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filters.im
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filters.im
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#include "imager.h"
#include "imageri.h"
#include <stdlib.h>
#include <math.h>
/*
=head1 NAME
filters.im - implements filters that operate on images
=head1 SYNOPSIS
i_contrast(im, 0.8);
i_hardinvert(im);
i_hardinvertall(im);
i_unsharp_mask(im, 2.0, 1.0);
... and more
=head1 DESCRIPTION
filters.c implements basic filters for Imager. These filters
should be accessible from the filter interface as defined in
the pod for Imager.
=head1 FUNCTION REFERENCE
Some of these functions are internal.
=over
=cut
*/
/*
=item saturate(in)
Clamps the input value between 0 and 255. (internal)
in - input integer
=cut
*/
static
unsigned char
saturate(int in) {
if (in>255) { return 255; }
else if (in>0) return in;
return 0;
}
/*
=item i_contrast(im, intensity)
Scales the pixel values by the amount specified.
im - image object
intensity - scalefactor
=cut
*/
void
i_contrast(i_img *im, float intensity) {
int x, y;
unsigned char ch;
unsigned int new_color;
i_color rcolor;
mm_log((1,"i_contrast(im %p, intensity %f)\n", im, intensity));
if(intensity < 0) return;
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
i_gpix(im, x, y, &rcolor);
for(ch = 0; ch < im->channels; ch++) {
new_color = (unsigned int) rcolor.channel[ch];
new_color *= intensity;
if(new_color > 255) {
new_color = 255;
}
rcolor.channel[ch] = (unsigned char) new_color;
}
i_ppix(im, x, y, &rcolor);
}
}
static int
s_hardinvert_low(i_img *im, int all) {
int x, y;
int ch;
int invert_channels = all ? im->channels : i_img_color_channels(im);
mm_log((1,"i_hardinvert(im %p)\n", im));
#code im->bits <= 8
IM_COLOR *row, *entry;
/* always rooms to allocate a single line of i_color */
row = mymalloc(sizeof(IM_COLOR) * im->xsize); /* checked 17feb2005 tonyc */
for(y = 0; y < im->ysize; y++) {
IM_GLIN(im, 0, im->xsize, y, row);
entry = row;
for(x = 0; x < im->xsize; x++) {
for(ch = 0; ch < invert_channels; ch++) {
entry->channel[ch] = IM_SAMPLE_MAX - entry->channel[ch];
}
++entry;
}
IM_PLIN(im, 0, im->xsize, y, row);
}
myfree(row);
#/code
return 1;
}
/*
=item i_hardinvert(im)
Inverts the color channels of the input image.
im - image object
=cut
*/
void
i_hardinvert(i_img *im) {
s_hardinvert_low(im, 0);
}
/*
=item i_hardinvertall(im)
Inverts all channels of the input image.
im - image object
=cut
*/
void
i_hardinvertall(i_img *im) {
s_hardinvert_low(im, 1);
}
/*
=item i_noise(im, amount, type)
Inverts the pixel values by the amount specified.
im - image object
amount - deviation in pixel values
type - noise individual for each channel if true
=cut
*/
#ifdef WIN32
/* random() is non-ASCII, even if it is better than rand() */
#define random() rand()
#endif
void
i_noise(i_img *im, float amount, unsigned char type) {
int x, y;
unsigned char ch;
int new_color;
float damount = amount * 2;
i_color rcolor;
int color_inc = 0;
mm_log((1,"i_noise(im %p, intensity %.2f\n", im, amount));
if(amount < 0) return;
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
i_gpix(im, x, y, &rcolor);
if(type == 0) {
color_inc = (amount - (damount * ((float)random() / RAND_MAX)));
}
for(ch = 0; ch < im->channels; ch++) {
new_color = (int) rcolor.channel[ch];
if(type != 0) {
new_color += (amount - (damount * ((float)random() / RAND_MAX)));
} else {
new_color += color_inc;
}
if(new_color < 0) {
new_color = 0;
}
if(new_color > 255) {
new_color = 255;
}
rcolor.channel[ch] = (unsigned char) new_color;
}
i_ppix(im, x, y, &rcolor);
}
}
/*
=item i_noise(im, amount, type)
Inverts the pixel values by the amount specified.
