#define IMAGER_NO_CONTEXT
#include "imager.h"
#include "draw.h"
#include "log.h"
#include "imageri.h"
#include "imrender.h"
#include <limits.h>
#define NDEBUG
#include <assert.h>
int
i_ppix_norm(i_img *im, i_img_dim x, i_img_dim y, i_color const *col) {
i_color src;
i_color work;
int dest_alpha;
int remains;
if (!col->channel[3])
return 0;
switch (im->channels) {
case 1:
work = *col;
i_adapt_colors(2, 4, &work, 1);
i_gpix(im, x, y, &src);
remains = 255 - work.channel[1];
src.channel[0] = (src.channel[0] * remains
+ work.channel[0] * work.channel[1]) / 255;
return i_ppix(im, x, y, &src);
case 2:
work = *col;
i_adapt_colors(2, 4, &work, 1);
i_gpix(im, x, y, &src);
remains = 255 - work.channel[1];
dest_alpha = work.channel[1] + remains * src.channel[1] / 255;
if (work.channel[1] == 255) {
return i_ppix(im, x, y, &work);
}
else {
src.channel[0] = (work.channel[1] * work.channel[0]
+ remains * src.channel[0] * src.channel[1] / 255) / dest_alpha;
src.channel[1] = dest_alpha;
return i_ppix(im, x, y, &src);
}
case 3:
work = *col;
i_gpix(im, x, y, &src);
remains = 255 - work.channel[3];
src.channel[0] = (src.channel[0] * remains
+ work.channel[0] * work.channel[3]) / 255;
src.channel[1] = (src.channel[1] * remains
+ work.channel[1] * work.channel[3]) / 255;
src.channel[2] = (src.channel[2] * remains
+ work.channel[2] * work.channel[3]) / 255;
return i_ppix(im, x, y, &src);
case 4:
work = *col;
i_gpix(im, x, y, &src);
remains = 255 - work.channel[3];
dest_alpha = work.channel[3] + remains * src.channel[3] / 255;
if (work.channel[3] == 255) {
return i_ppix(im, x, y, &work);
}
else {
src.channel[0] = (work.channel[3] * work.channel[0]
+ remains * src.channel[0] * src.channel[3] / 255) / dest_alpha;
src.channel[1] = (work.channel[3] * work.channel[1]
+ remains * src.channel[1] * src.channel[3] / 255) / dest_alpha;
src.channel[2] = (work.channel[3] * work.channel[2]
+ remains * src.channel[2] * src.channel[3] / 255) / dest_alpha;
src.channel[3] = dest_alpha;
return i_ppix(im, x, y, &src);
}
}
return 0;
}
static void
cfill_from_btm(i_img *im, i_fill_t *fill, struct i_bitmap *btm,
i_img_dim bxmin, i_img_dim bxmax, i_img_dim bymin, i_img_dim bymax);
void
i_mmarray_cr(i_mmarray *ar,i_img_dim l) {
i_img_dim i;
size_t alloc_size;
ar->lines=l;
alloc_size = sizeof(minmax) * l;
/* check for overflow */
if (alloc_size / l != sizeof(minmax)) {
fprintf(stderr, "overflow calculating memory allocation");
exit(3);
}
ar->data=mymalloc(alloc_size); /* checked 5jul05 tonyc */
for(i=0;i<l;i++) {
ar->data[i].max = -1;
ar->data[i].min = i_img_dim_MAX;
}
}
void
i_mmarray_dst(i_mmarray *ar) {
ar->lines=0;
if (ar->data != NULL) { myfree(ar->data); ar->data=NULL; }
}
void
i_mmarray_add(i_mmarray *ar,i_img_dim x,i_img_dim y) {
if (y>-1 && y<ar->lines)
{
if (x<ar->data[y].min) ar->data[y].min=x;
if (x>ar->data[y].max) ar->data[y].max=x;
}
}
i_img_dim
i_mmarray_gmin(i_mmarray *ar,i_img_dim y) {
if (y>-1 && y<ar->lines) return ar->data[y].min;
else return -1;
}
i_img_dim
i_mmarray_getm(i_mmarray *ar,i_img_dim y) {
if (y>-1 && y<ar->lines)
return ar->data[y].max;
else
return i_img_dim_MAX;
}
#if 0
/* unused? */
void
i_mmarray_render(i_img *im,i_mmarray *ar,i_color *val) {
i_img_dim i,x;
for(i=0;i<ar->lines;i++) if (ar->data[i].max!=-1) for(x=ar->data[i].min;x<ar->data[i].max;x++) i_ppix(im,x,i,val);
}
#endif
static
void
i_arcdraw(i_img_dim x1, i_img_dim y1, i_img_dim x2, i_img_dim y2, i_mmarray *ar) {
double alpha;
double dsec;
i_img_dim temp;
alpha=(double)(y2-y1)/(double)(x2-x1);
if (fabs(alpha) <= 1)
{
if (x2<x1) { temp=x1; x1=x2; x2=temp; temp=y1; y1=y2; y2=temp; }
dsec=y1;
while(x1<=x2)
{
i_mmarray_add(ar,x1,(i_img_dim)(dsec+0.5));
dsec+=alpha;
x1++;
}
}
else
{
alpha=1/alpha;
if (y2<y1) { temp=x1; x1=x2; x2=temp; temp=y1; y1=y2; y2=temp; }
dsec=x1;
while(y1<=y2)
{
i_mmarray_add(ar,(i_img_dim)(dsec+0.5),y1);
dsec+=alpha;
y1++;
}
}
}
void
i_mmarray_info(i_mmarray *ar) {
i_img_dim i;
for(i=0;i<ar->lines;i++)
if (ar->data[i].max!=-1)
printf("line %"i_DF ": min=%" i_DF ", max=%" i_DF ".\n",
i_DFc(i), i_DFc(ar->data[i].min), i_DFc(ar->data[i].max));
}
static void
i_arc_minmax(i_int_hlines *hlines,i_img_dim x,i_img_dim y, double rad,float d1,float d2) {
i_mmarray dot;
double f;
i_img_dim x1,y1;
i_mmarray_cr(&dot, hlines->limit_y);
x1=(i_img_dim)(x+0.5+rad*cos(d1*PI/180.0));
y1=(i_img_dim)(y+0.5+rad*sin(d1*PI/180.0));
/* printf("x1: %d.\ny1: %d.\n",x1,y1); */
i_arcdraw(x, y, x1, y1, &dot);
x1=(i_img_dim)(x+0.5+rad*cos(d2*PI/180.0));
y1=(i_img_dim)(y+0.5+rad*sin(d2*PI/180.0));
for(f=d1;f<=d2;f+=0.01)
i_mmarray_add(&dot,(i_img_dim)(x+0.5+rad*cos(f*PI/180.0)),(i_img_dim)(y+0.5+rad*sin(f*PI/180.0)));
/* printf("x1: %d.\ny1: %d.\n",x1,y1); */
i_arcdraw(x, y, x1, y1, &dot);
/* render the minmax values onto the hlines */
for (y = 0; y < dot.lines; y++) {
if (dot.data[y].max!=-1) {
i_img_dim minx, width;
minx = dot.data[y].min;
width = dot.data[y].max - dot.data[y].min + 1;
i_int_hlines_add(hlines, y, minx, width);
}
}
/* dot.info(); */
i_mmarray_dst(&dot);
}
static void
i_arc_hlines(i_int_hlines *hlines,i_img_dim x,i_img_dim y,double rad,float d1,float d2) {
if (d1 <= d2) {
i_arc_minmax(hlines, x, y, rad, d1, d2);
}
else {
i_arc_minmax(hlines, x, y, rad, d1, 360);
i_arc_minmax(hlines, x, y, rad, 0, d2);
}
}
/*
=item i_arc(im, x, y, rad, d1, d2, color)
=category Drawing
=synopsis i_arc(im, 50, 50, 20, 45, 135, &color);
Fills an arc centered at (x,y) with radius I<rad> covering the range
of angles in degrees from d1 to d2, with the color.
