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/*****************************************************************************
* Copyright (C) The Apache Software Foundation. All rights reserved. *
* ------------------------------------------------------------------------- *
* This software is published under the terms of the Apache Software License *
* version 1.1, a copy of which has been included with this distribution in *
* the LICENSE file. *
*****************************************************************************/
package com.kitfox.svg.batik;
import java.awt.Color;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.geom.NoninvertibleTransformException;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.ColorModel;
/**
* Provides the actual implementation for the LinearGradientPaint
* This is where the pixel processing is done.
*
* @author Nicholas Talian, Vincent Hardy, Jim Graham, Jerry Evans
* @author Vincent Hardy
* @version $Id: LinearGradientPaintContext.java,v 1.2 2007/02/04 01:28:05 kitfox Exp $
* @see java.awt.PaintContext
* @see java.awt.Paint
* @see java.awt.GradientPaint
*/
final class LinearGradientPaintContext extends MultipleGradientPaintContext {
/**
* The following invariants are used to process the gradient value from
* a device space coordinate, (X, Y):
* g(X, Y) = dgdX*X + dgdY*Y + gc
*/
private float dgdX, dgdY, gc, pixSz;
private static final int DEFAULT_IMPL = 1;
private static final int ANTI_ALIAS_IMPL = 3;
private int fillMethod;
/**
* Constructor for LinearGradientPaintContext.
*
* @param cm {@link ColorModel} that receives
* the Paint data. This is used only as a hint.
*
* @param deviceBounds the device space bounding box of the
* graphics primitive being rendered
*
* @param userBounds the user space bounding box of the
* graphics primitive being rendered
*
* @param t the {@link AffineTransform} from user
* space into device space (gradientTransform should be
* concatenated with this)
*
* @param hints the hints that the context object uses to choose
* between rendering alternatives
*
* @param start gradient start point, in user space
*
* @param end gradient end point, in user space
*
* @param fractions the fractions specifying the gradient distribution
*
* @param colors the gradient colors
*
* @param cycleMethod either NO_CYCLE, REFLECT, or REPEAT
*
* @param colorSpace which colorspace to use for interpolation,
* either SRGB or LINEAR_RGB
*
*/
public LinearGradientPaintContext(ColorModel cm,
Rectangle deviceBounds,
Rectangle2D userBounds,
AffineTransform t,
RenderingHints hints,
Point2D dStart,
Point2D dEnd,
float[] fractions,
Color[] colors,
MultipleGradientPaint.CycleMethodEnum
cycleMethod,
MultipleGradientPaint.ColorSpaceEnum
colorSpace)
throws NoninvertibleTransformException
{
super(cm, deviceBounds, userBounds, t, hints, fractions,
colors, cycleMethod, colorSpace);
// Use single precision floating points
Point2D.Float start = new Point2D.Float((float)dStart.getX(),
(float)dStart.getY());
Point2D.Float end = new Point2D.Float((float)dEnd.getX(),
(float)dEnd.getY());
// A given point in the raster should take on the same color as its
// projection onto the gradient vector.
// Thus, we want the projection of the current position vector
// onto the gradient vector, then normalized with respect to the
// length of the gradient vector, giving a value which can be mapped into
// the range 0-1.
// projection = currentVector dot gradientVector / length(gradientVector)
// normalized = projection / length(gradientVector)
float dx = end.x - start.x; // change in x from start to end
float dy = end.y - start.y; // change in y from start to end
float dSq = dx*dx + dy*dy; // total distance squared
//avoid repeated calculations by doing these divides once.
float constX = dx/dSq;
float constY = dy/dSq;
//incremental change along gradient for +x
dgdX = a00*constX + a10*constY;
//incremental change along gradient for +y
dgdY = a01*constX + a11*constY;
float dgdXAbs = Math.abs(dgdX);
float dgdYAbs = Math.abs(dgdY);
if (dgdXAbs > dgdYAbs) pixSz = dgdXAbs;
else pixSz = dgdYAbs;
//constant, incorporates the translation components from the matrix
gc = (a02-start.x)*constX + (a12-start.y)*constY;
Object colorRend = hints == null ? RenderingHints.VALUE_COLOR_RENDER_SPEED : hints.get(RenderingHints.KEY_COLOR_RENDERING);
Object rend = hints == null ? RenderingHints.VALUE_RENDER_SPEED : hints.get(RenderingHints.KEY_RENDERING);
fillMethod = DEFAULT_IMPL;
if ((cycleMethod == MultipleGradientPaint.REPEAT) ||
hasDiscontinuity) {
if (rend == RenderingHints.VALUE_RENDER_QUALITY)
fillMethod = ANTI_ALIAS_IMPL;
// ColorRend overrides rend.
