AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Eliminate the use of a tmp buffer for image blur

Browse Source 
Because the blur_one_direction routine, only reads the
source buffer once for each result, it can be used to
blur inplace. This allows the code to avoid using
a temporary buffer for the intermediate result.

This produces the same pixels according to skdiff, and
has the same speed.

Change-Id: I6485a71f0eb39936d69b8a98ab429a2cf592a7cd
Reviewed-on: https://skia-review.googlesource.com/74520
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Herb Derby <herb@google.com>
This commit is contained in:
Herb Derby 2017-11-20 14:04:15 -05:00 committed by Skia Commit-Bot
parent d46e85ff69
commit a0ec54829e
1 changed files with 26 additions and 36 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
src/core/SkBlurImageFilter.cpp
View File

@ -459,45 +459,35 @@ static sk_sp<SkSpecialImage> combined_pass_blur(
SkSTArenaAlloc<1024> alloc;
Sk4u* buffer = alloc.makeArrayDefault<Sk4u>(std::max(bufferSizeW, bufferSizeH));
if (windowW > 1 && windowH > 1) {
// Blur both directions.
if (windowW > 1 || windowH > 1) {
auto intermediateSrc = static_cast<uint32_t *>(src.getPixels());
auto intermediateRowBytesAsPixels = src.rowBytesAsPixels();
auto intermediateWidth = srcW;
auto tmpW = srcH,
tmpH = dstW;
if (windowW > 1) {
// For the horizontal blur, start part way down in anticipation of the vertical blur.
// If this is a horizontal only blur, then shift will be zero.
auto shift = (srcBounds.top() - dstBounds.top());
intermediateSrc = static_cast<uint32_t *>(dst.getPixels())
+ (shift > 0 ? shift * dst.rowBytesAsPixels() : 0);
intermediateRowBytesAsPixels = dst.rowBytesAsPixels();
intermediateWidth = dstW;
auto tmp = alloc.makeArrayDefault<uint32_t>(tmpW * tmpH);
blur_one_direction(
buffer, windowW,
srcBounds.left(), srcBounds.right(), dstBounds.right(),
static_cast<uint32_t *>(src.getPixels()), 1, src.rowBytesAsPixels(), srcH,
intermediateSrc, 1, intermediateRowBytesAsPixels);
}
// Blur horizontally, and transpose.
blur_one_direction(
buffer, windowW,
srcBounds.left(), srcBounds.right(), dstBounds.right(),
static_cast<uint32_t*>(src.getPixels()), 1, src.rowBytesAsPixels(), srcH,
tmp, tmpW, 1);
// Blur vertically (scan in memory order because of the transposition),
// and transpose back to the original orientation.
blur_one_direction(
buffer, windowH,
srcBounds.top(), srcBounds.bottom(), dstBounds.bottom(),
tmp, 1, tmpW, tmpH,
static_cast<uint32_t*>(dst.getPixels()), dst.rowBytesAsPixels(), 1);
} else if (windowW > 1) {
// Blur only horizontally.
blur_one_direction(
buffer, windowW,
srcBounds.left(), srcBounds.right(), dstBounds.right(),
static_cast<uint32_t*>(src.getPixels()), 1, src.rowBytesAsPixels(), srcH,
static_cast<uint32_t*>(dst.getPixels()), 1, dst.rowBytesAsPixels());
} else if (windowH > 1) {
// Blur only vertically.
blur_one_direction(
buffer, windowH,
srcBounds.top(), srcBounds.bottom(), dstBounds.bottom(),
static_cast<uint32_t*>(src.getPixels()), src.rowBytesAsPixels(), 1, srcW,
static_cast<uint32_t*>(dst.getPixels()), dst.rowBytesAsPixels(), 1);
} else {
if (windowH > 1) {
blur_one_direction(
buffer, windowH,
srcBounds.top(), srcBounds.bottom(), dstBounds.bottom(),
intermediateSrc, intermediateRowBytesAsPixels, 1, intermediateWidth,
static_cast<uint32_t *>(dst.getPixels()), dst.rowBytesAsPixels(), 1);
}
} else {
// There is no blurring to do, but we still need to copy the source while accounting for the
// dstBounds. Remember that the src was intersected with the dst.
int y = 0;