textmode.js / conversion / TextmodeConversionStrategy

Interface: TextmodeConversionStrategy

Interface for defining a custom textmode conversion strategy.

A conversion strategy defines how a source image is converted into textmode attributes (character index, primary color, secondary color) via a custom shader.

To register a custom strategy, implement this interface and pass it to TextmodeConversionManager.register.

Properties

Property	Modifier	Type	Description
id	readonly	string	Unique identifier for this conversion strategy. This ID is used to select the strategy via TextmodeSource.conversionMode.

Methods

createShader()

createShader(context): TextmodeShader;

Create the shader program for this conversion strategy. This method is called once when the strategy is first used for a given source.

The shader must output to 3 render targets (MRT):

• location 0: Character data (R=char index, G=unused, B=unused, A=unused)
• location 1: Primary color (RGBA)
• location 2: Secondary/Background color (RGBA)

Parameters

Parameter	Type	Description
context	TextmodeConversionContext	The conversion context containing renderer and source information.

Returns

TextmodeShader

The compiled GLShader instance.

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createUniforms()

createUniforms(context): Record<string, UniformValue>;

Create uniform values for this conversion strategy. This method is called every frame before rendering the conversion pass.

Use this to pass dynamic values (like time or source texture) to your shader.

Parameters

Parameter	Type	Description
context	TextmodeConversionContext	The conversion context containing renderer and source information.

Returns

Record<string, UniformValue>

An object mapping uniform names to values.