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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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/dom/WebGLRenderingContextBinding.h"
#include "mozilla/gfx/Logging.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/Scoped.h"
#include "mozilla/Unused.h"
#include "ScopedGLHelpers.h"
#include "WebGLContext.h"
#include "WebGLContextUtils.h"
#include "WebGLFramebuffer.h"
#include "WebGLSampler.h"
#include "WebGLTexelConversions.h"

namespace mozilla {

/*static*/ const WebGLTexture::ImageInfo WebGLTexture::ImageInfo::kUndefined;

////////////////////////////////////////

template <typename T>
static inline T& Mutable(const T& x) {
  return const_cast<T&>(x);
}

void WebGLTexture::ImageInfo::Clear(const char* funcName) {
  if (!IsDefined()) return;

  OnRespecify(funcName);

  Mutable(mFormat) = LOCAL_GL_NONE;
  Mutable(mWidth) = 0;
  Mutable(mHeight) = 0;
  Mutable(mDepth) = 0;

  MOZ_ASSERT(!IsDefined());
}

void WebGLTexture::ImageInfo::Set(const char* funcName, const ImageInfo& a) {
  Mutable(mFormat) = a.mFormat;
  Mutable(mWidth) = a.mWidth;
  Mutable(mHeight) = a.mHeight;
  Mutable(mDepth) = a.mDepth;

  mIsDataInitialized = a.mIsDataInitialized;

  // But *don't* transfer mAttachPoints!
  MOZ_ASSERT(a.mAttachPoints.empty());
  OnRespecify(funcName);
}

bool WebGLTexture::ImageInfo::IsPowerOfTwo() const {
  return mozilla::IsPowerOfTwo(mWidth) && mozilla::IsPowerOfTwo(mHeight) &&
         mozilla::IsPowerOfTwo(mDepth);
}

void WebGLTexture::ImageInfo::AddAttachPoint(WebGLFBAttachPoint* attachPoint) {
  const auto pair = mAttachPoints.insert(attachPoint);
  DebugOnly<bool> didInsert = pair.second;
  MOZ_ASSERT(didInsert);
}

void WebGLTexture::ImageInfo::RemoveAttachPoint(
    WebGLFBAttachPoint* attachPoint) {
  DebugOnly<size_t> numElemsErased = mAttachPoints.erase(attachPoint);
  MOZ_ASSERT_IF(IsDefined(), numElemsErased == 1);
}

void WebGLTexture::ImageInfo::OnRespecify(const char* funcName) const {
  for (auto cur : mAttachPoints) {
    cur->OnBackingStoreRespecified(funcName);
  }
}

size_t WebGLTexture::ImageInfo::MemoryUsage() const {
  if (!IsDefined()) return 0;

  const auto bytesPerTexel = mFormat->format->estimatedBytesPerPixel;
  return size_t(mWidth) * size_t(mHeight) * size_t(mDepth) * bytesPerTexel;
}

void WebGLTexture::ImageInfo::SetIsDataInitialized(bool isDataInitialized,
                                                   WebGLTexture* tex) {
  MOZ_ASSERT(tex);
  MOZ_ASSERT(this >= &tex->mImageInfoArr[0]);
  MOZ_ASSERT(this < &tex->mImageInfoArr[kMaxLevelCount * kMaxFaceCount]);

  mIsDataInitialized = isDataInitialized;
  tex->InvalidateResolveCache();
}

////////////////////////////////////////

JSObject* WebGLTexture::WrapObject(JSContext* cx,
                                   JS::Handle<JSObject*> givenProto) {
  return dom::WebGLTextureBinding::Wrap(cx, this, givenProto);
}