=cut
*/
void
i_arc(i_img *im, i_img_dim x, i_img_dim y,double rad,double d1,double d2,const i_color *val) {
i_int_hlines hlines;
dIMCTXim(im);
im_log((aIMCTX,1,"i_arc(im %p,(x,y)=(" i_DFp "), rad %f, d1 %f, d2 %f, col %p)",
im, i_DFcp(x, y), rad, d1, d2, val));
i_int_init_hlines_img(&hlines, im);
i_arc_hlines(&hlines, x, y, rad, d1, d2);
i_int_hlines_fill_color(im, &hlines, val);
i_int_hlines_destroy(&hlines);
}
/*
=item i_arc_cfill(im, x, y, rad, d1, d2, fill)
=category Drawing
=synopsis i_arc_cfill(im, 50, 50, 35, 90, 135, fill);
Fills an arc centered at (x,y) with radius I<rad> covering the range
of angles in degrees from d1 to d2, with the fill object.
=cut
*/
#define MIN_CIRCLE_STEPS 8
#define MAX_CIRCLE_STEPS 360
void
i_arc_cfill(i_img *im, i_img_dim x, i_img_dim y,double rad,double d1,double d2,i_fill_t *fill) {
i_int_hlines hlines;
dIMCTXim(im);
im_log((aIMCTX,1,"i_arc_cfill(im %p,(x,y)=(" i_DFp "), rad %f, d1 %f, d2 %f, fill %p)",
im, i_DFcp(x, y), rad, d1, d2, fill));
i_int_init_hlines_img(&hlines, im);
i_arc_hlines(&hlines, x, y, rad, d1, d2);
i_int_hlines_fill_fill(im, &hlines, fill);
i_int_hlines_destroy(&hlines);
}
static void
arc_poly(int *count, double **xvals, double **yvals,
double x, double y, double rad, double d1, double d2) {
double d1_rad, d2_rad;
double circum;
i_img_dim steps, point_count;
double angle_inc;
/* normalize the angles */
d1 = fmod(d1, 360);
if (d1 == 0) {
if (d2 >= 360) { /* default is 361 */
d2 = 360;
}
else {
d2 = fmod(d2, 360);
if (d2 < d1)
d2 += 360;
}
}
else {
d2 = fmod(d2, 360);
if (d2 < d1)
d2 += 360;
}
d1_rad = d1 * PI / 180;
d2_rad = d2 * PI / 180;
/* how many segments for the curved part?
we do a maximum of one per degree, with a minimum of 8/circle
we try to aim at having about one segment per 2 pixels
Work it out per circle to get a step size.
I was originally making steps = circum/2 but that looked horrible.
I think there might be an issue in the polygon filler.
*/
circum = 2 * PI * rad;
steps = circum;
if (steps > MAX_CIRCLE_STEPS)
steps = MAX_CIRCLE_STEPS;
else if (steps < MIN_CIRCLE_STEPS)
steps = MIN_CIRCLE_STEPS;
angle_inc = 2 * PI / steps;
point_count = steps + 5; /* rough */
/* point_count is always relatively small, so allocation won't overflow */
*xvals = mymalloc(point_count * sizeof(double)); /* checked 17feb2005 tonyc */
*yvals = mymalloc(point_count * sizeof(double)); /* checked 17feb2005 tonyc */
/* from centre to edge at d1 */
(*xvals)[0] = x;
(*yvals)[0] = y;
(*xvals)[1] = x + rad * cos(d1_rad);
(*yvals)[1] = y + rad * sin(d1_rad);
*count = 2;
/* step around the curve */
while (d1_rad < d2_rad) {
(*xvals)[*count] = x + rad * cos(d1_rad);
(*yvals)[*count] = y + rad * sin(d1_rad);
++*count;
d1_rad += angle_inc;
}
/* finish off the curve */
(*xvals)[*count] = x + rad * cos(d2_rad);
(*yvals)[*count] = y + rad * sin(d2_rad);
++*count;
}
/*
=item i_arc_aa(im, x, y, rad, d1, d2, color)
=category Drawing
=synopsis i_arc_aa(im, 50, 50, 35, 90, 135, &color);
Anti-alias fills an arc centered at (x,y) with radius I<rad> covering
the range of angles in degrees from d1 to d2, with the color.
=cut
*/
void
i_arc_aa(i_img *im, double x, double y, double rad, double d1, double d2,
const i_color *val) {
double *xvals, *yvals;
int count;
dIMCTXim(im);
im_log((aIMCTX,1,"i_arc_aa(im %p,(x,y)=(%f,%f), rad %f, d1 %f, d2 %f, col %p)",
im, x, y, rad, d1, d2, val));
arc_poly(&count, &xvals, &yvals, x, y, rad, d1, d2);
i_poly_aa(im, count, xvals, yvals, val);
myfree(xvals);
myfree(yvals);
}
/*
=item i_arc_aa_cfill(im, x, y, rad, d1, d2, fill)
=category Drawing
=synopsis i_arc_aa_cfill(im, 50, 50, 35, 90, 135, fill);
Anti-alias fills an arc centered at (x,y) with radius I<rad> covering
the range of angles in degrees from d1 to d2, with the fill object.
=cut
*/
void
i_arc_aa_cfill(i_img *im, double x, double y, double rad, double d1, double d2,
i_fill_t *fill) {
double *xvals, *yvals;
int count;
dIMCTXim(im);
im_log((aIMCTX,1,"i_arc_aa_cfill(im %p,(x,y)=(%f,%f), rad %f, d1 %f, d2 %f, fill %p)",
im, x, y, rad, d1, d2, fill));
arc_poly(&count, &xvals, &yvals, x, y, rad, d1, d2);
i_poly_aa_cfill(im, count, xvals, yvals, fill);
myfree(xvals);
myfree(yvals);
}
typedef i_img_dim frac;
static frac float_to_frac(double x) { return (frac)(0.5+x*16.0); }
typedef void
(*flush_render_t)(i_img *im, i_img_dim l, i_img_dim r, i_img_dim y, const i_sample_t *cover, void *ctx);
static void
i_circle_aa_low(i_img *im, double x, double y, double rad, flush_render_t r, void *ctx);
static void
scanline_flush_color(i_img *im, i_img_dim l, i_img_dim y, i_img_dim width, const i_sample_t *cover, void *ctx);
static void
scanline_flush_fill(i_img *im, i_img_dim l, i_img_dim y, i_img_dim width, const i_sample_t *cover, void *ctx);
typedef struct {
i_render r;
i_color c;
} flush_color_t;
typedef struct {
i_render r;
i_fill_t *fill;
} flush_fill_t;
/*
=item i_circle_aa(im, x, y, rad, color)
=category Drawing
=synopsis i_circle_aa(im, 50, 50, 45, &color);
Anti-alias fills a circle centered at (x,y) for radius I<rad> with
color.
=cut
*/
void
i_circle_aa(i_img *im, double x, double y, double rad, const i_color *val) {
flush_color_t fc;
fc.c = *val;
i_render_init(&fc.r, im, rad * 2 + 1);
i_circle_aa_low(im, x, y, rad, scanline_flush_color, &fc);
i_render_done(&fc.r);
}
/*
=item i_circle_aa_fill(im, x, y, rad, fill)
=category Drawing
=synopsis i_circle_aa_fill(im, 50, 50, 45, fill);
Anti-alias fills a circle centered at (x,y) for radius I<rad> with
fill.