im - image object
amount - deviation in pixel values
type - noise individual for each channel if true
=cut
*/
/*
=item i_applyimage(im, add_im, mode)
Apply's an image to another image
im - target image
add_im - image that is applied to target
mode - what method is used in applying:
0 Normal
1 Multiply
2 Screen
3 Overlay
4 Soft Light
5 Hard Light
6 Color dodge
7 Color Burn
8 Darker
9 Lighter
10 Add
11 Subtract
12 Difference
13 Exclusion
=cut
*/
void i_applyimage(i_img *im, i_img *add_im, unsigned char mode) {
int x, y;
int mx, my;
mm_log((1, "i_applyimage(im %p, add_im %p, mode %d", im, add_im, mode));
mx = (add_im->xsize <= im->xsize) ? add_im->xsize : add_im->xsize;
my = (add_im->ysize <= im->ysize) ? add_im->ysize : add_im->ysize;
for(x = 0; x < mx; x++) {
for(y = 0; y < my; y++) {
}
}
}
/*
=item i_bumpmap(im, bump, channel, light_x, light_y, st)
Makes a bumpmap on image im using the bump image as the elevation map.
im - target image
bump - image that contains the elevation info
channel - to take the elevation information from
light_x - x coordinate of light source
light_y - y coordinate of light source
st - length of shadow
=cut
*/
void
i_bumpmap(i_img *im, i_img *bump, int channel, int light_x, int light_y, int st) {
int x, y, ch;
int mx, my;
i_color x1_color, y1_color, x2_color, y2_color, dst_color;
double nX, nY;
double tX, tY, tZ;
double aX, aY, aL;
double fZ;
unsigned char px1, px2, py1, py2;
i_img new_im;
mm_log((1, "i_bumpmap(im %p, add_im %p, channel %d, light_x %d, light_y %d, st %d)\n",
im, bump, channel, light_x, light_y, st));
if(channel >= bump->channels) {
mm_log((1, "i_bumpmap: channel = %d while bump image only has %d channels\n", channel, bump->channels));
return;
}
mx = (bump->xsize <= im->xsize) ? bump->xsize : im->xsize;
my = (bump->ysize <= im->ysize) ? bump->ysize : im->ysize;
i_img_empty_ch(&new_im, im->xsize, im->ysize, im->channels);
aX = (light_x > (mx >> 1)) ? light_x : mx - light_x;
aY = (light_y > (my >> 1)) ? light_y : my - light_y;
aL = sqrt((aX * aX) + (aY * aY));
for(y = 1; y < my - 1; y++) {
for(x = 1; x < mx - 1; x++) {
i_gpix(bump, x + st, y, &x1_color);
i_gpix(bump, x, y + st, &y1_color);
i_gpix(bump, x - st, y, &x2_color);
i_gpix(bump, x, y - st, &y2_color);
i_gpix(im, x, y, &dst_color);
px1 = x1_color.channel[channel];
py1 = y1_color.channel[channel];
px2 = x2_color.channel[channel];
py2 = y2_color.channel[channel];
nX = px1 - px2;
nY = py1 - py2;
nX += 128;
nY += 128;
fZ = (sqrt((nX * nX) + (nY * nY)) / aL);
tX = abs(x - light_x) / aL;
tY = abs(y - light_y) / aL;
tZ = 1 - (sqrt((tX * tX) + (tY * tY)) * fZ);
if(tZ < 0) tZ = 0;
if(tZ > 2) tZ = 2;
for(ch = 0; ch < im->channels; ch++)
dst_color.channel[ch] = (unsigned char) (float)(dst_color.channel[ch] * tZ);
i_ppix(&new_im, x, y, &dst_color);
}
}
i_copyto(im, &new_im, 0, 0, (int)im->xsize, (int)im->ysize, 0, 0);
i_img_exorcise(&new_im);
}
typedef struct {
float x,y,z;
} fvec;
static
float
dotp(fvec *a, fvec *b) {
return a->x*b->x+a->y*b->y+a->z*b->z;
}
static
void
normalize(fvec *a) {
double d = sqrt(dotp(a,a));
a->x /= d;
a->y /= d;
a->z /= d;
}
/*
positive directions:
x - right,
y - down
z - out of the plane
I = Ia + Ip*( cd*Scol(N.L) + cs*(R.V)^n )
Here, the variables are:
* Ia - ambient colour
* Ip - intensity of the point light source
* cd - diffuse coefficient
* Scol - surface colour
* cs - specular coefficient
* n - objects shinyness
* N - normal vector
* L - lighting vector
* R - reflection vector
* V - vision vector
static void fvec_dump(fvec *x) {
printf("(%.2f %.2f %.2f)", x->x, x->y, x->z);
}
*/
/* XXX: Should these return a code for success? */
/*
=item i_bumpmap_complex(im, bump, channel, tx, ty, Lx, Ly, Lz, Ip, cd, cs, n, Ia, Il, Is)
Makes a bumpmap on image im using the bump image as the elevation map.
