Adding upstream version 124.0.1.upstream/124.0.1

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

1 files changed, 1111 insertions, 0 deletions

diff --git a/dom/canvas/WebGLTexture.cpp b/dom/canvas/WebGLTexture.cpp
new file mode 100644
index 0000000000..db8906f7f5
--- /dev/null
+++ b/dom/canvas/WebGLTexture.cpp
@@ -0,0 +1,1111 @@
+/* -*- 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 "WebGLTexture.h"
+
+#include <algorithm>
+#include "GLContext.h"
+#include "mozilla/Casting.h"
+#include "mozilla/dom/WebGLRenderingContextBinding.h"
+#include "mozilla/gfx/Logging.h"
+#include "mozilla/IntegerRange.h"
+#include "mozilla/MathAlgorithms.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/Unused.h"
+#include "ScopedGLHelpers.h"
+#include "WebGLContext.h"
+#include "WebGLContextUtils.h"
+#include "WebGLFormats.h"
+#include "WebGLFramebuffer.h"
+#include "WebGLSampler.h"
+#include "WebGLTexelConversions.h"
+
+namespace mozilla {
+namespace webgl {
+
+/*static*/ const ImageInfo ImageInfo::kUndefined;
+
+size_t ImageInfo::MemoryUsage() const {
+  if (!IsDefined()) return 0;
+
+  size_t samples = mSamples;
+  if (!samples) {
+    samples = 1;
+  }
+
+  const size_t bytesPerTexel = mFormat->format->estimatedBytesPerPixel;
+  return size_t(mWidth) * size_t(mHeight) * size_t(mDepth) * samples *
+         bytesPerTexel;
+}
+
+Maybe<ImageInfo> ImageInfo::NextMip(const GLenum target) const {
+  MOZ_ASSERT(IsDefined());
+
+  auto next = *this;
+
+  if (target == LOCAL_GL_TEXTURE_3D) {
+    if (mWidth <= 1 && mHeight <= 1 && mDepth <= 1) {
+      return {};
+    }
+
+    next.mDepth = std::max(uint32_t(1), next.mDepth / 2);
+  } else {
+    // TEXTURE_2D_ARRAY may have depth != 1, but that's normal.
+    if (mWidth <= 1 && mHeight <= 1) {
+      return {};
+    }
+  }
+  if (next.mUninitializedSlices) {
+    next.mUninitializedSlices = Some(std::vector<bool>(next.mDepth, true));
+  }
+
+  next.mWidth = std::max(uint32_t(1), next.mWidth / 2);
+  next.mHeight = std::max(uint32_t(1), next.mHeight / 2);
+  return Some(next);
+}
+
+}  // namespace webgl
+
+////////////////////////////////////////
+
+WebGLTexture::WebGLTexture(WebGLContext* webgl, GLuint tex)
+    : WebGLContextBoundObject(webgl),
+      mGLName(tex),
+      mTarget(LOCAL_GL_NONE),
+      mFaceCount(0),
+      mImmutable(false),
+      mImmutableLevelCount(0),
+      mBaseMipmapLevel(0),
+      mMaxMipmapLevel(1000) {}
+
+WebGLTexture::~WebGLTexture() {
+  for (auto& cur : mImageInfoArr) {
+    cur = webgl::ImageInfo();
+  }
+  InvalidateCaches();
+
+  if (!mContext) return;
+  mContext->gl->fDeleteTextures(1, &mGLName);
+}
+
+size_t WebGLTexture::MemoryUsage() const {
+  size_t accum = 0;
+  for (const auto& cur : mImageInfoArr) {
+    accum += cur.MemoryUsage();
+  }
+  return accum;
+}
+
+// ---------------------------
+
+void WebGLTexture::PopulateMipChain(const uint32_t maxLevel) {
+  // Used by GenerateMipmap and TexStorage.
+  // Populates based on mBaseMipmapLevel.
+
+  auto ref = BaseImageInfo();
+  MOZ_ASSERT(ref.mWidth && ref.mHeight && ref.mDepth);
+
+  for (auto level = mBaseMipmapLevel; level <= maxLevel; ++level) {
+    // GLES 3.0.4, p161
+    // "A cube map texture is mipmap complete if each of the six texture images,
+    //  considered individually, is mipmap complete."
+
+    for (uint8_t face = 0; face < mFaceCount; face++) {
+      auto& cur = ImageInfoAtFace(face, level);
+      cur = ref;
+    }
+
+    const auto next = ref.NextMip(mTarget.get());
+    if (!next) break;
+    ref = next.ref();
+  }
+  InvalidateCaches();
+}
+
+static bool ZeroTextureData(const WebGLContext* webgl, GLuint tex,
+                            TexImageTarget target, uint32_t level,
+                            const webgl::ImageInfo& info);
+
+bool WebGLTexture::IsMipAndCubeComplete(const uint32_t maxLevel,
+                                        const bool ensureInit,
+                                        bool* const out_initFailed) const {
+  *out_initFailed = false;
+
+  // Reference dimensions based on baseLevel.
+  auto ref = BaseImageInfo();
+  MOZ_ASSERT(ref.mWidth && ref.mHeight && ref.mDepth);
+
+  for (auto level = mBaseMipmapLevel; level <= maxLevel; ++level) {
+    // GLES 3.0.4, p161
+    // "A cube map texture is mipmap complete if each of the six texture images,
+    // considered individually, is mipmap complete."
+
+    for (uint8_t face = 0; face < mFaceCount; face++) {
+      auto& cur = ImageInfoAtFace(face, level);
+
+      // "* The set of mipmap arrays `level_base` through `q` (where `q`
+      //    is defined the "Mipmapping" discussion of section 3.8.10) were
+      //    each specified with the same effective internal format."
