You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
386 lines
9.5 KiB
386 lines
9.5 KiB
//========================================================================
|
|
//
|
|
// SplashScreen.cc
|
|
//
|
|
//========================================================================
|
|
|
|
#include <aconf.h>
|
|
|
|
#ifdef USE_GCC_PRAGMAS
|
|
#pragma implementation
|
|
#endif
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "gmem.h"
|
|
#include "SplashMath.h"
|
|
#include "SplashScreen.h"
|
|
|
|
//------------------------------------------------------------------------
|
|
|
|
static SplashScreenParams defaultParams = {
|
|
splashScreenDispersed, // type
|
|
2, // size
|
|
2, // dotRadius
|
|
1.0, // gamma
|
|
0.0, // blackThreshold
|
|
1.0 // whiteThreshold
|
|
};
|
|
|
|
//------------------------------------------------------------------------
|
|
|
|
struct SplashScreenPoint {
|
|
int x, y;
|
|
int dist;
|
|
};
|
|
|
|
static int cmpDistances(const void *p0, const void *p1) {
|
|
return ((SplashScreenPoint *)p0)->dist - ((SplashScreenPoint *)p1)->dist;
|
|
}
|
|
|
|
//------------------------------------------------------------------------
|
|
// SplashScreen
|
|
//------------------------------------------------------------------------
|
|
|
|
// If <clustered> is true, this generates a 45 degree screen using a
|
|
// circular dot spot function. DPI = resolution / ((size / 2) *
|
|
// sqrt(2)). If <clustered> is false, this generates an optimal
|
|
// threshold matrix using recursive tesselation. Gamma correction
|
|
// (gamma = 1 / 1.33) is also computed here.
|
|
SplashScreen::SplashScreen(SplashScreenParams *params) {
|
|
Guchar u, black, white;
|
|
int i;
|
|
|
|
if (!params) {
|
|
params = &defaultParams;
|
|
}
|
|
|
|
switch (params->type) {
|
|
|
|
case splashScreenDispersed:
|
|
// size must be a power of 2
|
|
for (size = 1; size < params->size; size <<= 1) ;
|
|
mat = (Guchar *)gmallocn(size * size, sizeof(Guchar));
|
|
buildDispersedMatrix(size/2, size/2, 1, size/2, 1);
|
|
break;
|
|
|
|
case splashScreenClustered:
|
|
// size must be even
|
|
size = (params->size >> 1) << 1;
|
|
if (size < 2) {
|
|
size = 2;
|
|
}
|
|
mat = (Guchar *)gmallocn(size * size, sizeof(Guchar));
|
|
buildClusteredMatrix();
|
|
break;
|
|
|
|
case splashScreenStochasticClustered:
|
|
// size must be at least 2*r
|
|
if (params->size < 2 * params->dotRadius) {
|
|
size = 2 * params->dotRadius;
|
|
} else {
|
|
size = params->size;
|
|
}
|
|
mat = (Guchar *)gmallocn(size * size, sizeof(Guchar));
|
|
buildSCDMatrix(params->dotRadius);
|
|
break;
|
|
}
|
|
|
|
// do gamma correction and compute minVal/maxVal
|
|
minVal = 255;
|
|
maxVal = 0;
|
|
black = splashRound((SplashCoord)255.0 * params->blackThreshold);
|
|
if (black < 1) {
|
|
black = 1;
|
|
}
|
|
int whiteAux = splashRound((SplashCoord)255.0 * params->whiteThreshold);
|
|
if (whiteAux > 255) {
|
|
white = 255;
|
|
} else {
|
|
white = whiteAux;
|
|
}
|
|
for (i = 0; i < size * size; ++i) {
|
|
u = splashRound((SplashCoord)255.0 *
|
|
splashPow((SplashCoord)mat[i] / 255.0, params->gamma));
|
|
if (u < black) {
|
|
u = black;
|
|
} else if (u >= white) {
|
|
u = white;