WebGLTexture::WebGLTexture(WebGLContext* webgl, GLuint tex)
    : WebGLRefCountedObject(webgl),
      mGLName(tex),
      mTarget(LOCAL_GL_NONE),
      mFaceCount(0),
      mMinFilter(LOCAL_GL_NEAREST_MIPMAP_LINEAR),
      mMagFilter(LOCAL_GL_LINEAR),
      mWrapS(LOCAL_GL_REPEAT),
      mWrapT(LOCAL_GL_REPEAT),
      mImmutable(false),
      mImmutableLevelCount(0),
      mBaseMipmapLevel(0),
      mMaxMipmapLevel(1000),
      mTexCompareMode(LOCAL_GL_NONE),
      mIsResolved(false),
      mResolved_Swizzle(nullptr) {
  mContext->mTextures.insertBack(this);
}

void WebGLTexture::Delete() {
  const char funcName[] = "WebGLTexture::Delete";
  for (auto& cur : mImageInfoArr) {
    cur.Clear(funcName);
  }

  mContext->gl->fDeleteTextures(1, &mGLName);

  LinkedListElement<WebGLTexture>::removeFrom(mContext->mTextures);
}

size_t WebGLTexture::MemoryUsage() const {
  if (IsDeleted()) return 0;

  size_t accum = 0;
  for (const auto& cur : mImageInfoArr) {
    accum += cur.MemoryUsage();
  }
  return accum;
}

void WebGLTexture::SetImageInfo(const char* funcName, ImageInfo* target,
                                const ImageInfo& newInfo) {
  target->Set(funcName, newInfo);

  InvalidateResolveCache();
}

void WebGLTexture::SetImageInfosAtLevel(const char* funcName, uint32_t level,
                                        const ImageInfo& newInfo) {
  for (uint8_t i = 0; i < mFaceCount; i++) {
    ImageInfoAtFace(i, level).Set(funcName, newInfo);
  }

  InvalidateResolveCache();
}

bool WebGLTexture::IsMipmapComplete(const char* funcName, uint32_t texUnit,
                                    bool* const out_initFailed) {
  *out_initFailed = false;
  MOZ_ASSERT(DoesMinFilterRequireMipmap());
  // GLES 3.0.4, p161

  uint32_t maxLevel;
  if (!MaxEffectiveMipmapLevel(texUnit, &maxLevel)) return false;

  // "* `level_base <= level_max`"
  if (mBaseMipmapLevel > maxLevel) return false;

  // Make a copy so we can modify it.
  const ImageInfo& baseImageInfo = BaseImageInfo();

  // Reference dimensions based on the current level.
  uint32_t refWidth = baseImageInfo.mWidth;
  uint32_t refHeight = baseImageInfo.mHeight;
  uint32_t refDepth = baseImageInfo.mDepth;
  MOZ_ASSERT(refWidth && refHeight && refDepth);

  for (uint32_t level = mBaseMipmapLevel; level <= maxLevel; level++) {
    if (!EnsureLevelInitialized(funcName, level)) {
      *out_initFailed = true;
      return false;
    }

    // "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++) {
      const ImageInfo& 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 != refWidth || cur.mHeight != refHeight ||
          cur.mDepth != refDepth || cur.mFormat != baseImageInfo.mFormat) {
        return false;
      }
    }

    // GLES 3.0.4, p158:
    // "[...] until the last array is reached with dimension 1 x 1 x 1."
    if (mTarget == LOCAL_GL_TEXTURE_3D) {
      if (refWidth == 1 && refHeight == 1 && refDepth == 1) {
        break;
      }

      refDepth = std::max(uint32_t(1), refDepth / 2);
    } else {
      // TEXTURE_2D_ARRAY may have depth != 1, but that's normal.
      if (refWidth == 1 && refHeight == 1) {
        break;
      }
    }

    refWidth = std::max(uint32_t(1), refWidth / 2);
    refHeight = std::max(uint32_t(1), refHeight / 2);
  }

  return true;
}

bool WebGLTexture::IsCubeComplete() const {
  // GLES 3.0.4, p161
  // "[...] a cube map texture is cube complete if the following conditions all
  // hold
  //  true:
  //  * The `level_base` arrays of each of the six texture images making up the
  //  cube map
  //    have identical, positive, and square dimensions.
  //  * The `level_base` arrays were each specified with the same effective
  //  internal
  //    format."

