Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1037 insertions, 0 deletions

diff --git a/dom/canvas/TexUnpackBlob.cpp b/dom/canvas/TexUnpackBlob.cpp
new file mode 100644
index 0000000000..8598c36227
--- /dev/null
+++ b/dom/canvas/TexUnpackBlob.cpp
@@ -0,0 +1,1037 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "TexUnpackBlob.h"
+
+#include "GLBlitHelper.h"
+#include "GLContext.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/HTMLCanvasElement.h"
+#include "mozilla/gfx/Logging.h"
+#include "mozilla/layers/ImageDataSerializer.h"
+#include "mozilla/layers/TextureHost.h"
+#include "mozilla/layers/VideoBridgeParent.h"
+#include "mozilla/RefPtr.h"
+#include "nsLayoutUtils.h"
+#include "WebGLBuffer.h"
+#include "WebGLContext.h"
+#include "WebGLFormats.h"
+#include "WebGLTexelConversions.h"
+#include "WebGLTexture.h"
+
+namespace mozilla {
+
+bool webgl::PixelPackingState::AssertCurrentUnpack(gl::GLContext& gl,
+                                                   const bool isWebgl2) const {
+  auto actual = PixelPackingState{};
+  gl.GetInt(LOCAL_GL_UNPACK_ALIGNMENT, &actual.alignmentInTypeElems);
+  if (isWebgl2) {
+    gl.GetInt(LOCAL_GL_UNPACK_ROW_LENGTH, &actual.rowLength);
+    gl.GetInt(LOCAL_GL_UNPACK_IMAGE_HEIGHT, &actual.imageHeight);
+
+    gl.GetInt(LOCAL_GL_UNPACK_SKIP_PIXELS, &actual.skipPixels);
+    gl.GetInt(LOCAL_GL_UNPACK_SKIP_ROWS, &actual.skipRows);
+    gl.GetInt(LOCAL_GL_UNPACK_SKIP_IMAGES, &actual.skipImages);
+  }
+  if (*this == actual) return true;
+
+  const auto ToStr = [](const PixelPackingState& x) {
+    const auto text = nsPrintfCString(
+        "%u,%u,%u;%u,%u,%u", x.alignmentInTypeElems, x.rowLength, x.imageHeight,
+        x.skipPixels, x.skipRows, x.skipImages);
+    return mozilla::ToString(text);
+  };
+
+  const auto was = ToStr(actual);
+  const auto expected = ToStr(*this);
+  gfxCriticalError() << "PixelUnpackStateGl was not current. Was " << was
+                     << ". Expected << " << expected << ".";
+  return false;
+}
+
+void webgl::PixelPackingState::ApplyUnpack(gl::GLContext& gl,
+                                           const bool isWebgl2,
+                                           const uvec3& uploadSize) const {
+  gl.fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
+                  AssertedCast<GLsizei>(alignmentInTypeElems));
+  if (!isWebgl2) return;
+
+  // Re-simplify. (ANGLE seems to have an issue with imageHeight ==
+  // uploadSize.y)
+  auto rowLengthOrZero = rowLength;
+  auto imageHeightOrZero = imageHeight;
+  if (rowLengthOrZero == uploadSize.x) {
+    rowLengthOrZero = 0;
+  }
+  if (imageHeightOrZero == uploadSize.y) {
+    imageHeightOrZero = 0;
+  }
+
+  gl.fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH,
+                  AssertedCast<GLsizei>(rowLengthOrZero));
+  gl.fPixelStorei(LOCAL_GL_UNPACK_IMAGE_HEIGHT,
+                  AssertedCast<GLsizei>(imageHeightOrZero));
+
+  gl.fPixelStorei(LOCAL_GL_UNPACK_SKIP_PIXELS,
+                  AssertedCast<GLsizei>(skipPixels));
+  gl.fPixelStorei(LOCAL_GL_UNPACK_SKIP_ROWS, AssertedCast<GLsizei>(skipRows));
+  gl.fPixelStorei(LOCAL_GL_UNPACK_SKIP_IMAGES,
+                  AssertedCast<GLsizei>(skipImages));
+}
+
+namespace webgl {
+
+static bool IsPIValidForDOM(const webgl::PackingInfo& pi) {
+  // https://www.khronos.org/registry/webgl/specs/latest/2.0/#TEXTURE_TYPES_FORMATS_FROM_DOM_ELEMENTS_TABLE
+
+  // Just check for invalid individual formats and types, not combinations.