+
+      // "* The dimensions of the arrays follow the sequence described in
+      //    the "Mipmapping" discussion of section 3.8.10."
+
+      if (cur.mWidth != ref.mWidth || cur.mHeight != ref.mHeight ||
+          cur.mDepth != ref.mDepth || cur.mFormat != ref.mFormat) {
+        return false;
+      }
+
+      if (MOZ_UNLIKELY(ensureInit && cur.mUninitializedSlices)) {
+        auto imageTarget = mTarget.get();
+        if (imageTarget == LOCAL_GL_TEXTURE_CUBE_MAP) {
+          imageTarget = LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X + face;
+        }
+        if (!ZeroTextureData(mContext, mGLName, imageTarget, level, cur)) {
+          mContext->ErrorOutOfMemory("Failed to zero tex image data.");
+          *out_initFailed = true;
+          return false;
+        }
+        cur.mUninitializedSlices = Nothing();
+      }
+    }
+
+    const auto next = ref.NextMip(mTarget.get());
+    if (!next) break;
+    ref = next.ref();
+  }
+
+  return true;
+}
+
+Maybe<const WebGLTexture::CompletenessInfo> WebGLTexture::CalcCompletenessInfo(
+    const bool ensureInit, const bool skipMips) const {
+  Maybe<CompletenessInfo> ret = Some(CompletenessInfo());
+
+  // -
+
+  const auto level_base = Es3_level_base();
+  if (level_base > kMaxLevelCount - 1) {
+    ret->incompleteReason = "`level_base` too high.";
+    return ret;
+  }
+
+  // Texture completeness is established at GLES 3.0.4, p160-161.
+  // "[A] texture is complete unless any of the following conditions hold true:"
+
+  // "* Any dimension of the `level_base` array is not positive."
+  const auto& baseImageInfo = ImageInfoAtFace(0, level_base);
+  if (!baseImageInfo.IsDefined()) {
+    // In case of undefined texture image, we don't print any message because
+    // this is a very common and often legitimate case (asynchronous texture
+    // loading).
+    ret->incompleteReason = nullptr;
+    return ret;
+  }
+
+  if (!baseImageInfo.mWidth || !baseImageInfo.mHeight ||
+      !baseImageInfo.mDepth) {
+    ret->incompleteReason =
+        "The dimensions of `level_base` are not all positive.";
+    return ret;
+  }
+
+  // "* The texture is a cube map texture, and is not cube complete."
+  bool initFailed = false;
+  if (!IsMipAndCubeComplete(level_base, ensureInit, &initFailed)) {
+    if (initFailed) return {};
+
+    // Can only fail if not cube-complete.
+    ret->incompleteReason = "Cubemaps must be \"cube complete\".";
+    return ret;
+  }
+  ret->levels = 1;
+  ret->usage = baseImageInfo.mFormat;
+  RefreshSwizzle();
+
+  ret->powerOfTwo = mozilla::IsPowerOfTwo(baseImageInfo.mWidth) &&
+                    mozilla::IsPowerOfTwo(baseImageInfo.mHeight);
+  if (mTarget == LOCAL_GL_TEXTURE_3D) {
+    ret->powerOfTwo &= mozilla::IsPowerOfTwo(baseImageInfo.mDepth);
+  }
+
+  // -
+
+  if (!mContext->IsWebGL2() && !ret->powerOfTwo) {
+    // WebGL 1 mipmaps require POT.
+    ret->incompleteReason = "Mipmapping requires power-of-two sizes.";
+    return ret;
+  }
+
+  // "* `level_base <= level_max`"
+
+  const auto level_max = Es3_level_max();
+  const auto maxLevel_aka_q = Es3_q();
+  if (level_base > level_max) {  // `level_max` not `q`!
+    ret->incompleteReason = "`level_base > level_max`.";
+    return ret;
+  }
+
+  if (skipMips) return ret;
+
+  if (!IsMipAndCubeComplete(maxLevel_aka_q, ensureInit, &initFailed)) {
+    if (initFailed) return {};
+
+    ret->incompleteReason = "Bad mipmap dimension or format.";
+    return ret;
+  }
+  ret->levels = AutoAssertCast(maxLevel_aka_q - level_base + 1);
+  ret->mipmapComplete = true;
+
+  // -
+
+  return ret;
+}
+
+Maybe<const webgl::SampleableInfo> WebGLTexture::CalcSampleableInfo(
+    const WebGLSampler* const sampler) const {
+  Maybe<webgl::SampleableInfo> ret = Some(webgl::SampleableInfo());
+
+  const bool ensureInit = true;
+  const auto completeness = CalcCompletenessInfo(ensureInit);
+  if (!completeness) return {};
+
+  ret->incompleteReason = completeness->incompleteReason;
+
+  if (!completeness->levels) return ret;
+
+  const auto* sampling = &mSamplingState;
+  if (sampler) {
+    sampling = &sampler->State();
+  }
+  const auto isDepthTex = bool(completeness->usage->format->d);
+  ret->isDepthTexCompare = isDepthTex & bool(sampling->compareMode.get());
+  // Because if it's not a depth texture, we always ignore compareMode.
