Added SkImage::MakeCrossContextFromEncoded

Designed for Flutter's threading architecture, with
an eye to being useful to other clients. Under the
hood, uses a new image generator class to lazily wrap
a texture for multiple GrContexts.

Re-land of https://skia-review.googlesource.com/c/14180/

Bug: skia:
Change-Id: I3dd382640629b79b3058f18fee68d043566e43e5
Reviewed-on: https://skia-review.googlesource.com/15895
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 41 insertions, 0 deletions

diff --git a/src/image/SkImage_Gpu.cpp b/src/image/SkImage_Gpu.cpp
index 1fdd084fa2..9bb98fbf10 100644
--- a/src/image/SkImage_Gpu.cpp
+++ b/src/image/SkImage_Gpu.cpp
@@ -11,6 +11,7 @@
 
 #include "SkAutoPixmapStorage.h"
 #include "GrBackendSurface.h"
+#include "GrBackendTextureImageGenerator.h"
 #include "GrBitmapTextureMaker.h"
 #include "GrCaps.h"
 #include "GrContext.h"
@@ -461,6 +462,46 @@ sk_sp<SkImage> SkImage::makeTextureImage(GrContext* context, SkColorSpace* dstCo
     return nullptr;
 }
 
+sk_sp<SkImage> SkImage::MakeCrossContextFromEncoded(GrContext* context, sk_sp<SkData> encoded,
+                                                    bool buildMips, SkColorSpace* dstColorSpace) {
+    sk_sp<SkImage> codecImage = SkImage::MakeFromEncoded(std::move(encoded));
+    if (!codecImage) {
+        return nullptr;
+    }
+
+    // Some backends or drivers don't support (safely) moving resources between contexts
+    if (!context || !context->caps()->crossContextTextureSupport()) {
+        return codecImage;
+    }
+
+    // Turn the codec image into a GrTextureProxy
+    GrImageTextureMaker maker(context, codecImage.get(), kDisallow_CachingHint);
+    sk_sp<SkColorSpace> texColorSpace;
+    GrSamplerParams params(SkShader::kClamp_TileMode,
+                           buildMips ? GrSamplerParams::kMipMap_FilterMode
+                                     : GrSamplerParams::kBilerp_FilterMode);
+    sk_sp<GrTextureProxy> proxy(maker.refTextureProxyForParams(params, dstColorSpace,
+                                                               &texColorSpace, nullptr));
+    if (!proxy) {
+        return codecImage;
+    }
+
+    sk_sp<GrTexture> texture(sk_ref_sp(proxy->instantiate(context->resourceProvider())));
+    if (!texture) {
+        return codecImage;
+    }
+
+    // Flush any writes or uploads
+    context->contextPriv().prepareSurfaceForExternalIO(proxy.get());
+
+    sk_sp<GrSemaphore> sema = context->getGpu()->prepareTextureForCrossContextUsage(texture.get());
+
+    auto gen = GrBackendTextureImageGenerator::Make(std::move(texture), std::move(sema),
+                                                    codecImage->alphaType(),
+                                                    std::move(texColorSpace));
+    return SkImage::MakeFromGenerator(std::move(gen));
+}
+
 std::unique_ptr<SkCrossContextImageData> SkCrossContextImageData::MakeFromEncoded(
         GrContext* context, sk_sp<SkData> encoded, SkColorSpace* dstColorSpace) {
     sk_sp<SkImage> codecImage = SkImage::MakeFromEncoded(std::move(encoded));