com.bitfire.postprocessing.filters.FxaaFilter.java Source code

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Here is the source code for com.bitfire.postprocessing.filters.FxaaFilter.java

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/*******************************************************************************
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.bitfire.postprocessing.filters;

import com.badlogic.gdx.math.Vector2;
import com.bitfire.utils.ShaderLoader;

/** Fast approximate anti-aliasing filter.
 * @author Toni Sagrista */
public final class FxaaFilter extends Filter<FxaaFilter> {
    private Vector2 viewportInverse;
    private float FXAA_REDUCE_MIN;
    private float FXAA_REDUCE_MUL;
    private float FXAA_SPAN_MAX;

    public enum Param implements Parameter {
        // @formatter:off
        Texture("u_texture0", 0), ViewportInverse("u_viewportInverse", 2), FxaaReduceMin("FXAA_REDUCE_MIN",
                0), FxaaReduceMul("FXAA_REDUCE_MUL", 0), FxaaSpanMax("FXAA_SPAN_MAX", 0),;
        // @formatter:on

        private String mnemonic;
        private int elementSize;

        private Param(String mnemonic, int arrayElementSize) {
            this.mnemonic = mnemonic;
            this.elementSize = arrayElementSize;
        }

        @Override
        public String mnemonic() {
            return this.mnemonic;
        }

        @Override
        public int arrayElementSize() {
            return this.elementSize;
        }
    }

    public FxaaFilter(int viewportWidth, int viewportHeight) {
        this(new Vector2(viewportWidth, viewportHeight), 1f / 128f, 1f / 8f, 8f);
    }

    public FxaaFilter(int viewportWidth, int viewportHeight, float fxaa_reduce_min, float fxaa_reduce_mul,
            float fxaa_span_max) {
        this(new Vector2(viewportWidth, viewportHeight), fxaa_reduce_min, fxaa_reduce_mul, fxaa_span_max);
    }

    public FxaaFilter(Vector2 viewportSize, float fxaa_reduce_min, float fxaa_reduce_mul, float fxaa_span_max) {
        super(ShaderLoader.fromFile("screenspace", "fxaa"));
        this.viewportInverse = viewportSize;
        this.viewportInverse.x = 1f / this.viewportInverse.x;
        this.viewportInverse.y = 1f / this.viewportInverse.y;

        this.FXAA_REDUCE_MIN = fxaa_reduce_min;
        this.FXAA_REDUCE_MUL = fxaa_reduce_mul;
        this.FXAA_SPAN_MAX = fxaa_span_max;
        rebind();
    }

    public void setViewportSize(float width, float height) {
        this.viewportInverse.set(1f / width, 1f / height);
        setParam(Param.ViewportInverse, this.viewportInverse);
    }

    /** Sets the parameter. The default value is 1/128.
     * @param value */
    public void setFxaaReduceMin(float value) {
        this.FXAA_REDUCE_MIN = value;
        setParam(Param.FxaaReduceMin, this.FXAA_REDUCE_MIN);
    }

    /** Sets the parameter. The default value is 1/8.
     * @param value */
    public void setFxaaReduceMul(float value) {
        this.FXAA_REDUCE_MUL = value;
        setParam(Param.FxaaReduceMul, this.FXAA_REDUCE_MUL);
    }

    /** Sets the parameter. The default value is 8;
     * @param value */
    public void setFxaaSpanMax(float value) {
        this.FXAA_SPAN_MAX = value;
        setParam(Param.FxaaSpanMax, this.FXAA_SPAN_MAX);
    }

    public Vector2 getViewportSize() {
        return viewportInverse;
    }

    @Override
    public void rebind() {
        // reimplement super to batch every parameter
        setParams(Param.Texture, u_texture0);
        setParams(Param.ViewportInverse, viewportInverse);
        setParams(Param.FxaaReduceMin, FXAA_REDUCE_MIN);
        setParams(Param.FxaaReduceMul, FXAA_REDUCE_MUL);
        setParams(Param.FxaaSpanMax, FXAA_SPAN_MAX);
        endParams();
    }

    @Override
    protected void onBeforeRender() {
        inputTexture.bind(u_texture0);
    }
}