+  switch (pi.format) {
+    case LOCAL_GL_RGB:
+    case LOCAL_GL_RGBA:
+    case LOCAL_GL_LUMINANCE_ALPHA:
+    case LOCAL_GL_LUMINANCE:
+    case LOCAL_GL_ALPHA:
+    case LOCAL_GL_RED:
+    case LOCAL_GL_RED_INTEGER:
+    case LOCAL_GL_RG:
+    case LOCAL_GL_RG_INTEGER:
+    case LOCAL_GL_RGB_INTEGER:
+    case LOCAL_GL_RGBA_INTEGER:
+      break;
+
+    case LOCAL_GL_SRGB:
+    case LOCAL_GL_SRGB_ALPHA:
+      // Allowed in WebGL1+EXT_srgb
+      break;
+
+    default:
+      return false;
+  }
+
+  switch (pi.type) {
+    case LOCAL_GL_UNSIGNED_BYTE:
+    case LOCAL_GL_UNSIGNED_SHORT_5_6_5:
+    case LOCAL_GL_UNSIGNED_SHORT_4_4_4_4:
+    case LOCAL_GL_UNSIGNED_SHORT_5_5_5_1:
+    case LOCAL_GL_HALF_FLOAT:
+    case LOCAL_GL_HALF_FLOAT_OES:
+    case LOCAL_GL_FLOAT:
+    case LOCAL_GL_UNSIGNED_INT_10F_11F_11F_REV:
+      break;
+
+    default:
+      return false;
+  }
+
+  return true;
+}
+
+static bool ValidatePIForDOM(const WebGLContext* const webgl,
+                             const webgl::PackingInfo& pi) {
+  if (!IsPIValidForDOM(pi)) {
+    webgl->ErrorInvalidValue("Format or type is invalid for DOM sources.");
+    return false;
+  }
+  return true;
+}
+
+static WebGLTexelFormat FormatForPackingInfo(const PackingInfo& pi) {
+  switch (pi.type) {
+    case LOCAL_GL_UNSIGNED_BYTE:
+      switch (pi.format) {
+        case LOCAL_GL_RED:
+        case LOCAL_GL_LUMINANCE:
+        case LOCAL_GL_RED_INTEGER:
+          return WebGLTexelFormat::R8;
+
+        case LOCAL_GL_ALPHA:
+          return WebGLTexelFormat::A8;
+
+        case LOCAL_GL_LUMINANCE_ALPHA:
+          return WebGLTexelFormat::RA8;
+
+        case LOCAL_GL_RGB:
+        case LOCAL_GL_RGB_INTEGER:
+        case LOCAL_GL_SRGB:
+          return WebGLTexelFormat::RGB8;
+
+        case LOCAL_GL_RGBA:
+        case LOCAL_GL_RGBA_INTEGER:
+        case LOCAL_GL_SRGB_ALPHA:
+          return WebGLTexelFormat::RGBA8;
+
+        case LOCAL_GL_RG:
+        case LOCAL_GL_RG_INTEGER:
+          return WebGLTexelFormat::RG8;
+
+        default:
+          break;
+      }
+      break;
+
+    case LOCAL_GL_UNSIGNED_SHORT_5_6_5:
+      if (pi.format == LOCAL_GL_RGB) return WebGLTexelFormat::RGB565;
+      break;
+
+    case LOCAL_GL_UNSIGNED_SHORT_5_5_5_1:
+      if (pi.format == LOCAL_GL_RGBA) return WebGLTexelFormat::RGBA5551;
+      break;
+
+    case LOCAL_GL_UNSIGNED_SHORT_4_4_4_4:
+      if (pi.format == LOCAL_GL_RGBA) return WebGLTexelFormat::RGBA4444;
+      break;
+
+    case LOCAL_GL_HALF_FLOAT:
+    case LOCAL_GL_HALF_FLOAT_OES:
+      switch (pi.format) {
+        case LOCAL_GL_RED:
+        case LOCAL_GL_LUMINANCE:
+          return WebGLTexelFormat::R16F;
+
+        case LOCAL_GL_ALPHA:
+          return WebGLTexelFormat::A16F;
+        case LOCAL_GL_LUMINANCE_ALPHA:
+          return WebGLTexelFormat::RA16F;
+        case LOCAL_GL_RG:
+          return WebGLTexelFormat::RG16F;
+        case LOCAL_GL_RGB:
+          return WebGLTexelFormat::RGB16F;
+        case LOCAL_GL_RGBA:
+          return WebGLTexelFormat::RGBA16F;
+
+        default:
+          break;
+      }
+      break;
+
+    case LOCAL_GL_FLOAT:
+      switch (pi.format) {
+        case LOCAL_GL_RED:
+        case LOCAL_GL_LUMINANCE:
+          return WebGLTexelFormat::R32F;
+
+        case LOCAL_GL_ALPHA:
+          return WebGLTexelFormat::A32F;
+        case LOCAL_GL_LUMINANCE_ALPHA:
+          return WebGLTexelFormat::RA32F;
+        case LOCAL_GL_RG:
+          return WebGLTexelFormat::RG32F;
+        case LOCAL_GL_RGB:
+          return WebGLTexelFormat::RGB32F;
+        case LOCAL_GL_RGBA:
+          return WebGLTexelFormat::RGBA32F;
+
+        default:
+          break;
+      }
+      break;
+
+    case LOCAL_GL_UNSIGNED_INT_10F_11F_11F_REV:
+      if (pi.format == LOCAL_GL_RGB) return WebGLTexelFormat::RGB11F11F10F;
+      break;
+
+    default:
+      break;
+  }
+
+  return WebGLTexelFormat::FormatNotSupportingAnyConversion;
+}
+
+////////////////////
+
+static uint32_t ZeroOn2D(const GLenum target, const uint32_t val) {
+  const bool is2d = !IsTexTarget3D(target);
+  if (is2d) return 0;
+  return val;
+}
+
+static bool ValidateUnpackPixels(const WebGLContext* webgl,
+                                 const webgl::PackingInfo& pi,
+                                 const uint32_t availRows,
+                                 const webgl::TexUnpackBlob& blob) {
+  const auto& unpackingRes = blob.mDesc.ExplicitUnpacking(pi, {});
+  if (!unpackingRes.isOk()) {
+    webgl->ErrorInvalidOperation("%s", unpackingRes.inspectErr().c_str());
+    return false;
+  }
+  const auto& unpacking = unpackingRes.inspect();
+
+  if (availRows < unpacking.metrics.totalRows) {
+    webgl->ErrorInvalidOperation(
+        "Desired upload requires more rows (%zu) than is"
+        " available (%zu).",
+        unpacking.metrics.totalRows, availRows);
+    return false;
+  }
+
+  return true;
+}
+
+static bool ValidateUnpackBytes(const WebGLContext* const webgl,
+                                const webgl::PackingInfo& pi,
+                                const size_t availByteCount,
+                                const webgl::TexUnpackBlob& blob) {
+  const auto& unpackingRes = blob.mDesc.ExplicitUnpacking(pi, {});
+  if (!unpackingRes.isOk()) {
+    webgl->ErrorInvalidOperation("%s", unpackingRes.inspectErr().c_str());
+    return false;
+  }
+  const auto& unpacking = unpackingRes.inspect();
+
+  if (availByteCount < unpacking.metrics.totalBytesUsed) {
+    webgl->ErrorInvalidOperation(
+        "Desired upload requires more bytes (%zu) than are"
+        " available (%zu).",
+        unpacking.metrics.totalBytesUsed, availByteCount);
+    return false;
+  }
+
+  return true;
+}
+
+////////////////////
+
+// Check if the surface descriptor describes a memory which contains a single
+// RGBA data source.
