Struct ShaderProgram

pub struct ShaderProgram(/* private fields */);

Expand description

ShaderProgram defines programmable vertex and fragment operations done by the GPU for a draw call.

For each draw call, graphics device executes a vertex shader for each vertex, rasterizes primitives, and for each rasterized fragment, the fragment shader is executed.

In order to create a ShaderProgram, you must prepare ShaderProgram::CreateInfo structure and make sure it is valid using CreateInfo::validate(), then create the ShaderProgram with ShaderProgram::create(). If ShaderProgram creation parameters are not valid, ShaderProgram::create() will throw an exception, which can stop program execution. See: ShaderProgram::CreateInfo See: ShaderProgram::CreateInfoShaderSources See: ShaderProgram::CreateInfoShaderBinary See: ShaderProgram::CreateInfoProgramBinary

ShaderProgram consist of vertex shader, fragment shader, specification of vertex attributes consumed by the vertex shader, and specification of property types that are used to control uniforms,

Shader programs consume per vertex attribute data, and per draw call values known as uniforms.

Vertex attribute data is typically sourced from Meshes. Kanzi Shader lists a number of shader vertex attributes. Shader vertex attributes have name, semantic and semantic type. When Kanzi prepares a draw call, a mesh is typically used as source for attribute data that is consumed by the shader program. Each mesh has a number of mesh vertex attributes; these are mapped to shader vertex attributes based on attribute semantic and semantic index.

Uniforms are typically sourced from properties, for example Material properties, or from engine. Engine uniforms are for example final transform for the current Model3D node being drawn, camera transformation, or positions and colors of lights in the scene. Engine uniforms are also called “fixed uniforms” in Kanzi.

Values of uniforms can be transformed by Kanzi before they are sent to shader program. Currently only color uniforms have transformations available. With linear to sRGB transform, a linear color is convertex to sRGB when it is sent to uniform. With sRGB to linear transform, a sRGB color value is transformed to linear when it is sent to uniform.

Methods from Deref<Target = GPUResource>§

pub fn get_gpu_memory_usage(&self) -> Result<u32, Error>

Gets the amount of GPU memory consumed by the resource.

§Returns

GPU memory consumption in bytes.

pub fn is_deployed(&self) -> Result<bool, Error>

Indicates whether a GPU resource is deployed.

Methods from Deref<Target = Resource>§

pub fn get_name(&self) -> Result<KanziString, Error>

Gets the resource name.

pub fn get_url(&self) -> Result<KanziString, Error>

Gets the resource URL. Note that the URL is not necessarily in URL form if resource has been just created.

§Returns

URL string.

pub fn set_keep_alive(&self, keep_alive: bool) -> Result<(), Error>

Sets the keep alive flag. Can be set only before the resource is registered to the resource manager. Normally set by loadFromKZB.

§Arguments

keep_alive - Value for the keep alive flag.

Methods from Deref<Target = Object>§

pub fn as_ptr(&self) -> *mut ObjectWrapper

pub fn as_wrapper(&self) -> &ObjectWrapper

pub fn as_object(&self) -> &Object

Represents any type inheriting from Object as &Object. This is useful for comparisions when PartialEq traits failed to compare objects of different types.

let child = screen.get_child(0)?;
let parent = child.get_parent()?.into_error(ErrorKind::ObjectNotFound)?;
// assert_eq!(screen, parent); // <- Fails to compile!
assert_eq!(screen.as_object(), parent.as_object());

pub fn get_native(&self) -> Result<NonNull<c_void>, Error>

Gets a pointer to the backing C++ instance.

pub fn is_stale(&self) -> bool

Checks whether the weak reference has expired.

pub fn get_property<T>( &self, property_type: &PropertyType<T>, ) -> Result<<T as VariantConstraint>::RetArg, Error>
where T: PropertyTypeConstraint,

Returns the current value of a property disregarding modifiers.

Base value is affected by the following inputs where the highest entry in the list determines the base value:

Local value set with setProperty or loaded from kzb
Value set by a style affecting the property.
Value defined by class metadata.

Modifiers are not applied, the highest-priority base value is returned.

If no inputs to the property value can be established the system returns the value default value from property type metadata.

§Arguments

property_type - The property type identifying the property to retrieve.

§Returns

The evaluated property value.

pub fn get_optional_property<T>( &self, property_type: &PropertyType<T>, ) -> Result<Option<<T as VariantConstraint>::RetArg>, Error>
where T: PropertyTypeConstraint,

Returns the current value of a property disregarding modifiers, but does not default to the value in property metadata if there are no inputs to the property value.

If there is no value sources, None is returned.

If no inputs to the property value can be established the system returns the value default value from property type metadata.