Fallback to creating Skia managed images on platforms that dont provide a GL...

Fallback to creating Skia managed images on platforms that dont provide a GL context on the resource loader. (#2849)

flow/texture_image.cc

@@ -9,6 +9,18 @@
 
 namespace flow {
 
+enum class TextureImageFormat {
+  Grey,
+  GreyAlpha,
+  RGB,
+  RGBA,
+};
+
+enum class TextureImageDataFormat {
+  UnsignedByte,
+  UnsignedShort565,
+};
+
 static inline GLint ToGLFormat(TextureImageFormat format) {
   switch (format) {
     case TextureImageFormat::RGBA:
@@ -56,7 +68,81 @@ static inline SkColorType ToSkColorType(TextureImageFormat format) {
   return kRGB_565_SkColorType;
 }
 
-sk_sp<SkImage> TextureImageCreate(GrContext* context, const SkBitmap& bitmap) {
+static sk_sp<SkImage> TextureImageCreate(GrContext* context,
+                                         TextureImageFormat format,
+                                         const SkISize& size,
+                                         TextureImageDataFormat dataFormat,
+                                         const uint8_t* data) {
+  TRACE_EVENT2("flutter", __func__, "width", size.width(), "height",
+               size.height());
+
+  if (context == nullptr) {
+    return nullptr;
+  }
+
+  GLuint handle = GL_NONE;
+
+  // Generate the texture handle.
+  glGenTextures(1, &handle);
+
+  // Bind the texture.
+  glBindTexture(GL_TEXTURE_2D, handle);
+
+  // Specify default texture properties.
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+  // Update unpack alignment based on format.
+  glPixelStorei(GL_UNPACK_ALIGNMENT,
+                dataFormat == TextureImageDataFormat::UnsignedByte ? 4 : 2);
+
+  GLint gl_format = ToGLFormat(format);
+
+  // Upload the texture.
+  glTexImage2D(GL_TEXTURE_2D,               // target
+               0,                           // level
+               gl_format,                   // internal format
+               size.fWidth,                 // width
+               size.fHeight,                // height
+               0,                           // border
+               gl_format,                   // format
+               ToGLDataFormat(dataFormat),  // format
+               data);
+
+  // Clear the binding. We are done.
+  glBindTexture(GL_TEXTURE_2D, GL_NONE);
+
+  GrGLTextureInfo texInfo;
+  texInfo.fTarget = GL_TEXTURE_2D;
+  texInfo.fID = handle;
+
+  // Create an SkImage handle from the texture.
+  GrBackendTextureDesc desc;
+
+  desc.fOrigin = kTopLeft_GrSurfaceOrigin;
+  desc.fFlags = kNone_GrBackendTextureFlag;
+  desc.fWidth = size.fWidth;
+  desc.fHeight = size.fHeight;
+  desc.fTextureHandle = reinterpret_cast<GrBackendObject>(&texInfo);
+
+  desc.fConfig = ToGrPixelConfig(dataFormat);
+
+  if (auto image = SkImage::MakeFromAdoptedTexture(context, desc)) {
+    // Texture handle was successfully adopted by the SkImage.
+    return image;
+  }
+
+  // We could not create an SkImage from the texture. Since it could not be
+  // adopted, delete the handle and return null.
+  glDeleteTextures(1, &handle);
+
+  return nullptr;
+}
+
+static sk_sp<SkImage> TextureImageCreate(GrContext* context,
+                                         const SkBitmap& bitmap) {
   if (context == nullptr) {
     return nullptr;
   }
@@ -91,13 +177,23 @@ sk_sp<SkImage> TextureImageCreate(GrContext* context, const SkBitmap& bitmap) {
       );
 }
 
+sk_sp<SkImage> BitmapImageCreate(SkImageGenerator& generator) {
+  SkBitmap bitmap;
+
+  if (generator.tryGenerateBitmap(&bitmap)) {
+    return SkImage::MakeFromBitmap(bitmap);
+  }
+
+  return nullptr;
+}
+
 sk_sp<SkImage> TextureImageCreate(GrContext* context,
-                                  std::unique_ptr<SkImageGenerator> generator) {
-  if (context == nullptr || generator == nullptr) {
+                                  SkImageGenerator& generator) {
+  if (context == nullptr) {
     return nullptr;
   }
 