=cut
*/
void
i_circle_aa_fill(i_img *im, double x, double y, double rad, i_fill_t *fill) {
flush_fill_t ff;
ff.fill = fill;
i_render_init(&ff.r, im, rad * 2 + 1);
i_circle_aa_low(im, x, y, rad, scanline_flush_fill, &ff);
i_render_done(&ff.r);
}
static void
i_circle_aa_low(i_img *im, double x, double y, double rad, flush_render_t r,
void *ctx) {
i_color temp;
i_img_dim ly;
dIMCTXim(im);
i_img_dim first_row = floor(y) - ceil(rad);
i_img_dim last_row = ceil(y) + ceil(rad);
double r_sqr = rad * rad;
i_img_dim max_width = 2 * ceil(rad) + 1;
unsigned char *coverage = NULL;
size_t coverage_size;
int sub;
im_log((aIMCTX, 1, "i_circle_aa_low(im %p, centre(" i_DFp "), rad %.2f, r %p, ctx %p)\n",
im, i_DFcp(x, y), rad, r, ctx));
if (first_row < 0)
first_row = 0;
if (last_row > im->ysize-1)
last_row = im->ysize - 1;
if (rad <= 0 || last_row < first_row) {
/* outside the image */
return;
}
coverage_size = max_width;
coverage = mymalloc(coverage_size);
for(ly = first_row; ly < last_row; ly++) {
frac min_frac_x[16];
frac max_frac_x[16];
i_img_dim min_frac_left_x = im->xsize * 16;
i_img_dim max_frac_left_x = -1;
i_img_dim min_frac_right_x = im->xsize * 16;
i_img_dim max_frac_right_x = -1;
/* reset work_y each row so the error doesn't build up */
double work_y = ly;
double dy, dy_sqr;
for (sub = 0; sub < 16; ++sub) {
work_y += 1.0 / 16.0;
dy = work_y - y;
dy_sqr = dy * dy;
if (dy_sqr < r_sqr) {
double dx = sqrt(r_sqr - dy_sqr);
double left_x = x - dx;
double right_x = x + dx;
frac frac_left_x = float_to_frac(left_x);
frac frac_right_x = float_to_frac(right_x);
if (frac_left_x < min_frac_left_x)
min_frac_left_x = frac_left_x;
if (frac_left_x > max_frac_left_x)
max_frac_left_x = frac_left_x;
if (frac_right_x < min_frac_right_x)
min_frac_right_x = frac_right_x;
if (frac_right_x > max_frac_right_x)
max_frac_right_x = frac_right_x;
min_frac_x[sub] = frac_left_x;
max_frac_x[sub] = frac_right_x;
}
else {
min_frac_x[sub] = max_frac_x[sub] = 0;
max_frac_left_x = im->xsize * 16;
min_frac_right_x = -1;
}
}
if (min_frac_left_x != -1) {
/* something to draw on this line */
i_img_dim min_x = (min_frac_left_x / 16);
i_img_dim max_x = (max_frac_right_x + 15) / 16;
i_img_dim left_solid = (max_frac_left_x + 15) / 16;
i_img_dim right_solid = min_frac_right_x / 16;
i_img_dim work_x;
i_img_dim frac_work_x;
i_sample_t *cout = coverage;
for (work_x = min_x, frac_work_x = min_x * 16;
work_x <= max_x;
++work_x, frac_work_x += 16) {
if (work_x <= left_solid || work_x >= right_solid) {
int pix_coverage = 0;
int ch;
double ratio;
i_img_dim frac_work_right = frac_work_x + 16;
for (sub = 0; sub < 16; ++sub) {
frac pix_left = min_frac_x[sub];
frac pix_right = max_frac_x[sub];
if (pix_left < pix_right
&& pix_left < frac_work_right
&& pix_right >= frac_work_x) {
if (pix_left < frac_work_x)
pix_left = frac_work_x;
if (pix_right > frac_work_right)
pix_right = frac_work_right;
pix_coverage += pix_right - pix_left;
}
}
assert(pix_coverage <= 256);
*cout++ = pix_coverage * 255 / 256;
}
else {
/* full coverage */
*cout++ = 255;
}
}
r(im, min_x, ly, max_x - min_x + 1, coverage, ctx);
}
}
myfree(coverage);
}
static void
scanline_flush_color(i_img *im, i_img_dim x, i_img_dim y, i_img_dim width, const unsigned char *cover, void *ctx) {
flush_color_t *fc = ctx;
i_render_color(&fc->r, x, y, width, cover, &fc->c);
}
static void
scanline_flush_fill(i_img *im, i_img_dim x, i_img_dim y, i_img_dim width, const unsigned char *cover, void *ctx) {
flush_fill_t *ff = ctx;
i_render_fill(&ff->r, x, y, width, cover, ff->fill);
}
/*
=item i_circle_out(im, x, y, r, col)
=category Drawing
=synopsis i_circle_out(im, 50, 50, 45, &color);
Draw a circle outline centered at (x,y) with radius r,
non-anti-aliased.
Parameters:
=over
=item *
(x, y) - the center of the circle
=item *
r - the radius of the circle in pixels, must be non-negative
=back
Returns non-zero on success.
Implementation:
=cut
*/
int
i_circle_out(i_img *im, i_img_dim xc, i_img_dim yc, i_img_dim r,
const i_color *col) {
i_img_dim x, y;
i_img_dim dx, dy;
int error;
dIMCTXim(im);
im_log((aIMCTX, 1, "i_circle_out(im %p, centre(" i_DFp "), rad %" i_DF ", col %p)\n",
im, i_DFcp(xc, yc), i_DFc(r), col));
im_clear_error(aIMCTX);
if (r < 0) {
im_push_error(aIMCTX, 0, "circle: radius must be non-negative");
return 0;
}
i_ppix(im, xc+r, yc, col);
i_ppix(im, xc-r, yc, col);
i_ppix(im, xc, yc+r, col);
i_ppix(im, xc, yc-r, col);
x = 0;
y = r;
dx = 1;
dy = -2 * r;
error = 1 - r;
while (x < y) {
if (error >= 0) {
--y;
dy += 2;
error += dy;
}
++x;
dx += 2;
error += dx;
i_ppix(im, xc + x, yc + y, col);
i_ppix(im, xc + x, yc - y, col);
i_ppix(im, xc - x, yc + y, col);
i_ppix(im, xc - x, yc - y, col);
if (x != y) {
i_ppix(im, xc + y, yc + x, col);
i_ppix(im, xc + y, yc - x, col);
i_ppix(im, xc - y, yc + x, col);
i_ppix(im, xc - y, yc - x, col);
}
}
return 1;
}
/*
=item arc_seg(angle)
Convert an angle in degrees into an angle measure we can generate
simply from the numbers we have when drawing the circle.
=cut
*/
static i_img_dim
arc_seg(double angle, int scale) {
i_img_dim seg = (angle + 45) / 90;
double remains = angle - seg * 90; /* should be in the range [-45,45] */
while (seg > 4)
seg -= 4;
if (seg == 4 && remains > 0)
seg = 0;
return scale * (seg * 2 + sin(remains * PI/180));
}
/*
=item i_arc_out(im, x, y, r, d1, d2, col)
=category Drawing
=synopsis i_arc_out(im, 50, 50, 45, 45, 135, &color);
Draw an arc outline centered at (x,y) with radius r, non-anti-aliased
over the angle range d1 through d2 degrees.
Parameters:
=over
=item *
(x, y) - the center of the circle
=item *
r - the radius of the circle in pixels, must be non-negative
=item *
d1, d2 - the range of angles to draw the arc over, in degrees.
=back
Returns non-zero on success.