im - target image
bump - image that contains the elevation info
channel - to take the elevation information from
tx - shift in x direction of where to start applying bumpmap
ty - shift in y direction of where to start applying bumpmap
Lx - x position/direction of light
Ly - y position/direction of light
Lz - z position/direction of light
Ip - light intensity
cd - diffuse coefficient
cs - specular coefficient
n - surface shinyness
Ia - ambient colour
Il - light colour
Is - specular colour
if z<0 then the L is taken to be the direction the light is shining in. Otherwise
the L is taken to be the position of the Light, Relative to the image.
=cut
*/
void
i_bumpmap_complex(i_img *im,
i_img *bump,
int channel,
int tx,
int ty,
float Lx,
float Ly,
float Lz,
float cd,
float cs,
float n,
i_color *Ia,
i_color *Il,
i_color *Is) {
i_img new_im;
int inflight;
int x, y, ch;
int mx, Mx, my, My;
float cdc[MAXCHANNELS];
float csc[MAXCHANNELS];
i_color x1_color, y1_color, x2_color, y2_color;
i_color Scol; /* Surface colour */
fvec L; /* Light vector */
fvec N; /* surface normal */
fvec R; /* Reflection vector */
fvec V; /* Vision vector */
mm_log((1, "i_bumpmap_complex(im %p, bump %p, channel %d, tx %d, ty %d, Lx %.2f, Ly %.2f, Lz %.2f, cd %.2f, cs %.2f, n %.2f, Ia %p, Il %p, Is %p)\n",
im, bump, channel, tx, ty, Lx, Ly, Lz, cd, cs, n, Ia, Il, Is));
if (channel >= bump->channels) {
mm_log((1, "i_bumpmap_complex: channel = %d while bump image only has %d channels\n", channel, bump->channels));
return;
}
for(ch=0; ch<im->channels; ch++) {
cdc[ch] = (float)Il->channel[ch]*cd/255.f;
csc[ch] = (float)Is->channel[ch]*cs/255.f;
}
mx = 1;
my = 1;
Mx = bump->xsize-1;
My = bump->ysize-1;
V.x = 0;
V.y = 0;
V.z = 1;
if (Lz < 0) { /* Light specifies a direction vector, reverse it to get the vector from surface to light */
L.x = -Lx;
L.y = -Ly;
L.z = -Lz;
normalize(&L);
} else { /* Light is the position of the light source */
inflight = 0;
L.x = -0.2;
L.y = -0.4;
L.z = 1;
normalize(&L);
}
i_img_empty_ch(&new_im, im->xsize, im->ysize, im->channels);
for(y = 0; y < im->ysize; y++) {
for(x = 0; x < im->xsize; x++) {
double dp1, dp2;
double dx = 0, dy = 0;
/* Calculate surface normal */
if (mx<x && x<Mx && my<y && y<My) {
i_gpix(bump, x + 1, y, &x1_color);
i_gpix(bump, x - 1, y, &x2_color);
i_gpix(bump, x, y + 1, &y1_color);
i_gpix(bump, x, y - 1, &y2_color);
dx = x2_color.channel[channel] - x1_color.channel[channel];
dy = y2_color.channel[channel] - y1_color.channel[channel];
} else {
dx = 0;
dy = 0;
}
N.x = -dx * 0.015;
N.y = -dy * 0.015;
N.z = 1;
normalize(&N);
/* Calculate Light vector if needed */
if (Lz>=0) {
L.x = Lx - x;
L.y = Ly - y;
L.z = Lz;
normalize(&L);
}
dp1 = dotp(&L,&N);
R.x = -L.x + 2*dp1*N.x;
R.y = -L.y + 2*dp1*N.y;
R.z = -L.z + 2*dp1*N.z;
dp2 = dotp(&R,&V);
dp1 = dp1<0 ?0 : dp1;
dp2 = pow(dp2<0 ?0 : dp2,n);
i_gpix(im, x, y, &Scol);
for(ch = 0; ch < im->channels; ch++)
Scol.channel[ch] =
saturate( Ia->channel[ch] + cdc[ch]*Scol.channel[ch]*dp1 + csc[ch]*dp2 );
i_ppix(&new_im, x, y, &Scol);
}
}
i_copyto(im, &new_im, 0, 0, (int)im->xsize, (int)im->ysize, 0, 0);
i_img_exorcise(&new_im);
}
/*
=item i_postlevels(im, levels)
Quantizes Images to fewer levels.
