Bug 1355430 - Part2: Implement Require Fastpath for texture copy; r=baku,jgilbert

MozReview-Commit-ID: EPNSJbbJHP4

--HG--
extra : rebase_source : b27a254e247a40285873b53edb036b5b97d4e0d8

dom/canvas/TexUnpackBlob.cpp

@@ -710,9 +710,16 @@ TexUnpackImage::TexOrSubImage(bool isSubImage, bool needsRespec, const char* fun
         return true;
     } while (false);
 
-    webgl->GeneratePerfWarning("%s: Failed to hit GPU-copy fast-path. (src type %u)"
-                               " Falling back to CPU upload. (%s)",
-                               funcName, uint32_t(mImage->GetFormat()), fallbackReason);
+    const nsPrintfCString perfMsg("%s: Failed to hit GPU-copy fast-path: %s (src type %u)",
+                                  funcName, fallbackReason, uint32_t(mImage->GetFormat()));
+
+    if (webgl->mPixelStore_RequireFastPath) {
+        webgl->ErrorInvalidOperation("%s", perfMsg.BeginReading());
+        return false;
+    }
+
+    webgl->GeneratePerfWarning("%s Falling back to CPU upload.",
+                               perfMsg.BeginReading());
 
     const RefPtr<gfx::SourceSurface> surf = mImage->GetAsSourceSurface();
 

dom/canvas/WebGLContext.h

@@ -321,6 +321,9 @@ class WebGLContext
     enum {
         UNPACK_FLIP_Y_WEBGL = 0x9240,
         UNPACK_PREMULTIPLY_ALPHA_WEBGL = 0x9241,
+        // We throw InvalidOperation in TexImage if we fail to use GPU fast-path
+        // for texture copy when it is set to true, only for debug purpose.
+        UNPACK_REQUIRE_FASTPATH = 0x10001,
         CONTEXT_LOST_WEBGL = 0x9242,
         UNPACK_COLORSPACE_CONVERSION_WEBGL = 0x9243,
         BROWSER_DEFAULT_WEBGL = 0x9244,
@@ -1871,6 +1874,7 @@ protected:
     GLenum mPixelStore_ColorspaceConversion;
     bool mPixelStore_FlipY;
     bool mPixelStore_PremultiplyAlpha;
+    bool mPixelStore_RequireFastPath;
 
     ////////////////////////////////////
     class FakeBlackTexture {

dom/canvas/WebGLContextGL.cpp

@@ -1128,6 +1128,13 @@ WebGLContext::PixelStorei(GLenum pname, GLint param)
             return;
         }
 
+    case UNPACK_REQUIRE_FASTPATH:
+        if (IsExtensionEnabled(WebGLExtensionID::MOZ_debug)) {
+            mPixelStore_RequireFastPath = bool(param);
+            return;
+        }
+        break;
+
     case LOCAL_GL_PACK_ALIGNMENT:
     case LOCAL_GL_UNPACK_ALIGNMENT:
         switch (param) {

dom/canvas/WebGLContextValidate.cpp

@@ -701,6 +701,7 @@ WebGLContext::InitAndValidateGL(FailureReason* const out_failReason)
     mPixelStore_FlipY = false;
     mPixelStore_PremultiplyAlpha = false;
     mPixelStore_ColorspaceConversion = BROWSER_DEFAULT_WEBGL;
+    mPixelStore_RequireFastPath = false;
 
     // GLES 3.0.4, p259:
     mPixelStore_UnpackImageHeight = 0;

dom/webidl/WebGLRenderingContext.webidl

@@ -1088,6 +1088,7 @@ interface EXT_disjoint_timer_query {
 interface MOZ_debug {
     const GLenum EXTENSIONS = 0x1F03;
     const GLenum WSI_INFO   = 0x10000;
+    const GLenum UNPACK_REQUIRE_FASTPATH = 0x10001;
 
     [Throws]
     any getParameter(GLenum pname);