Move setAlphaAndRequiredFrame to src/codec
The corresponding declaration is already in src/codec/SkFrameHolder.h
That code is not solely used by third_party/gif, and in the future, we
may have another GIF implementation.
Bug: skia:
Change-Id: If04cfd4a5b1106f380c89e11c34a8d854ce2b05a
Reviewed-on: https://skia-review.googlesource.com/144240
Reviewed-by: Leon Scroggins <scroggo@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>
diff --git a/src/codec/SkCodec.cpp b/src/codec/SkCodec.cpp
index 130fcd1..d534be0 100644
--- a/src/codec/SkCodec.cpp
+++ b/src/codec/SkCodec.cpp
@@ -734,3 +734,104 @@
return "bogus result value";
}
}
+
+static SkIRect frame_rect_on_screen(SkIRect frameRect,
+ const SkIRect& screenRect) {
+ if (!frameRect.intersect(screenRect)) {
+ return SkIRect::MakeEmpty();
+ }
+
+ return frameRect;
+}
+
+static bool independent(const SkFrame& frame) {
+ return frame.getRequiredFrame() == SkCodec::kNone;
+}
+
+static bool restore_bg(const SkFrame& frame) {
+ return frame.getDisposalMethod() == SkCodecAnimation::DisposalMethod::kRestoreBGColor;
+}
+
+void SkFrameHolder::setAlphaAndRequiredFrame(SkFrame* frame) {
+ const bool reportsAlpha = frame->reportedAlpha() != SkEncodedInfo::kOpaque_Alpha;
+ const auto screenRect = SkIRect::MakeWH(fScreenWidth, fScreenHeight);
+ const auto frameRect = frame_rect_on_screen(frame->frameRect(), screenRect);
+
+ const int i = frame->frameId();
+ if (0 == i) {
+ frame->setHasAlpha(reportsAlpha || frameRect != screenRect);
+ frame->setRequiredFrame(SkCodec::kNone);
+ return;
+ }
+
+
+ const bool blendWithPrevFrame = frame->getBlend() == SkCodecAnimation::Blend::kPriorFrame;
+ if ((!reportsAlpha || !blendWithPrevFrame) && frameRect == screenRect) {
+ frame->setHasAlpha(reportsAlpha);
+ frame->setRequiredFrame(SkCodec::kNone);
+ return;
+ }
+
+ const SkFrame* prevFrame = this->getFrame(i-1);
+ while (prevFrame->getDisposalMethod() == SkCodecAnimation::DisposalMethod::kRestorePrevious) {
+ const int prevId = prevFrame->frameId();
+ if (0 == prevId) {
+ frame->setHasAlpha(true);
+ frame->setRequiredFrame(SkCodec::kNone);
+ return;
+ }
+
+ prevFrame = this->getFrame(prevId - 1);
+ }
+
+ const bool clearPrevFrame = restore_bg(*prevFrame);
+ auto prevFrameRect = frame_rect_on_screen(prevFrame->frameRect(), screenRect);
+
+ if (clearPrevFrame) {
+ if (prevFrameRect == screenRect || independent(*prevFrame)) {
+ frame->setHasAlpha(true);
+ frame->setRequiredFrame(SkCodec::kNone);
+ return;
+ }
+ }
+
+ if (reportsAlpha && blendWithPrevFrame) {
+ // Note: We could be more aggressive here. If prevFrame clears
+ // to background color and covers its required frame (and that
+ // frame is independent), prevFrame could be marked independent.
+ // Would this extra complexity be worth it?
+ frame->setRequiredFrame(prevFrame->frameId());
+ frame->setHasAlpha(prevFrame->hasAlpha() || clearPrevFrame);
+ return;
+ }
+
+ while (frameRect.contains(prevFrameRect)) {
+ const int prevRequiredFrame = prevFrame->getRequiredFrame();
+ if (prevRequiredFrame == SkCodec::kNone) {
+ frame->setRequiredFrame(SkCodec::kNone);
+ frame->setHasAlpha(true);
+ return;
+ }
+
+ prevFrame = this->getFrame(prevRequiredFrame);
+ prevFrameRect = frame_rect_on_screen(prevFrame->frameRect(), screenRect);
+ }
+
+ if (restore_bg(*prevFrame)) {
+ frame->setHasAlpha(true);
+ if (prevFrameRect == screenRect || independent(*prevFrame)) {
+ frame->setRequiredFrame(SkCodec::kNone);
+ } else {
+ // Note: As above, frame could still be independent, e.g. if
+ // prevFrame covers its required frame and that frame is
+ // independent.
