Java RadialGradientPaint.getFractions方法代码示例

import java.awt.RadialGradientPaint; //导入方法依赖的package包/类
/**
 * Create a new Gradient with its colours darkened.
 *
 * @param paint a <code>RadialGradientPaint</code>
 *
 * @return a darker version of the <code>RadialGradientPaint</code>
 */
private static Paint darkerRadialGradientPaint(RadialGradientPaint paint) {
    final Color[] paintColors = paint.getColors();
    for (int i = 0; i < paintColors.length; i++) {
        paintColors[i] = darker(paintColors[i]);
    }
    return new RadialGradientPaint(paint.getCenterPoint(), 
            paint.getRadius(), paint.getFocusPoint(), 
            paint.getFractions(), paintColors, paint.getCycleMethod(),
            paint.getColorSpace(), paint.getTransform());
}
 

import java.awt.RadialGradientPaint; //导入方法依赖的package包/类
/**
 * Create a new Gradient with its colours darkened.
 *
 * @param paint a {@code RadialGradientPaint}
 *
 * @return a darker version of the {@code RadialGradientPaint}
 */
private static Paint darkerRadialGradientPaint(RadialGradientPaint paint) {
    final Color[] paintColors = paint.getColors();
    for (int i = 0; i < paintColors.length; i++) {
        paintColors[i] = darker(paintColors[i]);
    }
    return new RadialGradientPaint(paint.getCenterPoint(), 
            paint.getRadius(), paint.getFocusPoint(), 
            paint.getFractions(), paintColors, paint.getCycleMethod(),
            paint.getColorSpace(), paint.getTransform());
}
 

import java.awt.RadialGradientPaint; //导入方法依赖的package包/类
/**
 * This method calculates six m** values and a focusX value that
 * are used by the native fragment shader.  These techniques are
 * based on a whitepaper by Daniel Rice on radial gradient performance
 * (attached to the bug report for 6521533).  One can refer to that
 * document for the complete set of formulas and calculations, but
 * the basic goal is to compose a transform that will convert an
 * (x,y) position in device space into a "u" value that represents
 * the relative distance to the gradient focus point.  The resulting
 * value can be used to look up the appropriate color by linearly
 * interpolating between the two nearest colors in the gradient.
 */
private static void setRadialGradientPaint(RenderQueue rq,
                                           SunGraphics2D sg2d,
                                           RadialGradientPaint paint,
                                           boolean useMask)
{
    boolean linear =
        (paint.getColorSpace() == ColorSpaceType.LINEAR_RGB);
    int cycleMethod = paint.getCycleMethod().ordinal();
    float[] fractions = paint.getFractions();
    Color[] colors = paint.getColors();
    int numStops = colors.length;
    int[] pixels = convertToIntArgbPrePixels(colors, linear);
    Point2D center = paint.getCenterPoint();
    Point2D focus = paint.getFocusPoint();
    float radius = paint.getRadius();

    // save original (untransformed) center and focus points
    double cx = center.getX();
    double cy = center.getY();
    double fx = focus.getX();
    double fy = focus.getY();

    // transform from gradient coords to device coords
    AffineTransform at = paint.getTransform();
    at.preConcatenate(sg2d.transform);
    focus = at.transform(focus, focus);

    // transform unit circle to gradient coords; we start with the
    // unit circle (center=(0,0), focus on positive x-axis, radius=1)
    // and then transform into gradient space
    at.translate(cx, cy);
    at.rotate(fx - cx, fy - cy);
    at.scale(radius, radius);

    // invert to get mapping from device coords to unit circle
    try {
        at.invert();
    } catch (Exception e) {
        at.setToScale(0.0, 0.0);
    }
    focus = at.transform(focus, focus);

    // clamp the focus point so that it does not rest on, or outside
    // of, the circumference of the gradient circle
    fx = Math.min(focus.getX(), 0.99);

    // assert rq.lock.isHeldByCurrentThread();
    rq.ensureCapacity(20 + 28 + (numStops*4*2));
    RenderBuffer buf = rq.getBuffer();
    buf.putInt(SET_RADIAL_GRADIENT_PAINT);
    buf.putInt(useMask ? 1 : 0);
    buf.putInt(linear  ? 1 : 0);
    buf.putInt(numStops);
    buf.putInt(cycleMethod);
    buf.putFloat((float)at.getScaleX());
    buf.putFloat((float)at.getShearX());
    buf.putFloat((float)at.getTranslateX());
    buf.putFloat((float)at.getShearY());
    buf.putFloat((float)at.getScaleY());
    buf.putFloat((float)at.getTranslateY());
    buf.putFloat((float)fx);
    buf.put(fractions);
    buf.put(pixels);
}