Remove UNSAFE_TODOs in CPDF_DIB::LoadJpxBitmap()
Convert code to use spans. To help facilitate this, add templated
CFX_DIBBase::GetScanlineAs() and CFX_DIBitmap::GetWritableScanlineAs()
to allow converting bytes to structs defined in fx_dib.h.
Bug: 42271176
Change-Id: Iabd2afd211da4646e617d9bcbc95877d8354d284
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/120178
Reviewed-by: Thomas Sepez <tsepez@google.com>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fpdfapi/page/cpdf_dib.cpp b/core/fpdfapi/page/cpdf_dib.cpp
index 6b09d43..96ad994 100644
--- a/core/fpdfapi/page/cpdf_dib.cpp
+++ b/core/fpdfapi/page/cpdf_dib.cpp
@@ -759,36 +759,38 @@
m_JpxInlineData.height = image_info.height;
m_JpxInlineData.data.reserve(image_info.width * image_info.height);
for (uint32_t row = 0; row < image_info.height; ++row) {
- const uint8_t* src = result_bitmap->GetScanline(row).data();
- uint8_t* dest = rgb_bitmap->GetWritableScanline(row).data();
- UNSAFE_TODO({
- for (uint32_t col = 0; col < image_info.width; ++col) {
- uint8_t a = src[3];
- m_JpxInlineData.data.push_back(a);
- uint8_t na = 255 - a;
- uint8_t b = (src[0] * a + 255 * na) / 255;
- uint8_t g = (src[1] * a + 255 * na) / 255;
- uint8_t r = (src[2] * a + 255 * na) / 255;
- dest[0] = b;
- dest[1] = g;
- dest[2] = r;
- src += 4;
- dest += 3;
- }
- });
+ auto src =
+ result_bitmap->GetScanlineAs<FX_BGRA_STRUCT<uint8_t>>(row).first(
+ image_info.width);
+ auto dest =
+ rgb_bitmap->GetWritableScanlineAs<FX_BGR_STRUCT<uint8_t>>(row)
+ .first(image_info.width);
+ for (const auto& input : src) {
+ auto& output = dest.front();
+ m_JpxInlineData.data.push_back(input.alpha);
+ const uint8_t na = 255 - input.alpha;
+ output.blue = (input.blue * input.alpha + 255 * na) / 255;
+ output.green = (input.green * input.alpha + 255 * na) / 255;
+ output.red = (input.red * input.alpha + 255 * na) / 255;
+ dest = dest.subspan(1);
+ }
}
} else {
// TODO(thestig): Is there existing code that does this already?
for (uint32_t row = 0; row < image_info.height; ++row) {
- const uint8_t* src = result_bitmap->GetScanline(row).data();
- uint8_t* dest = rgb_bitmap->GetWritableScanline(row).data();
- UNSAFE_TODO({
- for (uint32_t col = 0; col < image_info.width; ++col) {
- FXSYS_memcpy(dest, src, 3);
- src += 4;
- dest += 3;
- }
- });
+ auto src =
+ result_bitmap->GetScanlineAs<FX_BGRA_STRUCT<uint8_t>>(row).first(
+ image_info.width);
+ auto dest =
+ rgb_bitmap->GetWritableScanlineAs<FX_BGR_STRUCT<uint8_t>>(row)
+ .first(image_info.width);
+ for (const auto& input : src) {
+ auto& output = dest.front();
+ output.green = input.green;
+ output.red = input.red;
+ output.blue = input.blue;
+ dest = dest.subspan(1);
+ }
}
}
result_bitmap = std::move(rgb_bitmap);
@@ -797,13 +799,11 @@
m_bpc < 8) {
int scale = 8 - m_bpc;
for (uint32_t row = 0; row < image_info.height; ++row) {
- uint8_t* scanline = result_bitmap->GetWritableScanline(row).data();
- UNSAFE_TODO({
- for (uint32_t col = 0; col < image_info.width; ++col) {
- *scanline = (*scanline) >> scale;
- ++scanline;
- }
- });
+ pdfium::span<uint8_t> scanline =
+ result_bitmap->GetWritableScanline(row).first(image_info.width);
+ for (auto& pixel : scanline) {
+ pixel >>= scale;
+ }
}
}
diff --git a/core/fxge/dib/cfx_dibbase.h b/core/fxge/dib/cfx_dibbase.h
index 12677ed..c5c3c4e 100644
--- a/core/fxge/dib/cfx_dibbase.h
+++ b/core/fxge/dib/cfx_dibbase.h
@@ -14,6 +14,7 @@
#include "core/fxcrt/data_vector.h"
#include "core/fxcrt/retain_ptr.h"
#include "core/fxcrt/span.h"
+#include "core/fxcrt/span_util.h"
#include "core/fxge/dib/fx_dib.h"
#if defined(PDF_USE_SKIA)
@@ -50,6 +51,11 @@
virtual RetainPtr<const CFX_DIBitmap> RealizeIfNeeded() const;
#endif
+ template <typename T>
+ pdfium::span<const T> GetScanlineAs(int line) const {
+ return fxcrt::truncating_reinterpret_span<const T>(GetScanline(line));
+ }
+
int GetWidth() const { return m_Width; }
int GetHeight() const { return m_Height; }
uint32_t GetPitch() const { return m_Pitch; }
diff --git a/core/fxge/dib/cfx_dibitmap.h b/core/fxge/dib/cfx_dibitmap.h
index bd9d9b4..2af64ca 100644
--- a/core/fxge/dib/cfx_dibitmap.h
+++ b/core/fxge/dib/cfx_dibitmap.h
@@ -17,6 +17,7 @@
#include "core/fxcrt/maybe_owned.h"
#include "core/fxcrt/retain_ptr.h"
#include "core/fxcrt/span.h"
+#include "core/fxcrt/span_util.h"
#include "core/fxge/dib/cfx_dibbase.h"
#include "core/fxge/dib/fx_dib.h"
@@ -55,10 +56,16 @@
pdfium::span<uint8_t> GetWritableScanline(int line) {
pdfium::span<const uint8_t> src = GetScanline(line);
+ // SAFETY: const_cast<>() doesn't change size.
return UNSAFE_BUFFERS(
pdfium::make_span(const_cast<uint8_t*>(src.data()), src.size()));
}
+ template <typename T>
+ pdfium::span<T> GetWritableScanlineAs(int line) {
+ return fxcrt::truncating_reinterpret_span<T>(GetWritableScanline(line));
+ }
+
void TakeOver(RetainPtr<CFX_DIBitmap>&& pSrcBitmap);
bool ConvertFormat(FXDIB_Format format);
void Clear(uint32_t color);