Implementation:
=cut
*/
int
i_arc_out(i_img *im, i_img_dim xc, i_img_dim yc, i_img_dim r,
double d1, double d2, const i_color *col) {
i_img_dim x, y;
i_img_dim dx, dy;
int error;
i_img_dim segs[2][2];
int seg_count;
i_img_dim sin_th;
i_img_dim seg_d1, seg_d2;
int seg_num;
i_img_dim scale = r + 1;
i_img_dim seg1 = scale * 2;
i_img_dim seg2 = scale * 4;
i_img_dim seg3 = scale * 6;
i_img_dim seg4 = scale * 8;
dIMCTXim(im);
im_log((aIMCTX,1,"i_arc_out(im %p,centre(" i_DFp "), rad %" i_DF ", d1 %f, d2 %f, col %p)",
im, i_DFcp(xc, yc), i_DFc(r), d1, d2, col));
im_clear_error(aIMCTX);
if (r <= 0) {
im_push_error(aIMCTX, 0, "arc: radius must be non-negative");
return 0;
}
if (d1 + 360 <= d2)
return i_circle_out(im, xc, yc, r, col);
if (d1 < 0)
d1 += 360 * floor((-d1 + 359) / 360);
if (d2 < 0)
d2 += 360 * floor((-d2 + 359) / 360);
d1 = fmod(d1, 360);
d2 = fmod(d2, 360);
seg_d1 = arc_seg(d1, scale);
seg_d2 = arc_seg(d2, scale);
if (seg_d2 < seg_d1) {
/* split into two segments */
segs[0][0] = 0;
segs[0][1] = seg_d2;
segs[1][0] = seg_d1;
segs[1][1] = seg4;
seg_count = 2;
}
else {
segs[0][0] = seg_d1;
segs[0][1] = seg_d2;
seg_count = 1;
}
for (seg_num = 0; seg_num < seg_count; ++seg_num) {
i_img_dim seg_start = segs[seg_num][0];
i_img_dim seg_end = segs[seg_num][1];
if (seg_start == 0)
i_ppix(im, xc+r, yc, col);
if (seg_start <= seg1 && seg_end >= seg1)
i_ppix(im, xc, yc+r, col);
if (seg_start <= seg2 && seg_end >= seg2)
i_ppix(im, xc-r, yc, col);
if (seg_start <= seg3 && seg_end >= seg3)
i_ppix(im, xc, yc-r, col);
y = 0;
x = r;
dy = 1;
dx = -2 * r;
error = 1 - r;
while (y < x) {
if (error >= 0) {
--x;
dx += 2;
error += dx;
}
++y;
dy += 2;
error += dy;
sin_th = y;
if (seg_start <= sin_th && seg_end >= sin_th)
i_ppix(im, xc + x, yc + y, col);
if (seg_start <= seg1 - sin_th && seg_end >= seg1 - sin_th)
i_ppix(im, xc + y, yc + x, col);
if (seg_start <= seg1 + sin_th && seg_end >= seg1 + sin_th)
i_ppix(im, xc - y, yc + x, col);
if (seg_start <= seg2 - sin_th && seg_end >= seg2 - sin_th)
i_ppix(im, xc - x, yc + y, col);
if (seg_start <= seg2 + sin_th && seg_end >= seg2 + sin_th)
i_ppix(im, xc - x, yc - y, col);
if (seg_start <= seg3 - sin_th && seg_end >= seg3 - sin_th)
i_ppix(im, xc - y, yc - x, col);
if (seg_start <= seg3 + sin_th && seg_end >= seg3 + sin_th)
i_ppix(im, xc + y, yc - x, col);
if (seg_start <= seg4 - sin_th && seg_end >= seg4 - sin_th)
i_ppix(im, xc + x, yc - y, col);
}
}
return 1;
}
static double
cover(i_img_dim r, i_img_dim j) {
double rjsqrt = sqrt(r*r - j*j);
return ceil(rjsqrt) - rjsqrt;
}
/*
=item i_circle_out_aa(im, xc, yc, r, col)
=synopsis i_circle_out_aa(im, 50, 50, 45, &color);
Draw a circle outline centered at (x,y) with radius r, anti-aliased.
Parameters:
=over
=item *
(xc, yc) - the center of the circle
=item *
r - the radius of the circle in pixels, must be non-negative
=item *
col - an i_color for the color to draw in.
=back
Returns non-zero on success.
=cut
Based on "Fast Anti-Aliased Circle Generation", Xiaolin Wu, Graphics
Gems.
I use floating point for I<D> since for large circles the precision of
a [0,255] value isn't sufficient when approaching the end of the
octant.
*/
int
i_circle_out_aa(i_img *im, i_img_dim xc, i_img_dim yc, i_img_dim r, const i_color *col) {
i_img_dim i, j;
double t;
i_color workc = *col;
int orig_alpha = col->channel[3];
dIMCTXim(im);
im_log((aIMCTX,1,"i_circle_out_aa(im %p,centre(" i_DFp "), rad %" i_DF ", col %p)",
im, i_DFcp(xc, yc), i_DFc(r), col));
im_clear_error(aIMCTX);
if (r <= 0) {
im_push_error(aIMCTX, 0, "arc: radius must be non-negative");
return 0;
}
i = r;
j = 0;
t = 0;
i_ppix_norm(im, xc+i, yc+j, col);
i_ppix_norm(im, xc-i, yc+j, col);
i_ppix_norm(im, xc+j, yc+i, col);
i_ppix_norm(im, xc+j, yc-i, col);
while (i > j+1) {
double d;
int cv, inv_cv;
j++;
d = cover(r, j);
cv = (int)(d * 255 + 0.5);
inv_cv = 255-cv;
if (d < t) {
--i;
}
if (inv_cv) {
workc.channel[3] = orig_alpha * inv_cv / 255;
i_ppix_norm(im, xc+i, yc+j, &workc);
i_ppix_norm(im, xc-i, yc+j, &workc);
i_ppix_norm(im, xc+i, yc-j, &workc);
i_ppix_norm(im, xc-i, yc-j, &workc);
if (i != j) {
i_ppix_norm(im, xc+j, yc+i, &workc);
i_ppix_norm(im, xc-j, yc+i, &workc);
i_ppix_norm(im, xc+j, yc-i, &workc);
i_ppix_norm(im, xc-j, yc-i, &workc);
}
}
if (cv && i > j) {
workc.channel[3] = orig_alpha * cv / 255;
i_ppix_norm(im, xc+i-1, yc+j, &workc);
i_ppix_norm(im, xc-i+1, yc+j, &workc);
i_ppix_norm(im, xc+i-1, yc-j, &workc);
i_ppix_norm(im, xc-i+1, yc-j, &workc);
if (j != i-1) {
i_ppix_norm(im, xc+j, yc+i-1, &workc);
i_ppix_norm(im, xc-j, yc+i-1, &workc);
i_ppix_norm(im, xc+j, yc-i+1, &workc);
i_ppix_norm(im, xc-j, yc-i+1, &workc);
}
}
t = d;
}
return 1;
}
/*
=item i_arc_out_aa(im, xc, yc, r, d1, d2, col)
=synopsis i_arc_out_aa(im, 50, 50, 45, 45, 125, &color);
Draw a circle arc outline centered at (x,y) with radius r, from angle
d1 degrees through angle d2 degrees, anti-aliased.
Parameters:
=over
=item *
(xc, yc) - the center of the circle
=item *
r - the radius of the circle in pixels, must be non-negative
=item *
d1, d2 - the range of angle in degrees to draw the arc through. If
d2-d1 >= 360 a full circle is drawn.
=back
Returns non-zero on success.
=cut
Based on "Fast Anti-Aliased Circle Generation", Xiaolin Wu, Graphics
Gems.