if (colorRend == RenderingHints.VALUE_COLOR_RENDER_SPEED)
fillMethod = DEFAULT_IMPL;
else if (colorRend == RenderingHints.VALUE_COLOR_RENDER_QUALITY)
fillMethod = ANTI_ALIAS_IMPL;
}
}
protected void fillHardNoCycle(int[] pixels, int off, int adjust,
int x, int y, int w, int h) {
//constant which can be pulled out of the inner loop
final float initConst = (dgdX*x) + gc;
for(int i=0; i= 1)
val = gradientOverflow;
else {
// Could be a binary search...
int gradIdx = 0;
while (gradIdx < gradientsLength-1) {
if (g < fractions[gradIdx+1])
break;
gradIdx++;
}
float delta = (g-fractions[gradIdx]);
float idx = ((delta*GRADIENT_SIZE_INDEX)
/normalizedIntervals[gradIdx])+0.5f;
val = gradients[gradIdx][(int)idx];
}
while (off < rowLimit) {
pixels[off++] = val;
}
} else {
// System.out.println("In fillHard2: " + g);
int gradSteps;
int preGradSteps;
final int preVal, postVal;
if (dgdX >= 0) {
gradSteps = (int) ((1-g)/dgdX);
preGradSteps = (int)Math.ceil((0-g)/dgdX);
preVal = gradientUnderflow;
postVal = gradientOverflow;
} else { // dgdX < 0
gradSteps = (int) ((0-g)/dgdX);
preGradSteps = (int)Math.ceil((1-g)/dgdX);
preVal = gradientOverflow;
postVal = gradientUnderflow;
}
if (gradSteps > w)
gradSteps = w;
final int gradLimit = off + gradSteps;
if (preGradSteps > 0) {
if (preGradSteps > w)
preGradSteps = w;
final int preGradLimit = off + preGradSteps;
while (off < preGradLimit) {
pixels[off++] = preVal;
}
g += dgdX*preGradSteps;
}
if (dgdX > 0) {
// Could be a binary search...
int gradIdx = 0;
while (gradIdx < gradientsLength-1) {
if (g < fractions[gradIdx+1])
break;
gradIdx++;
}
while (off < gradLimit) {
float delta = (g-fractions[gradIdx]);
final int [] grad = gradients[gradIdx];
int steps =
(int)Math.ceil((fractions[gradIdx+1]-g)/dgdX);
int subGradLimit = off + steps;
if (subGradLimit > gradLimit)
subGradLimit = gradLimit;
int idx = (int)(((delta*GRADIENT_SIZE_INDEX)
/normalizedIntervals[gradIdx])
*(1<<16)) + (1<<15);
int step = (int)(((dgdX*GRADIENT_SIZE_INDEX)
/normalizedIntervals[gradIdx])
*(1<<16));
while (off < subGradLimit) {
pixels[off++] = grad[idx>>16];
idx += step;
}
g+=dgdX*steps;
gradIdx++;
}
} else {
// Could be a binary search...
