Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

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

1 files changed, 412 insertions, 0 deletions

diff --git a/dom/canvas/WebGLTexelConversions.cpp b/dom/canvas/WebGLTexelConversions.cpp
new file mode 100644
index 0000000000..279d8a1cc2
--- /dev/null
+++ b/dom/canvas/WebGLTexelConversions.cpp
@@ -0,0 +1,412 @@
+/* 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 "WebGLContext.h"
+#include "WebGLTexelConversions.h"
+
+namespace mozilla {
+
+using namespace WebGLTexelConversions;
+
+namespace {
+
+/** @class WebGLImageConverter
+ *
+ * This class is just a helper to implement WebGLContext::ConvertImage below.
+ *
+ * Design comments:
+ *
+ * WebGLContext::ConvertImage has to handle hundreds of format conversion paths.
+ * It is important to minimize executable code size here. Instead of passing
+ * around a large number of function parameters hundreds of times, we create a
+ * WebGLImageConverter object once, storing these parameters, and then we call
+ * the run() method on it.
+ */
+class WebGLImageConverter {
+  const size_t mWidth, mHeight;
+  const void* const mSrcStart;
+  void* const mDstStart;
+  const ptrdiff_t mSrcStride, mDstStride;
+  bool mAlreadyRun;
+  bool mSuccess;
+
+  /*
+   * Returns sizeof(texel)/sizeof(type). The point is that we will iterate over
+   * texels with typed pointers and this value will tell us by how much we need
+   * to increment these pointers to advance to the next texel.
+   */
+  template <WebGLTexelFormat Format>
+  static size_t NumElementsPerTexelForFormat() {
+    switch (Format) {
+      case WebGLTexelFormat::A8:
+      case WebGLTexelFormat::A16F:
+      case WebGLTexelFormat::A32F:
+      case WebGLTexelFormat::R8:
+      case WebGLTexelFormat::R16F:
+      case WebGLTexelFormat::R32F:
+      case WebGLTexelFormat::RGB565:
+      case WebGLTexelFormat::RGB11F11F10F:
+      case WebGLTexelFormat::RGBA4444:
+      case WebGLTexelFormat::RGBA5551:
+        return 1;
+      case WebGLTexelFormat::RA8:
+      case WebGLTexelFormat::RA16F:
+      case WebGLTexelFormat::RA32F:
+      case WebGLTexelFormat::RG8:
+      case WebGLTexelFormat::RG16F:
+      case WebGLTexelFormat::RG32F:
+        return 2;
+      case WebGLTexelFormat::RGB8:
+      case WebGLTexelFormat::RGB16F:
+      case WebGLTexelFormat::RGB32F:
+        return 3;
+      case WebGLTexelFormat::RGBA8:
+      case WebGLTexelFormat::RGBA16F:
+      case WebGLTexelFormat::RGBA32F:
+      case WebGLTexelFormat::BGRX8:
+      case WebGLTexelFormat::BGRA8:
+        return 4;
+      default:
+        MOZ_ASSERT(false, "Unknown texel format. Coding mistake?");
+        return 0;
+    }
+  }
+
+  /*
+   * This is the completely format-specific templatized conversion function,
+   * that will be instantiated hundreds of times for all different combinations.
+   * It is important to avoid generating useless code here. In particular, many
+   * instantiations of this function template will never be called, so we try
+   * to return immediately in these cases to allow the compiler to avoid
+   * generating useless code.
+   */
+  template <WebGLTexelFormat SrcFormat, WebGLTexelFormat DstFormat,
+            WebGLTexelPremultiplicationOp PremultiplicationOp>
+  void run() {
+    // check for never-called cases. We early-return to allow the compiler
+    // to avoid generating this code. It would be tempting to abort() instead,
+    // as returning early does leave the destination surface with uninitialized
+    // data, but that would not allow the compiler to avoid generating this
+    // code. So instead, we return early, so Success() will return false, and
+    // the caller must check that and abort in that case. See
+    // WebGLContext::ConvertImage.
+
+    if (SrcFormat == DstFormat &&
+        PremultiplicationOp == WebGLTexelPremultiplicationOp::None) {
+      // Should have used a fast exit path earlier, rather than entering this
+      // function. we explicitly return here to allow the compiler to avoid
+      // generating this code
+      return;
+    }
+
+    // Only textures uploaded from DOM elements or ImageData can allow DstFormat
+    // != SrcFormat. DOM elements can only give BGRA8, BGRX8, A8, RGB565
+    // formats. See DOMElementToImageSurface. ImageData is always RGBA8. So all
+    // other SrcFormat will always satisfy DstFormat==SrcFormat, so we can avoid
+    // compiling the code for all the unreachable paths.