  // Note that "cube complete" does not imply "mipmap complete".

  const ImageInfo& reference = BaseImageInfo();
  if (!reference.IsDefined()) return false;

  auto refWidth = reference.mWidth;
  auto refFormat = reference.mFormat;

  for (uint8_t face = 0; face < mFaceCount; face++) {
    const ImageInfo& cur = ImageInfoAtFace(face, mBaseMipmapLevel);
    if (!cur.IsDefined()) return false;

    MOZ_ASSERT(cur.mDepth == 1);
    if (cur.mFormat != refFormat ||  // Check effective formats.
        cur.mWidth !=
            refWidth ||  // Check both width and height against refWidth to
        cur.mHeight != refWidth)  // to enforce positive and square dimensions.
    {
      return false;
    }
  }

  return true;
}

bool WebGLTexture::IsComplete(const char* funcName, uint32_t texUnit,
                              const char** const out_reason,
                              bool* const out_initFailed) {
  *out_initFailed = false;

  const auto maxLevel = kMaxLevelCount - 1;
  if (mBaseMipmapLevel > maxLevel) {
    *out_reason = "`level_base` too high.";
    return false;
  }

  // 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 ImageInfo& baseImageInfo = BaseImageInfo();
  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).
    *out_reason = nullptr;
    return false;
  }

  if (!baseImageInfo.mWidth || !baseImageInfo.mHeight ||
      !baseImageInfo.mDepth) {
    *out_reason = "The dimensions of `level_base` are not all positive.";
    return false;
  }

  // "* The texture is a cube map texture, and is not cube complete."
  if (IsCubeMap() && !IsCubeComplete()) {
    *out_reason = "Cubemaps must be \"cube complete\".";
    return false;
  }

  WebGLSampler* sampler = mContext->mBoundSamplers[texUnit];
  TexMinFilter minFilter = sampler ? sampler->mMinFilter : mMinFilter;
  TexMagFilter magFilter = sampler ? sampler->mMagFilter : mMagFilter;

  // "* The minification filter requires a mipmap (is neither NEAREST nor
  // LINEAR) and
  //    the texture is not mipmap complete."
  const bool requiresMipmap =
      (minFilter != LOCAL_GL_NEAREST && minFilter != LOCAL_GL_LINEAR);
  if (requiresMipmap && !IsMipmapComplete(funcName, texUnit, out_initFailed)) {
    if (*out_initFailed) return false;

    *out_reason =
        "Because the minification filter requires mipmapping, the texture"
        " must be \"mipmap complete\".";
    return false;
  }

  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) {
    auto formatUsage = baseImageInfo.mFormat;
    auto format = formatUsage->format;

    bool isFilterable = formatUsage->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 (format->d && mTexCompareMode != LOCAL_GL_NONE) {
      isFilterable = true;
    }

    // "* 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) {
      *out_reason =
          "Because minification or magnification filtering is not NEAREST"
          " or NEAREST_MIPMAP_NEAREST, and the texture's format must be"
          " \"texture-filterable\".";
      return false;
    }
  }

  // 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()) {
    // 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."
    if (!baseImageInfo.IsPowerOfTwo()) {
      TexWrap wrapS = sampler ? sampler->mWrapS : mWrapS;
      TexWrap wrapT = sampler ? sampler->mWrapT : mWrapT;
      // "either the texture wrap mode is not CLAMP_TO_EDGE"
      if (wrapS != LOCAL_GL_CLAMP_TO_EDGE || wrapT != LOCAL_GL_CLAMP_TO_EDGE) {
        *out_reason =
            "Non-power-of-two textures must have a wrap mode of"
            " CLAMP_TO_EDGE.";
        return false;
      }

      // "or the minification filter is neither NEAREST nor LINEAR"
      if (requiresMipmap) {
        *out_reason = "Mipmapping requires power-of-two textures.";
        return false;
      }
    }

