com.idrsolutions.pdf.color.shading.FunctionContext Maven / Gradle / Ivy

/*
 * ===========================================
 * Java Pdf Extraction Decoding Access Library
 * ===========================================
 *
 * Project Info:  http://www.idrsolutions.com
 * Help section for developers at http://www.idrsolutions.com/support/
 *
 * (C) Copyright 1997-2017 IDRsolutions and Contributors.
 *
 * This file is part of JPedal/JPDF2HTML5
 *
 @LICENSE@
 *
 * ---------------
 * FunctionContext.java
 * ---------------
 */
package com.idrsolutions.pdf.color.shading;

import java.awt.Color;
import java.awt.PaintContext;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;

import org.jpedal.color.GenericColorSpace;
import org.jpedal.function.PDFFunction;
import org.jpedal.parser.DecoderOptions;

public class FunctionContext implements PaintContext {

    final GenericColorSpace shadingColorSpace;

    private float scaling = 1f;

    private final PDFFunction[] function;

    //private FunctionContext(){}

    private final int pageHeight;

    private final boolean colorsReversed;

    private int xstart, ystart;

    //private float[] domain;

    FunctionContext(final int pHeight, final float scaling, final GenericColorSpace shadingColorSpace, final boolean colorsReversed, final PDFFunction[] function) {

        this.colorsReversed = colorsReversed;
        this.pageHeight = pHeight;
        //this.domain=domain;

        this.shadingColorSpace = shadingColorSpace;
        this.function = function;
        this.scaling = scaling;


    }

    @Override
    public void dispose() {
    }

    @Override
    public ColorModel getColorModel() {
        return ColorModel.getRGBdefault();
    }

    /**
     * setup the raster with the colors
     */
    @Override
    public Raster getRaster(final int xstart, final int ystart, final int w, final int h) {

        this.xstart = xstart;
        this.ystart = ystart;

        //sets up the array of pixel values
        //WritableRaster raster =getColorModel().createCompatibleWritableRaster(w, h);

        //create buffer to hold all this data
        final int[] data = new int[w * h * 4];

        //workout color range
        Color c;

        //set current calues to default
        int cr, cg, cb;

        //y co-ordinates
        for (int y = 0; y < h; y++) {

            //x co-ordinates
            for (int x = 0; x < w; x++) {

                c = calculateColor(x, y);

                if (colorsReversed) {
                    cr = 255 - c.getRed();
                    cg = 255 - c.getGreen();
                    cb = 255 - c.getBlue();
                } else {
                    cr = c.getRed();
                    cg = c.getGreen();
                    cb = c.getBlue();
                }

                //set color for the pixel with values
                final int base = (y * w + x) * 4;
                data[base] = cr;
                data[base + 1] = cg;
                data[base + 2] = cb;
                data[base + 3] = 255; //(int)(col.getAlpha());

            }
        }

        //set values
        final WritableRaster raster = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB).getRaster();
        raster.setPixels(0, 0, w, h, data);

        return raster;
    }

    /**
     * workout rgb color
     */
    private Color calculateColor(final float x, final float y) {

        final float cx;
        final float cy;

        /*
         *take x and y and pass through conversion with domain values - this gives us xx
		 */
        //hack for MAC which is f**king broken
        if (DecoderOptions.isRunningOnMac) {
            cx = scaling * (x + xstart);
            cy = scaling * (y + ystart);
        } else {
            cx = scaling * (x + xstart);
            cy = scaling * (pageHeight - (y + ystart));
        }

        final float[] values = {cx, cy};

        final float[] colValues = ShadingFactory.applyFunctions(function, values);

        /*
         * this value is converted to a color
         */
        final int count = colValues.length;
        shadingColorSpace.setColor(colValues, count);

        return (Color) shadingColorSpace.getColor();
    }
}