im - target image
levels - number of levels
=cut
*/
void
i_postlevels(i_img *im, int levels) {
int x, y, ch;
float pv;
int rv;
float av;
i_color rcolor;
rv = (int) ((float)(256 / levels));
av = (float)levels;
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
i_gpix(im, x, y, &rcolor);
for(ch = 0; ch < im->channels; ch++) {
pv = (((float)rcolor.channel[ch] / 255)) * av;
pv = (int) ((int)pv * rv);
if(pv < 0) pv = 0;
else if(pv > 255) pv = 255;
rcolor.channel[ch] = (unsigned char) pv;
}
i_ppix(im, x, y, &rcolor);
}
}
/*
=item i_mosaic(im, size)
Makes an image looks like a mosaic with tilesize of size
im - target image
size - size of tiles
=cut
*/
void
i_mosaic(i_img *im, int size) {
int x, y, ch;
int lx, ly, z;
long sqrsize;
i_color rcolor;
long col[256];
sqrsize = size * size;
for(y = 0; y < im->ysize; y += size) for(x = 0; x < im->xsize; x += size) {
for(z = 0; z < 256; z++) col[z] = 0;
for(lx = 0; lx < size; lx++) {
for(ly = 0; ly < size; ly++) {
i_gpix(im, (x + lx), (y + ly), &rcolor);
for(ch = 0; ch < im->channels; ch++) {
col[ch] += rcolor.channel[ch];
}
}
}
for(ch = 0; ch < im->channels; ch++)
rcolor.channel[ch] = (int) ((float)col[ch] / sqrsize);
for(lx = 0; lx < size; lx++)
for(ly = 0; ly < size; ly++)
i_ppix(im, (x + lx), (y + ly), &rcolor);
}
}
/*
=item i_watermark(im, wmark, tx, ty, pixdiff)
Applies a watermark to the target image
im - target image
wmark - watermark image
tx - x coordinate of where watermark should be applied
ty - y coordinate of where watermark should be applied
pixdiff - the magnitude of the watermark, controls how visible it is
=cut
*/
void
i_watermark(i_img *im, i_img *wmark, int tx, int ty, int pixdiff) {
int vx, vy, ch;
i_color val, wval;
int mx = wmark->xsize;
int my = wmark->ysize;
for(vx=0;vx<mx;vx++) for(vy=0;vy<my;vy++) {
i_gpix(im, tx+vx, ty+vy,&val );
i_gpix(wmark, vx, vy, &wval);
for(ch=0;ch<im->channels;ch++)
val.channel[ch] = saturate( val.channel[ch] + (pixdiff* (wval.channel[0]-128) )/128 );
i_ppix(im,tx+vx,ty+vy,&val);
}
}
/*
=item i_autolevels(im, lsat, usat, skew)
Scales and translates each color such that it fills the range completely.
