/*
Copyright 2006 Jerry Huxtable

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.jhlabs.composite;

import java.awt.Color;
import java.awt.CompositeContext;
import java.awt.color.ColorSpace;
import java.awt.image.ColorModel;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;

public class MiscCompositeContext implements CompositeContext {

    // Multiply two numbers in the range 0..255 such that 255*255=255
    static int multiply255(int a, int b) {
        int t = a * b + 0x80;
        return ((t >> 8) + t) >> 8;
    }

    static int clamp(int a) {
        return a < 0 ? 0 : a > 255 ? 255 : a;
    }

	private final int rule;
	private final float alpha;
	private final ColorModel srcColorModel;
	private final ColorModel dstColorModel;
	private final ColorSpace srcColorSpace;
	private final ColorSpace dstColorSpace;
	private boolean srcNeedsConverting;
	private boolean dstNeedsConverting;

	public MiscCompositeContext(int rule,
						 float alpha,
						 ColorModel srcColorModel,
						 ColorModel dstColorModel) {
		this.rule = rule;
		this.alpha = alpha;
		this.srcColorModel = srcColorModel;
		this.dstColorModel = dstColorModel;
		this.srcColorSpace = srcColorModel.getColorSpace();
		this.dstColorSpace = dstColorModel.getColorSpace();
		ColorModel srgbCM = ColorModel.getRGBdefault();
//		srcNeedsConverting = !srcColorModel.equals(srgbCM);
//		dstNeedsConverting = !dstColorModel.equals(srgbCM);
	}

        @Override
	public void dispose() {
	}
        @Override
	public void compose( Raster src, Raster dstIn, WritableRaster dstOut) {
            float a=0, ac=0;
            float alpha = this.alpha;
            int t;
            
            float[] sHsv = null, diHsv = null, doHsv = null;
            switch ( rule ) {
                case MiscComposite.HUE:
                case MiscComposite.SATURATION:
                case MiscComposite.VALUE:
                case MiscComposite.COLOR:
                    sHsv = new float[3];
                    diHsv = new float[3];
                    doHsv = new float[3];
                    break;
            }
            
            int[] srcPix = null;
            int[] dstPix = null;
            
            int x = dstOut.getMinX();
            int w = dstOut.getWidth();
            
            int y0 = dstOut.getMinY();
            int y1 = y0 + dstOut.getHeight();
            
            for ( int y = y0; y < y1; y++ ) {
                srcPix = src.getPixels(x, y, w, 1, srcPix);
                dstPix = dstIn.getPixels(x, y, w, 1, dstPix);
                int i = 0;
                int end = w*4;
                
                while ( i < end ) {
                    int sr = srcPix[i];
                    int dir = dstPix[i];
                    int sg = srcPix[i+1];
                    int dig = dstPix[i+1];
                    int sb = srcPix[i+2];
                    int dib = dstPix[i+2];
                    int sa = srcPix[i+3];
                    int dia = dstPix[i+3];
                    int dor, dog, dob, doa;
                    
                    switch ( rule ) {
                        case MiscComposite.ADD:
                        default:
                            dor = dir + sr;
                            if ( dor > 255 ) {
                                dor = 255;
                            }
                            dog = dig + sg;
                            if ( dog > 255 ) {
                                dog = 255;
                            }
                            dob = dib + sb;
                            if ( dob > 255 ) {
                                dob = 255;
                            }
                            break;
                            
                        case MiscComposite.SUBTRACT:
                            dor = dir - sr;
                            if ( dor < 0 ) {
                                dor = 0;
                            }
                            dog = dig - sg;
                            if ( dog < 0 ) {
                                dog = 0;
                            }
                            dob = dib - sb;
                            if ( dob < 0 ) {
                                dob = 0;
                            }
                            break;
                            
                        case MiscComposite.DIFFERENCE:
                            dor = dir - sr;
                            if ( dor < 0 ) {
                                dor = -dor;
                            }
                            dog = dig - sg;
                            if ( dog < 0 ) {
                                dog = -dog;
                            }
                            dob = dib - sb;
                            if ( dob < 0 ) {
                                dob = -dob;
                            }
                            break;
                            
