gecko-dev/gfx/2d/DataSurfaceHelpers.cpp

201 строка
5.7 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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 <cstring>
#include "2D.h"
#include "DataSurfaceHelpers.h"
#include "Logging.h"
#include "mozilla/MathAlgorithms.h"
#include "Tools.h"
namespace mozilla {
namespace gfx {
void
ConvertBGRXToBGRA(uint8_t* aData, const IntSize &aSize, int32_t aStride)
{
uint32_t* pixel = reinterpret_cast<uint32_t*>(aData);
for (int row = 0; row < aSize.height; ++row) {
for (int column = 0; column < aSize.width; ++column) {
#ifdef IS_BIG_ENDIAN
pixel[column] |= 0x000000FF;
#else
pixel[column] |= 0xFF000000;
#endif
}
pixel += (aStride/4);
}
}
void
CopySurfaceDataToPackedArray(uint8_t* aSrc, uint8_t* aDst, IntSize aSrcSize,
int32_t aSrcStride, int32_t aBytesPerPixel)
{
MOZ_ASSERT(aBytesPerPixel > 0,
"Negative stride for aDst not currently supported");
MOZ_ASSERT(BufferSizeFromStrideAndHeight(aSrcStride, aSrcSize.height) > 0,
"How did we end up with a surface with such a big buffer?");
int packedStride = aSrcSize.width * aBytesPerPixel;
if (aSrcStride == packedStride) {
// aSrc is already packed, so we can copy with a single memcpy.
memcpy(aDst, aSrc, packedStride * aSrcSize.height);
} else {
// memcpy one row at a time.
for (int row = 0; row < aSrcSize.height; ++row) {
memcpy(aDst, aSrc, packedStride);
aSrc += aSrcStride;
aDst += packedStride;
}
}
}
void
CopyBGRXSurfaceDataToPackedBGRArray(uint8_t* aSrc, uint8_t* aDst,
IntSize aSrcSize, int32_t aSrcStride)
{
int packedStride = aSrcSize.width * 3;
uint8_t* srcPx = aSrc;
uint8_t* dstPx = aDst;
for (int row = 0; row < aSrcSize.height; ++row) {
for (int col = 0; col < aSrcSize.height; ++col) {
dstPx[0] = srcPx[0];
dstPx[1] = srcPx[1];
dstPx[2] = srcPx[2];
// srcPx[3] (unused or alpha component) dropped on floor
srcPx += 4;
dstPx += 3;
}
srcPx = aSrc += aSrcStride;
dstPx = aDst += packedStride;
}
}
uint8_t*
SurfaceToPackedBGRA(DataSourceSurface *aSurface)
{
SurfaceFormat format = aSurface->GetFormat();
if (format != SurfaceFormat::B8G8R8A8 && format != SurfaceFormat::B8G8R8X8) {
return nullptr;
}
IntSize size = aSurface->GetSize();
uint8_t* imageBuffer = new (std::nothrow) uint8_t[size.width * size.height * sizeof(uint32_t)];
if (!imageBuffer) {
return nullptr;
}
DataSourceSurface::MappedSurface map;
if (!aSurface->Map(DataSourceSurface::MapType::READ, &map)) {
delete [] imageBuffer;
return nullptr;
}
CopySurfaceDataToPackedArray(map.mData, imageBuffer, size,
map.mStride, 4 * sizeof(uint8_t));
aSurface->Unmap();
if (format == SurfaceFormat::B8G8R8X8) {
// Convert BGRX to BGRA by setting a to 255.
ConvertBGRXToBGRA(reinterpret_cast<uint8_t *>(imageBuffer), size, size.width * sizeof(uint32_t));
}
return imageBuffer;
}
uint8_t*
SurfaceToPackedBGR(DataSourceSurface *aSurface)
{
SurfaceFormat format = aSurface->GetFormat();
MOZ_ASSERT(format == SurfaceFormat::B8G8R8X8, "Format not supported");
if (format != SurfaceFormat::B8G8R8X8) {
// To support B8G8R8A8 we'd need to un-pre-multiply alpha
return nullptr;
}
IntSize size = aSurface->GetSize();
uint8_t* imageBuffer = new (std::nothrow) uint8_t[size.width * size.height * 3 * sizeof(uint8_t)];
if (!imageBuffer) {
return nullptr;
}
DataSourceSurface::MappedSurface map;
if (!aSurface->Map(DataSourceSurface::MapType::READ, &map)) {
delete [] imageBuffer;
return nullptr;
}
CopyBGRXSurfaceDataToPackedBGRArray(map.mData, imageBuffer, size,
map.mStride);
aSurface->Unmap();
return imageBuffer;
}
void
ClearDataSourceSurface(DataSourceSurface *aSurface)
{
DataSourceSurface::MappedSurface map;
if (!aSurface->Map(DataSourceSurface::MapType::WRITE, &map)) {
MOZ_ASSERT(false, "Failed to map DataSourceSurface");
return;
}
// We avoid writing into the gaps between the rows here since we can't be
// sure that some drivers don't use those bytes.
uint32_t width = aSurface->GetSize().width;
uint32_t bytesPerRow = width * BytesPerPixel(aSurface->GetFormat());
uint8_t* row = map.mData;
// converting to size_t here because otherwise the temporaries can overflow
// and we can end up with |end| being a bad address!
uint8_t* end = row + size_t(map.mStride) * size_t(aSurface->GetSize().height);
while (row != end) {
memset(row, 0, bytesPerRow);
row += map.mStride;
}
aSurface->Unmap();
}
size_t
BufferSizeFromStrideAndHeight(int32_t aStride,
int32_t aHeight,
int32_t aExtraBytes)
{
if (MOZ_UNLIKELY(aHeight <= 0)) {
return 0;
}
// We limit the length returned to values that can be represented by int32_t
// because we don't want to allocate buffers any bigger than that. This
// allows for a buffer size of over 2 GiB which is already rediculously
// large and will make the process janky. (Note the choice of the signed type
// is deliberate because we specifically don't want the returned value to
// overflow if someone stores the buffer length in an int32_t variable.)
CheckedInt32 requiredBytes =
CheckedInt32(aStride) * CheckedInt32(aHeight) + CheckedInt32(aExtraBytes);
if (MOZ_UNLIKELY(!requiredBytes.isValid())) {
gfxWarning() << "Buffer size too big; returning zero";
return 0;
}
return requiredBytes.value();
}
}
}