nr-filter-component-transfer.cpp revision 354e9a1515ed6d7957de6b135670bfb538468351
/*
* feComponentTransfer filter primitive renderer
*
* Authors:
* Felipe Corrêa da Silva Sanches <juca@members.fsf.org>
* Jasper van de Gronde <th.v.d.gronde@hccnet.nl>
*
* Copyright (C) 2007 authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include <math.h>
#include "display/cairo-templates.h"
#include "display/cairo-utils.h"
#include "display/nr-filter-component-transfer.h"
#include "display/nr-filter-slot.h"
namespace Inkscape {
namespace Filters {
FilterComponentTransfer::FilterComponentTransfer()
{
}
FilterPrimitive * FilterComponentTransfer::create() {
return new FilterComponentTransfer();
}
FilterComponentTransfer::~FilterComponentTransfer()
{}
struct ComponentTransfer {
ComponentTransfer(guint32 color)
: _shift(color * 8)
, _mask(0xff << _shift)
{}
protected:
guint32 _shift;
guint32 _mask;
};
template <bool alpha>
struct ComponentTransferTable;
template <>
struct ComponentTransferTable<false> : public ComponentTransfer {
ComponentTransferTable(guint32 color, std::vector<double> const &values)
: ComponentTransfer(color)
, _v(values.size())
{
for (unsigned i = 0; i< values.size(); ++i) {
_v[i] = round(CLAMP(values[i], 0.0, 1.0) * 255);
}
}
guint32 operator()(guint32 in) {
guint32 component = (in & _mask) >> _shift;
guint32 alpha = (in & 0xff000000) >> 24;
if (alpha == 0) return in;
component = (255 * component + alpha/2) / alpha;
guint32 k = (_v.size() - 1) * component;
guint32 dx = k % 255; k /= 255;
component = _v[k]*255 + (_v[k+1] - _v[k])*dx;
component = (component + 127) / 255;
component = premul_alpha(component, alpha);
return (in & ~_mask) | (component << _shift);
}
private:
std::vector<guint32> _v;
};
template <>
struct ComponentTransferTable<true> {
ComponentTransferTable(std::vector<double> const &values)
: _v(values.size())
{
for (unsigned i = 0; i< values.size(); ++i) {
_v[i] = round(CLAMP(values[i], 0.0, 1.0) * 255);
}
}
guint32 operator()(guint32 in) {
guint32 alpha = (in & 0xff000000) >> 24;
if (alpha == 0) return in;
guint32 k = (_v.size() - 1) * alpha;
guint32 dx = k % 255; k /= 255;
alpha = _v[k]*255 + (_v[k+1] - _v[k])*dx;
alpha = (alpha + 127) / 255;
return (in & 0x00ffffff) | (alpha << 24);
}
private:
std::vector<guint32> _v;
};
template <bool alpha>
struct ComponentTransferDiscrete;
template <>
struct ComponentTransferDiscrete<false> : public ComponentTransfer {
ComponentTransferDiscrete(guint32 color, std::vector<double> const &values)
: ComponentTransfer(color)
, _v(values.size())
{
for (unsigned i = 0; i< values.size(); ++i) {
_v[i] = round(CLAMP(values[i], 0.0, 1.0) * 255);
}
}
guint32 operator()(guint32 in) {
guint32 component = (in & _mask) >> _shift;
guint32 alpha = (in & 0xff000000) >> 24;
if (alpha == 0) return in;
component = (255 * component + alpha/2) / alpha;
guint32 k = (_v.size() - 1) * component / 255;
component = _v[k];
component = premul_alpha(component, alpha);
return (in & ~_mask) | (component << _shift);
}
private:
std::vector<guint32> _v;
};
template <>
struct ComponentTransferDiscrete<true> {
ComponentTransferDiscrete(std::vector<double> const &values)
: _v(values.size())
{
for (unsigned i = 0; i< values.size(); ++i) {
_v[i] = round(CLAMP(values[i], 0.0, 1.0) * 255);
}
}
guint32 operator()(guint32 in) {
guint32 alpha = (in & 0xff000000) >> 24;
if (alpha == 0) return in;
guint32 k = (_v.size() - 1) * alpha / 255;
alpha = _v[k];
return (in & 0x00ffffff) | (alpha << 24);
}
private:
std::vector<guint32> _v;
};
template <bool alpha>
struct ComponentTransferLinear;
template <>
struct ComponentTransferLinear<false> : public ComponentTransfer {
ComponentTransferLinear(guint32 color, double intercept, double slope)
: ComponentTransfer(color)
, _intercept(round(intercept*255*255))
, _slope(round(slope*255))
{}
guint32 operator()(guint32 in) {
gint32 component = (in & _mask) >> _shift;
guint32 alpha = (in & 0xff000000) >> 24;
if (alpha == 0) return 0;
// TODO: this can probably be reduced to something simpler
component = (255 * component + alpha/2) / alpha;
