private void drawSeparationLines(Canvas canvas) {
        final PieChartData data = dataProvider.getPieChartData();
        if (data.getValues().size() < 2) {
            //No need for separation lines for 0 or 1 slices.
            return;
        }
        final int sliceSpacing = ChartUtils.dp2px(density, data.getSlicesSpacing());
        if (sliceSpacing < 1) {
            //No need for separation lines
            return;
        }
        final float sliceScale = 360f / maxSum;
        float lastAngle = rotation;
        final float circleRadius = originCircleOval.width() / 2f;
        separationLinesPaint.setStrokeWidth(sliceSpacing);
        for (SliceValue sliceValue : data.getValues()) {
            final float angle = Math.abs(sliceValue.getValue()) * sliceScale;

            sliceVector.set((float) (Math.cos(Math.toRadians(lastAngle))),
                    (float) (Math.sin(Math.toRadians(lastAngle))));
            normalizeVector(sliceVector);

            float x1 = sliceVector.x * (circleRadius + touchAdditional) + originCircleOval.centerX();
            float y1 = sliceVector.y * (circleRadius + touchAdditional) + originCircleOval.centerY();

            canvas.drawLine(originCircleOval.centerX(), originCircleOval.centerY(), x1, y1, separationLinesPaint);

            lastAngle += angle;
        }
    }
Draw all slices for this PieChart, if mode == {@link #MODE_HIGHLIGHT} currently selected slices will be redrawn
and
highlighted.

@param canvas
hellocharts-library/src/lecho/lib/hellocharts/renderer/PieChartRenderer.java