|
|
}
|
|
mat[i] = u;
|
|
if (u < minVal) {
|
|
minVal = u;
|
|
} else if (u > maxVal) {
|
|
maxVal = u;
|
|
}
|
|
}
|
|
}
|
|
|
|
void SplashScreen::buildDispersedMatrix(int i, int j, int val,
|
|
int delta, int offset) {
|
|
if (delta == 0) {
|
|
// map values in [1, size^2] --> [1, 255]
|
|
mat[i * size + j] = 1 + (254 * (val - 1)) / (size * size - 1);
|
|
} else {
|
|
buildDispersedMatrix(i, j,
|
|
val, delta / 2, 4*offset);
|
|
buildDispersedMatrix((i + delta) % size, (j + delta) % size,
|
|
val + offset, delta / 2, 4*offset);
|
|
buildDispersedMatrix((i + delta) % size, j,
|
|
val + 2*offset, delta / 2, 4*offset);
|
|
buildDispersedMatrix((i + 2*delta) % size, (j + delta) % size,
|
|
val + 3*offset, delta / 2, 4*offset);
|
|
}
|
|
}
|
|
|
|
void SplashScreen::buildClusteredMatrix() {
|
|
SplashCoord *dist;
|
|
SplashCoord u, v, d;
|
|
Guchar val;
|
|
int size2, x, y, x1, y1, i;
|
|
|
|
size2 = size >> 1;
|
|
|
|
// initialize the threshold matrix
|
|
for (y = 0; y < size; ++y) {
|
|
for (x = 0; x < size; ++x) {
|
|
mat[y * size + x] = 0;
|
|
}
|
|
}
|
|
|
|
// build the distance matrix
|
|
dist = (SplashCoord *)gmallocn(size * size2, sizeof(SplashCoord));
|
|
for (y = 0; y < size2; ++y) {
|
|
for (x = 0; x < size2; ++x) {
|
|
if (x + y < size2 - 1) {
|
|
u = (SplashCoord)x + 0.5 - 0;
|
|
v = (SplashCoord)y + 0.5 - 0;
|
|
} else {
|
|
u = (SplashCoord)x + 0.5 - (SplashCoord)size2;
|
|
v = (SplashCoord)y + 0.5 - (SplashCoord)size2;
|
|
}
|
|
dist[y * size2 + x] = u*u + v*v;
|
|
}
|
|
}
|
|
for (y = 0; y < size2; ++y) {
|
|
for (x = 0; x < size2; ++x) {
|
|
if (x < y) {
|
|
u = (SplashCoord)x + 0.5 - 0;
|
|
v = (SplashCoord)y + 0.5 - (SplashCoord)size2;
|
|
} else {
|
|
u = (SplashCoord)x + 0.5 - (SplashCoord)size2;
|
|
v = (SplashCoord)y + 0.5 - 0;
|
|
}
|
|
dist[(size2 + y) * size2 + x] = u*u + v*v;
|
|
}
|
|
}
|
|
|
|
// build the threshold matrix
|
|
minVal = 1;
|
|
maxVal = 0;
|
|
x1 = y1 = 0; // make gcc happy
|
|
for (i = 0; i < size * size2; ++i) {
|
|
d = -1;
|
|
for (y = 0; y < size; ++y) {
|
|
for (x = 0; x < size2; ++x) {
|
|
if (mat[y * size + x] == 0 &&
|
|
dist[y * size2 + x] > d) {
|
|
x1 = x;
|
|
y1 = y;
|
|
d = dist[y1 * size2 + x1];
|
|
}
|
|
}
|
|
}
|
|
// map values in [0, 2*size*size2-1] --> [1, 255]
|
|
val = 1 + (254 * (2*i)) / (2*size*size2 - 1);
|
|
mat[y1 * size + x1] = val;
|
|
val = 1 + (254 * (2*i+1)) / (2*size*size2 - 1);
|
|
if (y1 < size2) {
|
|
mat[(y1 + size2) * size + x1 + size2] = val;
|
|
} else {
|
|
mat[(y1 - size2) * size + x1 + size2] = val;
|
|
}
|
|
}
|
|
|
|
gfree(dist);
|
|
}
|
|
|
|
// Compute the distance between two points on a toroid.
|
|
int SplashScreen::distance(int x0, int y0, int x1, int y1) {
|
|
int dx0, dx1, dx, dy0, dy1, dy;
|
|
|
|
dx0 = abs(x0 - x1);
|
|
dx1 = size - dx0;
|
|
dx = dx0 < dx1 ? dx0 : dx1;
|
|
dy0 = abs(y0 - y1);
|
|
dy1 = size - dy0;
|
|
dy = dy0 < dy1 ? dy0 : dy1;
|
|
return dx * dx + dy * dy;
|
|
}
|
|
|
|
// Algorithm taken from:
|
|
// Victor Ostromoukhov and Roger D. Hersch, "Stochastic Clustered-Dot
|
|
// Dithering" in Color Imaging: Device-Independent Color, Color
|
|
// Hardcopy, and Graphic Arts IV, SPIE Vol. 3648, pp. 496-505, 1999.
