//#include "trop.h"
#include "tpalette.h"
#include "tropcm.h"
//------------------------------------------------------------------------------
namespace
{
inline double gauss(double x, double y, double x0, double y0, double s)
{
return exp(-((x - x0) * (x - x0) + (y - y0) * (y - y0)) / s) / (s * TConsts::pi);
}
//------------------------------------------------------------------------------
double integ_gauss(double xmin, double ymin, double xmax, double ymax,
double x0, double y0, double s)
{
int i, j, n;
double x1, y1, x2, y2, xstep, ystep, area;
double sum;
n = 50;
sum = 0;
xstep = (xmax - xmin) / n;
ystep = (ymax - ymin) / n;
area = xstep * ystep;
for (i = 0; i < n; i++)
for (j = 0; j < n; j++) {
x1 = xmin + xstep * i;
y1 = ymin + ystep * i;
x2 = x1 + xstep;
y2 = y1 + ystep;
sum += area * (gauss(x1, y1, x0, y0, s) +
gauss(x1, y2, x0, y0, s) +
gauss(x2, y2, x0, y0, s) +
gauss(x2, y1, x0, y0, s)) /
4;
}
return sum;
}
//------------------------------------------------------------------------------
void build_filter(double h[], double x0, double y0, double s)
{
double sum, vv;
int i, j, k;
double x1, y1, x2, y2;
k = 0;
sum = 0.0;
for (i = 0; i < 3; i++)
for (j = 0; j < 3; j++) {
x1 = -1.5 + j;
y1 = -1.5 + i;
x2 = x1 + 1.0;
y2 = y1 + 1.0;
h[k++] = vv = integ_gauss(x1, y1, x2, y2, x0, y0, s);
sum += vv;
}
if (sum > 0.0) {
sum = 1.0 / sum;
for (k = 0; k < 9; k++)
h[k] *= sum;
}
}
} // anonymous namespace
//------------------------------------------------------------------------------
void TRop::fracmove(TRasterP rout, TRasterP rin, double dx, double dy)
{
//Using a bilinear filter is best - consider that only 4 pixels should contribute
//to a fractionarily shifted one, with weights proportional to the intersection areas.
double w[4] = {1, 0, 0, 0};
double sum = 0;
int idx = tfloor(dx);
int idy = tfloor(dy);
double fracX = dx - idx;
double fracY = dy - idy;
int i, j;
for (i = 0; i < 2; ++i)
for (j = 0; j < 2; ++j)
sum += w[j + 2 * i] = fabs(fracX - j) * fabs(fracY - i);
for (i = 0; i < 4; ++i)
w[i] /= sum;
TRop::convolve_i(rout, rin, idx, idy, w, 2);
}
//------------------------------------------------------------------------------
void TRop::fracmove(TRasterP rout, TRasterCM32P rin, const TPaletteP &palette, double dx, double dy)
{
double w[4] = {1, 0, 0, 0};
double sum = 0;
int idx = tfloor(dx);
int idy = tfloor(dy);
double fracX = dx - idx;
double fracY = dy - idy;
int i, j;
for (i = 0; i < 2; ++i)
for (j = 0; j < 2; ++j)
sum += w[j + 2 * i] = fabs(fracX - j) * fabs(fracY - i);
for (i = 0; i < 4; ++i)
w[i] /= sum;
TRop::convolve_i(rout, rin, idx, idy, w, 2);
}