component = pxclamp(_slope * component + _intercept, 0, 255*255);
component = (component + 127) / 255;
component = premul_alpha(component, alpha);
return (in & ~_mask) | (component << _shift);
}
private:
gint32 _intercept;
gint32 _slope;
};
template <>
struct ComponentTransferLinear<true> {
ComponentTransferLinear(double intercept, double slope)
: _intercept(round(intercept*255*255))
, _slope(round(slope*255))
{}
guint32 operator()(guint32 in) {
gint32 alpha = (in & 0xff000000) >> 24;
alpha = pxclamp(_slope * alpha + _intercept, 0, 255*255);
alpha = (alpha + 127) / 255;
return (in & 0x00ffffff) | (alpha << 24);
}
private:
gint32 _intercept;
gint32 _slope;
};
template <bool alpha>
struct ComponentTransferGamma;
template <>
struct ComponentTransferGamma<false> : public ComponentTransfer {
ComponentTransferGamma(guint32 color, double amplitude, double exponent, double offset)
: ComponentTransfer(color)
, _amplitude(amplitude)
, _exponent(exponent)
, _offset(offset)
{}
guint32 operator()(guint32 in) {
double component = (in & _mask) >> _shift;
guint32 alpha = (in & 0xff000000) >> 24;
if (alpha == 0) return 0;
double alphaf = alpha;
component /= alphaf;
component = _amplitude * pow(component, _exponent) + _offset;
guint32 cpx = pxclamp(component * alphaf, 0, 255);
return (in & ~_mask) | (cpx << _shift);
}
private:
double _amplitude;
double _exponent;
double _offset;
};
template <>
struct ComponentTransferGamma<true> {
ComponentTransferGamma(double amplitude, double exponent, double offset)
: _amplitude(amplitude)
, _exponent(exponent)
, _offset(offset)
{}
guint32 operator()(guint32 in) {
double alpha = (in & 0xff000000) >> 24;
alpha /= 255.0;
alpha = _amplitude * pow(alpha, _exponent) + _offset;
guint32 cpx = pxclamp(alpha * 255.0, 0, 255);
return (in & 0x00ffffff) | (cpx << 24);
}
private:
double _amplitude;
double _exponent;
double _offset;
};
void FilterComponentTransfer::render_cairo(FilterSlot &slot)
{
cairo_surface_t *input = slot.getcairo(_input);
cairo_surface_t *out = ink_cairo_surface_create_same_size(input, CAIRO_CONTENT_COLOR_ALPHA);
//cairo_surface_t *outtemp = ink_cairo_surface_create_identical(out);
ink_cairo_surface_blit(input, out);
// parameters: R = 0, G = 1, B = 2, A = 3
// Cairo: R = 2, G = 1, B = 0, A = 3
for (unsigned i = 0; i < 3; ++i) {
guint32 color = 2 - i;
switch (type[i]) {
case COMPONENTTRANSFER_TYPE_TABLE:
ink_cairo_surface_filter(out, out,
ComponentTransferTable<false>(color, tableValues[i]));
break;
case COMPONENTTRANSFER_TYPE_DISCRETE:
ink_cairo_surface_filter(out, out,
ComponentTransferDiscrete<false>(color, tableValues[i]));
break;
case COMPONENTTRANSFER_TYPE_LINEAR:
ink_cairo_surface_filter(out, out,
ComponentTransferLinear<false>(color, intercept[i], slope[i]));
break;
case COMPONENTTRANSFER_TYPE_GAMMA:
ink_cairo_surface_filter(out, out,
ComponentTransferGamma<false>(color, amplitude[i], exponent[i], offset[i]));
break;
case COMPONENTTRANSFER_TYPE_ERROR:
case COMPONENTTRANSFER_TYPE_IDENTITY:
default:
break;
}
//ink_cairo_surface_blit(out, outtemp);
}
// fast paths for alpha channel
switch (type[3]) {
case COMPONENTTRANSFER_TYPE_TABLE:
ink_cairo_surface_filter(out, out,
ComponentTransferTable<true>(tableValues[3]));
break;
case COMPONENTTRANSFER_TYPE_DISCRETE:
ink_cairo_surface_filter(out, out,
ComponentTransferDiscrete<true>(tableValues[3]));
break;
case COMPONENTTRANSFER_TYPE_LINEAR:
ink_cairo_surface_filter(out, out,
ComponentTransferLinear<true>(intercept[3], slope[3]));
break;
case COMPONENTTRANSFER_TYPE_GAMMA:
ink_cairo_surface_filter(out, out,
ComponentTransferGamma<true>(amplitude[3], exponent[3], offset[3]));
break;
case COMPONENTTRANSFER_TYPE_ERROR:
case COMPONENTTRANSFER_TYPE_IDENTITY:
default:
break;
}
slot.set(_output, out);
cairo_surface_destroy(out);
//cairo_surface_destroy(outtemp);
}
bool FilterComponentTransfer::can_handle_affine(Geom::Matrix const &)
{
return true;
}
void FilterComponentTransfer::area_enlarge(NRRectL &/*area*/, Geom::Matrix const &/*trans*/)
{
}
} /* namespace Filters */
} /* namespace Inkscape */
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :