.f, 1.f};
+    const float gauss_weight = 16.f;
+
+    vec3 sampled_color = vec3(0.f);
+
+    for(int i = -1; i <= 1; i++)
+    {
+        for(int j = -1; j <= 1; j++)
+        {
+            vec2 sample_location = UV + vec2(j, i) * pixel_size;
+            vec3 color = texture(sampler2D(inUpsampleImage, inImageSampler), sample_location).rgb;
+            color *= gauss_kernel[j+1];
+            color *= gauss_kernel[i+1];
+            color /= gauss_weight;
+
+            sampled_color += color;
+        }
+    }
+
+    //vec3 prev_color = imageLoad(outUpsampleImage, pixel_coord).rgb;
+    //float bloomRimStrength = 0.75f; // adjust this to change strength of bloom
+    //sampled_color = mix(prev_color, sampled_color, bloomRimStrength);
+
+    imageStore(outUpsampleImage, pixel_coord, vec4(sampled_color, 1.f));
+}
\ No newline at end of file

projects/particle_simulation/shaders/particleShading.inc

+float circleFactor(vec2 triangleCoordinates){
+    // percentage of distance from center to circle edge
+    float p = clamp((0.4 - length(triangleCoordinates)) / 0.4, 0, 1);
+    // remapping for nice falloff
+    return sqrt(p);
+}
\ No newline at end of file

projects/particle_simulation/shaders/shader.vert

+#version 460 core
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(location = 0) in vec3 particle;
+
+struct Particle
+{
+    vec3 position;
+    float lifeTime;
+    vec3 velocity;
+    float padding_2;
+    vec3 reset_velocity;
+    float padding_3;
+};
+
+layout(std430, binding = 2) coherent buffer buffer_inParticle
+{
+    Particle inParticle[];
+};
+
+layout( push_constant ) uniform constants{
+    mat4 view;
+    mat4 projection;
+};
+
+layout(location = 0) out vec2 passTriangleCoordinates;
+layout(location = 1) out vec3 passVelocity;
+layout(location = 2) out float passlifeTime;
+
+void main()
+{
+    int id = gl_InstanceIndex;
+    passVelocity = inParticle[id].velocity;
+    passlifeTime = inParticle[id].lifeTime;
+    // particle position in view space
+    vec4 positionView = view * vec4(inParticle[id].position, 1);
+    // by adding the triangle position in view space the mesh is always camera facing
+    positionView.xyz += particle;
+    // multiply with projection matrix for final position
+	gl_Position = projection * positionView;
+    
+    // 0.01 corresponds to vertex position size in main
+    float normalizationDivider  = 0.012;
+    passTriangleCoordinates     = particle.xy / normalizationDivider;
+}
\ No newline at end of file

projects/particle_simulation/shaders/shader_gravity.comp

+#version 450 core
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(local_size_x = 256) in;
+
+struct Particle
+{
+    vec3 position;
+    float lifeTime;
+    vec3 velocity;
+    float mass;
+    vec3 reset_velocity;
+    float _padding;
+};
+
+layout(std430, binding = 0) coherent buffer buffer_inParticle
+{
+    Particle inParticle[];
+};
+
+layout( push_constant ) uniform constants{
+    float deltaTime;
+    float rand;
+};
+
+const int n = 4;
+vec4 gravityPoint[n] = vec4[n](
+    vec4(-0.8, -0.5,  0.0, 3),
+    vec4(-0.4,  0.5,  0.8, 2),
+    vec4( 0.8,  0.8, -0.3, 4),
+    vec4( 0.5, -0.7, -0.5, 1)
+);
+
+const float G = 6.6743015e-11;
+const float sim_d_factor = 10e11;
+const float sim_g_factor = 10e30;
+const float sim_t_factor = 5;
+const float c = 299792458;
+
+void main() {
+    uint id = gl_GlobalInvocationID.x;
+    inParticle[id].lifeTime -= deltaTime;
+    vec3 pos = inParticle[id].position;
+    vec3 vel = inParticle[id].velocity;
+    float mass = inParticle[id].mass;
+
+    if(inParticle[id].lifeTime < 0.f)
+    {
+        inParticle[id].lifeTime = 5.f * rand;
+        inParticle[id].mass *= rand;
+
+        pos = vec3(0);
+        vel *= rand;
+    }
+
+    for(int i = 0; i < n; i++)
+    {
+        vec3 d = (gravityPoint[i].xyz - pos) * sim_d_factor;
+        float r = length(d);
+        float g = G * (gravityPoint[i].w * sim_g_factor) / (r * r);
+
+        if (r > 0) {
+            vec3 dvel = (deltaTime * sim_t_factor) * g * (d / r);
+
+            vel = (vel + dvel) / (1.0 + dot(vel, dvel) / (c*c));
+        }
+    }
+
+    pos += vel * (deltaTime * sim_t_factor);
+
+    vec3 a_pos = abs(pos);
+
+    if ((a_pos.x > 2.0) || (a_pos.y > 2.0) || (a_pos.z > 2.0))
+    {
+        inParticle[id].lifeTime *= 0.9;
+    }
+
+    inParticle[id].position = pos;
+    inParticle[id].velocity = vel;
+}

projects/particle_simulation/shaders/shader_space.comp

+#version 450 core
+#extension GL_ARB_separate_shader_objects : enable
+
+layout(local_size_x = 256) in;
+
+struct Particle
+{
+