+    const bool CanSrcFormatComeFromDOMElementOrImageData =
+        SrcFormat == WebGLTexelFormat::BGRA8 ||
+        SrcFormat == WebGLTexelFormat::BGRX8 ||
+        SrcFormat == WebGLTexelFormat::A8 ||
+        SrcFormat == WebGLTexelFormat::RGB565 ||
+        SrcFormat == WebGLTexelFormat::RGBA8;
+    if (!CanSrcFormatComeFromDOMElementOrImageData && SrcFormat != DstFormat) {
+      return;
+    }
+
+    // Likewise, only textures uploaded from DOM elements or ImageData can
+    // possibly have to be unpremultiplied.
+    if (!CanSrcFormatComeFromDOMElementOrImageData &&
+        PremultiplicationOp == WebGLTexelPremultiplicationOp::Unpremultiply) {
+      return;
+    }
+
+    // there is no point in premultiplication/unpremultiplication
+    // in the following cases:
+    //  - the source format has no alpha
+    //  - the source format has no color
+    //  - the destination format has no color
+    if (!HasAlpha(SrcFormat) || !HasColor(SrcFormat) || !HasColor(DstFormat)) {
+      if (PremultiplicationOp != WebGLTexelPremultiplicationOp::None) {
+        return;
+      }
+    }
+
+    // end of early return cases.
+
+    MOZ_ASSERT(!mAlreadyRun, "converter should be run only once!");
+    mAlreadyRun = true;
+
+    // gather some compile-time meta-data about the formats at hand.
+
+    using SrcType = typename DataTypeForFormat<SrcFormat>::Type;
+    using DstType = typename DataTypeForFormat<DstFormat>::Type;
+
+    const WebGLTexelFormat IntermediateSrcFormat =
+        IntermediateFormat<SrcFormat>::Value;
+    const WebGLTexelFormat IntermediateDstFormat =
+        IntermediateFormat<DstFormat>::Value;
+    using IntermediateSrcType =
+        typename DataTypeForFormat<IntermediateSrcFormat>::Type;
+    using IntermediateDstType =
+        typename DataTypeForFormat<IntermediateDstFormat>::Type;
+
+    const size_t NumElementsPerSrcTexel =
+        NumElementsPerTexelForFormat<SrcFormat>();
+    const size_t NumElementsPerDstTexel =
+        NumElementsPerTexelForFormat<DstFormat>();
+    const size_t MaxElementsPerTexel = 4;
+    MOZ_ASSERT(NumElementsPerSrcTexel <= MaxElementsPerTexel,
+               "unhandled format");
+    MOZ_ASSERT(NumElementsPerDstTexel <= MaxElementsPerTexel,
+               "unhandled format");
+
+    // we assume that the strides are multiples of the sizeof of respective
+    // types. this assumption will allow us to iterate over src and dst images
+    // using typed pointers, e.g. uint8_t* or uint16_t* or float*, instead of
+    // untyped pointers. So this assumption allows us to write cleaner and safer
+    // code, but it might not be true forever and if it eventually becomes
+    // wrong, we'll have to revert to always iterating using uint8_t* pointers
+    // regardless of the types at hand.
+    MOZ_ASSERT(
+        mSrcStride % sizeof(SrcType) == 0 && mDstStride % sizeof(DstType) == 0,
+        "Unsupported: texture stride is not a multiple of sizeof(type)");
+    const ptrdiff_t srcStrideInElements =
+        mSrcStride / static_cast<ptrdiff_t>(sizeof(SrcType));
+    const ptrdiff_t dstStrideInElements =
+        mDstStride / static_cast<ptrdiff_t>(sizeof(DstType));
+    // Pop quiz: What's `ptrdiff_t(-16) / sizeof(int32_t)`?
+    // Did you guess +4611686018427387900?