    // "* 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)
  }

  if (!EnsureLevelInitialized(funcName, mBaseMipmapLevel)) {
    *out_initFailed = true;
    return false;
  }

  return true;
}

bool WebGLTexture::MaxEffectiveMipmapLevel(uint32_t texUnit,
                                           uint32_t* const out) const {
  WebGLSampler* sampler = mContext->mBoundSamplers[texUnit];
  TexMinFilter minFilter = sampler ? sampler->mMinFilter : mMinFilter;
  if (minFilter == LOCAL_GL_NEAREST || minFilter == LOCAL_GL_LINEAR) {
    // No extra mips used.
    *out = mBaseMipmapLevel;
    return true;
  }

  const auto& imageInfo = BaseImageInfo();
  if (!imageInfo.IsDefined()) return false;

  uint32_t maxLevelBySize =
      mBaseMipmapLevel + imageInfo.PossibleMipmapLevels() - 1;
  *out = std::min<uint32_t>(maxLevelBySize, mMaxMipmapLevel);
  return true;
}

bool WebGLTexture::GetFakeBlackType(const char* funcName, uint32_t texUnit,
                                    FakeBlackType* const out_fakeBlack) {
  const char* incompleteReason;
  bool initFailed = false;
  if (!IsComplete(funcName, texUnit, &incompleteReason, &initFailed)) {
    if (initFailed) {
      mContext->ErrorOutOfMemory("%s: Failed to initialize texture data.",
                                 funcName);
      return false;  // The world just exploded.
    }

    if (incompleteReason) {
      mContext->GenerateWarning(
          "%s: Active texture %u for target 0x%04x is"
          " 'incomplete', and will be rendered as"
          " RGBA(0,0,0,1), as per the GLES 2.0.24 $3.8.2: %s",
          funcName, texUnit, mTarget.get(), incompleteReason);
    }
    *out_fakeBlack = FakeBlackType::RGBA0001;
    return true;
  }

  *out_fakeBlack = FakeBlackType::None;
  return true;
}

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(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_SWIZZLE_R,
                     swizzle[0]);
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_SWIZZLE_G,
                     swizzle[1]);
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_SWIZZLE_B,
                     swizzle[2]);
  gl->fTexParameteri(LOCAL_GL_TEXTURE_2D, LOCAL_GL_TEXTURE_SWIZZLE_A,
                     swizzle[3]);
}

bool WebGLTexture::ResolveForDraw(const char* funcName, uint32_t texUnit,
                                  FakeBlackType* const out_fakeBlack) {
  if (!mIsResolved) {
    if (!GetFakeBlackType(funcName, texUnit, &mResolved_FakeBlack))
      return false;

    // Check which swizzle we should use. Since the texture must be complete at
    // this point, just grab the format off any valid image.
    const GLint* newSwizzle = nullptr;
    if (mResolved_FakeBlack == FakeBlackType::None) {
      const auto& cur = ImageInfoAtFace(0, mBaseMipmapLevel);
      newSwizzle = cur.mFormat->textureSwizzleRGBA;
    }

    // Only set the swizzle if it changed since last time we did it.
    if (newSwizzle != mResolved_Swizzle) {
      mResolved_Swizzle = newSwizzle;

      // Set the new swizzle!
      mContext->gl->fActiveTexture(LOCAL_GL_TEXTURE0 + texUnit);
      SetSwizzle(mContext->gl, mTarget, mResolved_Swizzle);
      mContext->gl->fActiveTexture(LOCAL_GL_TEXTURE0 +
                                   mContext->mActiveTexture);
    }

    mIsResolved = true;
  }

  *out_fakeBlack = mResolved_FakeBlack;
  return true;
}

bool WebGLTexture::EnsureImageDataInitialized(const char* funcName,
                                              TexImageTarget target,
                                              uint32_t level) {
  auto& imageInfo = ImageInfoAt(target, level);
  if (!imageInfo.IsDefined()) return true;

