Simplify code since ProgressiveDecoder clipbox origin is always (0, 0)
By manual inspection of all writes to `m_clipBox`, the top-left corner
is always (0, 0). Then simplify all the code that adds / subtracts /
compares to 0.
Change-Id: Ie7ea539a38d080e8a4c1b0f5e69a0e8f101d9641
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/122292
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Tom Sepez <tsepez@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fxcodec/progressive_decoder.cpp b/core/fxcodec/progressive_decoder.cpp
index 5b909b5..c3f9806 100644
--- a/core/fxcodec/progressive_decoder.cpp
+++ b/core/fxcodec/progressive_decoder.cpp
@@ -252,20 +252,17 @@
bool ProgressiveDecoder::PngAskScanlineBuf(int line, uint8_t** pSrcBuf) {
RetainPtr<CFX_DIBitmap> pDIBitmap = m_pDeviceBitmap;
CHECK(pDIBitmap);
- if (line < m_clipBox.top || line >= m_clipBox.bottom)
+ if (line < 0 || line >= m_clipBox.bottom) {
return true;
+ }
double scale_y = static_cast<double>(m_SrcHeight) / m_clipBox.Height();
- int32_t row = static_cast<int32_t>((line - m_clipBox.top) * scale_y);
+ int32_t row = static_cast<int32_t>(line * scale_y);
*pSrcBuf = m_DecodeBuf.data();
int32_t src_Bpp = pDIBitmap->GetBPP() >> 3;
int32_t dest_Bpp = (m_SrcFormat & 0xff) >> 3;
- int32_t src_left = 0;
- int32_t dest_left = m_clipBox.left;
- pdfium::span<const uint8_t> src_span =
- pDIBitmap->GetScanline(row).subspan(src_left * src_Bpp);
- pdfium::span<uint8_t> dest_span =
- pdfium::make_span(m_DecodeBuf).subspan(dest_left * dest_Bpp);
+ pdfium::span<const uint8_t> src_span = pDIBitmap->GetScanline(row);
+ pdfium::span<uint8_t> dest_span = pdfium::make_span(m_DecodeBuf);
const uint8_t* src_scan = src_span.data();
uint8_t* dest_scan = dest_span.data();
@@ -319,16 +316,14 @@
void ProgressiveDecoder::PngFillScanlineBufCompleted(int pass, int line) {
RetainPtr<CFX_DIBitmap> pDIBitmap = m_pDeviceBitmap;
DCHECK(pDIBitmap);
- int src_top = m_clipBox.top;
int src_bottom = m_clipBox.bottom;
- int dest_top = 0;
int src_height = m_clipBox.Height();
int dest_height = m_SrcHeight;
- if (line >= src_top && line < src_bottom) {
+ if (line >= 0 && line < src_bottom) {
double scale_y = static_cast<double>(dest_height) / src_height;
- int src_row = line - src_top;
- int dest_row = (int)(src_row * scale_y) + dest_top;
- if (dest_row >= dest_top + dest_height) {
+ int src_row = line;
+ int dest_row = (int)(src_row * scale_y);
+ if (dest_row >= dest_height) {
return;
}
PngOneOneMapResampleHorz(pDIBitmap, dest_row, m_DecodeBuf, m_SrcFormat);
@@ -453,19 +448,19 @@
bool bLastPass = (row_num % 2) == 1;
int32_t line = row_num + m_GifFrameRect.top;
- int src_top = m_clipBox.top;
int src_bottom = m_clipBox.bottom;
- int dest_top = 0;
int src_height = m_clipBox.Height();
int dest_height = m_SrcHeight;