|
|
void SplashScreen::buildSCDMatrix(int r) {
|
|
SplashScreenPoint *dots, *pts;
|
|
int dotsLen, dotsSize;
|
|
char *tmpl;
|
|
char *grid;
|
|
int *region, *dist;
|
|
int x, y, xx, yy, x0, x1, y0, y1, i, j, d, iMin, dMin, n;
|
|
|
|
//~ this should probably happen somewhere else
|
|
srand(123);
|
|
|
|
// generate the random space-filling curve
|
|
pts = (SplashScreenPoint *)gmallocn(size * size, sizeof(SplashScreenPoint));
|
|
i = 0;
|
|
for (y = 0; y < size; ++y) {
|
|
for (x = 0; x < size; ++x) {
|
|
pts[i].x = x;
|
|
pts[i].y = y;
|
|
++i;
|
|
}
|
|
}
|
|
for (i = 0; i < size * size; ++i) {
|
|
j = i + (int)((double)(size * size - i) *
|
|
(double)rand() / ((double)RAND_MAX + 1.0));
|
|
x = pts[i].x;
|
|
y = pts[i].y;
|
|
pts[i].x = pts[j].x;
|
|
pts[i].y = pts[j].y;
|
|
pts[j].x = x;
|
|
pts[j].y = y;
|
|
}
|
|
|
|
// construct the circle template
|
|
tmpl = (char *)gmallocn((r+1)*(r+1), sizeof(char));
|
|
for (y = 0; y <= r; ++y) {
|
|
for (x = 0; x <= r; ++x) {
|
|
tmpl[y*(r+1) + x] = (x * y <= r * r) ? 1 : 0;
|
|
}
|
|
}
|
|
|
|
// mark all grid cells as free
|
|
grid = (char *)gmallocn(size * size, sizeof(char));
|
|
for (y = 0; y < size; ++y) {
|
|
for (x = 0; x < size; ++x) {
|
|
grid[y*size + x] = 0;
|
|
}
|
|
}
|
|
|
|
// walk the space-filling curve, adding dots
|
|
dotsLen = 0;
|
|
dotsSize = 32;
|
|
dots = (SplashScreenPoint *)gmallocn(dotsSize, sizeof(SplashScreenPoint));
|
|
for (i = 0; i < size * size; ++i) {
|
|
x = pts[i].x;
|
|
y = pts[i].y;
|
|
if (!grid[y*size + x]) {
|
|
if (dotsLen == dotsSize) {
|
|
dotsSize *= 2;
|
|
dots = (SplashScreenPoint *)greallocn(dots, dotsSize,
|
|
sizeof(SplashScreenPoint));
|
|
}
|
|
dots[dotsLen++] = pts[i];
|
|
for (yy = 0; yy <= r; ++yy) {
|
|
y0 = (y + yy) % size;
|
|
y1 = (y - yy + size) % size;
|
|
for (xx = 0; xx <= r; ++xx) {
|
|
if (tmpl[yy*(r+1) + xx]) {
|
|
x0 = (x + xx) % size;
|
|
x1 = (x - xx + size) % size;
|
|
grid[y0*size + x0] = 1;
|
|
grid[y0*size + x1] = 1;
|
|
grid[y1*size + x0] = 1;
|
|
grid[y1*size + x1] = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
gfree(tmpl);
|
|
gfree(grid);
|
|
|
|
// assign each cell to a dot, compute distance to center of dot
|
|
region = (int *)gmallocn(size * size, sizeof(int));
|
|
dist = (int *)gmallocn(size * size, sizeof(int));
|
|
for (y = 0; y < size; ++y) {
|
|
for (x = 0; x < size; ++x) {
|
|
iMin = 0;
|
|
dMin = distance(dots[0].x, dots[0].y, x, y);
|
|
for (i = 1; i < dotsLen; ++i) {
|
|
d = distance(dots[i].x, dots[i].y, x, y);
|
|
if (d < dMin) {
|
|
iMin = i;
|
|
dMin = d;
|
|
}
|
|
}
|
|
region[y*size + x] = iMin;
|
|
dist[y*size + x] = dMin;
|
|
}
|
|
}
|
|
|
|
// compute threshold values
|
|
for (i = 0; i < dotsLen; ++i) {
|
|
n = 0;
|
|
for (y = 0; y < size; ++y) {
|
|
for (x = 0; x < size; ++x) {
|
|
if (region[y*size + x] == i) {
|
|
pts[n].x = x;
|
|
pts[n].y = y;
|
|
pts[n].dist = distance(dots[i].x, dots[i].y, x, y);
|
|
++n;
|
|
}
|
|
}
|
|
}
|
|
qsort(pts, n, sizeof(SplashScreenPoint), &cmpDistances);
|
|
for (j = 0; j < n; ++j) {
|
|
// map values in [0 .. n-1] --> [255 .. 1]
|
|
mat[pts[j].y * size + pts[j].x] = 255 - (254 * j) / (n - 1);
|
|
}
|
|
}
|
|
|
|
gfree(pts);
|
|
gfree(region);
|
|
gfree(dist);
|
|
|
|
gfree(dots);
|
|
}
|
|
|
|
SplashScreen::SplashScreen(SplashScreen *screen) {
|
|
size = screen->size;
|
|
mat = (Guchar *)gmallocn(size * size, sizeof(Guchar));
|
|
memcpy(mat, screen->mat, size * size * sizeof(Guchar));
|
|
minVal = screen->minVal;
|
|
maxVal = screen->maxVal;
|
|
}
|
|
|
|
SplashScreen::~SplashScreen() {
|
|
gfree(mat);
|
|
}
|
|
|
|
int SplashScreen::test(int x, int y, Guchar value) {
|
|
int xx, yy;
|
|
|
|
if (value < minVal) {
|
|
return 0;
|
|
}
|
|
if (value >= maxVal) {
|
|
return 1;
|
|
}
|
|
if ((xx = x % size) < 0) {
|
|
xx = -xx;
|
|
}
|
|
if ((yy = y % size) < 0) {
|
|
yy = -yy;
|
|
}
|
|
return value < mat[yy * size + xx] ? 0 : 1;
|
|
}
|
|
|
|
GBool SplashScreen::isStatic(Guchar value) {
|
|
return value < minVal || value >= maxVal;
|
|
}
|