Spock Shader API (Licensed under the MPL 2.0)

Shader.kt

package quest.laxla.spock

/**
 * Any kind of shader.
 *
 * @since 0.0.1-alpha.4
 */
public interface Shader {
	/**
	 * The language this [Shader] is written in.
	 *
	 * @since 0.0.1-alpha.4
	 */
	public val language: Language

	/**
	 * The label the rendering API should refer to this shader under for logging purposes.
	 *
	 * @since 0.0.1-alpha.4
	 */
	public val label: String? get() = null

	/**
	 * Represents a shading language, such as [WGSL][Wgsl] or GLSL.
	 *
	 * Implementations **must** properly implement [equals] and [hashCode];
	 * Therefore, it is recommended to use `data object`s.
	 *
	 * @since 0.0.1-alpha.4
	 * @sample Wgsl
	 */
	public interface Language {
		/**
		 * Does this [shader] carry all metadata required by this shading language?
		 *
		 * This function always returns `false` if [shader].[language] does not equal to `this` language.
		 *
		 * @since 0.0.1-alpha.4
		 * @see Shader.isCarryingRequiredMetadata
		 */
		public infix fun accepts(shader: Shader): Boolean
	}

	/**
	 * Implemented by [Shader]s dynamically compiled from another shader of a different [Language] or form factor.
	 *
	 * @param L the language this shader was transpiled to.
	 * @since 0.0.1-alpha.4
	 * @see Transpiler
	 */
	public interface Transpiled<L> : Shader where L : Language {
		/**
		 * The original [Shader] this one was compiled from.
		 *
		 * @since 0.0.1-alpha.4
		 */
		public val original: Shader

		override val language: L
	}

	/**
	 * Transpiles [Shader] from one [Language] or form factor to another if not supported by the [Renderer].
	 *
	 * @since 0.0.1-alpha.4
	 * @see Transpiled
	 */
	public interface Transpiler<L> where L : Language {
		/**
		 * The [Language] the shaders this transpiler outputs are written in.
		 *
		 * @since 0.0.1-alpha.4
		 */
		public val outputLanguage: L

		/**
		 * Transpiles the [input] [Shader] to the [outputLanguage].
		 *
		 * It is expected but not required that the output is [accept][Language.accepts]ed;
		 * However, if necessary, prefer returning an unaccepted shader over `null` when possible and not expensive.
		 *
		 * @return `null` if this [Transpiler] does not support this [input].
		 * @since 0.0.1-alpha.4
		 */
		public suspend operator fun invoke(input: Shader): Transpiled<L>?
	}
}

Shaders.kt

package quest.laxla.spock

/**
 * Does this [Shader] carry all metadata required by the [language][Shader.language] it is written in?
 *
 * @since 0.0.1-alpha.4
 * @see Shader.Language.accepts
 */
public val Shader.isCarryingRequiredMetadata: Boolean get() = language accepts this

/**
 * @author Laxystem
 */
private data class WgslVertexShader<Vertex : Any>(
	override val vertexKind: VertexKind<Vertex>,
	override val code: String,
	override val entrypoint: String,
	override val label: String?
) : VertexShader<Vertex>, Wgsl.Shader, StringShader

/**
 * Creates a [Wgsl]&nbsp;[VertexShader] from a [String].
 *
 * @since 0.0.1-alpha.4
 */
public fun <Vertex : Any> wgslVertexShaderOf(
	wgsl: String,
	vertexKind: VertexKind<Vertex>,
	entrypoint: String,
	label: String? = null
): VertexShader<Vertex> = WgslVertexShader(vertexKind, wgsl, entrypoint, label)

StringShader.kt

package quest.laxla.spock

/**
 * Non-compiled [Shader], that is passed as a [String][kotlin.String].
 *
 * @since 0.0.1-alpha.4
 */
public interface StringShader : Shader {
	/**
	 * The shader's non-compiled code, written in [language].
	 *
	 * There's no performance penalty to different [Shader]s sharing the same code,
	 * as it is the [Renderer]'s responsibility to handle such situations.
	 *
	 * @since 0.0.1-alpha.4
	 */
	public val code: String
}

Wgsl.kt

package quest.laxla.spock

import quest.laxla.spock.Shader as AnyShader
import quest.laxla.spock.Shader.Language as ShadingLanguage

/**
 * The WGSL shading language, developed for WebGPU.
 *
 * @since 0.0.1-alpha.4
 */
public data object Wgsl : ShadingLanguage {
	public interface Shader : AnyShader {
		/**
		 * The name of the function in this shader to be called by the GPU.
		 *
		 * @since 0.0.1-alpha.4
		 */
		public val entrypoint: String

		override val language: Wgsl get() = Wgsl
	}

	override fun accepts(shader: AnyShader): Boolean = shader is Wgsl.Shader
}