+static bool SDIsRGBBuffer(const layers::SurfaceDescriptor& sd) {
+  return sd.type() == layers::SurfaceDescriptor::TSurfaceDescriptorBuffer &&
+         sd.get_SurfaceDescriptorBuffer().desc().type() ==
+             layers::BufferDescriptor::TRGBDescriptor;
+}
+
+// Check if the surface descriptor describes a GPUVideo texture for which we
+// only have an opaque source/handle from SurfaceDescriptorRemoteDecoder to
+// derive the actual texture from.
+static bool SDIsNullRemoteDecoder(const layers::SurfaceDescriptor& sd) {
+  return sd.type() == layers::SurfaceDescriptor::TSurfaceDescriptorGPUVideo &&
+         sd.get_SurfaceDescriptorGPUVideo()
+                 .get_SurfaceDescriptorRemoteDecoder()
+                 .subdesc()
+                 .type() == layers::RemoteDecoderVideoSubDescriptor::Tnull_t;
+}
+
+// static
+std::unique_ptr<TexUnpackBlob> TexUnpackBlob::Create(
+    const TexUnpackBlobDesc& desc) {
+  return std::unique_ptr<TexUnpackBlob>{[&]() -> TexUnpackBlob* {
+    if (!IsTarget3D(desc.imageTarget) && desc.size.z != 1) {
+      MOZ_ASSERT(false);
+      return nullptr;
+    }
+
+    switch (desc.unpacking.alignmentInTypeElems) {
+      case 1:
+      case 2:
+      case 4:
+      case 8:
+        break;
+      default:
+        MOZ_ASSERT(false);
+        return nullptr;
+    }
+
+    if (desc.sd) {
+      // Shmem buffers need to be treated as if they were a DataSourceSurface.
+      // Otherwise, TexUnpackImage will try to blit the surface descriptor as
+      // if it can be mapped as a framebuffer, whereas the Shmem is still CPU
+      // data.
+      if (SDIsRGBBuffer(*desc.sd) || SDIsNullRemoteDecoder(*desc.sd)) {
+        return new TexUnpackSurface(desc);
+      }
+      return new TexUnpackImage(desc);
+    }
+    if (desc.dataSurf) {
+      return new TexUnpackSurface(desc);
+    }
+
+    if (desc.srcAlphaType != gfxAlphaType::NonPremult) {
+      MOZ_ASSERT(false);
+      return nullptr;
+    }
+    return new TexUnpackBytes(desc);
+  }()};
+}
+
+static bool HasColorAndAlpha(const WebGLTexelFormat format) {
+  switch (format) {
+    case WebGLTexelFormat::RA8:
+    case WebGLTexelFormat::RA16F:
+    case WebGLTexelFormat::RA32F:
+    case WebGLTexelFormat::RGBA8:
+    case WebGLTexelFormat::RGBA5551:
+    case WebGLTexelFormat::RGBA4444:
+    case WebGLTexelFormat::RGBA16F:
+    case WebGLTexelFormat::RGBA32F:
+    case WebGLTexelFormat::BGRA8:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool TexUnpackBlob::ConvertIfNeeded(
+    const WebGLContext* const webgl, const uint32_t rowLength,
+    const uint32_t rowCount, WebGLTexelFormat srcFormat,
+    const uint8_t* const srcBegin, const ptrdiff_t srcStride,
+    WebGLTexelFormat dstFormat, const ptrdiff_t dstStride,
+    const uint8_t** const out_begin,
+    UniqueBuffer* const out_anchoredBuffer) const {
+  MOZ_ASSERT(srcFormat != WebGLTexelFormat::FormatNotSupportingAnyConversion);
+  MOZ_ASSERT(dstFormat != WebGLTexelFormat::FormatNotSupportingAnyConversion);
+
+  *out_begin = srcBegin;
+
+  const auto& unpacking = mDesc.unpacking;
+
+  if (!rowLength || !rowCount) return true;
+
+  const auto srcIsPremult = (mDesc.srcAlphaType == gfxAlphaType::Premult);
+  auto dstIsPremult = unpacking.premultiplyAlpha;