+    MOZ_ASSERT(bool(srcStrideInElements < 0) == bool(mSrcStride < 0));
+    MOZ_ASSERT(bool(dstStrideInElements < 0) == bool(mDstStride < 0));
+
+    const SrcType* srcRowStart = static_cast<const SrcType*>(mSrcStart);
+    DstType* dstRowStart = static_cast<DstType*>(mDstStart);
+
+    // the loop performing the texture format conversion
+    for (size_t i = 0; i < mHeight; ++i) {
+      const SrcType* srcRowEnd = srcRowStart + mWidth * NumElementsPerSrcTexel;
+      const SrcType* srcPtr = srcRowStart;
+      DstType* dstPtr = dstRowStart;
+      while (srcPtr != srcRowEnd) {
+        // convert a single texel. We proceed in 3 steps: unpack the source
+        // texel so the corresponding interchange format (e.g. unpack RGB565 to
+        // RGBA8), convert the resulting data type to the destination type (e.g.
+        // convert from RGBA8 to RGBA32F), and finally pack the destination
+        // texel (e.g. pack RGBA32F to RGB32F).
+        IntermediateSrcType unpackedSrc[MaxElementsPerTexel];
+        IntermediateDstType unpackedDst[MaxElementsPerTexel];
+
+        // unpack a src texel to corresponding intermediate src format.
+        // for example, unpack RGB565 to RGBA8
+        unpack<SrcFormat>(srcPtr, unpackedSrc);
+        // convert the data type to the destination type, if needed.
+        // for example, convert RGBA8 to RGBA32F
+        convertType(unpackedSrc, unpackedDst);
+        // pack the destination texel.
+        // for example, pack RGBA32F to RGB32F
+        pack<DstFormat, PremultiplicationOp>(unpackedDst, dstPtr);
+
+        srcPtr += NumElementsPerSrcTexel;
+        dstPtr += NumElementsPerDstTexel;
+      }
+      srcRowStart += srcStrideInElements;
+      dstRowStart += dstStrideInElements;
+    }
+
+    mSuccess = true;
+  }
+
+  template <WebGLTexelFormat SrcFormat, WebGLTexelFormat DstFormat>
+  void run(WebGLTexelPremultiplicationOp premultiplicationOp) {
+#define WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP(PremultiplicationOp) \
+  case PremultiplicationOp:                                               \
+    return run<SrcFormat, DstFormat, PremultiplicationOp>();
+
+    switch (premultiplicationOp) {
+      WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP(
+          WebGLTexelPremultiplicationOp::None)
+      WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP(
+          WebGLTexelPremultiplicationOp::Premultiply)
+      WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP(
+          WebGLTexelPremultiplicationOp::Unpremultiply)
+      default:
+        MOZ_ASSERT(false, "unhandled case. Coding mistake?");
+    }
+
+#undef WEBGLIMAGECONVERTER_CASE_PREMULTIPLICATIONOP
+  }
+
+  template <WebGLTexelFormat SrcFormat>
+  void run(WebGLTexelFormat dstFormat,
+           WebGLTexelPremultiplicationOp premultiplicationOp) {
+#define WEBGLIMAGECONVERTER_CASE_DSTFORMAT(DstFormat) \
+  case DstFormat:                                     \
+    return run<SrcFormat, DstFormat>(premultiplicationOp);
+
+    switch (dstFormat) {
+      // 1-channel formats
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::A8)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::A16F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::A32F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::R8)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::R16F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::R32F)
+      // 2-channel formats
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RA8)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RA16F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RA32F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RG8)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RG16F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RG32F)
+      // 3-channel formats
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGB565)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGB8)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGB11F11F10F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGB16F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGB32F)
+      // 4-channel formats
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGBA4444)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGBA5551)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGBA8)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGBA16F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::RGBA32F)
+      WEBGLIMAGECONVERTER_CASE_DSTFORMAT(WebGLTexelFormat::BGRA8)
+
+      default:
+        MOZ_ASSERT(false, "unhandled case. Coding mistake?");
+    }
+
+#undef WEBGLIMAGECONVERTER_CASE_DSTFORMAT
+  }
+
+ public:
+  void run(WebGLTexelFormat srcFormat, WebGLTexelFormat dstFormat,