int gradIdx = gradientsLength-1;
while (gradIdx > 0) {
if (g > fractions[gradIdx])
break;
gradIdx--;
}
while (off < gradLimit) {
float delta = (g-fractions[gradIdx]);
final int [] grad = gradients[gradIdx];
int steps = (int)Math.ceil(delta/-dgdX);
int subGradLimit = off + steps;
if (subGradLimit > gradLimit)
subGradLimit = gradLimit;
int idx = (int)(((delta*GRADIENT_SIZE_INDEX)
/normalizedIntervals[gradIdx])
*(1<<16)) + (1<<15);
int step = (int)(((dgdX*GRADIENT_SIZE_INDEX)
/normalizedIntervals[gradIdx])
*(1<<16));
while (off < subGradLimit) {
pixels[off++] = grad[idx>>16];
idx += step;
}
g+=dgdX*steps;
gradIdx--;
}
}
while (off < rowLimit) {
pixels[off++] = postVal;
}
}
off += adjust; //change in off from row to row
}
}
protected void fillSimpleNoCycle(int[] pixels, int off, int adjust,
int x, int y, int w, int h) {
//constant which can be pulled out of the inner loop
final float initConst = (dgdX*x) + gc;
final float step = dgdX*fastGradientArraySize;
final int fpStep = (int)(step*(1<<16)); // fix point step
final int [] grad = gradient;
for(int i=0; i=fastGradientArraySize)
val = gradientOverflow;
else
val = grad[(int)g];
while (off < rowLimit) {
pixels[off++] = val;
}
} else {
// System.out.println("In fillSimpleNC2: " + g);
int gradSteps;
int preGradSteps;
final int preVal, postVal;
if (dgdX > 0) {
gradSteps = (int)((fastGradientArraySize-g)/step);
preGradSteps = (int)Math.ceil(0-g/step);
preVal = gradientUnderflow;
postVal = gradientOverflow;
} else { // dgdX < 0
gradSteps = (int)((0-g)/step);
preGradSteps =
(int)Math.ceil((fastGradientArraySize-g)/step);
preVal = gradientOverflow;
postVal = gradientUnderflow;
}
if (gradSteps > w)
gradSteps = w;
final int gradLimit = off + gradSteps;
if (preGradSteps > 0) {
if (preGradSteps > w)
preGradSteps = w;
final int preGradLimit = off + preGradSteps;
while (off < preGradLimit) {
pixels[off++] = preVal;
}
g += step*preGradSteps;
}
int fpG = (int)(g*(1<<16));
while (off < gradLimit) {
pixels[off++] = grad[fpG>>16];
fpG += fpStep;
}
while (off < rowLimit) {
pixels[off++] = postVal;
}
}
off += adjust; //change in off from row to row
}
}
protected void fillSimpleRepeat(int[] pixels, int off, int adjust,
int x, int y, int w, int h) {
final float initConst = (dgdX*x) + gc;
// Limit step to fractional part of
// fastGradientArraySize (the non fractional part has
// no affect anyways, and would mess up lots of stuff
// below).
float step = (dgdX - (int)dgdX)*fastGradientArraySize;
// Make it a Positive step (a small negative step is
// the same as a positive step slightly less than
// fastGradientArraySize.
if (step < 0)
step += fastGradientArraySize;
final int [] grad = gradient;
for(int i=0; i= fastGradientArraySize) {
g -= fastGradientArraySize;
idx -= fastGradientArraySize;
}
pixels[off++] = grad[idx];
g += step;
}
off += adjust; //change in off from row to row
}
}
protected void fillSimpleReflect(int[] pixels, int off, int adjust,
int x, int y, int w, int h) {
final float initConst = (dgdX*x) + gc;
final int [] grad = gradient;
for (int i=0; i2
g = g - 2*((int)(g/2.0f));
float step = dgdX;
// Pull it into the positive half
if (g < 0) {
g = -g; //take absolute value
step = - step; // Change direction..
}
// Now do the same for dgdX. This is safe because
// any step that is a multiple of 2.0 has no
// affect, hence we can remove it which the first
// part does. The second part simply adds 2.0
// (which has no affect due to the cylcle) to move
// all negative step values into the positive
// side.
step = step - 2*((int)step/2.0f);
if (step < 0)
step += 2.0;
final int reflectMax = 2*fastGradientArraySize;
// Scale for gradient array.
g *= fastGradientArraySize;
g += 0.5;
step *= fastGradientArraySize;
final int rowLimit = off+w; // end of row iteration
while (off < rowLimit) {
int idx = (int)g;
if (idx >= reflectMax) {
g -= reflectMax;
idx -= reflectMax;
}
if (idx <= fastGradientArraySize)
pixels[off++] = grad[idx];
else
pixels[off++] = grad[reflectMax-idx];
g+= step;
}
off += adjust; //change in off from row to row
}
}
/**
* Return a Raster containing the colors generated for the graphics
* operation. This is where the area is filled with colors distributed
* linearly.
*
* @param x,y,w,h The area in device space for which colors are
* generated.
*
*/
protected void fillRaster(int[] pixels, int off, int adjust,
int x, int y, int w, int h) {
//constant which can be pulled out of the inner loop
final float initConst = (dgdX*x) + gc;
if (fillMethod == ANTI_ALIAS_IMPL) {
//initialize current value to be start.
for(int i=0; i