+  const auto fnHasPremultMismatch = [&]() {
+    if (mDesc.srcAlphaType == gfxAlphaType::Opaque) return false;
+
+    if (!HasColorAndAlpha(srcFormat)) return false;
+
+    return srcIsPremult != dstIsPremult;
+  };
+
+  const auto srcOrigin =
+      (unpacking.flipY ? gl::OriginPos::TopLeft : gl::OriginPos::BottomLeft);
+  auto dstOrigin = gl::OriginPos::BottomLeft;
+
+  if (!mDesc.applyUnpackTransforms) {
+    dstIsPremult = srcIsPremult;
+    dstOrigin = srcOrigin;
+  }
+
+  if (srcFormat != dstFormat) {
+    webgl->GeneratePerfWarning(
+        "Conversion requires pixel reformatting. (%u->%u)", uint32_t(srcFormat),
+        uint32_t(dstFormat));
+  } else if (fnHasPremultMismatch()) {
+    webgl->GeneratePerfWarning(
+        "Conversion requires change in"
+        " alpha-premultiplication.");
+  } else if (srcOrigin != dstOrigin) {
+    webgl->GeneratePerfWarning("Conversion requires y-flip.");
+  } else if (srcStride != dstStride) {
+    webgl->GeneratePerfWarning("Conversion requires change in stride. (%u->%u)",
+                               uint32_t(srcStride), uint32_t(dstStride));
+  } else {
+    return true;
+  }
+
+  ////
+
+  const auto dstTotalBytes = CheckedUint32(rowCount) * dstStride;
+  if (!dstTotalBytes.isValid()) {
+    webgl->ErrorOutOfMemory("Calculation failed.");
+    return false;
+  }
+
+  auto dstBuffer = UniqueBuffer::Take(calloc(1u, dstTotalBytes.value()));
+  if (!dstBuffer.get()) {
+    webgl->ErrorOutOfMemory("Failed to allocate dest buffer.");
+    return false;
+  }
+  const auto dstBegin = static_cast<uint8_t*>(dstBuffer.get());
+
+  ////
+
+  // And go!:
+  bool wasTrivial;
+  if (!ConvertImage(rowLength, rowCount, srcBegin, srcStride, srcOrigin,
+                    srcFormat, srcIsPremult, dstBegin, dstStride, dstOrigin,
+                    dstFormat, dstIsPremult, &wasTrivial)) {
+    webgl->ErrorImplementationBug("ConvertImage failed.");
+    return false;
+  }
+
+  *out_begin = dstBegin;
+  *out_anchoredBuffer = std::move(dstBuffer);
+  return true;
+}
+
+static GLenum DoTexOrSubImage(bool isSubImage, gl::GLContext* gl,
+                              TexImageTarget target, GLint level,
+                              const DriverUnpackInfo* dui, GLint xOffset,
+                              GLint yOffset, GLint zOffset, GLsizei width,
+                              GLsizei height, GLsizei depth, const void* data) {
+  if (isSubImage) {
+    return DoTexSubImage(gl, target, level, xOffset, yOffset, zOffset, width,
+                         height, depth, dui->ToPacking(), data);
+  } else {
+    return DoTexImage(gl, target, level, dui, width, height, depth, data);
+  }
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+// TexUnpackBytes
+
+bool TexUnpackBytes::Validate(const WebGLContext* const webgl,
+                              const webgl::PackingInfo& pi) {
+  if (!HasData()) return true;
+
+  CheckedInt<size_t> availBytes = 0;
+  if (mDesc.cpuData) {
+    const auto& range = mDesc.cpuData->Data();
+    availBytes = range.length();
+  } else if (mDesc.pboOffset) {
+    const auto& pboOffset = *mDesc.pboOffset;
+
+    const auto& pbo =
+        webgl->ValidateBufferSelection(LOCAL_GL_PIXEL_UNPACK_BUFFER);
+    if (!pbo) return false;  // Might be invalid e.g. due to in-use by TF.