+
+  const auto& minFilter = sampling->minFilter;
+  const auto& magFilter = sampling->magFilter;
+
+  // -
+
+  const bool needsMips = (minFilter == LOCAL_GL_NEAREST_MIPMAP_NEAREST ||
+                          minFilter == LOCAL_GL_NEAREST_MIPMAP_LINEAR ||
+                          minFilter == LOCAL_GL_LINEAR_MIPMAP_NEAREST ||
+                          minFilter == LOCAL_GL_LINEAR_MIPMAP_LINEAR);
+  if (needsMips & !completeness->mipmapComplete) return ret;
+
+  const bool isMinFilteringNearest =
+      (minFilter == LOCAL_GL_NEAREST ||
+       minFilter == LOCAL_GL_NEAREST_MIPMAP_NEAREST);
+  const bool isMagFilteringNearest = (magFilter == LOCAL_GL_NEAREST);
+  const bool isFilteringNearestOnly =
+      (isMinFilteringNearest && isMagFilteringNearest);
+  if (!isFilteringNearestOnly) {
+    bool isFilterable = completeness->usage->isFilterable;
+
+    // "* The effective internal format specified for the texture arrays is a
+    //    sized internal depth or depth and stencil format, the value of
+    //    TEXTURE_COMPARE_MODE is NONE[1], and either the magnification filter
+    //    is not NEAREST, or the minification filter is neither NEAREST nor
+    //    NEAREST_MIPMAP_NEAREST."
+    // [1]: This sounds suspect, but is explicitly noted in the change log for
+    //      GLES 3.0.1:
+    //      "* Clarify that a texture is incomplete if it has a depth component,
+    //         no shadow comparison, and linear filtering (also Bug 9481)."
+    // In short, depth formats are not filterable, but shadow-samplers are.
+    if (ret->isDepthTexCompare) {
+      isFilterable = true;
+
+      if (mContext->mWarnOnce_DepthTexCompareFilterable) {
+        mContext->mWarnOnce_DepthTexCompareFilterable = false;
+        mContext->GenerateWarning(
+            "Depth texture comparison requests (e.g. `LINEAR`) Filtering, but"
+            " behavior is implementation-defined, and so on some systems will"
+            " sometimes behave as `NEAREST`. (warns once)");
+      }
+    }
+
+    // "* The effective internal format specified for the texture arrays is a
+    //    sized internal color format that is not texture-filterable, and either
+    //    the magnification filter is not NEAREST or the minification filter is
+    //    neither NEAREST nor NEAREST_MIPMAP_NEAREST."
+    // Since all (GLES3) unsized color formats are filterable just like their
+    // sized equivalents, we don't have to care whether its sized or not.
+    if (!isFilterable) {
+      ret->incompleteReason =
+          "Minification or magnification filtering is not"
+          " NEAREST or NEAREST_MIPMAP_NEAREST, and the"
+          " texture's format is not \"texture-filterable\".";
+      return ret;
+    }
+  }
+
+  // Texture completeness is effectively (though not explicitly) amended for
+  // GLES2 by the "Texture Access" section under $3.8 "Fragment Shaders". This
+  // also applies to vertex shaders, as noted on GLES 2.0.25, p41.
+  if (!mContext->IsWebGL2() && !completeness->powerOfTwo) {
+    // GLES 2.0.25, p87-88:
+    // "Calling a sampler from a fragment shader will return (R,G,B,A)=(0,0,0,1)
+    // if
+    //  any of the following conditions are true:"
+
+    // "* A two-dimensional sampler is called, the minification filter is one
+    //    that requires a mipmap[...], and the sampler's associated texture
+    //    object is not complete[.]"
+    // (already covered)
+
+    // "* A two-dimensional sampler is called, the minification filter is
+    //    not one that requires a mipmap (either NEAREST nor[sic] LINEAR), and
+    //    either dimension of the level zero array of the associated texture
+    //    object is not positive."
+    // (already covered)
+
+    // "* A two-dimensional sampler is called, the corresponding texture
+    //    image is a non-power-of-two image[...], and either the texture wrap
+    //    mode is not CLAMP_TO_EDGE, or the minification filter is neither
+    //    NEAREST nor LINEAR."
+
+    // "* A cube map sampler is called, any of the corresponding texture
+    //    images are non-power-of-two images, and either the texture wrap mode
+    //    is not CLAMP_TO_EDGE, or the minification filter is neither NEAREST
+    //    nor LINEAR."
+    // "either the texture wrap mode is not CLAMP_TO_EDGE"
+    if (sampling->wrapS != LOCAL_GL_CLAMP_TO_EDGE ||
+        sampling->wrapT != LOCAL_GL_CLAMP_TO_EDGE) {
+      ret->incompleteReason =
+          "Non-power-of-two textures must have a wrap mode of"
+          " CLAMP_TO_EDGE.";
+      return ret;
+    }
+
+    // "* A cube map sampler is called, and either the corresponding cube
+    //    map texture image is not cube complete, or TEXTURE_MIN_FILTER is one
+    //    that requires a mipmap and the texture is not mipmap cube complete."
+    // (already covered)
+  }
+
+  // Mark complete.
+  ret->incompleteReason =
+      nullptr;  // NB: incompleteReason is also null for undefined
+  ret->levels = completeness->levels;  //   textures.
