Simplify CFX_DIBBase::RealizeSkImage()
Simplifies CFX_DIBBase::RealizeSkImage() by moving the logic for
iterating over pixels to a generic function template. The remaining
logic can focus just on the transformation between pixel formats.
Bug: pdfium:2034
Change-Id: I3084f2a18de274b33afc0321d12b05d1c4603dd6
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/108570
Reviewed-by: Nigi <nigi@chromium.org>
Commit-Queue: K. Moon <kmoon@chromium.org>
diff --git a/core/fxge/skia/cfx_dibbase_skia.cpp b/core/fxge/skia/cfx_dibbase_skia.cpp
index f293bc9..89ae4c4 100644
--- a/core/fxge/skia/cfx_dibbase_skia.cpp
+++ b/core/fxge/skia/cfx_dibbase_skia.cpp
@@ -8,16 +8,17 @@
#include <stdint.h>
#include <memory>
+#include <type_traits>
#include <utility>
#include "core/fxcrt/fx_2d_size.h"
#include "core/fxcrt/fx_memory.h"
#include "core/fxcrt/fx_memory_wrappers.h"
+#include "core/fxcrt/fx_safe_types.h"
#include "core/fxcrt/retain_ptr.h"
-#include "core/fxcrt/unowned_ptr.h"
+#include "core/fxge/calculate_pitch.h"
#include "core/fxge/dib/cfx_dibitmap.h"
#include "core/fxge/dib/fx_dib.h"
-#include "third_party/abseil-cpp/absl/types/variant.h"
#include "third_party/base/check_op.h"
#include "third_party/base/notreached.h"
#include "third_party/base/span.h"
@@ -32,160 +33,179 @@
namespace {
-// A builder that can create an `SkImage` either from a `CFX_DIBBase`, or from
-// newly-allocated memory.
-class SkiaImageBuilder {
- public:
- SkiaImageBuilder() = default;
-
- // Constructs a builder backed by pixels shared with a `CFX_DIBBase`. The
- // pixels are not accessible from the builder. The `CFX_DIBBase` must outlive
- // the builder, as the reference count on the `CFX_DIBBase` is not incremented
- // until `Build()` is called.
- SkiaImageBuilder(const CFX_DIBBase* source, SkColorType color_type)
- : info_(SkImageInfo::Make(source->GetWidth(),
- source->GetHeight(),
- color_type,
- kPremul_SkAlphaType)),
- data_(UnownedType(source)) {
- // TODO(crbug.com/pdfium/2047): `Realize()` if there's no buffer?
- row_bytes_ = source->GetPitch();
- }
-
- // Constructs a builder backed by allocated pixels.
- explicit SkiaImageBuilder(const SkImageInfo& info) : info_(info) {
- row_bytes_ = info_.minRowBytes();
- data_size_ = Fx2DSizeOrDie(row_bytes_, info_.height());
- data_ = AllocatedType(FX_Alloc(uint8_t, data_size_));
- }
-
- SkiaImageBuilder(SkiaImageBuilder&&) = default;
- SkiaImageBuilder& operator=(SkiaImageBuilder&&) = default;
-
- // Gets the number of bytes per row.
- size_t row_bytes() const { return row_bytes_; }
-
- // Gets the 8-bit pixels (if using allocated memory).
- pdfium::span<uint8_t> allocated_pixels8() {
- DCHECK_EQ(static_cast<size_t>(info_.bytesPerPixel()), sizeof(uint8_t));
- return pdfium::make_span(
- reinterpret_cast<uint8_t*>(absl::get<AllocatedType>(data_).get()),
- data_size_);
- }
-
- // Gets the 32-bit pixels (if using allocated memory).
- pdfium::span<uint32_t> allocated_pixels32() {
- DCHECK_EQ(static_cast<size_t>(info_.bytesPerPixel()), sizeof(uint32_t));
- return pdfium::make_span(
- reinterpret_cast<uint32_t*>(absl::get<AllocatedType>(data_).get()),
- data_size_ / sizeof(uint32_t));
- }
-
- // Builds an `SkImage` that takes ownership of the pixels. If sharing pixels
- // with a `CFX_DIBBase`, this increments the reference count on the
- // `CFX_DIBBase`.
