FEComponentTransfer.cpp [plain text]
#include "config.h"
#include "FEComponentTransfer.h"
#include "Filter.h"
#include "GraphicsContext.h"
#include <JavaScriptCore/Uint8ClampedArray.h>
#include <wtf/MathExtras.h>
#include <wtf/StdLibExtras.h>
#include <wtf/text/TextStream.h>
namespace WebCore {
FEComponentTransfer::FEComponentTransfer(Filter& filter, const ComponentTransferFunction& redFunction,
const ComponentTransferFunction& greenFunction, const ComponentTransferFunction& blueFunction, const ComponentTransferFunction& alphaFunction)
: FilterEffect(filter)
, m_redFunction(redFunction)
, m_greenFunction(greenFunction)
, m_blueFunction(blueFunction)
, m_alphaFunction(alphaFunction)
{
}
Ref<FEComponentTransfer> FEComponentTransfer::create(Filter& filter, const ComponentTransferFunction& redFunction,
const ComponentTransferFunction& greenFunction, const ComponentTransferFunction& blueFunction, const ComponentTransferFunction& alphaFunction)
{
return adoptRef(*new FEComponentTransfer(filter, redFunction, greenFunction, blueFunction, alphaFunction));
}
void FEComponentTransfer::computeIdentityTable(LookupTable&, const ComponentTransferFunction&)
{
}
void FEComponentTransfer::computeTabularTable(LookupTable& values, const ComponentTransferFunction& transferFunction)
{
const Vector<float>& tableValues = transferFunction.tableValues;
unsigned n = tableValues.size();
if (n < 1)
return;
for (unsigned i = 0; i < values.size(); ++i) {
double c = i / 255.0;
unsigned k = static_cast<unsigned>(c * (n - 1));
double v1 = tableValues[k];
double v2 = tableValues[std::min((k + 1), (n - 1))];
double val = 255.0 * (v1 + (c * (n - 1) - k) * (v2 - v1));
val = std::max(0.0, std::min(255.0, val));
values[i] = static_cast<uint8_t>(val);
}
}
void FEComponentTransfer::computeDiscreteTable(LookupTable& values, const ComponentTransferFunction& transferFunction)
{
const Vector<float>& tableValues = transferFunction.tableValues;
unsigned n = tableValues.size();
if (n < 1)
return;
for (unsigned i = 0; i < values.size(); ++i) {
unsigned k = static_cast<unsigned>((i * n) / 255.0);
k = std::min(k, n - 1);
double val = 255 * tableValues[k];
val = std::max(0.0, std::min(255.0, val));
values[i] = static_cast<uint8_t>(val);
}
}
void FEComponentTransfer::computeLinearTable(LookupTable& values, const ComponentTransferFunction& transferFunction)
{
for (unsigned i = 0; i < values.size(); ++i) {
double val = transferFunction.slope * i + 255 * transferFunction.intercept;
val = std::max(0.0, std::min(255.0, val));
values[i] = static_cast<uint8_t>(val);
}
}
void FEComponentTransfer::computeGammaTable(LookupTable& values, const ComponentTransferFunction& transferFunction)
{
for (unsigned i = 0; i < values.size(); ++i) {
double exponent = transferFunction.exponent; double val = 255.0 * (transferFunction.amplitude * pow((i / 255.0), exponent) + transferFunction.offset);
val = std::max(0.0, std::min(255.0, val));
values[i] = static_cast<uint8_t>(val);
}
}
void FEComponentTransfer::platformApplySoftware()
{
FilterEffect* in = inputEffect(0);
Uint8ClampedArray* pixelArray = createUnmultipliedImageResult();
if (!pixelArray)
return;
LookupTable redTable;
LookupTable greenTable;
LookupTable blueTable;
LookupTable alphaTable;
computeLookupTables(redTable, greenTable, blueTable, alphaTable);
IntRect drawingRect = requestedRegionOfInputImageData(in->absolutePaintRect());
in->copyUnmultipliedResult(*pixelArray, drawingRect);