+  if (!needsMips && ret->levels) {
+    ret->levels = 1;
+  }
+  ret->usage = completeness->usage;
+  return ret;
+}
+
+const webgl::SampleableInfo* WebGLTexture::GetSampleableInfo(
+    const WebGLSampler* const sampler) const {
+  auto itr = mSamplingCache.Find(sampler);
+  if (!itr) {
+    const auto info = CalcSampleableInfo(sampler);
+    if (!info) return nullptr;
+
+    auto entry = mSamplingCache.MakeEntry(sampler, info.value());
+    entry->AddInvalidator(*this);
+    if (sampler) {
+      entry->AddInvalidator(*sampler);
+    }
+    itr = mSamplingCache.Insert(std::move(entry));
+  }
+  return itr;
+}
+
+// ---------------------------
+
+uint32_t WebGLTexture::Es3_q() const {
+  const auto& imageInfo = BaseImageInfo();
+  if (!imageInfo.IsDefined()) return mBaseMipmapLevel;
+
+  uint32_t largestDim = std::max(imageInfo.mWidth, imageInfo.mHeight);
+  if (mTarget == LOCAL_GL_TEXTURE_3D) {
+    largestDim = std::max(largestDim, imageInfo.mDepth);
+  }
+  if (!largestDim) return mBaseMipmapLevel;
+
+  // GLES 3.0.4, 3.8 - Mipmapping: `floor(log2(largest_of_dims)) + 1`
+  const auto numLevels = FloorLog2Size(largestDim) + 1;
+
+  const auto maxLevelBySize = mBaseMipmapLevel + numLevels - 1;
+  return std::min<uint32_t>(maxLevelBySize, mMaxMipmapLevel);
+}
+
+// -
+
+static void SetSwizzle(gl::GLContext* gl, TexTarget target,
+                       const GLint* swizzle) {
+  static const GLint kNoSwizzle[4] = {LOCAL_GL_RED, LOCAL_GL_GREEN,
+                                      LOCAL_GL_BLUE, LOCAL_GL_ALPHA};
+  if (!swizzle) {
+    swizzle = kNoSwizzle;
+  } else if (!gl->IsSupported(gl::GLFeature::texture_swizzle)) {
+    MOZ_CRASH("GFX: Needs swizzle feature to swizzle!");
+  }
+
+  gl->fTexParameteri(target.get(), LOCAL_GL_TEXTURE_SWIZZLE_R, swizzle[0]);
+  gl->fTexParameteri(target.get(), LOCAL_GL_TEXTURE_SWIZZLE_G, swizzle[1]);
+  gl->fTexParameteri(target.get(), LOCAL_GL_TEXTURE_SWIZZLE_B, swizzle[2]);
+  gl->fTexParameteri(target.get(), LOCAL_GL_TEXTURE_SWIZZLE_A, swizzle[3]);
+}
+
+void WebGLTexture::RefreshSwizzle() const {
+  const auto& imageInfo = BaseImageInfo();
+  const auto& swizzle = imageInfo.mFormat->textureSwizzleRGBA;
+
+  if (swizzle != mCurSwizzle) {
+    const gl::ScopedBindTexture scopeBindTexture(mContext->gl, mGLName,
+                                                 mTarget.get());
+    SetSwizzle(mContext->gl, mTarget, swizzle);
+    mCurSwizzle = swizzle;
+  }
+}
+
+bool WebGLTexture::EnsureImageDataInitialized(const TexImageTarget target,
+                                              const uint32_t level) {
+  auto& imageInfo = ImageInfoAt(target, level);
+  if (!imageInfo.IsDefined()) return true;
+
+  if (!imageInfo.mUninitializedSlices) return true;
+
+  if (!ZeroTextureData(mContext, mGLName, target, level, imageInfo)) {
+    return false;
+  }
+  imageInfo.mUninitializedSlices = Nothing();
+  return true;
+}
+
+static bool ClearDepthTexture(const WebGLContext& webgl, const GLuint tex,
+                              const TexImageTarget imageTarget,
+                              const uint32_t level,
+                              const webgl::ImageInfo& info) {
+  const auto& gl = webgl.gl;
+  const auto& usage = info.mFormat;
+  const auto& format = usage->format;
+
+  // Depth resources actually clear to 1.0f, not 0.0f!
+  // They are also always renderable.
+  MOZ_ASSERT(usage->IsRenderable());
+  MOZ_ASSERT(info.mUninitializedSlices);
+
+  GLenum attachPoint = LOCAL_GL_DEPTH_ATTACHMENT;
+  GLbitfield clearBits = LOCAL_GL_DEPTH_BUFFER_BIT;
+
+  if (format->s) {
+    attachPoint = LOCAL_GL_DEPTH_STENCIL_ATTACHMENT;
+    clearBits |= LOCAL_GL_STENCIL_BUFFER_BIT;
+  }
+
+  // -
+
+  gl::ScopedFramebuffer scopedFB(gl);
+  const gl::ScopedBindFramebuffer scopedBindFB(gl, scopedFB.FB());
+  const webgl::ScopedPrepForResourceClear scopedPrep(webgl);
+
+  const auto fnAttach = [&](const uint32_t z) {
+    switch (imageTarget.get()) {
+      case LOCAL_GL_TEXTURE_3D:
+      case LOCAL_GL_TEXTURE_2D_ARRAY:
+        gl->fFramebufferTextureLayer(LOCAL_GL_FRAMEBUFFER, attachPoint, tex,
+                                     level, z);
+        break;
+      default:
+        if (attachPoint == LOCAL_GL_DEPTH_STENCIL_ATTACHMENT) {
+          gl->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER,
+                                    LOCAL_GL_DEPTH_ATTACHMENT,
+                                    imageTarget.get(), tex, level);
+          gl->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER,
+                                    LOCAL_GL_STENCIL_ATTACHMENT,
+                                    imageTarget.get(), tex, level);
+        } else {
+          gl->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER, attachPoint,
+                                    imageTarget.get(), tex, level);
+        }
+        break;
+    }
+  };
+
+  for (const auto z : IntegerRange(info.mDepth)) {
+    if ((*info.mUninitializedSlices)[z]) {
+      fnAttach(z);
+      gl->fClear(clearBits);
+    }
+  }
+  const auto& status = gl->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
+  const bool isComplete = (status == LOCAL_GL_FRAMEBUFFER_COMPLETE);
+  MOZ_ASSERT(isComplete);
+  return isComplete;
+}
+
+static bool ZeroTextureData(const WebGLContext* webgl, GLuint tex,
+                            TexImageTarget target, uint32_t level,
+                            const webgl::ImageInfo& info) {
+  // This has one usecase:
+  // Lazy zeroing of uninitialized textures:
+  //    a. Before draw.