Skew is not implemented yet - purpose is to control the color skew that can
occur when changing the contrast.
im - target image
lsat - fraction of pixels that will be truncated at the lower end of the spectrum
usat - fraction of pixels that will be truncated at the higher end of the spectrum
skew - not used yet
=cut
*/
void
i_autolevels(i_img *im, float lsat, float usat, float skew) {
i_color val;
int i, x, y, rhist[256], ghist[256], bhist[256];
int rsum, rmin, rmax;
int gsum, gmin, gmax;
int bsum, bmin, bmax;
int rcl, rcu, gcl, gcu, bcl, bcu;
mm_log((1,"i_autolevels(im %p, lsat %f,usat %f,skew %f)\n", im, lsat,usat,skew));
rsum=gsum=bsum=0;
for(i=0;i<256;i++) rhist[i]=ghist[i]=bhist[i] = 0;
/* create histogram for each channel */
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
i_gpix(im, x, y, &val);
rhist[val.channel[0]]++;
ghist[val.channel[1]]++;
bhist[val.channel[2]]++;
}
for(i=0;i<256;i++) {
rsum+=rhist[i];
gsum+=ghist[i];
bsum+=bhist[i];
}
rmin = gmin = bmin = 0;
rmax = gmax = bmax = 255;
rcu = rcl = gcu = gcl = bcu = bcl = 0;
for(i=0; i<256; i++) {
rcl += rhist[i]; if ( (rcl<rsum*lsat) ) rmin=i;
rcu += rhist[255-i]; if ( (rcu<rsum*usat) ) rmax=255-i;
gcl += ghist[i]; if ( (gcl<gsum*lsat) ) gmin=i;
gcu += ghist[255-i]; if ( (gcu<gsum*usat) ) gmax=255-i;
bcl += bhist[i]; if ( (bcl<bsum*lsat) ) bmin=i;
bcu += bhist[255-i]; if ( (bcu<bsum*usat) ) bmax=255-i;
}
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
i_gpix(im, x, y, &val);
val.channel[0]=saturate((val.channel[0]-rmin)*255/(rmax-rmin));
val.channel[1]=saturate((val.channel[1]-gmin)*255/(gmax-gmin));
val.channel[2]=saturate((val.channel[2]-bmin)*255/(bmax-bmin));
i_ppix(im, x, y, &val);
}
}
/*
=item Noise(x,y)
Pseudo noise utility function used to generate perlin noise. (internal)
x - x coordinate
y - y coordinate
=cut
*/
static
float
Noise(int x, int y) {
int n = x + y * 57;
n = (n<<13) ^ n;
return ( 1.0 - ( (n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0);
}
/*
=item SmoothedNoise1(x,y)
Pseudo noise utility function used to generate perlin noise. (internal)
x - x coordinate
y - y coordinate
=cut
*/
static
float
SmoothedNoise1(float x, float y) {
float corners = ( Noise(x-1, y-1)+Noise(x+1, y-1)+Noise(x-1, y+1)+Noise(x+1, y+1) ) / 16;
float sides = ( Noise(x-1, y) +Noise(x+1, y) +Noise(x, y-1) +Noise(x, y+1) ) / 8;
float center = Noise(x, y) / 4;
return corners + sides + center;
}
/*
=item G_Interpolate(a, b, x)
Utility function used to generate perlin noise. (internal)
=cut
*/
static
float C_Interpolate(float a, float b, float x) {
/* float ft = x * 3.1415927; */
float ft = x * PI;
float f = (1 - cos(ft)) * .5;
return a*(1-f) + b*f;
}
/*
=item InterpolatedNoise(x, y)
Utility function used to generate perlin noise. (internal)
=cut
*/
static
float
InterpolatedNoise(float x, float y) {
int integer_X = x;
float fractional_X = x - integer_X;
int integer_Y = y;
float fractional_Y = y - integer_Y;
float v1 = SmoothedNoise1(integer_X, integer_Y);
float v2 = SmoothedNoise1(integer_X + 1, integer_Y);
float v3 = SmoothedNoise1(integer_X, integer_Y + 1);
float v4 = SmoothedNoise1(integer_X + 1, integer_Y + 1);
float i1 = C_Interpolate(v1 , v2 , fractional_X);
float i2 = C_Interpolate(v3 , v4 , fractional_X);
return C_Interpolate(i1 , i2 , fractional_Y);
}
/*
=item PerlinNoise_2D(x, y)
Utility function used to generate perlin noise. (internal)
=cut
*/
static
float
PerlinNoise_2D(float x, float y) {
int i,frequency;
float amplitude;
float total = 0;
int Number_Of_Octaves=6;
int n = Number_Of_Octaves - 1;
for(i=0;i<n;i++) {
frequency = 2*i;
amplitude = PI;
total = total + InterpolatedNoise(x * frequency, y * frequency) * amplitude;
}
return total;
}
/*
=item i_radnoise(im, xo, yo, rscale, ascale)
Perlin-like radial noise.
