/** Set blur radius in screen pixels. Value is mapped in range [1, 254]. */
public void setBlurRadius(int radius) {
// Map radius into scaled down off-screen bitmap size
radius = Math.round(radius * BITMAP_SCALE_FACTOR);
// Setup radius struct
mRadiusStruct.radius = Math.max(1, Math.min(254, radius));
mRadiusStruct.div = mRadiusStruct.radius + mRadiusStruct.radius + 1;
mRadiusStruct.divsum = (mRadiusStruct.div + 1) >> 1;
mRadiusStruct.divsum *= mRadiusStruct.divsum;
// Prepare dv allocation
mAllocationDv = Allocation.createSized(mRS, Element.U8(mRS), 256 * mRadiusStruct.divsum);
mScriptStackBlur.set_initializeDv_divsum(mRadiusStruct.divsum);
mScriptStackBlur.forEach_initializeDv(mAllocationDv);
}
/** Applies blur to current off-screen bitmap */
public void applyBlur() {
// Copy current bitmap into allocation
mAllocationBitmap.copyFrom(mBitmap);
// Set script variables
mScriptStackBlur.bind_dv(mAllocationDv);
mScriptStackBlur.set_bitmap(mAllocationBitmap);
mScriptStackBlur.set_bitmapTmp(mAllocationBitmapTmp);
mScriptStackBlur.set_sizeStruct(mSizeStruct);
mScriptStackBlur.set_radiusStruct(mRadiusStruct);
// On first step iterate over y = [0, mBitmap.getHeight]
mLaunchOptions.setX(0, 1);
mLaunchOptions.setY(0, mBitmap.getHeight());
mScriptStackBlur.forEach_blurHorizontal(mAllocationBitmap, mLaunchOptions);
// On second step iterate over x = [0, mBitmap.getWidth]
mLaunchOptions.setX(0, mBitmap.getWidth());
mLaunchOptions.setY(0, 1);
mScriptStackBlur.forEach_blurVertical(mAllocationBitmap, mLaunchOptions);
// Copy bitmap allocation back to off-screen bitmap
mAllocationBitmap.copyTo(mBitmap);
}