-  const SkImageInfo& info = generator->getInfo();
+  const SkImageInfo& info = generator.getInfo();
 
   if (info.isEmpty()) {
     return nullptr;
@@ -123,7 +219,7 @@ sk_sp<SkImage> TextureImageCreate(GrContext* context,
     TRACE_EVENT1("flutter", "DecodePrimaryPreferrence", "Type",
                  preferOpaque ? "RGB565" : "RGBA8888");
     // Try our preferred config.
-    if (generator->tryGenerateBitmap(&bitmap, preferredImageInfo, nullptr)) {
+    if (generator.tryGenerateBitmap(&bitmap, preferredImageInfo, nullptr)) {
       // Our got our preferred bitmap.
       return TextureImageCreate(context, bitmap);
     }
@@ -132,7 +228,7 @@ sk_sp<SkImage> TextureImageCreate(GrContext* context,
   {
     TRACE_EVENT0("flutter", "DecodeRecommended");
     // Try the guessed config.
-    if (generator->tryGenerateBitmap(&bitmap)) {
+    if (generator.tryGenerateBitmap(&bitmap)) {
       return TextureImageCreate(context, bitmap);
     }
   }
@@ -140,77 +236,4 @@ sk_sp<SkImage> TextureImageCreate(GrContext* context,
   return nullptr;
 }
 
-sk_sp<SkImage> TextureImageCreate(GrContext* context,
-                                  TextureImageFormat format,
-                                  const SkISize& size,
-                                  TextureImageDataFormat dataFormat,
-                                  const uint8_t* data) {
-  TRACE_EVENT2("flutter", __func__, "width", size.width(), "height",
-               size.height());
-
-  if (context == nullptr) {
-    return nullptr;
-  }
-
-  GLuint handle = GL_NONE;
-
-  // Generate the texture handle.
-  glGenTextures(1, &handle);
-
-  // Bind the texture.
-  glBindTexture(GL_TEXTURE_2D, handle);
-
-  // Specify default texture properties.
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-
-  // Update unpack alignment based on format.
-  glPixelStorei(GL_UNPACK_ALIGNMENT,
-                dataFormat == TextureImageDataFormat::UnsignedByte ? 4 : 2);
-
-  GLint gl_format = ToGLFormat(format);
-
-  // Upload the texture.
-  glTexImage2D(GL_TEXTURE_2D,               // target
-               0,                           // level
-               gl_format,                   // internal format
-               size.fWidth,                 // width
-               size.fHeight,                // height
-               0,                           // border
-               gl_format,                   // format
-               ToGLDataFormat(dataFormat),  // format
-               data);
-
-  // Clear the binding. We are done.
-  glBindTexture(GL_TEXTURE_2D, GL_NONE);
-
-  GrGLTextureInfo texInfo;
-  texInfo.fTarget = GL_TEXTURE_2D;
-  texInfo.fID = handle;
-
-  // Create an SkImage handle from the texture.
-  GrBackendTextureDesc desc;
-
-  desc.fOrigin = kTopLeft_GrSurfaceOrigin;
-  desc.fFlags = kNone_GrBackendTextureFlag;
-  desc.fWidth = size.fWidth;
-  desc.fHeight = size.fHeight;
-  desc.fTextureHandle = reinterpret_cast<GrBackendObject>(&texInfo);
-
-  desc.fConfig = ToGrPixelConfig(dataFormat);
-
-  if (auto image = SkImage::MakeFromAdoptedTexture(context, desc)) {
-    // Texture handle was successfully adopted by the SkImage.
-    return image;
-  }
-
-  // We could not create an SkImage from the texture. Since it could not be
-  // adopted, delete the handle and return null.
-  glDeleteTextures(1, &handle);
-
-  return nullptr;
-}
-
 }  // namespace flow

flow/texture_image.h

@@ -10,28 +10,10 @@
 
 namespace flow {
 
-enum class TextureImageFormat {
-  Grey,
-  GreyAlpha,
-  RGB,
-  RGBA,
-};
-
-enum class TextureImageDataFormat {
-  UnsignedByte,
-  UnsignedShort565,
-};
-
-sk_sp<SkImage> TextureImageCreate(GrContext* context, const SkBitmap& bitmap);
-
 sk_sp<SkImage> TextureImageCreate(GrContext* context,
-                                  std::unique_ptr<SkImageGenerator> generator);
+                                  SkImageGenerator& generator);
 
-sk_sp<SkImage> TextureImageCreate(GrContext* context,
-                                  TextureImageFormat format,
-                                  const SkISize& size,
-                                  TextureImageDataFormat dataFormat,
-                                  const uint8_t* data);
+sk_sp<SkImage> BitmapImageCreate(SkImageGenerator& generator);
 
 }  // namespace flow
 

flutter/lib/ui/painting/image_decoding.cc

@@ -48,7 +48,14 @@ sk_sp<SkImage> DecodeImage(PassRefPtr<SharedBuffer> buffer) {
   auto context = reinterpret_cast<GrContext*>(
       sky::shell::PlatformView::ResourceContext.Get());
 
-  return flow::TextureImageCreate(context, std::move(generator));
+  // First, try to create a texture image from the generator.
+  if (auto image = flow::TextureImageCreate(context, *generator)) {
+    return image;
+  }
+
+  // The, as a fallback, try to create a regular Skia managed image. These
+  // don't require a context ready.
+  return flow::BitmapImageCreate(*generator);
 }
 
 void InvokeImageCallback(sk_sp<SkImage> image,