Only use the gainmap shader if we might need it
Skip using the gainmap shader when drawing to a bitmap
with a known SDR colorspace as it'll be a no-op in
rendering results since W=1.0, but it'll be very expensive
in runtime due to CPU evaluation of the SKSL shader.
Before:
createScaledBitmapWithGainmap_median (ns): 179,455,037
After:
createScaledBitmapWithGainmap_median (ns): 15,643,742
Bug: 311085927
Test: benchmark in CL
Change-Id: I3f2506a2bd86bbe29c6e0837d31e4a231a7c182a
diff --git a/libs/hwui/SkiaCanvas.cpp b/libs/hwui/SkiaCanvas.cpp
index 31fc929..008ea3a 100644
--- a/libs/hwui/SkiaCanvas.cpp
+++ b/libs/hwui/SkiaCanvas.cpp
@@ -589,10 +589,40 @@
// Canvas draw operations: Bitmaps
// ----------------------------------------------------------------------------
+bool SkiaCanvas::useGainmapShader(Bitmap& bitmap) {
+ // If the bitmap doesn't have a gainmap, don't use the gainmap shader
+ if (!bitmap.hasGainmap()) return false;
+
+ // If we don't have an owned canvas, then we're either hardware accelerated or drawing
+ // to a picture - use the gainmap shader out of caution. Ideally a picture canvas would
+ // use a drawable here instead to defer making that decision until the last possible
+ // moment
+ if (!mCanvasOwned) return true;
+
+ auto info = mCanvasOwned->imageInfo();
+
+ // If it's an unknown colortype then it's not a bitmap-backed canvas
+ if (info.colorType() == SkColorType::kUnknown_SkColorType) return true;
+
+ skcms_TransferFunction tfn;
+ info.colorSpace()->transferFn(&tfn);
+
+ auto transferType = skcms_TransferFunction_getType(&tfn);
+ switch (transferType) {
+ case skcms_TFType_HLGish:
+ case skcms_TFType_HLGinvish:
+ case skcms_TFType_PQish:
+ return true;
+ case skcms_TFType_Invalid:
+ case skcms_TFType_sRGBish:
+ return false;
+ }
+}
+
void SkiaCanvas::drawBitmap(Bitmap& bitmap, float left, float top, const Paint* paint) {
auto image = bitmap.makeImage();
- if (bitmap.hasGainmap()) {
+ if (useGainmapShader(bitmap)) {
Paint gainmapPaint = paint ? *paint : Paint();
sk_sp<SkShader> gainmapShader = uirenderer::MakeGainmapShader(
image, bitmap.gainmap()->bitmap->makeImage(), bitmap.gainmap()->info,
@@ -619,7 +649,7 @@
SkRect srcRect = SkRect::MakeLTRB(srcLeft, srcTop, srcRight, srcBottom);
SkRect dstRect = SkRect::MakeLTRB(dstLeft, dstTop, dstRight, dstBottom);
- if (bitmap.hasGainmap()) {
+ if (useGainmapShader(bitmap)) {
Paint gainmapPaint = paint ? *paint : Paint();
sk_sp<SkShader> gainmapShader = uirenderer::MakeGainmapShader(
image, bitmap.gainmap()->bitmap->makeImage(), bitmap.gainmap()->info,