Support downscaling to max texture size when making cross-context images

This is one solution to https://github.com/flutter/flutter/issues/16454

Change-Id: Iacd59f07e1bf87b6caccb64df16ab8827dfc78b1
Reviewed-on: https://skia-review.googlesource.com/121342
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>

1 files changed, 20 insertions, 16 deletions

diff --git a/docs/SkImage_Reference.bmh b/docs/SkImage_Reference.bmh
index 7d93555b68..32ddbe3397 100644
--- a/docs/SkImage_Reference.bmh
+++ b/docs/SkImage_Reference.bmh
@@ -465,7 +465,8 @@ for (auto origin : { kBottomLeft_GrSurfaceOrigin, kTopLeft_GrSurfaceOrigin } ) {
 
 #Method static sk_sp<SkImage> MakeCrossContextFromEncoded(GrContext* context, sk_sp<SkData> data,
                                                       bool buildMips,
-                                                      SkColorSpace* dstColorSpace)
+                                                      SkColorSpace* dstColorSpace,
+                                                      bool limitToMaxTextureSize = false)
 #In Constructor
 #Line # creates Image from encoded data, and uploads to GPU ##
 
@@ -491,6 +492,7 @@ moving resources between contexts.
 #Param data  Image to decode ##
 #Param buildMips  create Image as Mip_Map if true ##
 #Param dstColorSpace  range of colors of matching Surface on GPU ##
+#Param limitToMaxTextureSize  downscale image to GPU maximum texture size, if necessary ##
 
 #Return created Image, or nullptr ##
 
@@ -512,7 +514,8 @@ canvas->drawImage(image, 0, 0);
 
 #Method static sk_sp<SkImage> MakeCrossContextFromPixmap(GrContext* context, const SkPixmap& pixmap,
                                                       bool buildMips,
-                                                      SkColorSpace* dstColorSpace)
+                                                      SkColorSpace* dstColorSpace,
+                                                      bool limitToMaxTextureSize = false)
 #In Constructor
 #Line # creates Image from Pixmap, and uploads to GPU ##
 
@@ -538,6 +541,7 @@ Recognized GPU formats vary by platform and GPU back-end.
 #Param pixmap  Image_Info, pixel address, and row bytes ##
 #Param buildMips  create Image as Mip_Map if true ##
 #Param dstColorSpace  range of colors of matching Surface on GPU ##
+#Param limitToMaxTextureSize  downscale image to GPU maximum texture size, if necessary ##
 
 #Return created Image, or nullptr ##
 
@@ -1413,20 +1417,20 @@ If origin in not nullptr, copies location of content drawn into Image.
 #Example
 #Image 3
 #Platform gpu
-    GrContext* grContext = canvas->getGrContext();

-    if (!grContext) {

-        canvas->drawString("GPU only!", 20, 40, SkPaint());

-        return;

-    }

-    sk_sp<SkImage> imageFromBackend = SkImage::MakeFromAdoptedTexture(grContext, backEndTexture,

-            kBottomLeft_GrSurfaceOrigin, kRGBA_8888_SkColorType, kOpaque_SkAlphaType);

-    GrBackendTexture textureFromImage = imageFromBackend->getBackendTexture(false);

-    if (!textureFromImage.isValid()) {

-        return;

-    }

-    sk_sp<SkImage> imageFromTexture = SkImage::MakeFromAdoptedTexture(grContext, textureFromImage,

-            kTopLeft_GrSurfaceOrigin, kRGBA_8888_SkColorType, kOpaque_SkAlphaType);

-    canvas->drawImage(imageFromTexture, 0, 0);

+    GrContext* grContext = canvas->getGrContext();
+    if (!grContext) {
+        canvas->drawString("GPU only!", 20, 40, SkPaint());
+        return;
+    }
+    sk_sp<SkImage> imageFromBackend = SkImage::MakeFromAdoptedTexture(grContext, backEndTexture,
+            kBottomLeft_GrSurfaceOrigin, kRGBA_8888_SkColorType, kOpaque_SkAlphaType);
+    GrBackendTexture textureFromImage = imageFromBackend->getBackendTexture(false);
+    if (!textureFromImage.isValid()) {
+        return;
+    }
+    sk_sp<SkImage> imageFromTexture = SkImage::MakeFromAdoptedTexture(grContext, textureFromImage,
+            kTopLeft_GrSurfaceOrigin, kRGBA_8888_SkColorType, kOpaque_SkAlphaType);
+    canvas->drawImage(imageFromTexture, 0, 0);
     canvas->drawImage(imageFromBackend, 128, 128);
 ##