  if (imageInfo.IsDataInitialized()) return true;

  return InitializeImageData(funcName, target, level);
}

bool WebGLTexture::EnsureLevelInitialized(const char* funcName,
                                          uint32_t level) {
  if (mTarget != LOCAL_GL_TEXTURE_CUBE_MAP)
    return EnsureImageDataInitialized(funcName, mTarget.get(), level);

  for (GLenum texImageTarget = LOCAL_GL_TEXTURE_CUBE_MAP_POSITIVE_X;
       texImageTarget <= LOCAL_GL_TEXTURE_CUBE_MAP_NEGATIVE_Z;
       ++texImageTarget) {
    if (!EnsureImageDataInitialized(funcName, texImageTarget, level))
      return false;
  }
  return true;
}

static void ZeroANGLEDepthTexture(WebGLContext* webgl, GLuint tex,
                                  const webgl::FormatUsageInfo* usage,
                                  uint32_t width, uint32_t height) {
  const auto& format = usage->format;
  GLenum attachPoint = 0;
  GLbitfield clearBits = 0;

  if (format->d) {
    attachPoint = LOCAL_GL_DEPTH_ATTACHMENT;
    clearBits |= LOCAL_GL_DEPTH_BUFFER_BIT;
  }

  if (format->s) {
    attachPoint = (format->d ? LOCAL_GL_DEPTH_STENCIL_ATTACHMENT
                             : LOCAL_GL_STENCIL_ATTACHMENT);
    clearBits |= LOCAL_GL_STENCIL_BUFFER_BIT;
  }

  MOZ_RELEASE_ASSERT(attachPoint && clearBits, "GFX: No bits cleared.");

  ////
  const auto& gl = webgl->gl;
  MOZ_ASSERT(gl->IsCurrent());

  gl::ScopedFramebuffer scopedFB(gl);
  const gl::ScopedBindFramebuffer scopedBindFB(gl, scopedFB.FB());

  gl->fFramebufferTexture2D(LOCAL_GL_FRAMEBUFFER, attachPoint,
                            LOCAL_GL_TEXTURE_2D, tex, 0);

  const auto& status = gl->fCheckFramebufferStatus(LOCAL_GL_FRAMEBUFFER);
  MOZ_RELEASE_ASSERT(status == LOCAL_GL_FRAMEBUFFER_COMPLETE);

  ////

  const bool fakeNoAlpha = false;
  webgl->ForceClearFramebufferWithDefaultValues(clearBits, fakeNoAlpha);
}

static bool ZeroTextureData(WebGLContext* webgl, const char* funcName,
                            GLuint tex, TexImageTarget target, uint32_t level,
                            const webgl::FormatUsageInfo* usage, uint32_t width,
                            uint32_t height, uint32_t depth) {
  // This has two usecases:
  // 1. Lazy zeroing of uninitialized textures:
  //    a. Before draw, when FakeBlack isn't viable. (TexStorage + Draw*)
  //    b. Before partial upload. (TexStorage + TexSubImage)
  // 2. Zero subrects from out-of-bounds blits. (CopyTex(Sub)Image)

  // We have no sympathy for any of these cases.

  // "Doctor, it hurts when I do this!" "Well don't do that!"
  webgl->GenerateWarning(
      "%s: This operation requires zeroing texture data. This is"
      " slow.",
      funcName);

  gl::GLContext* gl = webgl->GL();

  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);
  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;
    checkedByteCount *= depth;

    if (!checkedByteCount.isValid()) return false;

    const size_t byteCount = checkedByteCount.value();

    UniqueBuffer zeros = calloc(1, byteCount);
    if (!zeros) return false;

    ScopedUnpackReset scopedReset(webgl);
    gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                     1);  // Don't bother with striding it
                          // well.