+  //    b. Before partial upload. (TexStorage + TexSubImage)
+
+  // We have no sympathy for this case.
+
+  // "Doctor, it hurts when I do this!" "Well don't do that!"
+  MOZ_ASSERT(info.mUninitializedSlices);
+
+  const auto targetStr = EnumString(target.get());
+  webgl->GenerateWarning(
+      "Tex image %s level %u is incurring lazy initialization.",
+      targetStr.c_str(), level);
+
+  gl::GLContext* gl = webgl->GL();
+  const auto& width = info.mWidth;
+  const auto& height = info.mHeight;
+  const auto& depth = info.mDepth;
+  const auto& usage = info.mFormat;
+
+  GLenum scopeBindTarget;
+  switch (target.get()) {
+    case LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X:
+    case LOCAL_GL_TEXTURE_CUBE_MAP_NEGATIVE_X:
+    case LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_Y:
+    case LOCAL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Y:
+    case LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_Z:
+    case LOCAL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Z:
+      scopeBindTarget = LOCAL_GL_TEXTURE_CUBE_MAP;
+      break;
+    default:
+      scopeBindTarget = target.get();
+      break;
+  }
+  const gl::ScopedBindTexture scopeBindTexture(gl, tex, scopeBindTarget);
+  const auto& compression = usage->format->compression;
+  if (compression) {
+    auto sizedFormat = usage->format->sizedFormat;
+    MOZ_RELEASE_ASSERT(sizedFormat, "GFX: texture sized format not set");
+
+    const auto fnSizeInBlocks = [](CheckedUint32 pixels,
+                                   uint8_t pixelsPerBlock) {
+      return RoundUpToMultipleOf(pixels, pixelsPerBlock) / pixelsPerBlock;
+    };
+
+    const auto widthBlocks = fnSizeInBlocks(width, compression->blockWidth);
+    const auto heightBlocks = fnSizeInBlocks(height, compression->blockHeight);
+
+    CheckedUint32 checkedByteCount = compression->bytesPerBlock;
+    checkedByteCount *= widthBlocks;
+    checkedByteCount *= heightBlocks;
+
+    if (!checkedByteCount.isValid()) return false;
+
+    const size_t sliceByteCount = checkedByteCount.value();
+
+    const auto zeros = UniqueBuffer::Take(calloc(1u, sliceByteCount));
+    if (!zeros) return false;
+
+    // Don't bother with striding it well.
+    // TODO: We shouldn't need to do this for CompressedTexSubImage.
+    webgl::PixelPackingState{}.AssertCurrentUnpack(*gl, webgl->IsWebGL2());
+    gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 1);
+    const auto revert = MakeScopeExit(
+        [&]() { gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4); });
+
+    GLenum error = 0;
+    for (const auto z : IntegerRange(depth)) {
+      if ((*info.mUninitializedSlices)[z]) {
+        error = DoCompressedTexSubImage(gl, target.get(), level, 0, 0, z, width,
+                                        height, 1, sizedFormat, sliceByteCount,
+                                        zeros.get());
+        if (error) break;
+      }
+    }
+    return !error;
+  }
+
+  const auto driverUnpackInfo = usage->idealUnpack;
+  MOZ_RELEASE_ASSERT(driverUnpackInfo, "GFX: ideal unpack info not set.");
+
+  if (usage->format->d) {
+    // ANGLE_depth_texture does not allow uploads, so we have to clear.
+    // (Restriction because of D3D9)
+    // Also, depth resources are cleared to 1.0f and are always renderable, so
+    // just use FB clears.
+    return ClearDepthTexture(*webgl, tex, target, level, info);
+  }
+
+  const webgl::PackingInfo packing = driverUnpackInfo->ToPacking();
+
+  const auto bytesPerPixel = webgl::BytesPerPixel(packing);
+
+  CheckedUint32 checkedByteCount = bytesPerPixel;
+  checkedByteCount *= width;
+  checkedByteCount *= height;
+
+  if (!checkedByteCount.isValid()) return false;
+
+  const size_t sliceByteCount = checkedByteCount.value();
+
+  const auto zeros = UniqueBuffer::Take(calloc(1u, sliceByteCount));
+  if (!zeros) return false;
+
+  // Don't bother with striding it well.
+  webgl::PixelPackingState{}.AssertCurrentUnpack(*gl, webgl->IsWebGL2());
+  gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 1);
+  const auto revert =
+      MakeScopeExit([&]() { gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT, 4); });
+
+  GLenum error = 0;
+  for (const auto z : IntegerRange(depth)) {
+    if ((*info.mUninitializedSlices)[z]) {
+      error = DoTexSubImage(gl, target, level, 0, 0, z, width, height, 1,
+                            packing, zeros.get());
+      if (error) break;
+    }
+  }
+  return !error;
+}
+
+template <typename T, typename R>
+static constexpr R Clamp(const T val, const R min, const R max) {
+  if (val < min) return min;
+  if (val > max) return max;
+  return static_cast<R>(val);
+}
+
+void WebGLTexture::ClampLevelBaseAndMax() {
+  if (!mImmutable) return;
+
+  // GLES 3.0.4, p158:
+  // "For immutable-format textures, `level_base` is clamped to the range
+  //  `[0, levels-1]`, `level_max` is then clamped to the range `
+  //  `[level_base, levels-1]`, where `levels` is the parameter passed to
+  //   TexStorage* for the texture object."