*/
int
i_arc_out_aa(i_img *im, i_img_dim xc, i_img_dim yc, i_img_dim r, double d1, double d2, const i_color *col) {
i_img_dim i, j;
double t;
i_color workc = *col;
i_img_dim segs[2][2];
int seg_count;
i_img_dim sin_th;
i_img_dim seg_d1, seg_d2;
int seg_num;
int orig_alpha = col->channel[3];
i_img_dim scale = r + 1;
i_img_dim seg1 = scale * 2;
i_img_dim seg2 = scale * 4;
i_img_dim seg3 = scale * 6;
i_img_dim seg4 = scale * 8;
dIMCTXim(im);
im_log((aIMCTX,1,"i_arc_out_aa(im %p,centre(" i_DFp "), rad %" i_DF ", d1 %f, d2 %f, col %p)",
im, i_DFcp(xc, yc), i_DFc(r), d1, d2, col));
im_clear_error(aIMCTX);
if (r <= 0) {
im_push_error(aIMCTX, 0, "arc: radius must be non-negative");
return 0;
}
if (d1 + 360 <= d2)
return i_circle_out_aa(im, xc, yc, r, col);
if (d1 < 0)
d1 += 360 * floor((-d1 + 359) / 360);
if (d2 < 0)
d2 += 360 * floor((-d2 + 359) / 360);
d1 = fmod(d1, 360);
d2 = fmod(d2, 360);
seg_d1 = arc_seg(d1, scale);
seg_d2 = arc_seg(d2, scale);
if (seg_d2 < seg_d1) {
/* split into two segments */
segs[0][0] = 0;
segs[0][1] = seg_d2;
segs[1][0] = seg_d1;
segs[1][1] = seg4;
seg_count = 2;
}
else {
segs[0][0] = seg_d1;
segs[0][1] = seg_d2;
seg_count = 1;
}
for (seg_num = 0; seg_num < seg_count; ++seg_num) {
i_img_dim seg_start = segs[seg_num][0];
i_img_dim seg_end = segs[seg_num][1];
i = r;
j = 0;
t = 0;
if (seg_start == 0)
i_ppix_norm(im, xc+i, yc+j, col);
if (seg_start <= seg1 && seg_end >= seg1)
i_ppix_norm(im, xc+j, yc+i, col);
if (seg_start <= seg2 && seg_end >= seg2)
i_ppix_norm(im, xc-i, yc+j, col);
if (seg_start <= seg3 && seg_end >= seg3)
i_ppix_norm(im, xc+j, yc-i, col);
while (i > j+1) {
int cv, inv_cv;
double d;
j++;
d = cover(r, j);
cv = (int)(d * 255 + 0.5);
inv_cv = 255-cv;
if (d < t) {
--i;
}
sin_th = j;
if (inv_cv) {
workc.channel[3] = orig_alpha * inv_cv / 255;
if (seg_start <= sin_th && seg_end >= sin_th)
i_ppix_norm(im, xc+i, yc+j, &workc);
if (seg_start <= seg2 - sin_th && seg_end >= seg2 - sin_th)
i_ppix_norm(im, xc-i, yc+j, &workc);
if (seg_start <= seg4 - sin_th && seg_end >= seg4 - sin_th)
i_ppix_norm(im, xc+i, yc-j, &workc);
if (seg_start <= seg2 + sin_th && seg_end >= seg2 + sin_th)
i_ppix_norm(im, xc-i, yc-j, &workc);
if (i != j) {
if (seg_start <= seg1 - sin_th && seg_end >= seg1 - sin_th)
i_ppix_norm(im, xc+j, yc+i, &workc);
if (seg_start <= seg1 + sin_th && seg_end >= seg1 + sin_th)
i_ppix_norm(im, xc-j, yc+i, &workc);
if (seg_start <= seg3 + sin_th && seg_end >= seg3 + sin_th)
i_ppix_norm(im, xc+j, yc-i, &workc);
if (seg_start <= seg3 - sin_th && seg_end >= seg3 - sin_th)
i_ppix_norm(im, xc-j, yc-i, &workc);
}
}
if (cv && i > j) {
workc.channel[3] = orig_alpha * cv / 255;
if (seg_start <= sin_th && seg_end >= sin_th)
i_ppix_norm(im, xc+i-1, yc+j, &workc);
if (seg_start <= seg2 - sin_th && seg_end >= seg2 - sin_th)
i_ppix_norm(im, xc-i+1, yc+j, &workc);
if (seg_start <= seg4 - sin_th && seg_end >= seg4 - sin_th)
i_ppix_norm(im, xc+i-1, yc-j, &workc);
if (seg_start <= seg2 + sin_th && seg_end >= seg2 + sin_th)
i_ppix_norm(im, xc-i+1, yc-j, &workc);
if (seg_start <= seg1 - sin_th && seg_end >= seg1 - sin_th)
i_ppix_norm(im, xc+j, yc+i-1, &workc);
if (seg_start <= seg1 + sin_th && seg_end >= seg1 + sin_th)
i_ppix_norm(im, xc-j, yc+i-1, &workc);
if (seg_start <= seg3 + sin_th && seg_end >= seg3 + sin_th)
i_ppix_norm(im, xc+j, yc-i+1, &workc);
if (seg_start <= seg3 - sin_th && seg_end >= seg3 - sin_th)
i_ppix_norm(im, xc-j, yc-i+1, &workc);
}
t = d;
}
}
return 1;
}
/*
=item i_box(im, x1, y1, x2, y2, color)
=category Drawing
=synopsis i_box(im, 0, 0, im->xsize-1, im->ysize-1, &color).
Outlines the box from (x1,y1) to (x2,y2) inclusive with I<color>.
=cut
*/
void
i_box(i_img *im,i_img_dim x1,i_img_dim y1,i_img_dim x2,i_img_dim y2,const i_color *val) {
i_img_dim x,y;
dIMCTXim(im);
im_log((aIMCTX, 1,"i_box(im* %p, p1(" i_DFp "), p2(" i_DFp "),val %p)\n",
im, i_DFcp(x1,y1), i_DFcp(x2,y2), val));
for(x=x1;x<x2+1;x++) {
i_ppix(im,x,y1,val);
i_ppix(im,x,y2,val);
}
for(y=y1;y<y2+1;y++) {
i_ppix(im,x1,y,val);
i_ppix(im,x2,y,val);
}
}
/*
=item i_box_filled(im, x1, y1, x2, y2, color)
=category Drawing
=synopsis i_box_filled(im, 0, 0, im->xsize-1, im->ysize-1, &color);
Fills the box from (x1,y1) to (x2,y2) inclusive with color.
=cut
*/
void
i_box_filled(i_img *im,i_img_dim x1,i_img_dim y1,i_img_dim x2,i_img_dim y2, const i_color *val) {
i_img_dim x, y, width;
i_palidx index;
dIMCTXim(im);
im_log((aIMCTX,1,"i_box_filled(im* %p, p1(" i_DFp "), p2(" i_DFp "),val %p)\n",
im, i_DFcp(x1, y1), i_DFcp(x2,y2) ,val));
if (x1 > x2 || y1 > y2
|| x2 < 0 || y2 < 0
|| x1 >= im->xsize || y1 > im->ysize)
return;
if (x1 < 0)
x1 = 0;
if (x2 >= im->xsize)
x2 = im->xsize - 1;
if (y1 < 0)
y1 = 0;
if (y2 >= im->ysize)
y2 = im->ysize - 1;
width = x2 - x1 + 1;
if (im->type == i_palette_type
&& i_findcolor(im, val, &index)) {
i_palidx *line = mymalloc(sizeof(i_palidx) * width);
for (x = 0; x < width; ++x)
line[x] = index;
for (y = y1; y <= y2; ++y)
i_ppal(im, x1, x2+1, y, line);
myfree(line);
}
else {
i_color *line = mymalloc(sizeof(i_color) * width);
for (x = 0; x < width; ++x)
line[x] = *val;
for (y = y1; y <= y2; ++y)
i_plin(im, x1, x2+1, y, line);
myfree(line);
}
}
/*
=item i_box_filledf(im, x1, y1, x2, y2, color)
=category Drawing
=synopsis i_box_filledf(im, 0, 0, im->xsize-1, im->ysize-1, &fcolor);
Fills the box from (x1,y1) to (x2,y2) inclusive with a floating point
color.
=cut
*/
int
i_box_filledf(i_img *im,i_img_dim x1,i_img_dim y1,i_img_dim x2,i_img_dim y2, const i_fcolor *val) {
i_img_dim x, y, width;
dIMCTXim(im);
im_log((aIMCTX, 1,"i_box_filledf(im* %p, p1(" i_DFp "), p2(" i_DFp "),val %p)\n",
im, i_DFcp(x1, y1), i_DFcp(x2, y2), val));
if (x1 > x2 || y1 > y2
|| x2 < 0 || y2 < 0
|| x1 >= im->xsize || y1 > im->ysize)
return 0;
if (x1 < 0)
x1 = 0;
if (x2 >= im->xsize)
x2 = im->xsize - 1;
if (y1 < 0)
y1 = 0;
if (y2 >= im->ysize)
y2 = im->ysize - 1;
width = x2 - x1 + 1;
if (im->bits <= 8) {
i_color c;
c.rgba.r = SampleFTo8(val->rgba.r);
c.rgba.g = SampleFTo8(val->rgba.g);
c.rgba.b = SampleFTo8(val->rgba.b);
c.rgba.a = SampleFTo8(val->rgba.a);
i_box_filled(im, x1, y1, x2, y2, &c);
}
else {
i_fcolor *line = mymalloc(sizeof(i_fcolor) * width);
for (x = 0; x < width; ++x)
line[x] = *val;
for (y = y1; y <= y2; ++y)
i_plinf(im, x1, x2+1, y, line);
myfree(line);
}
return 1;
}
/*
=item i_box_cfill(im, x1, y1, x2, y2, fill)
=category Drawing
=synopsis i_box_cfill(im, 0, 0, im->xsize-1, im->ysize-1, fill);
Fills the box from (x1,y1) to (x2,y2) inclusive with fill.