+    availBytes = pbo->ByteLength();
+    availBytes -= pboOffset;
+  } else {
+    MOZ_ASSERT(false, "Must be one of the above");
+  }
+  if (!availBytes.isValid()) {
+    webgl->ErrorInvalidOperation("Offset is passed end of buffer.");
+    return false;
+  }
+
+  return ValidateUnpackBytes(webgl, pi, availBytes.value(), *this);
+}
+
+bool TexUnpackBytes::TexOrSubImage(bool isSubImage, bool needsRespec,
+                                   WebGLTexture* tex, GLint level,
+                                   const webgl::DriverUnpackInfo* dui,
+                                   GLint xOffset, GLint yOffset, GLint zOffset,
+                                   const webgl::PackingInfo& pi,
+                                   GLenum* const out_error) const {
+  const auto& webgl = tex->mContext;
+  const auto& target = mDesc.imageTarget;
+  const auto& size = mDesc.size;
+  const auto& webglUnpackState = mDesc.unpacking;
+
+  const auto unpackingRes = mDesc.ExplicitUnpacking(pi, {});
+
+  const auto format = FormatForPackingInfo(pi);
+
+  const uint8_t* uploadPtr = nullptr;
+  if (mDesc.cpuData) {
+    const auto range = mDesc.cpuData->Data();
+    uploadPtr = range.begin().get();
+    if (!uploadPtr) {
+      MOZ_ASSERT(!range.length());
+    }
+  } else if (mDesc.pboOffset) {
+    uploadPtr = reinterpret_cast<const uint8_t*>(*mDesc.pboOffset);
+  }
+
+  UniqueBuffer tempBuffer;
+
+  do {
+    if (mDesc.pboOffset || !uploadPtr) break;
+
+    if (!webglUnpackState.flipY && !webglUnpackState.premultiplyAlpha) {
+      break;
+    }
+
+    webgl->GenerateWarning(
+        "Alpha-premult and y-flip are deprecated for"
+        " non-DOM-Element uploads.");
+
+    MOZ_RELEASE_ASSERT(unpackingRes.isOk());
+    const auto& unpacking = unpackingRes.inspect();
+    const auto stride = unpacking.metrics.bytesPerRowStride;
+    // clang-format off
+    if (!ConvertIfNeeded(webgl, unpacking.state.rowLength,
+                         unpacking.metrics.totalRows,
+                         format, uploadPtr, AutoAssertCast(stride),
+                         format, AutoAssertCast(stride), &uploadPtr, &tempBuffer)) {
+      return false;
+    }
+    // clang-format on
+  } while (false);
+
+  //////
+
+  const auto& gl = webgl->gl;
+
+  bool useParanoidHandling = false;
+  if (mNeedsExactUpload && webgl->mBoundPixelUnpackBuffer) {
+    webgl->GenerateWarning(
+        "Uploads from a buffer with a final row with a byte"
+        " count smaller than the row stride can incur extra"
+        " overhead.");
+
+    if (gl->WorkAroundDriverBugs()) {
+      useParanoidHandling |= (gl->Vendor() == gl::GLVendor::NVIDIA);
+    }
+  }
+
+  if (!useParanoidHandling) {
+    const ScopedLazyBind bindPBO(gl, LOCAL_GL_PIXEL_UNPACK_BUFFER,
+                                 webgl->mBoundPixelUnpackBuffer);
+
+    *out_error =
+        DoTexOrSubImage(isSubImage, gl, target, level, dui, xOffset, yOffset,
+                        zOffset, size.x, size.y, size.z, uploadPtr);
+    return true;
+  }
+
+  //////
+
+  MOZ_ASSERT(webgl->mBoundPixelUnpackBuffer);
+
+  if (!isSubImage) {
+    // Alloc first to catch OOMs.
+    AssertUintParamCorrect(gl, LOCAL_GL_PIXEL_UNPACK_BUFFER_BINDING, 0);
+    *out_error =
+        DoTexOrSubImage(false, gl, target, level, dui, xOffset, yOffset,
+                        zOffset, size.x, size.y, size.z, nullptr);
+    if (*out_error) return true;
+  }
+  if (!size.x || !size.y || !size.z) {
+    // Nothing to do.
+    return true;
+  }
+
+  MOZ_RELEASE_ASSERT(unpackingRes.isOk());
+  const auto& unpacking = unpackingRes.inspect();
+
+  const ScopedLazyBind bindPBO(gl, LOCAL_GL_PIXEL_UNPACK_BUFFER,
+                               webgl->mBoundPixelUnpackBuffer);
+
+  //////
+
+  // Make our sometimes-implicit values explicit. Also this keeps them constant
+  // when we ask for height=mHeight-1 and such.
+  gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH,
+                   AutoAssertCast(unpacking.state.rowLength));
+  gl->fPixelStorei(LOCAL_GL_UNPACK_IMAGE_HEIGHT,
+                   AutoAssertCast(unpacking.state.imageHeight));
+
+  if (size.z > 1) {
+    *out_error =
+        DoTexOrSubImage(true, gl, target, level, dui, xOffset, yOffset, zOffset,
+                        size.x, size.y, size.z - 1, uploadPtr);
+  }
+
+  // Skip the images we uploaded.
+  const auto skipImages = ZeroOn2D(target, unpacking.state.skipImages);
+  gl->fPixelStorei(LOCAL_GL_UNPACK_SKIP_IMAGES, skipImages + size.z - 1);
+
+  if (size.y > 1) {
+    *out_error =
+        DoTexOrSubImage(true, gl, target, level, dui, xOffset, yOffset,
+                        zOffset + size.z - 1, size.x, size.y - 1, 1, uploadPtr);
+  }
+
+  // -
+
+  const auto lastRowOffset =
+      unpacking.metrics.totalBytesStrided - unpacking.metrics.bytesPerRowStride;
+  const auto lastRowPtr = uploadPtr + lastRowOffset;
+
+  gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 1);    // No stride padding.
+  gl->fPixelStorei(LOCAL_GL_UNPACK_ROW_LENGTH, 0);   // No padding in general.
+  gl->fPixelStorei(LOCAL_GL_UNPACK_SKIP_IMAGES, 0);  // Don't skip images,
+  gl->fPixelStorei(LOCAL_GL_UNPACK_SKIP_ROWS,
+                   0);  // or rows.
+                        // Keep skipping pixels though!