+  MOZ_ASSERT(mImmutableLevelCount > 0);
+  const auto oldBase = mBaseMipmapLevel;
+  const auto oldMax = mMaxMipmapLevel;
+  mBaseMipmapLevel = Clamp(mBaseMipmapLevel, 0u, mImmutableLevelCount - 1u);
+  mMaxMipmapLevel =
+      Clamp(mMaxMipmapLevel, mBaseMipmapLevel, mImmutableLevelCount - 1u);
+  if (oldBase != mBaseMipmapLevel &&
+      mBaseMipmapLevelState != MIPMAP_LEVEL_DEFAULT) {
+    mBaseMipmapLevelState = MIPMAP_LEVEL_DIRTY;
+  }
+  if (oldMax != mMaxMipmapLevel &&
+      mMaxMipmapLevelState != MIPMAP_LEVEL_DEFAULT) {
+    mMaxMipmapLevelState = MIPMAP_LEVEL_DIRTY;
+  }
+
+  // Note: This means that immutable textures are *always* texture-complete!
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////
+// GL calls
+
+bool WebGLTexture::BindTexture(TexTarget texTarget) {
+  const bool isFirstBinding = !mTarget;
+  if (!isFirstBinding && mTarget != texTarget) {
+    mContext->ErrorInvalidOperation(
+        "bindTexture: This texture has already been bound"
+        " to a different target.");
+    return false;
+  }
+
+  mTarget = texTarget;
+
+  mContext->gl->fBindTexture(mTarget.get(), mGLName);
+
+  if (isFirstBinding) {
+    mFaceCount = IsCubeMap() ? 6 : 1;
+
+    gl::GLContext* gl = mContext->gl;
+
+    // Thanks to the WebKit people for finding this out: GL_TEXTURE_WRAP_R
+    // is not present in GLES 2, but is present in GL and it seems as if for
+    // cube maps we need to set it to GL_CLAMP_TO_EDGE to get the expected
+    // GLES behavior.
+    // If we are WebGL 2 though, we'll want to leave it as REPEAT.
+    const bool hasWrapR = gl->IsSupported(gl::GLFeature::texture_3D);
+    if (IsCubeMap() && hasWrapR && !mContext->IsWebGL2()) {
+      gl->fTexParameteri(texTarget.get(), LOCAL_GL_TEXTURE_WRAP_R,
+                         LOCAL_GL_CLAMP_TO_EDGE);
+    }
+  }
+
+  return true;
+}
+
+static constexpr GLint ClampMipmapLevelForDriver(uint32_t level) {
+  return Clamp(level, uint8_t{0}, WebGLTexture::kMaxLevelCount);
+}
+
+void WebGLTexture::GenerateMipmap() {
+  // GLES 3.0.4 p160:
+  // "Mipmap generation replaces texel array levels level base + 1 through q
+  //  with arrrays derived from the level base array, regardless of their
+  //  previous contents. All other mipmap arrays, including the level base
+  //  array, are left unchanged by this computation."
+  // But only check and init the base level.
+  const bool ensureInit = true;
+  const bool skipMips = true;
+  const auto completeness = CalcCompletenessInfo(ensureInit, skipMips);
+  if (!completeness || !completeness->levels) {
+    mContext->ErrorInvalidOperation(
+        "The texture's base level must be complete.");
+    return;
+  }
+  const auto& usage = completeness->usage;
+  const auto& format = usage->format;
+  if (!mContext->IsWebGL2()) {
+    if (!completeness->powerOfTwo) {
+      mContext->ErrorInvalidOperation(
+          "The base level of the texture does not"
+          " have power-of-two dimensions.");
+      return;
+    }
+    if (format->isSRGB) {
+      mContext->ErrorInvalidOperation(
+          "EXT_sRGB forbids GenerateMipmap with"
+          " sRGB.");
+      return;
+    }
+  }
+
+  if (format->compression) {
+    mContext->ErrorInvalidOperation(
+        "Texture data at base level is compressed.");
+    return;
+  }
+
+  if (format->d) {
+    mContext->ErrorInvalidOperation("Depth textures are not supported.");
+    return;
+  }
+
+  // OpenGL ES 3.0.4 p160:
+  // If the level base array was not specified with an unsized internal format
+  // from table 3.3 or a sized internal format that is both color-renderable and
+  // texture-filterable according to table 3.13, an INVALID_OPERATION error
+  // is generated.
+  bool canGenerateMipmap = (usage->IsRenderable() && usage->isFilterable);
+  switch (usage->format->effectiveFormat) {
+    case webgl::EffectiveFormat::Luminance8:
+    case webgl::EffectiveFormat::Alpha8:
+    case webgl::EffectiveFormat::Luminance8Alpha8:
+      // Non-color-renderable formats from Table 3.3.
+      canGenerateMipmap = true;
+      break;
+    default:
+      break;
+  }
+
+  if (!canGenerateMipmap) {
+    mContext->ErrorInvalidOperation(
+        "Texture at base level is not unsized"
+        " internal format or is not"
+        " color-renderable or texture-filterable.");
+    return;
+  }
+
+  if (usage->IsRenderable() && !usage->IsExplicitlyRenderable()) {
+    mContext->WarnIfImplicit(usage->GetExtensionID());
+  }
+
+  // Done with validation. Do the operation.
+
+  gl::GLContext* gl = mContext->gl;
+
+  if (gl->WorkAroundDriverBugs()) {
+    // If we first set GL_TEXTURE_BASE_LEVEL to a number such as 20, then set
+    // MGL_TEXTURE_MAX_LEVEL to a smaller number like 8, our copy of the
+    // base level will be lowered, but we havn't yet updated the driver, we
+    // should do so now, before calling glGenerateMipmap().