- //
- // Note that an `SkImage` must be immutable, so the pixels must not be
- // modified during the lifetime of the `SkImage`.
- sk_sp<SkImage> Build() && {
- if (absl::holds_alternative<AllocatedType>(data_)) {
- // "Leak" allocated memory to `SkImage`.
- return SkImages::RasterFromPixmap(
- SkPixmap(info_, absl::get<AllocatedType>(data_).release(),
- row_bytes_),
- /*rasterReleaseProc=*/ReleaseAllocated,
- /*releaseContext=*/nullptr);
- }
-
- // Convert unowned pointer to a retained pointer, then "leak" to `SkImage`.
- RetainPtr<const CFX_DIBBase> retained(
- absl::get<UnownedType>(data_).ExtractAsDangling());
- const CFX_DIBBase* source = retained.Leak();
- return SkImages::RasterFromPixmap(
- SkPixmap(info_, source->GetBuffer().data(), row_bytes_),
- /*rasterReleaseProc=*/ReleaseRetained,
- /*releaseContext=*/const_cast<CFX_DIBBase*>(source));
- }
-
- private:
- using UnownedType = UnownedPtr<const CFX_DIBBase>;
- using AllocatedType = std::unique_ptr<void, FxFreeDeleter>;
-
- // Releases `CFX_DIBBase` "leaked" by `Build()`.
- static void ReleaseRetained(const void* /*pixels*/,
- SkImages::ReleaseContext context) {
- RetainPtr<const CFX_DIBBase> retained;
- retained.Unleak(reinterpret_cast<const CFX_DIBBase*>(context));
- }
-
- // Releases allocated memory "leaked" by `Build()`.
- static void ReleaseAllocated(const void* pixels,
- SkImages::ReleaseContext /*context*/) {
- FX_Free(const_cast<void*>(pixels));
- }
-
- SkImageInfo info_;
- size_t row_bytes_;
-
- // Similar to `MaybeOwned<uint32_t, FxFreeDeleter>`, but holds either an
- // unowned `CFX_DIBBase` pointer or an owned `void` pointer.
- absl::variant<UnownedType, AllocatedType> data_;
- size_t data_size_;
-};
-
-// Creates a `SkiaImageBuilder` using colors from a 1-bit-per-pixel palette.
-SkiaImageBuilder CreateSkiaImageBuilderUsingSingleBitPalette(
- const CFX_DIBBase* source) {
- DCHECK_EQ(1, source->GetBPP());
- int width = source->GetWidth();
- int height = source->GetHeight();
- const void* buffer = source->GetBuffer().data();
- DCHECK(buffer);
-
- uint32_t color0 = source->GetPaletteArgb(0);
- uint32_t color1 = source->GetPaletteArgb(1);
- SkiaImageBuilder image_builder(SkImageInfo::Make(
- width, height, kBGRA_8888_SkColorType, kPremul_SkAlphaType));
- pdfium::span<SkPMColor> dst32_pixels(image_builder.allocated_pixels32());
-
- for (int y = 0; y < height; ++y) {
- const uint8_t* src_row =
- static_cast<const uint8_t*>(buffer) + y * source->GetPitch();
- pdfium::span<uint32_t> dst_row = dst32_pixels.subspan(y * width);
- for (int x = 0; x < width; ++x) {
- bool use_color1 = src_row[x / 8] & (1 << (7 - x % 8));
- dst_row[x] = use_color1 ? color1 : color0;
- }
- }
- return image_builder;
+// Releases `CFX_DIBBase` "leaked" by `CreateSkiaImageFromDib()`.
+void ReleaseRetainedHeldBySkImage(const void* /*pixels*/,
+ SkImages::ReleaseContext context) {
+ RetainPtr<const CFX_DIBBase> retained;
+ retained.Unleak(reinterpret_cast<const CFX_DIBBase*>(context));
}
-// Creates a `SkiaImageBuilder` using colors from `palette`.