    const auto error =
        DoCompressedTexSubImage(gl, target.get(), level, 0, 0, 0, width, height,
                                depth, sizedFormat, byteCount, zeros.get());
    return !error;
  }

  const auto driverUnpackInfo = usage->idealUnpack;
  MOZ_RELEASE_ASSERT(driverUnpackInfo, "GFX: ideal unpack info not set.");

  if (webgl->IsExtensionEnabled(WebGLExtensionID::WEBGL_depth_texture) &&
      gl->IsANGLE() && usage->format->d) {
    // ANGLE_depth_texture does not allow uploads, so we have to clear.
    // (Restriction because of D3D9)
    MOZ_ASSERT(target == LOCAL_GL_TEXTURE_2D);
    MOZ_ASSERT(level == 0);
    ZeroANGLEDepthTexture(webgl, tex, usage, width, height);
    return true;
  }

  const webgl::PackingInfo packing = driverUnpackInfo->ToPacking();

  const auto bytesPerPixel = webgl::BytesPerPixel(packing);

  CheckedUint32 checkedByteCount = bytesPerPixel;
  checkedByteCount *= width;
  checkedByteCount *= height;
  checkedByteCount *= depth;

  if (!checkedByteCount.isValid()) return false;

  const size_t byteCount = checkedByteCount.value();

  UniqueBuffer zeros = calloc(1, byteCount);
  if (!zeros) return false;

  ScopedUnpackReset scopedReset(webgl);
  gl->fPixelStorei(LOCAL_GL_UNPACK_ALIGNMENT,
                   1);  // Don't bother with striding it well.
  const auto error = DoTexSubImage(gl, target, level, 0, 0, 0, width, height,
                                   depth, packing, zeros.get());
  return !error;
}

bool WebGLTexture::InitializeImageData(const char* funcName,
                                       TexImageTarget target, uint32_t level) {
  auto& imageInfo = ImageInfoAt(target, level);
  MOZ_ASSERT(imageInfo.IsDefined());
  MOZ_ASSERT(!imageInfo.IsDataInitialized());

  const auto& usage = imageInfo.mFormat;
  const auto& width = imageInfo.mWidth;
  const auto& height = imageInfo.mHeight;
  const auto& depth = imageInfo.mDepth;

  if (!ZeroTextureData(mContext, funcName, mGLName, target, level, usage, width,
                       height, depth)) {
    return false;
  }

  imageInfo.SetIsDataInitialized(true, this);
  return true;
}

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."
  mBaseMipmapLevel =
      Clamp<uint32_t>(mBaseMipmapLevel, 0, mImmutableLevelCount - 1);
  mMaxMipmapLevel = Clamp<uint32_t>(mMaxMipmapLevel, mBaseMipmapLevel,
                                    mImmutableLevelCount - 1);
}

void WebGLTexture::PopulateMipChain(const char* funcName, uint32_t firstLevel,
                                    uint32_t lastLevel) {
  const ImageInfo& baseImageInfo = ImageInfoAtFace(0, firstLevel);
  MOZ_ASSERT(baseImageInfo.IsDefined());

  uint32_t refWidth = baseImageInfo.mWidth;
  uint32_t refHeight = baseImageInfo.mHeight;
  uint32_t refDepth = baseImageInfo.mDepth;
  if (!refWidth || !refHeight || !refDepth) return;

  for (uint32_t level = firstLevel + 1; level <= lastLevel; level++) {
    bool isMinimal = (refWidth == 1 && refHeight == 1);
    if (mTarget == LOCAL_GL_TEXTURE_3D) {
      isMinimal &= (refDepth == 1);
    }

    // Higher levels are unaffected.
    if (isMinimal) break;

    refWidth = std::max(uint32_t(1), refWidth / 2);
    refHeight = std::max(uint32_t(1), refHeight / 2);
    if (mTarget == LOCAL_GL_TEXTURE_3D) {  // But not TEXTURE_2D_ARRAY!
      refDepth = std::max(uint32_t(1), refDepth / 2);
    }

    const ImageInfo cur(baseImageInfo.mFormat, refWidth, refHeight, refDepth,
                        baseImageInfo.IsDataInitialized());