+           WebGLTexelPremultiplicationOp premultiplicationOp) {
+#define WEBGLIMAGECONVERTER_CASE_SRCFORMAT(SrcFormat) \
+  case SrcFormat:                                     \
+    return run<SrcFormat>(dstFormat, premultiplicationOp);
+
+    switch (srcFormat) {
+      // 1-channel formats
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::A8)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::A16F)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::A32F)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::R8)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::R16F)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::R32F)
+      // 2-channel formats
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RA8)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RA16F)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RA32F)
+      // 3-channel formats
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGB565)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGB8)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGB16F)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGB32F)
+      // 4-channel formats
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGBA4444)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGBA5551)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGBA8)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGBA16F)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::RGBA32F)
+      // DOM element source formats
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::BGRX8)
+      WEBGLIMAGECONVERTER_CASE_SRCFORMAT(WebGLTexelFormat::BGRA8)
+
+      default:
+        MOZ_ASSERT(false, "unhandled case. Coding mistake?");
+    }
+
+#undef WEBGLIMAGECONVERTER_CASE_SRCFORMAT
+  }
+
+  WebGLImageConverter(size_t width, size_t height, const void* srcStart,
+                      void* dstStart, ptrdiff_t srcStride, ptrdiff_t dstStride)
+      : mWidth(width),
+        mHeight(height),
+        mSrcStart(srcStart),
+        mDstStart(dstStart),
+        mSrcStride(srcStride),
+        mDstStride(dstStride),
+        mAlreadyRun(false),
+        mSuccess(false) {}
+
+  bool Success() const { return mSuccess; }
+};
+
+}  // end anonymous namespace
+
+bool ConvertImage(size_t width, size_t height, const void* srcBegin,
+                  size_t srcStride, gl::OriginPos srcOrigin,
+                  WebGLTexelFormat srcFormat, bool srcPremultiplied,
+                  void* dstBegin, size_t dstStride, gl::OriginPos dstOrigin,
+                  WebGLTexelFormat dstFormat, bool dstPremultiplied,
+                  bool* const out_wasTrivial) {
+  *out_wasTrivial = true;
+
+  if (srcFormat == WebGLTexelFormat::FormatNotSupportingAnyConversion ||
+      dstFormat == WebGLTexelFormat::FormatNotSupportingAnyConversion) {
+    return false;
+  }
+
+  if (!width || !height) return true;
+
+  const bool shouldYFlip = (srcOrigin != dstOrigin);
+
+  const bool canSkipPremult =
+      (!HasAlpha(srcFormat) || !HasColor(srcFormat) || !HasColor(dstFormat));
+
+  WebGLTexelPremultiplicationOp premultOp;
+  if (canSkipPremult) {
+    premultOp = WebGLTexelPremultiplicationOp::None;
+  } else if (!srcPremultiplied && dstPremultiplied) {
+    premultOp = WebGLTexelPremultiplicationOp::Premultiply;
+  } else if (srcPremultiplied && !dstPremultiplied) {
+    premultOp = WebGLTexelPremultiplicationOp::Unpremultiply;
+  } else {
+    premultOp = WebGLTexelPremultiplicationOp::None;
+  }
+
+  const uint8_t* srcItr = (const uint8_t*)srcBegin;
+  const uint8_t* const srcEnd = srcItr + srcStride * height;
+  uint8_t* dstItr = (uint8_t*)dstBegin;
+  ptrdiff_t dstItrStride = dstStride;
+  if (shouldYFlip) {
+    dstItr = dstItr + dstStride * (height - 1);
+    dstItrStride = -dstItrStride;
+  }
+
+  if (srcFormat == dstFormat &&
+      premultOp == WebGLTexelPremultiplicationOp::None) {
+    // Fast exit path: we just have to memcpy all the rows.
+
+    const auto bytesPerPixel = TexelBytesForFormat(srcFormat);
+    const size_t bytesPerRow = bytesPerPixel * width;
+
+    while (srcItr != srcEnd) {
+      memcpy(dstItr, srcItr, bytesPerRow);
+      srcItr += srcStride;
+      dstItr += dstItrStride;
+    }
+    return true;
+  }
+
+  *out_wasTrivial = false;
+
+  WebGLImageConverter converter(width, height, srcItr, dstItr, srcStride,
+                                dstItrStride);
+  converter.run(srcFormat, dstFormat, premultOp);
+
+  if (!converter.Success()) {
+    // the dst image may be left uninitialized, so we better not try to
+    // continue even in release builds. This should never happen anyway,
+    // and would be a bug in our code.
+    MOZ_CRASH("programming mistake in WebGL texture conversions");
+  }
+
+  return true;
+}
+
+}  // end namespace mozilla