- if (line < src_top || line >= src_bottom)
+ if (line < 0 || line >= src_bottom) {
return;
+ }
double scale_y = static_cast<double>(dest_height) / src_height;
- int src_row = line - src_top;
- int dest_row = (int)(src_row * scale_y) + dest_top;
- if (dest_row >= dest_top + dest_height)
+ int src_row = line;
+ int dest_row = (int)(src_row * scale_y);
+ if (dest_row >= dest_height) {
return;
+ }
ResampleScanline(pDIBitmap, dest_row, decode_span, m_SrcFormat);
if (scale_y > 1.0 && m_SrcPassNumber == 1) {
@@ -475,7 +470,7 @@
if (scale_y <= 1.0)
return;
- int dest_bottom = dest_top + m_SrcHeight;
+ int dest_bottom = m_SrcHeight;
int dest_Bpp = pDIBitmap->GetBPP() >> 3;
if (dest_row + (int)scale_y >= dest_bottom - 1) {
const uint8_t* scan_src = pDIBitmap->GetScanline(dest_row).data();
@@ -505,21 +500,19 @@
fxcrt::Copy(row_buf.first(m_ScanlineSize), m_DecodeBuf);
- int src_top = m_clipBox.top;
int src_bottom = m_clipBox.bottom;
- int dest_top = 0;
int src_height = m_clipBox.Height();
int dest_height = m_SrcHeight;
- if ((src_top >= 0 && row_num < static_cast<uint32_t>(src_top)) ||
- src_bottom < 0 || row_num >= static_cast<uint32_t>(src_bottom)) {
+ if (src_bottom < 0 || row_num >= static_cast<uint32_t>(src_bottom)) {
return;
}
double scale_y = static_cast<double>(dest_height) / src_height;
- int src_row = row_num - src_top;
- int dest_row = (int)(src_row * scale_y) + dest_top;
- if (dest_row >= dest_top + dest_height)
+ int src_row = row_num;
+ int dest_row = (int)(src_row * scale_y);
+ if (dest_row >= dest_height) {
return;
+ }
ResampleScanline(pDIBitmap, dest_row, m_DecodeBuf, m_SrcFormat);
if (scale_y <= 1.0)
@@ -537,7 +530,6 @@
double scale_y,
int dest_row) {
int dest_Bpp = pDeviceBitmap->GetBPP() >> 3;
- int dest_top = 0;
int dest_bottom = m_SrcHeight;
FX_SAFE_INT32 check_dest_row_1 = dest_row;
check_dest_row_1 += pdfium::checked_cast<int>(scale_y);
@@ -556,13 +548,11 @@
for (; dest_row_1 > dest_row; dest_row_1--) {
uint8_t* scan_des = pDeviceBitmap->GetWritableScanline(dest_row_1)
.data();
- PixelWeight* pWeight = m_WeightVert.GetPixelWeight(dest_row_1 - dest_top);
+ PixelWeight* pWeight = m_WeightVert.GetPixelWeight(dest_row_1);
const uint8_t* scan_src1 =
- pDeviceBitmap->GetScanline(pWeight->m_SrcStart + dest_top)
- .data();
+ pDeviceBitmap->GetScanline(pWeight->m_SrcStart).data();
const uint8_t* scan_src2 =
- pDeviceBitmap->GetScanline(pWeight->m_SrcEnd + dest_top)
- .data();
+ pDeviceBitmap->GetScanline(pWeight->m_SrcEnd).data();
switch (pDeviceBitmap->GetFormat()) {
case FXDIB_Format::kInvalid:
case FXDIB_Format::k1bppMask:
@@ -806,24 +796,21 @@
double scale_y,
int dest_row) {
int dest_Bpp = pDeviceBitmap->GetBPP() >> 3;
- int dest_top = 0;
pdfium::CheckedNumeric<double> scale_y2 = scale_y;
scale_y2 *= 2;