-SkiaImageBuilder CreateSkiaImageBuilderUsingPalette(
- const CFX_DIBBase* source,
- pdfium::span<const uint32_t> palette) {
- DCHECK_EQ(8, source->GetBPP());
- int width = source->GetWidth();
- int height = source->GetHeight();
- const void* buffer = source->GetBuffer().data();
- DCHECK(buffer);
- SkiaImageBuilder image_builder(SkImageInfo::Make(
- width, height, kBGRA_8888_SkColorType, kPremul_SkAlphaType));
- pdfium::span<SkPMColor> dst32_pixels(image_builder.allocated_pixels32());
+// Creates an `SkImage` from a `CFX_DIBBase`, sharing the underlying pixels if
+// possible.
+//
+// Note that an `SkImage` must be immutable, so if sharing pixels, they must not
+// be modified during the lifetime of the `SkImage`.
+sk_sp<SkImage> CreateSkiaImageFromDib(const CFX_DIBBase* source,
+ SkColorType color_type) {
+ // Make sure the DIB is backed by a buffer.
+ RetainPtr<const CFX_DIBBase> retained;
+ if (source->GetBuffer().empty()) {
+ retained = source->Realize();
+ if (!retained) {
+ return nullptr;
+ }
+ DCHECK(!source->GetBuffer().empty());
+ } else {
+ retained.Reset(source);
+ }
- for (int y = 0; y < height; ++y) {
- const uint8_t* src_row =
- static_cast<const uint8_t*>(buffer) + y * source->GetPitch();
- pdfium::span<uint32_t> dst_row = dst32_pixels.subspan(y * width);
- for (int x = 0; x < width; ++x) {
- unsigned index = src_row[x];
- if (index >= palette.size()) {
- index = 0;
+ // Convert unowned pointer to a retained pointer, then "leak" to `SkImage`.
+ source = retained.Leak();
+ SkImageInfo info = SkImageInfo::Make(source->GetWidth(), source->GetHeight(),
+ color_type, kPremul_SkAlphaType);
+ return SkImages::RasterFromPixmap(
+ SkPixmap(info, source->GetBuffer().data(), source->GetPitch()),
+ /*rasterReleaseProc=*/ReleaseRetainedHeldBySkImage,
+ /*releaseContext=*/const_cast<CFX_DIBBase*>(source));
+}
+
+// Releases allocated memory "leaked" by `CreateSkiaImageFromTransformedDib()`.
+void ReleaseAllocatedHeldBySkImage(const void* pixels,
+ SkImages::ReleaseContext /*context*/) {
+ FX_Free(const_cast<void*>(pixels));
+}
+
+// Template defining traits of a pixel transform function.
+template <size_t source_bits_per_pixel, typename PixelTransform>
+class PixelTransformTraits;
+
+template <typename PixelTransform>
+class PixelTransformTraits<1, PixelTransform> {
+ public:
+ using Result = std::invoke_result_t<PixelTransform, bool>;
+
+ static Result Invoke(PixelTransform&& pixel_transform,
+ const uint8_t* scanline,
+ size_t column) {
+ uint8_t kMask = 1 << (7 - column % 8);
+ return pixel_transform(!!(scanline[column / 8] & kMask));
+ }
+};
+
+template <typename PixelTransform>
+class PixelTransformTraits<8, PixelTransform> {
+ public:
+ using Result = std::invoke_result_t<PixelTransform, uint8_t>;
+
+ static Result Invoke(PixelTransform&& pixel_transform,
+ const uint8_t* scanline,
+ size_t column) {
+ return pixel_transform(scanline[column]);
+ }
+};
+
+template <typename PixelTransform>
+class PixelTransformTraits<24, PixelTransform> {
+ public:
+ using Result =
+ std::invoke_result_t<PixelTransform, uint8_t, uint8_t, uint8_t>;
+
+ static Result Invoke(PixelTransform&& pixel_transform,
+ const uint8_t* scanline,
+ size_t column) {
+ size_t offset = column * 3;
+ return pixel_transform(scanline[offset + 2], scanline[offset + 1],
+ scanline[offset]);
+ }
+};
+
+void ValidateScanlineSize(pdfium::span<const uint8_t> scanline,
+ size_t min_row_bytes) {
+ DCHECK_GE(scanline.size(), min_row_bytes);
+}
+
+void ValidateBufferSize(pdfium::span<const uint8_t> buffer,
+ const CFX_DIBBase& source) {
+#if DCHECK_IS_ON()
+ if (source.GetHeight() == 0) {
+ return;
+ }
+
+ FX_SAFE_SIZE_T buffer_size = source.GetHeight() - 1;
+ buffer_size *= source.GetPitch();
+ buffer_size += fxge::CalculatePitch8OrDie(source.GetBPP(), /*components=*/1,
+ source.GetWidth());
+
+ DCHECK_GE(buffer.size(), buffer_size.ValueOrDie());
+#endif // DCHECK_IS_ON()
+}
+
+// Creates an `SkImage` from a `CFX_DIBBase`, transforming the source pixels
+// using `pixel_transform`.