+ frame->setRequiredFrame(prevFrame->frameId());
+ }
+ return;
+ }
+
+ SkASSERT(prevFrame->getDisposalMethod() == SkCodecAnimation::DisposalMethod::kKeep);
+ frame->setRequiredFrame(prevFrame->frameId());
+ frame->setHasAlpha(prevFrame->hasAlpha() || (reportsAlpha && !blendWithPrevFrame));
+}
+
diff --git a/third_party/gif/SkGifImageReader.cpp b/third_party/gif/SkGifImageReader.cpp
index a04f8e1..c62b788 100644
--- a/third_party/gif/SkGifImageReader.cpp
+++ b/third_party/gif/SkGifImageReader.cpp
@@ -862,23 +862,6 @@
}
}
-static SkIRect frame_rect_on_screen(SkIRect frameRect,
- const SkIRect& screenRect) {
- if (!frameRect.intersect(screenRect)) {
- return SkIRect::MakeEmpty();
- }
-
- return frameRect;
-}
-
-static bool independent(const SkFrame& frame) {
- return frame.getRequiredFrame() == SkCodec::kNone;
-}
-
-static bool restore_bg(const SkFrame& frame) {
- return frame.getDisposalMethod() == SkCodecAnimation::DisposalMethod::kRestoreBGColor;
-}
-
SkEncodedInfo::Alpha SkGIFFrameContext::onReportedAlpha() const {
// Note: We could correct these after decoding - i.e. some frames may turn out to be
// independent and opaque if they do not use the transparent pixel, but that would require
@@ -887,89 +870,6 @@
: SkEncodedInfo::kOpaque_Alpha;
}
-void SkFrameHolder::setAlphaAndRequiredFrame(SkFrame* frame) {
- const bool reportsAlpha = frame->reportedAlpha() != SkEncodedInfo::kOpaque_Alpha;
- const auto screenRect = SkIRect::MakeWH(fScreenWidth, fScreenHeight);
- const auto frameRect = frame_rect_on_screen(frame->frameRect(), screenRect);
-
- const int i = frame->frameId();
- if (0 == i) {
- frame->setHasAlpha(reportsAlpha || frameRect != screenRect);
- frame->setRequiredFrame(SkCodec::kNone);
- return;
- }
-
-
- const bool blendWithPrevFrame = frame->getBlend() == SkCodecAnimation::Blend::kPriorFrame;
- if ((!reportsAlpha || !blendWithPrevFrame) && frameRect == screenRect) {
- frame->setHasAlpha(reportsAlpha);
- frame->setRequiredFrame(SkCodec::kNone);
- return;
- }
-
- const SkFrame* prevFrame = this->getFrame(i-1);
- while (prevFrame->getDisposalMethod() == SkCodecAnimation::DisposalMethod::kRestorePrevious) {
- const int prevId = prevFrame->frameId();
- if (0 == prevId) {
- frame->setHasAlpha(true);
- frame->setRequiredFrame(SkCodec::kNone);
- return;
- }
-
- prevFrame = this->getFrame(prevId - 1);
- }
-
- const bool clearPrevFrame = restore_bg(*prevFrame);
- auto prevFrameRect = frame_rect_on_screen(prevFrame->frameRect(), screenRect);
-
- if (clearPrevFrame) {
- if (prevFrameRect == screenRect || independent(*prevFrame)) {
- frame->setHasAlpha(true);
- frame->setRequiredFrame(SkCodec::kNone);
- return;
- }
- }
-
- if (reportsAlpha && blendWithPrevFrame) {
- // Note: We could be more aggressive here. If prevFrame clears
- // to background color and covers its required frame (and that
- // frame is independent), prevFrame could be marked independent.
- // Would this extra complexity be worth it?
- frame->setRequiredFrame(prevFrame->frameId());
- frame->setHasAlpha(prevFrame->hasAlpha() || clearPrevFrame);
- return;
- }
-
- while (frameRect.contains(prevFrameRect)) {
- const int prevRequiredFrame = prevFrame->getRequiredFrame();
- if (prevRequiredFrame == SkCodec::kNone) {
- frame->setRequiredFrame(SkCodec::kNone);
- frame->setHasAlpha(true);
- return;
- }
-
- prevFrame = this->getFrame(prevRequiredFrame);
- prevFrameRect = frame_rect_on_screen(prevFrame->frameRect(), screenRect);
- }
-
- if (restore_bg(*prevFrame)) {
- frame->setHasAlpha(true);
- if (prevFrameRect == screenRect || independent(*prevFrame)) {
- frame->setRequiredFrame(SkCodec::kNone);
- } else {
- // Note: As above, frame could still be independent, e.g. if
- // prevFrame covers its required frame and that frame is
- // independent.
- frame->setRequiredFrame(prevFrame->frameId());
- }
- return;
- }
-
- SkASSERT(prevFrame->getDisposalMethod() == SkCodecAnimation::DisposalMethod::kKeep);
- frame->setRequiredFrame(prevFrame->frameId());
- frame->setHasAlpha(prevFrame->hasAlpha() || (reportsAlpha && !blendWithPrevFrame));
-}
-
// FIXME: Move this method to close to doLZW().
bool SkGIFLZWContext::prepareToDecode()
{