+  *out_error = DoTexOrSubImage(true, gl, target, level, dui, xOffset,
+                               yOffset + size.y - 1, zOffset + size.z - 1,
+                               AutoAssertCast(size.x), 1, 1, lastRowPtr);
+
+  // Caller will reset all our modified PixelStorei state.
+
+  return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+// TexUnpackImage
+
+TexUnpackImage::~TexUnpackImage() = default;
+
+bool TexUnpackImage::Validate(const WebGLContext* const webgl,
+                              const webgl::PackingInfo& pi) {
+  if (!ValidatePIForDOM(webgl, pi)) return false;
+
+  if (!mDesc.structuredSrcSize) {
+    gfxCriticalError() << "TexUnpackImage missing structuredSrcSize.";
+    return false;
+  }
+  const auto& elemSize = *mDesc.structuredSrcSize;
+  if (mDesc.dataSurf) {
+    const auto& surfSize = mDesc.dataSurf->GetSize();
+    const auto surfSize2 = ivec2::FromSize(surfSize)->StaticCast<uvec2>();
+    if (uvec2{elemSize.x, elemSize.y} != surfSize2) {
+      gfxCriticalError()
+          << "TexUnpackImage mismatched structuredSrcSize for dataSurf.";
+      return false;
+    }
+  }
+
+  const auto fullRows = elemSize.y;
+  return ValidateUnpackPixels(webgl, pi, fullRows, *this);
+}
+
+Maybe<std::string> BlitPreventReason(const int32_t level, const ivec3& offset,
+                                     const GLenum internalFormat,
+                                     const webgl::PackingInfo& pi,
+                                     const TexUnpackBlobDesc& desc,
+                                     const bool isRgb8Renderable) {
+  const auto& size = desc.size;
+  const auto& unpacking = desc.unpacking;
+
+  const auto ret = [&]() -> const char* {
+    if (size.z != 1) {
+      return "depth is not 1";
+    }
+    if (offset.x != 0 || offset.y != 0 || offset.z != 0) {
+      return "x/y/zOffset is not 0";
+    }
+
+    if (unpacking.skipPixels || unpacking.skipRows || unpacking.skipImages) {
+      return "non-zero UNPACK_SKIP_* not yet supported";
+    }
+
+    const auto premultReason = [&]() -> const char* {
+      if (desc.srcAlphaType == gfxAlphaType::Opaque) return nullptr;
+
+      const bool srcIsPremult = (desc.srcAlphaType == gfxAlphaType::Premult);
+      const auto& dstIsPremult = unpacking.premultiplyAlpha;
+      if (srcIsPremult == dstIsPremult) return nullptr;
+
+      if (dstIsPremult) {
+        return "UNPACK_PREMULTIPLY_ALPHA_WEBGL is not true";
+      } else {
+        return "UNPACK_PREMULTIPLY_ALPHA_WEBGL is not false";
+      }
+    }();
+    if (premultReason) return premultReason;
+
+    const auto formatReason = [&]() -> const char* {
+      if (pi.type != LOCAL_GL_UNSIGNED_BYTE) {
+        return "`type` must be `UNSIGNED_BYTE`";
+      }
+
+      switch (internalFormat) {
+        case LOCAL_GL_RGBA:
+        case LOCAL_GL_RGBA8:
+          return nullptr;
+
+        case LOCAL_GL_RGB:
+        case LOCAL_GL_RGB8:
+          if (isRgb8Renderable) {
+            return nullptr;
+          }
+          break;
+      }
+      if (isRgb8Renderable) {
+        return "effective format must be RGB8 or RGBA8";
+      } else {
+        return "effective format must be RGBA8";
+      }
+    }();
+    if (formatReason) return formatReason;
+
+    return nullptr;
+  }();
+  if (ret) {
+    return Some(std::string(ret));
+  }
+  return {};
+}
+
+bool TexUnpackImage::TexOrSubImage(bool isSubImage, bool needsRespec,
+                                   WebGLTexture* tex, GLint level,
+                                   const webgl::DriverUnpackInfo* dui,
+                                   GLint xOffset, GLint yOffset, GLint zOffset,
+                                   const webgl::PackingInfo& pi,
+                                   GLenum* const out_error) const {
+  MOZ_ASSERT_IF(needsRespec, !isSubImage);
+
+  const auto& webgl = tex->mContext;
+  const auto& target = mDesc.imageTarget;
+  const auto& size = mDesc.size;
+  const auto& sd = *(mDesc.sd);
+  const auto& unpacking = mDesc.unpacking;
+
+  const auto& gl = webgl->GL();
+
+  // -
+
+  const auto reason =
+      BlitPreventReason(level, {xOffset, yOffset, zOffset}, dui->internalFormat,
+                        pi, mDesc, webgl->mIsRgb8Renderable);
+  if (reason) {
+    webgl->GeneratePerfWarning(
+        "Failed to hit GPU-copy fast-path."