                        case MiscComposite.MULTIPLY:
                            t = dir * sr + 0x80;
                            dor = ((t >> 8) + t) >> 8;
                            t = dig * sg + 0x80;
                            dog = ((t >> 8) + t) >> 8;
                            t = dib * sb + 0x80;
                            dob = ((t >> 8) + t) >> 8;
                            break;
                            
                        case MiscComposite.SCREEN:
                            t = (255-dir) * (255-sr) + 0x80;
                            dor = 255 - ( ((t >> 8) + t) >> 8 );
                            t = (255-dig) * (255-sg) + 0x80;
                            dog = 255 - ( ((t >> 8) + t) >> 8 );
                            t = (255-dib) * (255-sb) + 0x80;
                            dob = 255 - ( ((t >> 8) + t) >> 8 );
                            break;
                            
                        case MiscComposite.OVERLAY:
                            if ( dir < 128 ) {
                                t = dir * sr + 0x80;
                                dor = 2 * (((t >> 8) + t) >> 8);
                            } else {
                                t = (255-dir) * (255-sr) + 0x80;
                                dor = 2 * (255 - ( ((t >> 8) + t) >> 8 ));
                            }
                            if ( dig < 128 ) {
                                t = dig * sg + 0x80;
                                dog = 2 * (((t >> 8) + t) >> 8);
                            } else {
                                t = (255-dig) * (255-sg) + 0x80;
                                dog = 2 * (255 - ( ((t >> 8) + t) >> 8 ));
                            }
                            if ( dib < 128 ) {
                                t = dib * sb + 0x80;
                                dob = 2 * (((t >> 8) + t) >> 8);
                            } else {
                                t = (255-dib) * (255-sb) + 0x80;
                                dob = 2 * (255 - ( ((t >> 8) + t) >> 8 ));
                            }
                            break;
                            
                        case MiscComposite.DARKEN:
                            dor = dir < sr ? dir : sr;
                            dog = dig < sg ? dig : sg;
                            dob = dib < sb ? dib : sb;
                            break;
                            
                        case MiscComposite.LIGHTEN:
                            dor = dir > sr ? dir : sr;
                            dog = dig > sg ? dig : sg;
                            dob = dib > sb ? dib : sb;
                            break;
                            
                        case MiscComposite.AVERAGE:
                            dor = (dir + sr) / 2;
                            dog = (dig + sg) / 2;
                            dob = (dib + sb) / 2;
                            break;
                            
                        case MiscComposite.HUE:
                        case MiscComposite.SATURATION:
                        case MiscComposite.VALUE:
                        case MiscComposite.COLOR:
                            Color.RGBtoHSB(sr, sg, sb, sHsv);
                            Color.RGBtoHSB(dir, dig, dib, diHsv);
                            
                            switch(rule) {
                                case MiscComposite.HUE:
                                    doHsv[0] = sHsv[0];
                                    doHsv[1] = diHsv[1];
                                    doHsv[2] = diHsv[2];
                                    break;
                                case MiscComposite.SATURATION:
                                    doHsv[0] = diHsv[0];
                                    doHsv[1] = sHsv[1];
                                    doHsv[2] = diHsv[2];
                                    break;
                                case MiscComposite.VALUE:
                                    doHsv[0] = diHsv[0];
                                    doHsv[1] = diHsv[1];
                                    doHsv[2] = sHsv[2];
                                    break;
                                case MiscComposite.COLOR:
                                    doHsv[0] = sHsv[0];
                                    doHsv[1] = sHsv[1];
                                    doHsv[2] = diHsv[2];
                                    break;
                            }
                            
                            int doRGB = Color.HSBtoRGB(doHsv[0], doHsv[1], doHsv[2]);
                            dor = (doRGB&0xff0000)>>16;
                            dog = (doRGB&0xff00)>>8;
                            dob = (doRGB&0xff);
                            break;
                            
