Struct NullBackend 

pub struct NullBackend { /* private fields */ }

A no-op render backend that tracks resource state without GPU access.

This backend is designed for headless testing in CI environments where no GPU or display server is available. All operations succeed immediately, and resource handles are tracked via generational allocators so that lifecycle tests (create/destroy/use-after-free) work correctly.

Implementations

impl NullBackend

pub fn new() -> Self

Creates a new headless null backend.

Trait Implementations

impl BufferOps for NullBackend

fn create_buffer( &mut self, buffer_type: BufferType, _usage: BufferUsage, data: &[u8], ) -> GoudResult<BufferHandle>

Creates a GPU buffer with the specified type, usage, and initial data.

fn update_buffer( &mut self, handle: BufferHandle, _offset: usize, _data: &[u8], ) -> GoudResult<()>

Updates the contents of an existing buffer.

fn destroy_buffer(&mut self, handle: BufferHandle) -> bool

Destroys a buffer and frees GPU memory.

fn is_buffer_valid(&self, handle: BufferHandle) -> bool

Checks if a buffer handle is valid and refers to an existing buffer.

fn buffer_size(&self, handle: BufferHandle) -> Option<usize>

Returns the size in bytes of a buffer, or None if the handle is invalid.

fn bind_buffer(&mut self, handle: BufferHandle) -> GoudResult<()>

Binds a buffer for use in subsequent draw calls.

fn unbind_buffer(&mut self, _buffer_type: BufferType)

Unbinds the currently bound buffer of the specified type.

impl ClearOps for NullBackend

fn set_clear_color(&mut self, r: f32, g: f32, b: f32, a: f32)

Sets the clear color for subsequent clear operations.

fn clear_color(&mut self)

Clears the color buffer using the current clear color.

fn clear_depth(&mut self)

Clears the depth buffer.

fn clear(&mut self)

Clears both color and depth buffers.

impl Default for NullBackend

fn default() -> Self

Returns the “default value” for a type.

impl DrawOps for NullBackend

fn set_vertex_attributes(&mut self, _layout: &VertexLayout)

Sets up vertex attribute pointers for the currently bound vertex buffer.

fn draw_arrays( &mut self, _topology: PrimitiveTopology, _first: u32, _count: u32, ) -> GoudResult<()>

Draws primitives using array-based vertex data.

fn draw_indexed( &mut self, _topology: PrimitiveTopology, _count: u32, _offset: usize, ) -> GoudResult<()>

Draws primitives using indexed vertex data.

fn draw_indexed_u16( &mut self, _topology: PrimitiveTopology, _count: u32, _offset: usize, ) -> GoudResult<()>

Draws primitives using indexed vertex data with u16 indices.

fn draw_arrays_instanced( &mut self, _topology: PrimitiveTopology, _first: u32, _count: u32, _instance_count: u32, ) -> GoudResult<()>

Draws multiple instances of primitives using array-based vertex data.

fn draw_indexed_instanced( &mut self, _topology: PrimitiveTopology, _count: u32, _offset: usize, _instance_count: u32, ) -> GoudResult<()>

Draws multiple instances of primitives using indexed vertex data.

impl FrameOps for NullBackend

fn begin_frame(&mut self) -> GoudResult<()>

Begins a new frame. Called once per frame before any rendering.

fn end_frame(&mut self) -> GoudResult<()>

Ends the current frame. Called once per frame after all rendering.

impl RenderBackend for NullBackend

fn info(&self) -> &BackendInfo

Returns information about this backend implementation.

fn capabilities(&self) -> &BackendCapabilities

Returns the capabilities of this backend.

impl ShaderOps for NullBackend

fn create_shader( &mut self, _vertex_src: &str, _fragment_src: &str, ) -> GoudResult<ShaderHandle>

Compiles and links a shader program from vertex and fragment shader sources.

fn destroy_shader(&mut self, handle: ShaderHandle) -> bool

Destroys a shader program and frees GPU memory.

fn is_shader_valid(&self, handle: ShaderHandle) -> bool

Checks if a shader handle is valid and refers to an existing shader program.

fn bind_shader(&mut self, handle: ShaderHandle) -> GoudResult<()>

Binds a shader program for use in subsequent draw calls.

fn unbind_shader(&mut self)

Unbinds the currently bound shader program.

fn get_uniform_location(&self, handle: ShaderHandle, _name: &str) -> Option<i32>

Gets the location of a uniform variable in a shader program.

fn set_uniform_int(&mut self, _location: i32, _value: i32)

Sets a uniform integer value.

fn set_uniform_float(&mut self, _location: i32, _value: f32)

Sets a uniform float value.

fn set_uniform_vec2(&mut self, _location: i32, _x: f32, _y: f32)

Sets a uniform vec2 value.

fn set_uniform_vec3(&mut self, _location: i32, _x: f32, _y: f32, _z: f32)

Sets a uniform vec3 value.

fn set_uniform_vec4( &mut self, _location: i32, _x: f32, _y: f32, _z: f32, _w: f32, )

Sets a uniform vec4 value.

fn set_uniform_mat4(&mut self, _location: i32, _matrix: &[f32; 16])

Sets a uniform mat4 value.

impl StateOps for NullBackend

fn set_viewport(&mut self, x: i32, y: i32, width: u32, height: u32)

Sets the viewport rectangle.

fn enable_depth_test(&mut self)

Enables depth testing.

fn disable_depth_test(&mut self)

Disables depth testing.

fn enable_blending(&mut self)

Enables alpha blending.

fn disable_blending(&mut self)

Disables alpha blending.

fn set_blend_func(&mut self, _src: BlendFactor, _dst: BlendFactor)

Sets the blend function.

fn enable_culling(&mut self)

Enables face culling.

fn disable_culling(&mut self)

Disables face culling.

fn set_cull_face(&mut self, _face: CullFace)

Sets which faces to cull.

fn set_depth_func(&mut self, _func: DepthFunc)

Sets the depth comparison function.

fn set_front_face(&mut self, _face: FrontFace)

Sets the front face winding order.

fn set_depth_mask(&mut self, enabled: bool)

Enables or disables writing to the depth buffer.

fn set_line_width(&mut self, width: f32)

Sets the line width for line primitives.

impl TextureOps for NullBackend

fn create_texture( &mut self, width: u32, height: u32, _format: TextureFormat, _filter: TextureFilter, _wrap: TextureWrap, _data: &[u8], ) -> GoudResult<TextureHandle>

Creates a GPU texture with the specified dimensions, format, and initial data.

fn update_texture( &mut self, handle: TextureHandle, _x: u32, _y: u32, _width: u32, _height: u32, _data: &[u8], ) -> GoudResult<()>

Updates a region of an existing texture with new pixel data.

fn destroy_texture(&mut self, handle: TextureHandle) -> bool

Destroys a texture and frees GPU memory.

fn is_texture_valid(&self, handle: TextureHandle) -> bool

Checks if a texture handle is valid and refers to an existing texture.

fn texture_size(&self, handle: TextureHandle) -> Option<(u32, u32)>

Returns the dimensions (width, height) of a texture, or None if invalid.

fn bind_texture(&mut self, handle: TextureHandle, _unit: u32) -> GoudResult<()>

Binds a texture to a texture unit for use in subsequent draw calls.

fn unbind_texture(&mut self, _unit: u32)

Unbinds any texture from the specified texture unit.

impl Send for NullBackend

impl Sync for NullBackend