    SetImageInfosAtLevel(funcName, level, cur);
  }
}

//////////////////////////////////////////////////////////////////////////////////////////
// GL calls

bool WebGLTexture::BindTexture(TexTarget texTarget) {
  if (IsDeleted()) {
    mContext->ErrorInvalidOperation(
        "bindTexture: Cannot bind a deleted object.");
    return false;
  }

  const bool isFirstBinding = !HasEverBeenBound();
  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;
}

void WebGLTexture::GenerateMipmap(TexTarget texTarget) {
  const char funcName[] = "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."
  const ImageInfo& baseImageInfo = BaseImageInfo();
  if (!baseImageInfo.IsDefined()) {
    mContext->ErrorInvalidOperation(
        "%s: The base level of the texture is not"
        " defined.",
        funcName);
    return;
  }

  if (IsCubeMap() && !IsCubeComplete()) {
    mContext->ErrorInvalidOperation("%s: Cube maps must be \"cube complete\".",
                                    funcName);
    return;
  }

  const auto format = baseImageInfo.mFormat->format;
  if (!mContext->IsWebGL2()) {
    if (!baseImageInfo.IsPowerOfTwo()) {
      mContext->ErrorInvalidOperation(
          "%s: The base level of the texture does not"
          " have power-of-two dimensions.",
          funcName);
      return;
    }
    if (format->isSRGB) {
      mContext->ErrorInvalidOperation(
          "%s: EXT_sRGB forbids GenerateMipmap with"
          " sRGB.",
          funcName);
      return;
    }
  }

  if (format->compression) {
    mContext->ErrorInvalidOperation(
        "%s: Texture data at base level is compressed.", funcName);
    return;
  }

  if (format->d) {
    mContext->ErrorInvalidOperation("%s: Depth textures are not supported.",
                                    funcName);
    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.
  const auto usage = baseImageInfo.mFormat;
  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(
        "%s: Texture at base level is not unsized"
        " internal format or is not"
        " color-renderable or texture-filterable.",
        funcName);
    return;
  }

  // Done with validation. Do the operation.

  gl::GLContext* gl = mContext->gl;

  if (gl->WorkAroundDriverBugs()) {
    // 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(texTarget.get(), LOCAL_GL_TEXTURE_MIN_FILTER,
                       LOCAL_GL_NEAREST_MIPMAP_NEAREST);
    gl->fGenerateMipmap(texTarget.get());
    gl->fTexParameteri(texTarget.get(), LOCAL_GL_TEXTURE_MIN_FILTER,
                       mMinFilter.get());
  } else {
    gl->fGenerateMipmap(texTarget.get());
  }

  // Record the results.
  // Note that we don't use MaxEffectiveMipmapLevel() here, since that returns
  // mBaseMipmapLevel if the min filter doesn't require mipmaps.
  const uint32_t maxLevel =
      mBaseMipmapLevel + baseImageInfo.PossibleMipmapLevels() - 1;
  PopulateMipChain(funcName, mBaseMipmapLevel, maxLevel);
}

JS::Value WebGLTexture::GetTexParameter(TexTarget texTarget, GLenum pname) {
  GLint i = 0;
  GLfloat f = 0.0f;

  switch (pname) {
    case LOCAL_GL_TEXTURE_MIN_FILTER:
      return JS::NumberValue(uint32_t(mMinFilter.get()));

    case LOCAL_GL_TEXTURE_MAG_FILTER:
      return JS::NumberValue(uint32_t(mMagFilter.get()));

    case LOCAL_GL_TEXTURE_WRAP_S:
      return JS::NumberValue(uint32_t(mWrapS.get()));

    case LOCAL_GL_TEXTURE_WRAP_T:
      return JS::NumberValue(uint32_t(mWrapT.get()));

    case LOCAL_GL_TEXTURE_BASE_LEVEL:
      return JS::NumberValue(mBaseMipmapLevel);