=cut
*/
void
i_box_cfill(i_img *im,i_img_dim x1,i_img_dim y1,i_img_dim x2,i_img_dim y2,i_fill_t *fill) {
i_render r;
dIMCTXim(im);
im_log((aIMCTX,1,"i_box_cfill(im* %p, p1(" i_DFp "), p2(" i_DFp "), fill %p)\n",
im, i_DFcp(x1, y1), i_DFcp(x2,y2), fill));
++x2;
if (x1 < 0)
x1 = 0;
if (y1 < 0)
y1 = 0;
if (x2 > im->xsize)
x2 = im->xsize;
if (y2 >= im->ysize)
y2 = im->ysize-1;
if (x1 >= x2 || y1 > y2)
return;
i_render_init(&r, im, x2-x1);
while (y1 <= y2) {
i_render_fill(&r, x1, y1, x2-x1, NULL, fill);
++y1;
}
i_render_done(&r);
}
/*
=item i_line(C<im>, C<x1>, C<y1>, C<x2>, C<y2>, C<color>, C<endp>)
=category Drawing
=for stopwords Bresenham's
Draw a line to image using Bresenham's line drawing algorithm
im - image to draw to
x1 - starting x coordinate
y1 - starting x coordinate
x2 - starting x coordinate
y2 - starting x coordinate
color - color to write to image
endp - endpoint flag (boolean)
=cut
*/
void
i_line(i_img *im, i_img_dim x1, i_img_dim y1, i_img_dim x2, i_img_dim y2, const i_color *val, int endp) {
i_img_dim x, y;
i_img_dim dx, dy;
i_img_dim p;
dx = x2 - x1;
dy = y2 - y1;
/* choose variable to iterate on */
if (i_abs(dx) > i_abs(dy)) {
i_img_dim dx2, dy2, cpy;
/* sort by x */
if (x1 > x2) {
i_img_dim t;
t = x1; x1 = x2; x2 = t;
t = y1; y1 = y2; y2 = t;
}
dx = i_abs(dx);
dx2 = dx*2;
dy = y2 - y1;
if (dy<0) {
dy = -dy;
cpy = -1;
} else {
cpy = 1;
}
dy2 = dy*2;
p = dy2 - dx;
y = y1;
for(x=x1; x<x2-1; x++) {
if (p<0) {
p += dy2;
} else {
y += cpy;
p += dy2-dx2;
}
i_ppix(im, x+1, y, val);
}
} else {
i_img_dim dy2, dx2, cpx;
/* sort bx y */
if (y1 > y2) {
i_img_dim t;
t = x1; x1 = x2; x2 = t;
t = y1; y1 = y2; y2 = t;
}
dy = i_abs(dy);
dx = x2 - x1;
dy2 = dy*2;
if (dx<0) {
dx = -dx;
cpx = -1;
} else {
cpx = 1;
}
dx2 = dx*2;
p = dx2 - dy;
x = x1;
for(y=y1; y<y2-1; y++) {
if (p<0) {
p += dx2;
} else {
x += cpx;
p += dx2-dy2;
}
i_ppix(im, x, y+1, val);
}
}
if (endp) {
i_ppix(im, x1, y1, val);
i_ppix(im, x2, y2, val);
} else {
if (x1 != x2 || y1 != y2)
i_ppix(im, x1, y1, val);
}
}
void
i_line_dda(i_img *im, i_img_dim x1, i_img_dim y1, i_img_dim x2, i_img_dim y2, i_color *val) {
double dy;
i_img_dim x;
for(x=x1; x<=x2; x++) {
dy = y1+ (x-x1)/(double)(x2-x1)*(y2-y1);
i_ppix(im, x, (i_img_dim)(dy+0.5), val);
}
}
/*
=item i_line_aa(C<im>, C<x1>, C<x2>, C<y1>, C<y2>, C<color>, C<endp>)
=category Drawing
Anti-alias draws a line from (x1,y1) to (x2, y2) in color.
The point (x2, y2) is drawn only if C<endp> is set.
=cut
*/
void
i_line_aa(i_img *im, i_img_dim x1, i_img_dim y1, i_img_dim x2, i_img_dim y2, const i_color *val, int endp) {
i_img_dim x, y;
i_img_dim dx, dy;
i_img_dim p;
dx = x2 - x1;
dy = y2 - y1;
/* choose variable to iterate on */
if (i_abs(dx) > i_abs(dy)) {
i_img_dim dx2, dy2, cpy;
/* sort by x */
if (x1 > x2) {
i_img_dim t;
t = x1; x1 = x2; x2 = t;
t = y1; y1 = y2; y2 = t;
}
dx = i_abs(dx);
dx2 = dx*2;
dy = y2 - y1;
if (dy<0) {
dy = -dy;
cpy = -1;
} else {
cpy = 1;
}
dy2 = dy*2;
p = dy2 - dx2; /* this has to be like this for AA */
y = y1;
for(x=x1; x<x2-1; x++) {
int ch;
i_color tval;
double t = (dy) ? -(float)(p)/(float)(dx2) : 1;
double t1, t2;
if (t<0) t = 0;
t1 = 1-t;
t2 = t;
i_gpix(im,x+1,y,&tval);
for(ch=0;ch<im->channels;ch++)
tval.channel[ch]=(unsigned char)(t1*(float)tval.channel[ch]+t2*(float)val->channel[ch]);
i_ppix(im,x+1,y,&tval);
i_gpix(im,x+1,y+cpy,&tval);
for(ch=0;ch<im->channels;ch++)
tval.channel[ch]=(unsigned char)(t2*(float)tval.channel[ch]+t1*(float)val->channel[ch]);
i_ppix(im,x+1,y+cpy,&tval);
if (p<0) {
p += dy2;
} else {
y += cpy;
p += dy2-dx2;
}
}
} else {
i_img_dim dy2, dx2, cpx;
/* sort bx y */
if (y1 > y2) {
i_img_dim t;
t = x1; x1 = x2; x2 = t;
t = y1; y1 = y2; y2 = t;
}
dy = i_abs(dy);
dx = x2 - x1;
dy2 = dy*2;
if (dx<0) {
dx = -dx;
cpx = -1;
} else {
cpx = 1;
}
dx2 = dx*2;
p = dx2 - dy2; /* this has to be like this for AA */
x = x1;
for(y=y1; y<y2-1; y++) {
int ch;
i_color tval;
double t = (dx) ? -(double)(p)/(double)(dy2) : 1;
double t1, t2;
if (t<0) t = 0;
t1 = 1-t;
t2 = t;
i_gpix(im,x,y+1,&tval);
for(ch=0;ch<im->channels;ch++)
tval.channel[ch]=(unsigned char)(t1*(double)tval.channel[ch]+t2*(double)val->channel[ch]);
i_ppix(im,x,y+1,&tval);
i_gpix(im,x+cpx,y+1,&tval);
for(ch=0;ch<im->channels;ch++)
tval.channel[ch]=(unsigned char)(t2*(double)tval.channel[ch]+t1*(double)val->channel[ch]);
i_ppix(im,x+cpx,y+1,&tval);
if (p<0) {
p += dx2;
} else {
x += cpx;
p += dx2-dy2;
}
}
}
if (endp) {
i_ppix(im, x1, y1, val);
i_ppix(im, x2, y2, val);
} else {
if (x1 != x2 || y1 != y2)
i_ppix(im, x1, y1, val);
}
}
static double
perm(i_img_dim n,i_img_dim k) {
double r;
i_img_dim i;
r=1;
for(i=k+1;i<=n;i++) r*=i;
for(i=1;i<=(n-k);i++) r/=i;
return r;
}
/* Note in calculating t^k*(1-t)^(n-k)
we can start by using t^0=1 so this simplifies to
t^0*(1-t)^n - we want to multiply that with t/(1-t) each iteration
to get a new level - this may lead to errors who knows lets test it */
void
i_bezier_multi(i_img *im,int l,const double *x,const double *y, const i_color *val) {
double *bzcoef;
double t,cx,cy;
int k,i;
i_img_dim lx = 0,ly = 0;
int n=l-1;
double itr,ccoef;
/* this is the same size as the x and y arrays, so shouldn't overflow */
bzcoef=mymalloc(sizeof(double)*l); /* checked 5jul05 tonyc */
for(k=0;k<l;k++) bzcoef[k]=perm(n,k);
ICL_info(val);
/* for(k=0;k<l;k++) printf("bzcoef: %d -> %f\n",k,bzcoef[k]); */
i=0;
for(t=0;t<=1;t+=0.005) {
cx=cy=0;
itr=t/(1-t);
ccoef=pow(1-t,n);
for(k=0;k<l;k++) {
/* cx+=bzcoef[k]*x[k]*pow(t,k)*pow(1-t,n-k);
cy+=bzcoef[k]*y[k]*pow(t,k)*pow(1-t,n-k);*/
cx+=bzcoef[k]*x[k]*ccoef;
cy+=bzcoef[k]*y[k]*ccoef;
ccoef*=itr;
}
/* printf("%f -> (%d,%d)\n",t,(int)(0.5+cx),(int)(0.5+cy)); */
if (i++) {
i_line_aa(im,lx,ly,(i_img_dim)(0.5+cx),(i_img_dim)(0.5+cy),val, 1);
}
/* i_ppix(im,(i_img_dim)(0.5+cx),(i_img_dim)(0.5+cy),val); */
lx=(i_img_dim)(0.5+cx);
ly=(i_img_dim)(0.5+cy);
}
ICL_info(val);
myfree(bzcoef);
}
/* Flood fill
REF: Graphics Gems I. page 282+
*/
/* This should be moved into a seperate file? */
/* This is the truncation used:
a double is multiplied by 16 and then truncated.