+        " (%s) Falling back to CPU upload.",
+        reason->c_str());
+    return false;
+  }
+
+  // -
+
+  if (needsRespec) {
+    *out_error =
+        DoTexOrSubImage(isSubImage, gl, target, level, dui, xOffset, yOffset,
+                        zOffset, size.x, size.y, size.z, nullptr);
+    if (*out_error) return true;
+  }
+
+  {
+    gl::ScopedFramebuffer scopedFB(gl);
+    gl::ScopedBindFramebuffer bindFB(gl, scopedFB.FB());
+
+    {
+      gl::GLContext::LocalErrorScope errorScope(*gl);
+
+      gl->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER,
+                                LOCAL_GL_COLOR_ATTACHMENT0, target,
+                                tex->mGLName, level);
+
+      const auto err = errorScope.GetError();
+      MOZ_ALWAYS_TRUE(!err);
+    }
+
+    const GLenum status = gl->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
+    MOZ_ALWAYS_TRUE(status == LOCAL_GL_FRAMEBUFFER_COMPLETE);
+
+    const auto dstOrigin =
+        (unpacking.flipY ? gl::OriginPos::TopLeft : gl::OriginPos::BottomLeft);
+    if (!gl->BlitHelper()->BlitSdToFramebuffer(sd, {size.x, size.y},
+                                               dstOrigin)) {
+      gfxCriticalNote << "BlitSdToFramebuffer failed for type "
+                      << int(sd.type());
+      // Maybe the resource isn't valid anymore?
+      gl->fClearColor(0.2, 0.0, 0.2, 1.0);
+      gl->fClear(LOCAL_GL_COLOR_BUFFER_BIT);
+      const auto& cur = webgl->mColorClearValue;
+      gl->fClearColor(cur[0], cur[1], cur[2], cur[3]);
+      webgl->GenerateWarning(
+          "Fast Tex(Sub)Image upload failed without recourse, clearing to "
+          "[0.2, 0.0, 0.2, 1.0]. Please file a bug!");
+    }
+  }
+
+  return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+// TexUnpackSurface
+
+TexUnpackSurface::~TexUnpackSurface() = default;
+
+//////////
+
+static bool GetFormatForSurf(const gfx::SourceSurface* surf,
+                             WebGLTexelFormat* const out_texelFormat,
+                             uint8_t* const out_bpp) {
+  const auto surfFormat = surf->GetFormat();
+  switch (surfFormat) {
+    case gfx::SurfaceFormat::B8G8R8A8:
+      *out_texelFormat = WebGLTexelFormat::BGRA8;
+      *out_bpp = 4;
+      return true;
+
+    case gfx::SurfaceFormat::B8G8R8X8:
+      *out_texelFormat = WebGLTexelFormat::BGRX8;
+      *out_bpp = 4;
+      return true;
+
+    case gfx::SurfaceFormat::R8G8B8A8:
+      *out_texelFormat = WebGLTexelFormat::RGBA8;
+      *out_bpp = 4;
+      return true;
+
+    case gfx::SurfaceFormat::R8G8B8X8:
+      *out_texelFormat = WebGLTexelFormat::RGBX8;
+      *out_bpp = 4;
+      return true;
+
+    case gfx::SurfaceFormat::R5G6B5_UINT16:
+      *out_texelFormat = WebGLTexelFormat::RGB565;
+      *out_bpp = 2;
+      return true;
+
+    case gfx::SurfaceFormat::A8:
+      *out_texelFormat = WebGLTexelFormat::A8;
+      *out_bpp = 1;
+      return true;
+
+    case gfx::SurfaceFormat::YUV:
+      // Ugh...
+      NS_ERROR("We don't handle uploads from YUV sources yet.");
+      // When we want to, check out gfx/ycbcr/YCbCrUtils.h. (specifically
+      // GetYCbCrToRGBDestFormatAndSize and ConvertYCbCrToRGB)
+      return false;
+
+    default:
+      return false;
+  }
+}
+
+//////////
+
+bool TexUnpackSurface::Validate(const WebGLContext* const webgl,
+                                const webgl::PackingInfo& pi) {
+  if (!ValidatePIForDOM(webgl, pi)) return false;
+
+  if (!mDesc.structuredSrcSize) {
+    gfxCriticalError() << "TexUnpackSurface missing structuredSrcSize.";
+    return false;
+  }
+  const auto& elemSize = *mDesc.structuredSrcSize;
+  if (mDesc.dataSurf) {
+    const auto& surfSize = mDesc.dataSurf->GetSize();
+    const auto surfSize2 = ivec2::FromSize(surfSize)->StaticCast<uvec2>();
+    if (uvec2{elemSize.x, elemSize.y} != surfSize2) {
+      gfxCriticalError()
+          << "TexUnpackSurface mismatched structuredSrcSize for dataSurf.";
+      return false;
+    }
+  }
+
+  const auto fullRows = elemSize.y;
+  return ValidateUnpackPixels(webgl, pi, fullRows, *this);
+}
+
+bool TexUnpackSurface::TexOrSubImage(bool isSubImage, bool needsRespec,
+                                     WebGLTexture* tex, GLint level,
+                                     const webgl::DriverUnpackInfo* dui,
+                                     GLint xOffset, GLint yOffset,
+                                     GLint zOffset,
+                                     const webgl::PackingInfo& dstPI,
+                                     GLenum* const out_error) const {
+  const auto& webgl = tex->mContext;
+  const auto& size = mDesc.size;
+  RefPtr<gfx::DataSourceSurface> surf;
+  if (mDesc.sd) {
+    // If we get here, we assume the SD describes an RGBA Shmem.