unsigned pixelArrayLength = pixelArray->length();
uint8_t* data = pixelArray->data();
for (unsigned pixelOffset = 0; pixelOffset < pixelArrayLength; pixelOffset += 4) {
data[pixelOffset] = redTable[data[pixelOffset]];
data[pixelOffset + 1] = greenTable[data[pixelOffset + 1]];
data[pixelOffset + 2] = blueTable[data[pixelOffset + 2]];
data[pixelOffset + 3] = alphaTable[data[pixelOffset + 3]];
}
}
void FEComponentTransfer::computeLookupTables(LookupTable& redTable, LookupTable& greenTable, LookupTable& blueTable, LookupTable& alphaTable)
{
for (unsigned i = 0; i < redTable.size(); ++i)
redTable[i] = greenTable[i] = blueTable[i] = alphaTable[i] = i;
using TransferType = void (*)(LookupTable&, const ComponentTransferFunction&);
TransferType callEffect[] = {
computeIdentityTable, computeIdentityTable, computeTabularTable, computeDiscreteTable, computeLinearTable, computeGammaTable };
ASSERT_WITH_SECURITY_IMPLICATION(static_cast<size_t>(m_redFunction.type) < WTF_ARRAY_LENGTH(callEffect));
ASSERT_WITH_SECURITY_IMPLICATION(static_cast<size_t>(m_greenFunction.type) < WTF_ARRAY_LENGTH(callEffect));
ASSERT_WITH_SECURITY_IMPLICATION(static_cast<size_t>(m_blueFunction.type) < WTF_ARRAY_LENGTH(callEffect));
ASSERT_WITH_SECURITY_IMPLICATION(static_cast<size_t>(m_alphaFunction.type) < WTF_ARRAY_LENGTH(callEffect));
callEffect[m_redFunction.type](redTable, m_redFunction);
callEffect[m_greenFunction.type](greenTable, m_greenFunction);
callEffect[m_blueFunction.type](blueTable, m_blueFunction);
callEffect[m_alphaFunction.type](alphaTable, m_alphaFunction);
}
static TextStream& operator<<(TextStream& ts, ComponentTransferType type)
{
switch (type) {
case FECOMPONENTTRANSFER_TYPE_UNKNOWN:
ts << "UNKNOWN";
break;
case FECOMPONENTTRANSFER_TYPE_IDENTITY:
ts << "IDENTITY";
break;
case FECOMPONENTTRANSFER_TYPE_TABLE:
ts << "TABLE";
break;
case FECOMPONENTTRANSFER_TYPE_DISCRETE:
ts << "DISCRETE";
break;
case FECOMPONENTTRANSFER_TYPE_LINEAR:
ts << "LINEAR";
break;
case FECOMPONENTTRANSFER_TYPE_GAMMA:
ts << "GAMMA";
break;
}
return ts;
}
static TextStream& operator<<(TextStream& ts, const ComponentTransferFunction& function)
{
ts << "type=\"" << function.type;
switch (function.type) {
case FECOMPONENTTRANSFER_TYPE_UNKNOWN:
break;
case FECOMPONENTTRANSFER_TYPE_IDENTITY:
break;
case FECOMPONENTTRANSFER_TYPE_TABLE:
ts << " " << function.tableValues;
break;
case FECOMPONENTTRANSFER_TYPE_DISCRETE:
ts << " " << function.tableValues;
break;
case FECOMPONENTTRANSFER_TYPE_LINEAR:
ts << "\" slope=\"" << function.slope << "\" intercept=\"" << function.intercept << "\"";
break;
case FECOMPONENTTRANSFER_TYPE_GAMMA:
ts << "\" amplitude=\"" << function.amplitude << "\" exponent=\"" << function.exponent << "\" offset=\"" << function.offset << "\"";
break;
}
return ts;
}
TextStream& FEComponentTransfer::externalRepresentation(TextStream& ts, RepresentationType representation) const
{
ts << indent << "[feComponentTransfer";
FilterEffect::externalRepresentation(ts, representation);
ts << "\n";
{
TextStream::IndentScope indentScope(ts, 2);
ts << indent << "{red: " << m_redFunction << "}\n";
ts << indent << "{green: " << m_greenFunction << "}\n";
ts << indent << "{blue: " << m_blueFunction << "}\n";
ts << indent << "{alpha: " << m_alphaFunction << "}]\n";
}
TextStream::IndentScope indentScope(ts);
inputEffect(0)->externalRepresentation(ts, representation);
return ts;
}
}