This means that 0 -> 0
So a triangle of (0,0) (10,10) (10,0) Will look like it's
not filling the (10,10) point nor the (10,0)-(10,10) line segment
*/
/* Flood fill algorithm - based on the Ken Fishkins (pixar) gem in
graphics gems I */
/*
struct stc {
i_img_dim mylx,myrx;
i_img_dim dadlx,dadrx;
i_img_dim myy;
int mydirection;
};
Not used code???
*/
struct stack_element {
i_img_dim myLx,myRx;
i_img_dim dadLx,dadRx;
i_img_dim myY;
int myDirection;
};
/* create the link data to put push onto the stack */
static
struct stack_element*
crdata(i_img_dim left,i_img_dim right,i_img_dim dadl,i_img_dim dadr,i_img_dim y, int dir) {
struct stack_element *ste;
ste = mymalloc(sizeof(struct stack_element)); /* checked 5jul05 tonyc */
ste->myLx = left;
ste->myRx = right;
ste->dadLx = dadl;
ste->dadRx = dadr;
ste->myY = y;
ste->myDirection = dir;
return ste;
}
/* i_ccomp compares two colors and gives true if they are the same */
typedef int (*ff_cmpfunc)(i_color const *c1, i_color const *c2, int channels);
static int
i_ccomp_normal(i_color const *val1, i_color const *val2, int ch) {
int i;
for(i = 0; i < ch; i++)
if (val1->channel[i] !=val2->channel[i])
return 0;
return 1;
}
static int
i_ccomp_border(i_color const *val1, i_color const *val2, int ch) {
int i;
for(i = 0; i < ch; i++)
if (val1->channel[i] !=val2->channel[i])
return 1;
return 0;
}
static int
i_lspan(i_img *im, i_img_dim seedx, i_img_dim seedy, i_color const *val, ff_cmpfunc cmpfunc) {
i_color cval;
while(1) {
if (seedx-1 < 0) break;
i_gpix(im,seedx-1,seedy,&cval);
if (!cmpfunc(val,&cval,im->channels))
break;
seedx--;
}
return seedx;
}
static int
i_rspan(i_img *im, i_img_dim seedx, i_img_dim seedy, i_color const *val, ff_cmpfunc cmpfunc) {
i_color cval;
while(1) {
if (seedx+1 > im->xsize-1) break;
i_gpix(im,seedx+1,seedy,&cval);
if (!cmpfunc(val,&cval,im->channels)) break;
seedx++;
}
return seedx;
}
#ifdef DEBUG_FLOOD_FILL
#define ST_PUSH_NOTE(left, right, dadl, dadr, y, dir) \
fprintf(stderr, "push(left %" i_DF ", right %" i_DF ", dadleft %" i_DF ", dadright %" i_DF ", y %" i_DF ", dir %d, line %d)\n", \
i_DFc(left), i_DFc(right), i_DFc(dadl), i_DFc(dadr), i_DFc(y), (dir), __LINE__)
#define ST_POP_NOTE(left, right, dadl, dadr, y, dir) \
fprintf(stderr, "popped(left %" i_DF ", right %" i_DF ", dadleft %" i_DF ", dadright %" i_DF ", y %" i_DF ", dir %d, line %d)\n", \
i_DFc(left), i_DFc(right), i_DFc(dadl), i_DFc(dadr), i_DFc(y), (dir), __LINE__)
#define ST_STACK_NOTE(dadl, dadr, left, right, y, dir) \
fprintf(stderr, "stack(left %" i_DF ", right %" i_DF ", dadleft %" i_DF ", dadright %" i_DF ", y %" i_DF ", dir %d, line %d)\n", \
i_DFc(left), i_DFc(right), i_DFc(dadl), i_DFc(dadr), i_DFc(y), (dir), __LINE__)
#else
#define ST_PUSH_NOTE(left, right, dadl, dadr, y, dir)
#define ST_POP_NOTE(left, right, dadl, dadr, y, dir)
#define ST_STACK_NOTE(dadl, dadr, left, right, y, dir)
#endif
/* Macro to create a link and push on to the list */
#define ST_PUSH(left,right,dadl,dadr,y,dir) do { \
struct stack_element *s = crdata(left,right,dadl,dadr,y,dir); \
ST_PUSH_NOTE(left, right, dadl, dadr, y, dir); \
llist_push(st,&s); \
} while (0)
/* pops the shadow on TOS into local variables lx,rx,y,direction,dadLx and dadRx */
/* No overflow check! */
#define ST_POP() do { \
struct stack_element *s; \
llist_pop(st,&s); \
lx = s->myLx; \
rx = s->myRx; \
dadLx = s->dadLx; \
dadRx = s->dadRx; \
y = s->myY; \
direction = s->myDirection; \
ST_POP_NOTE(lx, rx, dadLx, dadRx, y, direction); \
myfree(s); \
} while (0)
#define ST_STACK(dir,dadLx,dadRx,lx,rx,y) do { \
i_img_dim pushrx = rx+1; \
i_img_dim pushlx = lx-1; \
ST_STACK_NOTE(lx, rx, dadLx, dadRx, y, dir); \
ST_PUSH(lx,rx,pushlx,pushrx,y+dir,dir); \
if (rx > dadRx) \
ST_PUSH(dadRx+1,rx,pushlx,pushrx,y-dir,-dir); \
if (lx < dadLx) \
ST_PUSH(lx,dadLx-1,pushlx,pushrx,y-dir,-dir); \
} while (0)
#define SET(x,y) btm_set(btm,x,y)
/* INSIDE returns true if pixel is correct color and we haven't set it before. */
#define INSIDE(x,y, seed) \
(assert((x) >= 0 && (x) < (im)->xsize && (y) >= 0 && (y) < (im)->ysize), \
(!btm_test(btm,x,y) && \
( i_gpix(im,x,y,&cval),cmpfunc(seed,&cval,channels) ) ))
/* The function that does all the real work */
static struct i_bitmap *
i_flood_fill_low(i_img *im,i_img_dim seedx,i_img_dim seedy,
i_img_dim *bxminp, i_img_dim *bxmaxp, i_img_dim *byminp, i_img_dim *bymaxp,
i_color const *seed, ff_cmpfunc cmpfunc) {
i_img_dim ltx, rtx;
i_img_dim tx = 0;
i_img_dim bxmin = seedx;
i_img_dim bxmax = seedx;
i_img_dim bymin = seedy;
i_img_dim bymax = seedy;
struct llist *st;
struct i_bitmap *btm;
int channels;
i_img_dim xsize,ysize;
i_color cval; /* used by the INSIDE() macro */
channels = im->channels;
xsize = im->xsize;
ysize = im->ysize;
btm = btm_new(xsize, ysize);
st = llist_new(100, sizeof(struct stack_element*));
/* Find the starting span and fill it */
ltx = i_lspan(im, seedx, seedy, seed, cmpfunc);
rtx = i_rspan(im, seedx, seedy, seed, cmpfunc);
for(tx=ltx; tx<=rtx; tx++) SET(tx, seedy);
bxmin = ltx;
bxmax = rtx;
ST_PUSH(ltx, rtx, ltx, rtx, seedy+1, 1);
ST_PUSH(ltx, rtx, ltx, rtx, seedy-1, -1);
while(st->count) {
/* Stack variables */
i_img_dim lx,rx;
i_img_dim dadLx,dadRx;
i_img_dim y;
int direction;
i_img_dim x;
int wasIn=0;
ST_POP(); /* sets lx, rx, dadLx, dadRx, y, direction */
if (y<0 || y>ysize-1) continue;
if (bymin > y) bymin=y; /* in the worst case an extra line */
if (bymax < y) bymax=y;
x = lx+1;
if ( lx >= 0 && (wasIn = INSIDE(lx, y, seed)) ) {
SET(lx, y);
lx--;
while(lx >= 0 && INSIDE(lx, y, seed)) {
SET(lx,y);
lx--;
}
/* lx should point at the left-most INSIDE() pixel */
++lx;
}
if (bxmin > lx) bxmin = lx;
while(x <= xsize-1) {
/* printf("x=%d\n",x); */
if (wasIn) {
if (INSIDE(x, y, seed)) {
/* case 1: was inside, am still inside */
SET(x,y);
} else {
/* case 2: was inside, am no longer inside: just found the
right edge of a span */
ST_STACK(direction, dadLx, dadRx, lx, (x-1), y);
if (bxmax < x) bxmax = x;
wasIn=0;
}
} else {
if (x > rx) goto EXT;
if (INSIDE(x, y, seed)) {
SET(x, y);
/* case 3: Wasn't inside, am now: just found the start of a new run */
wasIn = 1;
lx = x;
} else {
/* case 4: Wasn't inside, still isn't */
}
}
x++;
}
EXT: /* out of loop */
if (wasIn) {
/* hit an edge of the frame buffer while inside a run */
ST_STACK(direction, dadLx, dadRx, lx, (x-1), y);
if (bxmax < x) bxmax = x;
}
}
llist_destroy(st);
*bxminp = bxmin;
*bxmaxp = bxmax;
*byminp = bymin;
*bymaxp = bymax;
return btm;
}
/*
=item i_flood_fill(C<im>, C<seedx>, C<seedy>, C<color>)
=category Drawing
=synopsis i_flood_fill(im, 50, 50, &color);
Flood fills the 4-connected region starting from the point (C<seedx>,
C<seedy>) with I<color>.