+    const auto& sd = *(mDesc.sd);
+    if (SDIsRGBBuffer(sd)) {
+      const auto& sdb = sd.get_SurfaceDescriptorBuffer();
+      const auto& rgb = sdb.desc().get_RGBDescriptor();
+      const auto& data = sdb.data();
+      MOZ_ASSERT(data.type() == layers::MemoryOrShmem::TShmem);
+      const auto& shmem = data.get_Shmem();
+      surf = gfx::Factory::CreateWrappingDataSourceSurface(
+          shmem.get<uint8_t>(), layers::ImageDataSerializer::GetRGBStride(rgb),
+          rgb.size(), rgb.format());
+    } else if (SDIsNullRemoteDecoder(sd)) {
+      const auto& sdrd = sd.get_SurfaceDescriptorGPUVideo()
+                             .get_SurfaceDescriptorRemoteDecoder();
+      RefPtr<layers::VideoBridgeParent> parent =
+          layers::VideoBridgeParent::GetSingleton(sdrd.source());
+      if (!parent) {
+        gfxCriticalNote << "TexUnpackSurface failed to get VideoBridgeParent";
+        return false;
+      }
+      RefPtr<layers::TextureHost> texture =
+          parent->LookupTexture(webgl->GetContentId(), sdrd.handle());
+      if (!texture) {
+        gfxCriticalNote << "TexUnpackSurface failed to get TextureHost";
+        return false;
+      }
+      surf = texture->GetAsSurface();
+    } else {
+      MOZ_ASSERT_UNREACHABLE("Unexpected surface descriptor!");
+    }
+    if (!surf) {
+      gfxCriticalError() << "TexUnpackSurface failed to create wrapping "
+                            "DataSourceSurface for Shmem.";
+      return false;
+    }
+  } else {
+    surf = mDesc.dataSurf;
+  }
+
+  ////
+
+  WebGLTexelFormat srcFormat;
+  uint8_t srcBPP;
+  if (!GetFormatForSurf(surf, &srcFormat, &srcBPP)) {
+    webgl->ErrorImplementationBug(
+        "GetFormatForSurf failed for"
+        " WebGLTexelFormat::%u.",
+        uint32_t(surf->GetFormat()));
+    return false;
+  }
+
+  gfx::DataSourceSurface::ScopedMap map(surf,
+                                        gfx::DataSourceSurface::MapType::READ);
+  if (!map.IsMapped()) {
+    webgl->ErrorOutOfMemory("Failed to map source surface for upload.");
+    return false;
+  }
+
+  const auto& srcBegin = map.GetData();
+  const auto srcStride = static_cast<size_t>(map.GetStride());
+
+  // -
+
+  const auto dstFormat = FormatForPackingInfo(dstPI);
+  const auto dstBpp = BytesPerPixel(dstPI);
+  const size_t dstUsedBytesPerRow = dstBpp * surf->GetSize().width;
+  auto dstStride = dstUsedBytesPerRow;
+  if (dstFormat == srcFormat) {
+    dstStride = srcStride;  // Try to match.
+  }
+
+  // -
+
+  auto dstUnpackingRes = mDesc.ExplicitUnpacking(dstPI, Some(dstStride));
+  if (dstUnpackingRes.isOk()) {
+    const auto& dstUnpacking = dstUnpackingRes.inspect();
+    if (!webgl->IsWebGL2() && dstUnpacking.state.rowLength != size.x) {
+      dstUnpackingRes = Err("WebGL1 can't handle rowLength != size.x");
+    }
+  }
+  if (!dstUnpackingRes.isOk()) {
+    dstStride = dstUsedBytesPerRow;
+    dstUnpackingRes = mDesc.ExplicitUnpacking(dstPI, Some(dstStride));
+  }
+  if (!dstUnpackingRes.isOk()) {
+    gfxCriticalError() << dstUnpackingRes.inspectErr();
+    webgl->ErrorImplementationBug("ExplicitUnpacking failed: %s",
+                                  dstUnpackingRes.inspectErr().c_str());
+    return false;
+  }
+  const auto& dstUnpacking = dstUnpackingRes.inspect();
+  MOZ_ASSERT(dstUnpacking.metrics.bytesPerRowStride == dstStride);
+
+  // -
+
+  const uint8_t* dstBegin = srcBegin;
+  UniqueBuffer tempBuffer;
+  // clang-format off
+  if (!ConvertIfNeeded(webgl, surf->GetSize().width, surf->GetSize().height,
+                       srcFormat, srcBegin, AutoAssertCast(srcStride),
+                       dstFormat, AutoAssertCast(dstUnpacking.metrics.bytesPerRowStride), &dstBegin,
+                       &tempBuffer)) {
+    return false;
+  }
+  // clang-format on
+
+  ////
+
+  const auto& gl = webgl->gl;
+  if (!gl->MakeCurrent()) {
+    *out_error = LOCAL_GL_CONTEXT_LOST;
+    return true;
+  }
+
+  dstUnpacking.state.ApplyUnpack(*gl, webgl->IsWebGL2(), size);
+
+  *out_error =
+      DoTexOrSubImage(isSubImage, gl, mDesc.imageTarget, level, dui, xOffset,
+                      yOffset, zOffset, size.x, size.y, size.z, dstBegin);
+
+  // Caller will reset all our modified PixelStorei state.
+
+  return true;
+}
+
+}  // namespace webgl
+}  // namespace mozilla