    case LOCAL_GL_TEXTURE_COMPARE_MODE:
      return JS::NumberValue(uint32_t(mTexCompareMode));

    case LOCAL_GL_TEXTURE_MAX_LEVEL:
      return JS::NumberValue(mMaxMipmapLevel);

    case LOCAL_GL_TEXTURE_IMMUTABLE_FORMAT:
      return JS::BooleanValue(mImmutable);

    case LOCAL_GL_TEXTURE_IMMUTABLE_LEVELS:
      return JS::NumberValue(uint32_t(mImmutableLevelCount));

    case LOCAL_GL_TEXTURE_COMPARE_FUNC:
    case LOCAL_GL_TEXTURE_WRAP_R:
      mContext->gl->fGetTexParameteriv(texTarget.get(), pname, &i);
      return JS::NumberValue(uint32_t(i));

    case LOCAL_GL_TEXTURE_MAX_ANISOTROPY_EXT:
    case LOCAL_GL_TEXTURE_MAX_LOD:
    case LOCAL_GL_TEXTURE_MIN_LOD:
      mContext->gl->fGetTexParameterfv(texTarget.get(), pname, &f);
      return JS::NumberValue(float(f));

    default:
      MOZ_CRASH("GFX: Unhandled pname.");
  }
}

bool WebGLTexture::IsTexture() const {
  return HasEverBeenBound() && !IsDeleted();
}

// 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(
          "texParameteri: pname 0x%04x: Invalid param"
          " 0x%04x.",
          pname, param.i);
    } else {
      mContext->ErrorInvalidEnum(
          "texParameterf: pname 0x%04x: Invalid param %g.", pname, param.f);
    }
    return;
  }

  if (paramBadValue) {
    if (!param.isFloat) {
      mContext->ErrorInvalidValue(
          "texParameteri: pname 0x%04x: Invalid param %i"
          " (0x%x).",
          pname, param.i, param.i);
    } else {
      mContext->ErrorInvalidValue(
          "texParameterf: pname 0x%04x: Invalid param %g.", pname, param.f);
    }
    return;
  }

  ////////////////
  // Store any needed values

  FloatOrInt clamped = param;
  switch (pname) {
    case LOCAL_GL_TEXTURE_BASE_LEVEL:
      mBaseMipmapLevel = clamped.i;
      ClampLevelBaseAndMax();
      clamped = FloatOrInt(GLint(mBaseMipmapLevel));
      break;

    case LOCAL_GL_TEXTURE_MAX_LEVEL:
      mMaxMipmapLevel = clamped.i;
      ClampLevelBaseAndMax();
      clamped = FloatOrInt(GLint(mMaxMipmapLevel));
      break;

    case LOCAL_GL_TEXTURE_MIN_FILTER:
      mMinFilter = clamped.i;
      break;

    case LOCAL_GL_TEXTURE_MAG_FILTER:
      mMagFilter = clamped.i;
      break;

    case LOCAL_GL_TEXTURE_WRAP_S:
      mWrapS = clamped.i;
      break;

    case LOCAL_GL_TEXTURE_WRAP_T:
      mWrapT = clamped.i;
      break;

    case LOCAL_GL_TEXTURE_COMPARE_MODE:
      mTexCompareMode = clamped.i;
      break;

      // We don't actually need to store the WRAP_R, since it doesn't change
      // texture completeness rules.
  }

  // Only a couple of pnames don't need to invalidate our resolve status cache.
  switch (pname) {
    case LOCAL_GL_TEXTURE_MAX_ANISOTROPY_EXT:
    case LOCAL_GL_TEXTURE_WRAP_R:
      break;

    default:
      InvalidateResolveCache();
      break;
  }

  ////////////////

  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) {
    SetImageInfo("OUT_OF_MEMORY", &cur, ImageInfo());
  }
}

////////////////////////////////////////////////////////////////////////////////

NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WebGLTexture)

NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WebGLTexture, AddRef)
NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WebGLTexture, Release)

}  // namespace mozilla