FX_SAFE_INT32 check_dest_row_1 = dest_row;
check_dest_row_1 -= scale_y2.ValueOrDie();
int dest_row_1 = check_dest_row_1.ValueOrDie();
- dest_row_1 = std::max(dest_row_1, dest_top);
+ dest_row_1 = std::max(dest_row_1, 0);
UNSAFE_TODO({
for (; dest_row_1 < dest_row; dest_row_1++) {
uint8_t* scan_des = pDeviceBitmap->GetWritableScanline(dest_row_1)
.data();
- PixelWeight* pWeight = m_WeightVert.GetPixelWeight(dest_row_1 - dest_top);
+ PixelWeight* pWeight = m_WeightVert.GetPixelWeight(dest_row_1);
const uint8_t* scan_src1 =
- pDeviceBitmap->GetScanline(pWeight->m_SrcStart + dest_top)
- .data();
+ pDeviceBitmap->GetScanline(pWeight->m_SrcStart).data();
const uint8_t* scan_src2 =
- pDeviceBitmap->GetScanline(pWeight->m_SrcEnd + dest_top)
- .data();
+ pDeviceBitmap->GetScanline(pWeight->m_SrcEnd).data();
switch (pDeviceBitmap->GetFormat()) {
case FXDIB_Format::kInvalid:
case FXDIB_Format::k1bppMask:
@@ -866,7 +853,7 @@
break;
}
}
- int dest_bottom = dest_top + m_SrcHeight - 1;
+ int dest_bottom = m_SrcHeight - 1;
if (dest_row + (int)(2 * scale_y) >= dest_bottom &&
dest_row + (int)scale_y < dest_bottom) {
GifDoubleLineResampleVert(pDeviceBitmap, scale_y,
@@ -993,9 +980,7 @@
m_DecodeBuf.data());
}
if (m_SrcFormat == FXCodec_Rgb) {
- int src_Bpp = (m_SrcFormat & 0xff) >> 3;
- RGB2BGR(UNSAFE_TODO(m_DecodeBuf.data() + m_clipBox.left * src_Bpp),
- m_clipBox.Width());
+ RGB2BGR(UNSAFE_TODO(m_DecodeBuf.data()), m_clipBox.Width());
}
if (m_SrcRow >= m_clipBox.bottom) {
m_pDeviceBitmap = nullptr;
@@ -1016,12 +1001,8 @@
FXCodec_Format src_format) {
int32_t src_Bpp = (m_SrcFormat & 0xff) >> 3;
int32_t dest_Bpp = pDeviceBitmap->GetBPP() >> 3;
- int32_t src_left = m_clipBox.left;
- int32_t dest_left = 0;
- uint8_t* src_scan = src_span.subspan(src_left * src_Bpp).data();
- uint8_t* dest_scan = pDeviceBitmap->GetWritableScanline(dest_line)
- .subspan(dest_left * dest_Bpp)
- .data();
+ uint8_t* src_scan = src_span.data();
+ uint8_t* dest_scan = pDeviceBitmap->GetWritableScanline(dest_line).data();
UNSAFE_TODO({
switch (pDeviceBitmap->GetFormat()) {
case FXDIB_Format::kInvalid:
@@ -1200,7 +1181,6 @@
FXCODEC_STATUS ProgressiveDecoder::TiffContinueDecode() {
bool ret = false;
if (m_pDeviceBitmap->GetBPP() == 32 &&
- m_clipBox.left == 0 && m_clipBox.top == 0 &&
m_clipBox.right == m_SrcWidth && m_clipBox.bottom == m_SrcHeight) {
ret = TiffDecoder::Decode(m_pTiffContext.get(), m_pDeviceBitmap);
m_pDeviceBitmap = nullptr;
@@ -1228,8 +1208,7 @@
return m_status;
}
RetainPtr<CFX_DIBitmap> pClipBitmap =
- (m_clipBox.left == 0 && m_clipBox.top == 0 &&
- m_clipBox.right == m_SrcWidth && m_clipBox.bottom == m_SrcHeight)
+ (m_clipBox.right == m_SrcWidth && m_clipBox.bottom == m_SrcHeight)
? pDIBitmap
: pDIBitmap->ClipTo(m_clipBox);
if (!pClipBitmap) {
@@ -1535,15 +1514,9 @@