                        case MiscComposite.BURN:
                            if (dir != 255) {
                                dor = clamp(255-(((int)(255-sr) << 8) / (dir+1)));
                            } else {
                                dor = sr;
                            }
                            if (dig != 255) {
                                dog = clamp(255-(((int)(255-sg) << 8) / (dig+1)));
                            } else {
                                dog = sg;
                            }
                            if (dib != 255) {
                                dob = clamp(255-(((int)(255-sb) << 8) / (dib+1)));
                            } else {
                                dob = sb;
                            }
                            break;
                            
                        case MiscComposite.COLOR_BURN:
                            if (sr != 0) {
                                dor = Math.max(255 - (((int)(255-dir) << 8) / sr), 0);
                            } else {
                                dor = sr;
                            }
                            if (sg != 0) {
                                dog = Math.max(255 - (((int)(255-dig) << 8) / sg), 0);
                            } else {
                                dog = sg;
                            }
                            if (sb != 0) {
                                dob = Math.max(255 - (((int)(255-dib) << 8) / sb), 0);
                            } else {
                                dob = sb;
                            }
                            break;
                            
                        case MiscComposite.DODGE:
                            dor = clamp((sr << 8) / (256-dir));
                            dog = clamp((sg << 8) / (256-dig));
                            dob = clamp((sb << 8) / (256-dib));
                            break;
                            
                        case MiscComposite.COLOR_DODGE:
                            if (sr != 255) {
                                dor = Math.min((dir << 8) / (255-sr), 255);
                            } else {
                                dor = sr;
                            }
                            if (sg != 255) {
                                dog = Math.min((dig << 8) / (255-sg), 255);
                            } else {
                                dog = sg;
                            }
                            if (sb != 255) {
                                dob = Math.min((dib << 8) / (255-sb), 255);
                            } else {
                                dob = sb;
                            }
                            break;
                            
                        case MiscComposite.SOFT_LIGHT:
                            int d;
                            d = multiply255(sr, dir);
                            dor = d + multiply255(dir, 255 - multiply255(255-dir, 255-sr)-d);
                            d = multiply255(sg, dig);
                            dog = d + multiply255(dig, 255 - multiply255(255-dig, 255-sg)-d);
                            d = multiply255(sb, dib);
                            dob = d + multiply255(dib, 255 - multiply255(255-dib, 255-sb)-d);
                            break;
                            
                        case MiscComposite.HARD_LIGHT:
                            if (sr > 127) {
                                dor = 255 - 2*multiply255(255 - sr, 255 - dir);
                            } else {
                                dor = 2*multiply255(sr, dir);
                            }
                            if (sg > 127) {
                                dog = 255 - 2*multiply255(255 - sg, 255 - dig);
                            } else {
                                dog = 2*multiply255(sg, dig);
                            }
                            if (sb > 127) {
                                dob = 255 - 2*multiply255(255 - sb, 255 - dib);
                            } else {
                                dob = 2*multiply255(sb, dib);
                            }
                            break;
                            
                        case MiscComposite.PIN_LIGHT:
                            dor = sr > 127 ? Math.max(sr, dir) : Math.min(sr, dir);
                            dog = sg > 127 ? Math.max(sg, dig) : Math.min(sg, dig);
                            dob = sb > 127 ? Math.max(sb, dib) : Math.min(sb, dib);
                            break;
                            
                        case MiscComposite.EXCLUSION:
                            dor = dir+multiply255(sr, (255-dir-dir));
                            dog = dig+multiply255(sg, (255-dig-dig));
                            dob = dib+multiply255(sb, (255-dib-dib));
                            break;
                            
                        case MiscComposite.NEGATION:
                            dor = 255 - Math.abs(255-sr-dir);
                            dog = 255 - Math.abs(255-sg-dig);
                            dob = 255 - Math.abs(255-sb-dib);
                            break;
                    }
                    
                    a = alpha*sa/255f;
                    ac = 1-a;
                    
                    dstPix[i] = (int)(a*dor + ac*dir);
                    dstPix[i+1] = (int)(a*dog + ac*dig);
                    dstPix[i+2] = (int)(a*dob + ac*dib);
                    dstPix[i+3] = (int)(sa*alpha + dia*ac);
                    i += 4;
                }
                dstOut.setPixels(x, y, w, 1, dstPix);
            }
        }
	

}
