import { PostProcess, PostProcessOptions } from "./postProcess";
import { Nullable } from "types";
import { Engine } from "Engine/engine";
import { Effect } from "Materials/effect";
import { Camera } from "Cameras/camera";

    /**
     * The BloomMergePostProcess merges blurred images with the original based on the values of the circle of confusion.
     */
    export class BloomMergePostProcess extends PostProcess {
        /**
         * Creates a new instance of @see BloomMergePostProcess
         * @param name The name of the effect.
         * @param originalFromInput Post process which's input will be used for the merge.
         * @param blurred Blurred highlights post process which's output will be used.
         * @param weight Weight of the bloom to be added to the original input.
         * @param options The required width/height ratio to downsize to before computing the render pass.
         * @param camera The camera to apply the render pass to.
         * @param samplingMode The sampling mode to be used when computing the pass. (default: 0)
         * @param engine The engine which the post process will be applied. (default: current engine)
         * @param reusable If the post process can be reused on the same frame. (default: false)
         * @param textureType Type of textures used when performing the post process. (default: 0)
         * @param blockCompilation If compilation of the shader should not be done in the constructor. The updateEffect method can be used to compile the shader at a later time. (default: false)
         */
        constructor(name: string, originalFromInput: PostProcess, blurred: PostProcess,
            /** Weight of the bloom to be added to the original input. */
            public weight: number,
            options: number | PostProcessOptions,
            camera: Nullable<Camera>, samplingMode?: number, engine?: Engine, reusable?: boolean, textureType: number = Engine.TEXTURETYPE_UNSIGNED_INT, blockCompilation = false) {
            super(name, "bloomMerge", ["bloomWeight"], ["circleOfConfusionSampler", "blurStep0", "blurStep1", "blurStep2", "bloomBlur"], options, camera, samplingMode, engine, reusable, null, textureType, undefined, null, true);
            this.onApplyObservable.add((effect: Effect) => {
                effect.setTextureFromPostProcess("textureSampler", originalFromInput);
                effect.setTextureFromPostProcessOutput("bloomBlur", blurred);
                effect.setFloat("bloomWeight", this.weight);
            });

            if (!blockCompilation) {
                this.updateEffect();
            }
        }
    }