Returns false if (C<seedx>, C<seedy>) are outside the image.
=cut
*/
undef_int
i_flood_fill(i_img *im, i_img_dim seedx, i_img_dim seedy, const i_color *dcol) {
i_img_dim bxmin, bxmax, bymin, bymax;
struct i_bitmap *btm;
i_img_dim x, y;
i_color val;
dIMCTXim(im);
im_log((aIMCTX, 1, "i_flood_fill(im %p, seed(" i_DFp "), col %p)",
im, i_DFcp(seedx, seedy), dcol));
im_clear_error(aIMCTX);
if (seedx < 0 || seedx >= im->xsize ||
seedy < 0 || seedy >= im->ysize) {
im_push_error(aIMCTX, 0, "i_flood_cfill: Seed pixel outside of image");
return 0;
}
/* Get the reference color */
i_gpix(im, seedx, seedy, &val);
btm = i_flood_fill_low(im, seedx, seedy, &bxmin, &bxmax, &bymin, &bymax,
&val, i_ccomp_normal);
for(y=bymin;y<=bymax;y++)
for(x=bxmin;x<=bxmax;x++)
if (btm_test(btm,x,y))
i_ppix(im,x,y,dcol);
btm_destroy(btm);
return 1;
}
/*
=item i_flood_cfill(C<im>, C<seedx>, C<seedy>, C<fill>)
=category Drawing
=synopsis i_flood_cfill(im, 50, 50, fill);
Flood fills the 4-connected region starting from the point (C<seedx>,
C<seedy>) with C<fill>.
Returns false if (C<seedx>, C<seedy>) are outside the image.
=cut
*/
undef_int
i_flood_cfill(i_img *im, i_img_dim seedx, i_img_dim seedy, i_fill_t *fill) {
i_img_dim bxmin, bxmax, bymin, bymax;
struct i_bitmap *btm;
i_color val;
dIMCTXim(im);
im_log((aIMCTX, 1, "i_flood_cfill(im %p, seed(" i_DFp "), fill %p)",
im, i_DFcp(seedx, seedy), fill));
im_clear_error(aIMCTX);
if (seedx < 0 || seedx >= im->xsize ||
seedy < 0 || seedy >= im->ysize) {
im_push_error(aIMCTX, 0, "i_flood_cfill: Seed pixel outside of image");
return 0;
}
/* Get the reference color */
i_gpix(im, seedx, seedy, &val);
btm = i_flood_fill_low(im, seedx, seedy, &bxmin, &bxmax, &bymin, &bymax,
&val, i_ccomp_normal);
cfill_from_btm(im, fill, btm, bxmin, bxmax, bymin, bymax);
btm_destroy(btm);
return 1;
}
/*
=item i_flood_fill_border(C<im>, C<seedx>, C<seedy>, C<color>, C<border>)
=category Drawing
=synopsis i_flood_fill_border(im, 50, 50, &color, &border);
Flood fills the 4-connected region starting from the point (C<seedx>,
C<seedy>) with C<color>, fill stops when the fill reaches a pixels
with color C<border>.
Returns false if (C<seedx>, C<seedy>) are outside the image.
=cut
*/
undef_int
i_flood_fill_border(i_img *im, i_img_dim seedx, i_img_dim seedy, const i_color *dcol,
const i_color *border) {
i_img_dim bxmin, bxmax, bymin, bymax;
struct i_bitmap *btm;
i_img_dim x, y;
dIMCTXim(im);
im_log((aIMCTX, 1, "i_flood_cfill(im %p, seed(" i_DFp "), dcol %p, border %p)",
im, i_DFcp(seedx, seedy), dcol, border));
im_clear_error(aIMCTX);
if (seedx < 0 || seedx >= im->xsize ||
seedy < 0 || seedy >= im->ysize) {
im_push_error(aIMCTX, 0, "i_flood_cfill: Seed pixel outside of image");
return 0;
}
btm = i_flood_fill_low(im, seedx, seedy, &bxmin, &bxmax, &bymin, &bymax,
border, i_ccomp_border);
for(y=bymin;y<=bymax;y++)
for(x=bxmin;x<=bxmax;x++)
if (btm_test(btm,x,y))
i_ppix(im,x,y,dcol);
btm_destroy(btm);
return 1;
}
/*
=item i_flood_cfill_border(C<im>, C<seedx>, C<seedy>, C<fill>, C<border>)
=category Drawing
=synopsis i_flood_cfill_border(im, 50, 50, fill, border);
Flood fills the 4-connected region starting from the point (C<seedx>,
C<seedy>) with C<fill>, the fill stops when it reaches pixels of color
C<border>.
Returns false if (C<seedx>, C<seedy>) are outside the image.
=cut
*/
undef_int
i_flood_cfill_border(i_img *im, i_img_dim seedx, i_img_dim seedy, i_fill_t *fill,
const i_color *border) {
i_img_dim bxmin, bxmax, bymin, bymax;
struct i_bitmap *btm;
dIMCTXim(im);
im_log((aIMCTX, 1, "i_flood_cfill_border(im %p, seed(" i_DFp "), fill %p, border %p)",
im, i_DFcp(seedx, seedy), fill, border));
im_clear_error(aIMCTX);
if (seedx < 0 || seedx >= im->xsize ||
seedy < 0 || seedy >= im->ysize) {
im_push_error(aIMCTX, 0, "i_flood_cfill_border: Seed pixel outside of image");
return 0;
}
btm = i_flood_fill_low(im, seedx, seedy, &bxmin, &bxmax, &bymin, &bymax,
border, i_ccomp_border);
cfill_from_btm(im, fill, btm, bxmin, bxmax, bymin, bymax);
btm_destroy(btm);
return 1;
}
static void
cfill_from_btm(i_img *im, i_fill_t *fill, struct i_bitmap *btm,
i_img_dim bxmin, i_img_dim bxmax, i_img_dim bymin, i_img_dim bymax) {
i_img_dim x, y;
i_img_dim start;
i_render r;
i_render_init(&r, im, bxmax - bxmin + 1);
for(y=bymin; y<=bymax; y++) {
x = bxmin;
while (x <= bxmax) {
while (x <= bxmax && !btm_test(btm, x, y)) {
++x;
}
if (btm_test(btm, x, y)) {
start = x;
while (x <= bxmax && btm_test(btm, x, y)) {
++x;
}
i_render_fill(&r, start, y, x-start, NULL, fill);
}
}
}
i_render_done(&r);
}
/*
=back
=cut
*/