pdfium::span<uint8_t> src_span,
FXCodec_Format src_format) {
uint8_t* src_scan = src_span.data();
- int src_left = m_clipBox.left;
- int dest_left = 0;
uint8_t* dest_scan = pDeviceBitmap->GetWritableScanline(dest_line).data();
int src_bytes_per_pixel = (src_format & 0xff) / 8;
int dest_bytes_per_pixel = pDeviceBitmap->GetBPP() / 8;
- UNSAFE_TODO({
- src_scan += src_left * src_bytes_per_pixel;
- dest_scan += dest_left * dest_bytes_per_pixel;
- });
for (int dest_col = 0; dest_col < m_SrcWidth; dest_col++) {
PixelWeight* pPixelWeights = m_WeightHorz.GetPixelWeight(dest_col);
switch (m_TransMethod) {
@@ -1710,12 +1683,11 @@
double scale_y,
int dest_row) {
int dest_Bpp = pDeviceBitmap->GetBPP() >> 3;
- int dest_top = 0;
FX_SAFE_INT32 check_dest_row_1 = dest_row;
check_dest_row_1 -= pdfium::checked_cast<int>(scale_y);
int dest_row_1 = check_dest_row_1.ValueOrDie();
- if (dest_row_1 < dest_top) {
- int dest_bottom = dest_top + m_SrcHeight;
+ if (dest_row_1 < 0) {
+ int dest_bottom = m_SrcHeight;
if (dest_row + (int)scale_y >= dest_bottom - 1) {
pdfium::span<const uint8_t> scan_src =
pDeviceBitmap->GetScanline(dest_row).first(m_SrcWidth * dest_Bpp);
@@ -1729,13 +1701,11 @@
for (; dest_row_1 < dest_row; dest_row_1++) {
uint8_t* scan_des = pDeviceBitmap->GetWritableScanline(dest_row_1)
.data();
- PixelWeight* pWeight = m_WeightVert.GetPixelWeight(dest_row_1 - dest_top);
+ PixelWeight* pWeight = m_WeightVert.GetPixelWeight(dest_row_1);
const uint8_t* scan_src1 =
- pDeviceBitmap->GetScanline(pWeight->m_SrcStart + dest_top)
- .data();
+ pDeviceBitmap->GetScanline(pWeight->m_SrcStart).data();
const uint8_t* scan_src2 =
- pDeviceBitmap->GetScanline(pWeight->m_SrcEnd + dest_top)
- .data();
+ pDeviceBitmap->GetScanline(pWeight->m_SrcEnd).data();
switch (pDeviceBitmap->GetFormat()) {
case FXDIB_Format::kInvalid:
case FXDIB_Format::k1bppMask:
@@ -1779,7 +1749,7 @@
}
}
});
- int dest_bottom = dest_top + m_SrcHeight;
+ int dest_bottom = m_SrcHeight;
if (dest_row + (int)scale_y >= dest_bottom - 1) {
pdfium::span<const uint8_t> scan_src =
pDeviceBitmap->GetScanline(dest_row).first(m_SrcWidth * dest_Bpp);
@@ -1793,16 +1763,15 @@
int32_t src_line,
uint8_t* src_scan,
FXCodec_Format src_format) {
- int src_top = m_clipBox.top;
- int dest_top = 0;
int src_height = m_clipBox.Height();
int dest_height = m_SrcHeight;
- if (src_line >= src_top) {
+ if (src_line >= 0) {
double scale_y = static_cast<double>(dest_height) / src_height;
- int src_row = src_line - src_top;
- int dest_row = (int)(src_row * scale_y) + dest_top;
- if (dest_row >= dest_top + dest_height)
+ int src_row = src_line;
+ int dest_row = (int)(src_row * scale_y);
+ if (dest_row >= dest_height) {
return;
+ }
ResampleScanline(pDeviceBitmap, dest_row, m_DecodeBuf, src_format);
if (scale_y > 1.0)
