Bug 1305540 - Lazily bind PBO targets. - r=ethlin

MozReview-Commit-ID: B9WiCNfNsfY

dom/canvas/TexUnpackBlob.cpp

@@ -395,15 +395,16 @@ TexUnpackBytes::TexOrSubImage(bool isSubImage, bool needsRespec, const char* fun
 
     if (!isSubImage) {
         // Alloc first to catch OOMs.
-        gl->fBindBuffer(LOCAL_GL_PIXEL_UNPACK_BUFFER, 0);
+        AssertUintParamCorrect(gl, LOCAL_GL_PIXEL_UNPACK_BUFFER, 0);
         *out_error = DoTexOrSubImage(false, gl, target, level, dui, xOffset, yOffset,
                                      zOffset, mWidth, mHeight, mDepth, nullptr);
-        gl->fBindBuffer(LOCAL_GL_PIXEL_UNPACK_BUFFER,
-                        webgl->mBoundPixelUnpackBuffer->mGLName);
         if (*out_error)
             return false;
     }
 
+    const ScopedLazyBind bindPBO(gl, LOCAL_GL_PIXEL_UNPACK_BUFFER,
+                                 webgl->mBoundPixelUnpackBuffer);
+
     //////
 
     // Make our sometimes-implicit values explicit. Also this keeps them constant when we

dom/canvas/WebGL2ContextBuffers.cpp

@@ -85,6 +85,8 @@ WebGL2Context::CopyBufferSubData(GLenum readTarget, GLenum writeTarget,
     }
 
     gl->MakeCurrent();
+    const ScopedLazyBind readBind(gl, readTarget, readBuffer);
+    const ScopedLazyBind writeBind(gl, writeTarget, writeBuffer);
     gl->fCopyBufferSubData(readTarget, writeTarget, readOffset, writeOffset, size);
 }
 
@@ -143,6 +145,7 @@ WebGL2Context::GetBufferSubData(GLenum target, GLintptr offset,
     ////
 
     gl->MakeCurrent();
+    const ScopedLazyBind readBind(gl, target, buffer);
 
     const auto ptr = gl->fMapBufferRange(target, offset, data.LengthAllowShared(),
                                          LOCAL_GL_MAP_READ_BIT);

dom/canvas/WebGLBuffer.cpp

@@ -114,6 +114,7 @@ WebGLBuffer::BufferData(GLenum target, size_t size, const void* data, GLenum usa
 
     const auto& gl = mContext->gl;
     gl->MakeCurrent();
+    const ScopedLazyBind lazyBind(gl, target, this);
     mContext->InvalidateBufferFetching();
 
 #ifdef XP_MACOSX

dom/canvas/WebGLContext.cpp

@@ -2159,6 +2159,39 @@ ScopedFBRebinder::UnwrapImpl()
     }
 }
 
+////////////////////
+
+static GLenum
+TargetIfLazy(GLenum target)
+{
+    switch (target) {
+    case LOCAL_GL_PIXEL_PACK_BUFFER:
+    case LOCAL_GL_PIXEL_UNPACK_BUFFER:
+        return target;
+
+    default:
+        return 0;
+    }
+}
+
+ScopedLazyBind::ScopedLazyBind(gl::GLContext* gl, GLenum target, const WebGLBuffer* buf)
+    : ScopedGLWrapper<ScopedLazyBind>(gl)
+    , mTarget(buf ? TargetIfLazy(target) : 0)
+    , mBuf(buf)
+{
+    if (mTarget) {
+        mGL->fBindBuffer(mTarget, mBuf->mGLName);
+    }
+}
+
+void
+ScopedLazyBind::UnwrapImpl()
+{
+    if (mTarget) {
+        mGL->fBindBuffer(mTarget, 0);
+    }
+}
+
 ////////////////////////////////////////
 
 void

dom/canvas/WebGLContext.h

@@ -1834,6 +1834,21 @@ private:
     void UnwrapImpl();
 };
 
+class ScopedLazyBind final
+    : public gl::ScopedGLWrapper<ScopedLazyBind>
+{
+    friend struct gl::ScopedGLWrapper<ScopedLazyBind>;
+
+    const GLenum mTarget;
+    const WebGLBuffer* const mBuf;
+
+public:
+    ScopedLazyBind(gl::GLContext* gl, GLenum target, const WebGLBuffer* buf);
+
+private:
+    void UnwrapImpl();
+};
+
 void
 ComputeLengthAndData(const dom::ArrayBufferViewOrSharedArrayBufferView& view,
                      void** const out_data, size_t* const out_length,

dom/canvas/WebGLContextBuffers.cpp

@@ -137,6 +137,13 @@ WebGLContext::BindBuffer(GLenum target, WebGLBuffer* buffer)
     if (buffer) {
         buffer->SetContentAfterBind(target);
     }
+
+    switch (target) {
+    case LOCAL_GL_PIXEL_PACK_BUFFER:
+    case LOCAL_GL_PIXEL_UNPACK_BUFFER:
+        gl->fBindBuffer(target, 0);
+        break;
+    }
 }
 
 ////////////////////////////////////////
@@ -429,6 +436,8 @@ WebGLContext::BufferSubDataT(GLenum target,
     }
 
     MakeContextCurrent();
+    const ScopedLazyBind lazyBind(gl, target, buffer);
+
     // Warning: Possibly shared memory.  See bug 1225033.
     gl->fBufferSubData(target, byteOffset, data.LengthAllowShared(),
                        data.DataAllowShared());

dom/canvas/WebGLContextGL.cpp

@@ -1528,6 +1528,9 @@ WebGL2Context::ReadPixels(GLint x, GLint y, GLsizei width, GLsizei height, GLenu
         bytesAfterOffset = checkedBytesAfterOffset.value();
     }
 
+    gl->MakeCurrent();
+    const ScopedLazyBind lazyBind(gl, LOCAL_GL_PIXEL_PACK_BUFFER, mBoundPixelPackBuffer);
+
     ReadPixelsImpl(x, y, width, height, format, type, (void*)offset, bytesAfterOffset);
 }