GDevelop/Extensions/ExampleJsExtension/dummyeffect.ts

//A simple PIXI filter doing some color changes
namespace gdjs {
  const logger = new gdjs.Logger('Dummy effect');

  const DummyPixiFilter = function () {
    var vertexShader = null;
    var fragmentShader = [
      'precision mediump float;',
      '',
      'varying vec2 vTextureCoord;',
      'uniform sampler2D uSampler;',
      'uniform float opacity;',
      '',
      'void main(void)',
      '{',
      '   mat3 nightMatrix = mat3(0.6, 0, 0, 0, 0.7, 0, 0, 0, 1.3);',
      '   gl_FragColor = texture2D(uSampler, vTextureCoord);',
      '   gl_FragColor.rgb = mix(gl_FragColor.rgb, nightMatrix * gl_FragColor.rgb, opacity);',
      '}',
    ].join('\n');
    var uniforms = {
      opacity: { type: '1f', value: 1 },
    };

    PIXI.Filter.call(this, vertexShader, fragmentShader, uniforms);
  };
  DummyPixiFilter.prototype = Object.create(PIXI.Filter.prototype);
  DummyPixiFilter.prototype.constructor = DummyPixiFilter;

  // Register the effect type and associate it with a "filter creator" object, containing
  // functions to create and manipulate the filter.
  // Don't forget your extension name in the effect type!
  gdjs.PixiFiltersTools.registerFilterCreator(
    'MyDummyExtension::DummyEffect',
    new (class extends gdjs.PixiFiltersTools.PixiFilterCreator {
      // MakePIXIFilter should return a PIXI.Filter, that will be applied on the PIXI.Container (for layers)
      // or the PIXI.DisplayObject (for objects).
      makePIXIFilter(layer, effectData) {
        const filter = new DummyPixiFilter();

        // If you need to store the time or some state, you can set it up now:
        // filter._time = 0;
        // But be careful about the existing member of the filter (consider
        // updating the filter uniforms directly).

        // You can also access to the effect properties, classified by type:
        // `effectData.doubleParameters.opacity`
        // `effectData.stringParameters.someImage`
        // `effectData.stringParameters.someColor`
        // `effectData.booleanParameters.someBoolean`
        logger.info(
          'The PIXI texture found for the Dummy Effect (not actually used):',
          (layer
            .getRuntimeScene()
            .getGame()
            .getImageManager() as gdjs.PixiImageManager).getPIXITexture(
            effectData.stringParameters.someImage
          )
        );
        return filter;
      }
      // Function called at every frame, after events and before the frame is rendered.
      updatePreRender(filter, layer) {
        // If your filter depends on the time, you can get the elapsed time
        // with `layer.getElapsedTime()`.
        // You can update the uniforms or other state of the filter.
      }
      // Function that will be called to update a (number) parameter of the PIXI filter with a new value
      updateDoubleParameter(filter, parameterName, value) {
        if (parameterName === 'opacity') {
          filter.uniforms.opacity = gdjs.PixiFiltersTools.clampValue(
            value,
            0,
            1
          );
        }
      }
      // Function that will be called to update a (string) parameter of the PIXI filter with a new value
      updateStringParameter(filter, parameterName, value) {}
      // Function that will be called to update a (boolean) parameter of the PIXI filter with a new value
      updateBooleanParameter(filter, parameterName, value) {}
    })()
  );
}