+template <size_t source_bits_per_pixel, typename PixelTransform>
+sk_sp<SkImage> CreateSkiaImageFromTransformedDib(
+ const CFX_DIBBase& source,
+ SkColorType color_type,
+ SkAlphaType alpha_type,
+ PixelTransform&& pixel_transform) {
+ using Traits = PixelTransformTraits<source_bits_per_pixel, PixelTransform>;
+ using Result = typename Traits::Result;
+
+ // Allocate output buffer.
+ const int width = source.GetWidth();
+ const int height = source.GetHeight();
+ SkImageInfo info = SkImageInfo::Make(width, height, color_type, alpha_type);
+ DCHECK_EQ(info.minRowBytes(), width * sizeof(Result));
+
+ size_t output_size = Fx2DSizeOrDie(info.minRowBytes(), height);
+ std::unique_ptr<void, FxFreeDeleter> output(
+ FX_TryAlloc(uint8_t, output_size));
+ if (!output) {
+ return nullptr;
+ }
+
+ // Transform source pixels to output pixels.
+ pdfium::span<const uint8_t> source_buffer = source.GetBuffer();
+ Result* output_cursor = reinterpret_cast<Result*>(output.get());
+ if (source_buffer.empty()) {
+ // No buffer; iterate by individual scanline.
+ const size_t min_row_bytes =
+ fxge::CalculatePitch8OrDie(source.GetBPP(), /*components=*/1, width);
+ DCHECK_LE(min_row_bytes, source.GetPitch());
+
+ int line = 0;
+ for (int row = 0; row < height; ++row) {
+ pdfium::span<const uint8_t> scanline = source.GetScanline(line++);
+ ValidateScanlineSize(scanline, min_row_bytes);
+
+ for (int column = 0; column < width; ++column) {
+ *output_cursor++ =
+ Traits::Invoke(std::forward<PixelTransform>(pixel_transform),
+ scanline.data(), column);
}
- dst_row[x] = palette[index];
+ }
+ } else {
+ // Iterate over the entire buffer.
+ ValidateBufferSize(source_buffer, source);
+ const size_t row_bytes = source.GetPitch();
+
+ const uint8_t* next_scanline = source_buffer.data();
+ for (int row = 0; row < height; ++row) {
+ const uint8_t* scanline = next_scanline;
+ next_scanline += row_bytes;
+
+ for (int column = 0; column < width; ++column) {
+ *output_cursor++ = Traits::Invoke(
+ std::forward<PixelTransform>(pixel_transform), scanline, column);
+ }
}
}
- return image_builder;
+
+ // "Leak" allocated memory to `SkImage`.