+    if (mBaseMipmapLevelState == MIPMAP_LEVEL_DIRTY) {
+      gl->fTexParameteri(mTarget.get(), LOCAL_GL_TEXTURE_BASE_LEVEL,
+                         ClampMipmapLevelForDriver(mBaseMipmapLevel));
+      mBaseMipmapLevelState = MIPMAP_LEVEL_CLEAN;
+    }
+    if (mMaxMipmapLevelState == MIPMAP_LEVEL_DIRTY) {
+      gl->fTexParameteri(mTarget.get(), LOCAL_GL_TEXTURE_MAX_LEVEL,
+                         ClampMipmapLevelForDriver(mMaxMipmapLevel));
+      mMaxMipmapLevelState = MIPMAP_LEVEL_CLEAN;
+    }
+
+    // bug 696495 - to work around failures in the texture-mips.html test on
+    // various drivers, we set the minification filter before calling
+    // glGenerateMipmap. This should not carry a significant performance
+    // overhead so we do it unconditionally.
+    //
+    // note that the choice of GL_NEAREST_MIPMAP_NEAREST really matters. See
+    // Chromium bug 101105.
+    gl->fTexParameteri(mTarget.get(), LOCAL_GL_TEXTURE_MIN_FILTER,
+                       LOCAL_GL_NEAREST_MIPMAP_NEAREST);
+    gl->fGenerateMipmap(mTarget.get());
+    gl->fTexParameteri(mTarget.get(), LOCAL_GL_TEXTURE_MIN_FILTER,
+                       mSamplingState.minFilter.get());
+  } else {
+    gl->fGenerateMipmap(mTarget.get());
+  }
+
+  // Record the results.
+
+  const auto maxLevel = Es3_q();
+  PopulateMipChain(maxLevel);
+}
+
+Maybe<double> WebGLTexture::GetTexParameter(GLenum pname) const {
+  GLint i = 0;
+  GLfloat f = 0.0f;
+
+  switch (pname) {
+    case LOCAL_GL_TEXTURE_BASE_LEVEL:
+      return Some(mBaseMipmapLevel);
+
+    case LOCAL_GL_TEXTURE_MAX_LEVEL:
+      return Some(mMaxMipmapLevel);
+
+    case LOCAL_GL_TEXTURE_IMMUTABLE_FORMAT:
+      return Some(mImmutable);
+
+    case LOCAL_GL_TEXTURE_IMMUTABLE_LEVELS:
+      return Some(uint32_t(mImmutableLevelCount));
+
+    case LOCAL_GL_TEXTURE_MIN_FILTER:
+    case LOCAL_GL_TEXTURE_MAG_FILTER:
+    case LOCAL_GL_TEXTURE_WRAP_S:
+    case LOCAL_GL_TEXTURE_WRAP_T:
+    case LOCAL_GL_TEXTURE_WRAP_R:
+    case LOCAL_GL_TEXTURE_COMPARE_MODE:
+    case LOCAL_GL_TEXTURE_COMPARE_FUNC: {
+      MOZ_ASSERT(mTarget);
+      const gl::ScopedBindTexture autoTex(mContext->gl, mGLName, mTarget.get());
+      mContext->gl->fGetTexParameteriv(mTarget.get(), pname, &i);
+      return Some(i);
+    }
+
+    case LOCAL_GL_TEXTURE_MAX_ANISOTROPY_EXT:
+    case LOCAL_GL_TEXTURE_MAX_LOD:
+    case LOCAL_GL_TEXTURE_MIN_LOD: {
+      MOZ_ASSERT(mTarget);
+      const gl::ScopedBindTexture autoTex(mContext->gl, mGLName, mTarget.get());
+      mContext->gl->fGetTexParameterfv(mTarget.get(), pname, &f);
+      return Some(f);
+    }
+
+    default:
+      MOZ_CRASH("GFX: Unhandled pname.");
+  }
+}
+
+// Here we have to support all pnames with both int and float params.
+// See this discussion:
+//   https://www.khronos.org/webgl/public-mailing-list/archives/1008/msg00014.html
+void WebGLTexture::TexParameter(TexTarget texTarget, GLenum pname,
+                                const FloatOrInt& param) {
+  bool isPNameValid = false;
+  switch (pname) {
+    // GLES 2.0.25 p76:
+    case LOCAL_GL_TEXTURE_WRAP_S:
+    case LOCAL_GL_TEXTURE_WRAP_T:
+    case LOCAL_GL_TEXTURE_MIN_FILTER:
+    case LOCAL_GL_TEXTURE_MAG_FILTER:
+      isPNameValid = true;
+      break;
+
+    // GLES 3.0.4 p149-150:
+    case LOCAL_GL_TEXTURE_BASE_LEVEL:
+    case LOCAL_GL_TEXTURE_COMPARE_MODE:
+    case LOCAL_GL_TEXTURE_COMPARE_FUNC:
+    case LOCAL_GL_TEXTURE_MAX_LEVEL:
+    case LOCAL_GL_TEXTURE_MAX_LOD:
+    case LOCAL_GL_TEXTURE_MIN_LOD:
+    case LOCAL_GL_TEXTURE_WRAP_R:
+      if (mContext->IsWebGL2()) isPNameValid = true;
+      break;
+
+    case LOCAL_GL_TEXTURE_MAX_ANISOTROPY_EXT:
+      if (mContext->IsExtensionEnabled(
+              WebGLExtensionID::EXT_texture_filter_anisotropic))
+        isPNameValid = true;
+      break;
+  }
+
+  if (!isPNameValid) {
+    mContext->ErrorInvalidEnumInfo("texParameter: pname", pname);
+    return;
+  }
+
+  ////////////////
+  // Validate params and invalidate if needed.
