Hi there,
I've come up with an alternative way of computing radial gradients,
which, according to my testing, is about twice as fast as the one in
batik right now. Interested? I've attached a partial patch (it's not
complete yet, it doesn't handle some cases).
Cheers,
-- Ulf
/*
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
this work for additional information regarding copyright ownership.
The ASF licenses this file to You 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.
*/
private void cyclicCircularGradientFillRaster(int pixels[], int off,
int adjust,
int x, int y,
int w, int h)
{
// constant parts of X, Y coordinates
final float constX = (a00*x) + (a01*y) + a02;
final float constY = (a10*x) + (a11*y) + a12;
// used to index pixels array
int indexer = off;
// incremental index change for pixels array
int pixInc = w+adjust;
float d2 =
(focusX-centerX)*(focusX-centerX)+(focusY-centerY)*(focusY-centerY);
float r2 = radiusSq;
if (d2 >= r2) {
throw new RuntimeException();
}
float c = d2 - r2; // d2 < r2 => c < 0, so the sqrt is always
well-defined
float dX = a00;
float dY = a10;
// for every row
for (int j = 0; j < h; j++) {
// user space point; these are constant from column to column
float X = (a01*j) + constX;
float Y = (a11*j) + constY;
float vX = (X-focusX)*(focusX-centerX);
float vY = (Y-focusY)*(focusY-centerY);
float b = vX+vY;
float db = dX*(focusX-centerX)+dY*(focusY-centerY);
float aX = (X-focusX);
float aY = (Y-focusY);
// for every column (inner loop begins here)
for (int i = 0; i < w; i++) {
float a = aX*aX + aY*aY;
float g = (float) (a / (-b + Math.sqrt(b * b - a * c)));
// store the color at this point
pixels[indexer + i] = indexIntoGradientsArrays(g);
// incremental change
b += db;
aX += dX;
aY += dY;
} //end inner loop
indexer += pixInc;
} //end outer loop
}
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