+ return SkImages::RasterFromPixmap(
+ SkPixmap(info, output.release(), info.minRowBytes()),
+ /*rasterReleaseProc=*/ReleaseAllocatedHeldBySkImage,
+ /*releaseContext=*/nullptr);
}
bool IsRGBColorGrayScale(uint32_t color) {
@@ -196,18 +216,9 @@
} // namespace
sk_sp<SkImage> CFX_DIBBase::RealizeSkImage(bool force_alpha) const {
- const uint8_t* const buffer = GetBuffer().data();
- if (!buffer) {
- return nullptr;
- }
-
const SkColorType color_type = force_alpha || IsMaskFormat()
? SkColorType::kAlpha_8_SkColorType
: SkColorType::kGray_8_SkColorType;
- const int width = GetWidth();
- const int height = GetHeight();
- const int row_bytes = GetPitch();
- SkiaImageBuilder image_builder(this, color_type);
switch (GetBPP()) {
case 1: {
// By default, the two colors for grayscale are 0xFF and 0x00 unless they
@@ -221,60 +232,48 @@
bool use_gray_colors = IsRGBColorGrayScale(palette_color0) &&
IsRGBColorGrayScale(palette_color1);
if (!use_gray_colors) {
- image_builder = CreateSkiaImageBuilderUsingSingleBitPalette(this);
- break;
+ return CreateSkiaImageFromTransformedDib</*source_bits_per_pixel=*/1>(
+ *this, kBGRA_8888_SkColorType, kPremul_SkAlphaType,
+ [palette_color0, palette_color1](bool bit) {
+ return bit ? palette_color1 : palette_color0;
+ });
}
color0 = FXARGB_R(palette_color0);
color1 = FXARGB_R(palette_color1);
}
- image_builder = SkiaImageBuilder(
- SkImageInfo::Make(width, height, color_type, kPremul_SkAlphaType));
- pdfium::span<uint8_t> dst8_pixels = image_builder.allocated_pixels8();
- for (int y = 0; y < height; ++y) {
- const uint8_t* src_row = buffer + y * row_bytes;
- pdfium::span<uint8_t> dst_row =
- dst8_pixels.subspan(y * image_builder.row_bytes());
- for (int x = 0; x < width; ++x) {
- dst_row[x] = src_row[x >> 3] & (1 << (~x & 0x07)) ? color1 : color0;
- }
- }
- break;
+ return CreateSkiaImageFromTransformedDib</*source_bits_per_pixel=*/1>(
+ *this, color_type, kPremul_SkAlphaType,
+ [color0, color1](bool bit) { return bit ? color1 : color0; });
}
+
case 8:
// we upscale ctables to 32bit.
if (HasPalette()) {
- const size_t src_palette_size = GetRequiredPaletteSize();
- pdfium::span<const uint32_t> src_palette = GetPaletteSpan();
- CHECK_LE(src_palette_size, src_palette.size());
- if (src_palette_size < src_palette.size()) {
- src_palette = src_palette.first(src_palette_size);
- }
+ return CreateSkiaImageFromTransformedDib</*source_bits_per_pixel=*/8>(
+ *this, kBGRA_8888_SkColorType, kPremul_SkAlphaType,
+ [palette = GetPaletteSpan().first(GetRequiredPaletteSize())](
+ uint8_t index) {
+ if (index >= palette.size()) {
+ index = 0;
+ }
+ return palette[index];
+ });
+ }
+ return CreateSkiaImageFromDib(this, color_type);
- image_builder = CreateSkiaImageBuilderUsingPalette(this, src_palette);
- }
- break;
- case 24: {
- image_builder = SkiaImageBuilder(SkImageInfo::Make(
- width, height, kBGRA_8888_SkColorType, kOpaque_SkAlphaType));
- pdfium::span<uint32_t> dst32_pixels = image_builder.allocated_pixels32();
- for (int y = 0; y < height; ++y) {
- const uint8_t* src_row = buffer + y * row_bytes;
- pdfium::span<uint32_t> dst_row = dst32_pixels.subspan(y * width);
- for (int x = 0; x < width; ++x) {
- dst_row[x] = SkPackARGB32NoCheck(
- 0xFF, src_row[x * 3 + 2], src_row[x * 3 + 1], src_row[x * 3 + 0]);
- }
- }
- break;
- }
+ case 24:
+ return CreateSkiaImageFromTransformedDib</*source_bits_per_pixel=*/24>(
+ *this, kBGRA_8888_SkColorType, kOpaque_SkAlphaType,
+ [](uint8_t red, uint8_t green, uint8_t blue) {
+ return SkPackARGB32NoCheck(0xFF, red, green, blue);
+ });
+
case 32:
- image_builder = SkiaImageBuilder(this, kBGRA_8888_SkColorType);
- break;
- default:
- NOTREACHED();
- }
+ return CreateSkiaImageFromDib(this, kBGRA_8888_SkColorType);
- return std::move(image_builder).Build();
+ default:
+ NOTREACHED_NORETURN();
+ }
}