+
+  bool paramBadEnum = false;
+  bool paramBadValue = false;
+
+  switch (pname) {
+    case LOCAL_GL_TEXTURE_BASE_LEVEL:
+    case LOCAL_GL_TEXTURE_MAX_LEVEL:
+      paramBadValue = (param.i < 0);
+      break;
+
+    case LOCAL_GL_TEXTURE_COMPARE_MODE:
+      paramBadValue = (param.i != LOCAL_GL_NONE &&
+                       param.i != LOCAL_GL_COMPARE_REF_TO_TEXTURE);
+      break;
+
+    case LOCAL_GL_TEXTURE_COMPARE_FUNC:
+      switch (param.i) {
+        case LOCAL_GL_LEQUAL:
+        case LOCAL_GL_GEQUAL:
+        case LOCAL_GL_LESS:
+        case LOCAL_GL_GREATER:
+        case LOCAL_GL_EQUAL:
+        case LOCAL_GL_NOTEQUAL:
+        case LOCAL_GL_ALWAYS:
+        case LOCAL_GL_NEVER:
+          break;
+
+        default:
+          paramBadValue = true;
+          break;
+      }
+      break;
+
+    case LOCAL_GL_TEXTURE_MIN_FILTER:
+      switch (param.i) {
+        case LOCAL_GL_NEAREST:
+        case LOCAL_GL_LINEAR:
+        case LOCAL_GL_NEAREST_MIPMAP_NEAREST:
+        case LOCAL_GL_LINEAR_MIPMAP_NEAREST:
+        case LOCAL_GL_NEAREST_MIPMAP_LINEAR:
+        case LOCAL_GL_LINEAR_MIPMAP_LINEAR:
+          break;
+
+        default:
+          paramBadEnum = true;
+          break;
+      }
+      break;
+
+    case LOCAL_GL_TEXTURE_MAG_FILTER:
+      switch (param.i) {
+        case LOCAL_GL_NEAREST:
+        case LOCAL_GL_LINEAR:
+          break;
+
+        default:
+          paramBadEnum = true;
+          break;
+      }
+      break;
+
+    case LOCAL_GL_TEXTURE_WRAP_S:
+    case LOCAL_GL_TEXTURE_WRAP_T:
+    case LOCAL_GL_TEXTURE_WRAP_R:
+      switch (param.i) {
+        case LOCAL_GL_CLAMP_TO_EDGE:
+        case LOCAL_GL_MIRRORED_REPEAT:
+        case LOCAL_GL_REPEAT:
+          break;
+
+        default:
+          paramBadEnum = true;
+          break;
+      }
+      break;
+
+    case LOCAL_GL_TEXTURE_MAX_ANISOTROPY_EXT:
+      if (param.f < 1.0f) paramBadValue = true;
+
+      break;
+  }
+
+  if (paramBadEnum) {
+    if (!param.isFloat) {
+      mContext->ErrorInvalidEnum(
+          "pname 0x%04x: Invalid param"
+          " 0x%04x.",
+          pname, param.i);
+    } else {
+      mContext->ErrorInvalidEnum("pname 0x%04x: Invalid param %g.", pname,
+                                 param.f);
+    }
+    return;
+  }
+
+  if (paramBadValue) {
+    if (!param.isFloat) {
+      mContext->ErrorInvalidValue(
+          "pname 0x%04x: Invalid param %i"
+          " (0x%x).",
+          pname, param.i, param.i);
+    } else {
+      mContext->ErrorInvalidValue("pname 0x%04x: Invalid param %g.", pname,
+                                  param.f);
+    }
+    return;
+  }
+
+  ////////////////
+  // Store any needed values
+
+  FloatOrInt clamped = param;
+  bool invalidate = true;
+  switch (pname) {
+    case LOCAL_GL_TEXTURE_BASE_LEVEL: {
+      mBaseMipmapLevel = clamped.i;
+      mBaseMipmapLevelState = MIPMAP_LEVEL_CLEAN;
+      ClampLevelBaseAndMax();
+      clamped = FloatOrInt(ClampMipmapLevelForDriver(mBaseMipmapLevel));
+      break;
+    }
+
+    case LOCAL_GL_TEXTURE_MAX_LEVEL: {
+      mMaxMipmapLevel = clamped.i;
+      mMaxMipmapLevelState = MIPMAP_LEVEL_CLEAN;
+      ClampLevelBaseAndMax();
+      clamped = FloatOrInt(ClampMipmapLevelForDriver(mMaxMipmapLevel));
+      break;
+    }
+
+    case LOCAL_GL_TEXTURE_MIN_FILTER:
+      mSamplingState.minFilter = clamped.i;
+      break;
+
+    case LOCAL_GL_TEXTURE_MAG_FILTER:
+      mSamplingState.magFilter = clamped.i;
+      break;
+
+    case LOCAL_GL_TEXTURE_WRAP_S:
+      mSamplingState.wrapS = clamped.i;
+      break;
+
+    case LOCAL_GL_TEXTURE_WRAP_T:
+      mSamplingState.wrapT = clamped.i;
+      break;
+
+    case LOCAL_GL_TEXTURE_COMPARE_MODE:
+      mSamplingState.compareMode = clamped.i;
+      break;
+
+    default:
+      invalidate = false;  // Texture completeness will not change.
+      break;
+  }
+
+  if (invalidate) {
+    InvalidateCaches();
+  }
+
+  ////////////////
+
+  if (!clamped.isFloat) {
+    mContext->gl->fTexParameteri(texTarget.get(), pname, clamped.i);
+  } else {
+    mContext->gl->fTexParameterf(texTarget.get(), pname, clamped.f);
+  }
+}
+
+void WebGLTexture::Truncate() {
+  for (auto& cur : mImageInfoArr) {
+    cur = {};
+  }
+  InvalidateCaches();
+}
+
+}  // namespace mozilla