im - target image
xo - x coordinate of center
yo - y coordinate of center
rscale - radial scale
ascale - angular scale
=cut
*/
void
i_radnoise(i_img *im, int xo, int yo, float rscale, float ascale) {
int x, y, ch;
i_color val;
unsigned char v;
float xc, yc, r;
double a;
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
xc = (float)x-xo+0.5;
yc = (float)y-yo+0.5;
r = rscale*sqrt(xc*xc+yc*yc)+1.2;
a = (PI+atan2(yc,xc))*ascale;
v = saturate(128+100*(PerlinNoise_2D(a,r)));
/* v=saturate(120+12*PerlinNoise_2D(xo+(float)x/scale,yo+(float)y/scale)); Good soft marble */
for(ch=0; ch<im->channels; ch++) val.channel[ch]=v;
i_ppix(im, x, y, &val);
}
}
/*
=item i_turbnoise(im, xo, yo, scale)
Perlin-like 2d noise noise.
im - target image
xo - x coordinate translation
yo - y coordinate translation
scale - scale of noise
=cut
*/
void
i_turbnoise(i_img *im, float xo, float yo, float scale) {
int x,y,ch;
unsigned char v;
i_color val;
for(y = 0; y < im->ysize; y++) for(x = 0; x < im->xsize; x++) {
/* v=saturate(125*(1.0+PerlinNoise_2D(xo+(float)x/scale,yo+(float)y/scale))); */
v = saturate(120*(1.0+sin(xo+(float)x/scale+PerlinNoise_2D(xo+(float)x/scale,yo+(float)y/scale))));
for(ch=0; ch<im->channels; ch++) val.channel[ch] = v;
i_ppix(im, x, y, &val);
}
}
/*
=item i_gradgen(im, num, xo, yo, ival, dmeasure)
Gradient generating function.
im - target image
num - number of points given
xo - array of x coordinates
yo - array of y coordinates
ival - array of i_color objects
dmeasure - distance measure to be used.
0 = Euclidean
1 = Euclidean squared
2 = Manhattan distance
=cut
*/
void
i_gradgen(i_img *im, int num, int *xo, int *yo, i_color *ival, int dmeasure) {
i_color val;
int p, x, y, ch;
int channels = im->channels;
int xsize = im->xsize;
int ysize = im->ysize;
int bytes;
float *fdist;
mm_log((1,"i_gradgen(im %p, num %d, xo %p, yo %p, ival %p, dmeasure %d)\n", im, num, xo, yo, ival, dmeasure));
for(p = 0; p<num; p++) {
mm_log((1,"i_gradgen: (%d, %d)\n", xo[p], yo[p]));
ICL_info(&ival[p]);
}
/* on the systems I have sizeof(float) == sizeof(int) and thus
this would be same size as the arrays xo and yo point at, but this
may not be true for other systems
since the arrays here are caller controlled, I assume that on
overflow is a programming error rather than an end-user error, so
calling exit() is justified.
*/
bytes = sizeof(float) * num;
if (bytes / num != sizeof(float)) {
fprintf(stderr, "integer overflow calculating memory allocation");
exit(1);
}
fdist = mymalloc( bytes ); /* checked 14jul05 tonyc */
for(y = 0; y<ysize; y++) for(x = 0; x<xsize; x++) {
float cs = 0;
float csd = 0;
for(p = 0; p<num; p++) {
int xd = x-xo[p];
int yd = y-yo[p];
switch (dmeasure) {