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xform.c
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xform.c
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/* xform.c - Image transformation functions for gifsicle.
Copyright (C) 1997-2017 Eddie Kohler, ekohler@gmail.com
This file is part of gifsicle.
Gifsicle is free software. It is distributed under the GNU Public License,
version 2; you can copy, distribute, or alter it at will, as long
as this notice is kept intact and this source code is made available. There
is no warranty, express or implied. */
#include <config.h>
#include "gifsicle.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <errno.h>
#include <math.h>
#include <limits.h>
#include "kcolor.h"
#if HAVE_UNISTD_H
# include <unistd.h>
#endif
#if HAVE_SYS_TYPES_H && HAVE_SYS_STAT_H
# include <sys/types.h>
# include <sys/stat.h>
#endif
#ifndef M_PI
/* -std=c89 does not define M_PI */
# define M_PI 3.14159265358979323846
#endif
/******
* color transforms
**/
Gt_ColorTransform *
append_color_transform(Gt_ColorTransform *list,
color_transform_func func, void *data)
{
Gt_ColorTransform *trav;
Gt_ColorTransform *xform = Gif_New(Gt_ColorTransform);
xform->next = 0;
xform->func = func;
xform->data = data;
for (trav = list; trav && trav->next; trav = trav->next)
;
if (trav) {
trav->next = xform;
return list;
} else
return xform;
}
Gt_ColorTransform *
delete_color_transforms(Gt_ColorTransform *list, color_transform_func func)
{
Gt_ColorTransform *prev = 0, *trav = list;
while (trav) {
Gt_ColorTransform *next = trav->next;
if (trav->func == func) {
if (prev) prev->next = next;
else list = next;
Gif_Delete(trav);
} else
prev = trav;
trav = next;
}
return list;
}
void
apply_color_transforms(Gt_ColorTransform *list, Gif_Stream *gfs)
{
int i;
Gt_ColorTransform *xform;
for (xform = list; xform; xform = xform->next) {
if (gfs->global)
xform->func(gfs->global, xform->data);
for (i = 0; i < gfs->nimages; i++)
if (gfs->images[i]->local)
xform->func(gfs->images[i]->local, xform->data);
}
}
typedef struct Gt_ColorChange {
struct Gt_ColorChange *next;
Gif_Color old_color;
Gif_Color new_color;
} Gt_ColorChange;
void
color_change_transformer(Gif_Colormap *gfcm, void *thunk)
{
int i, have;
Gt_ColorChange *first_change = (Gt_ColorChange *)thunk;
Gt_ColorChange *change;
/* change colors named by color */
for (i = 0; i < gfcm->ncol; i++)
for (change = first_change; change; change = change->next) {
if (!change->old_color.haspixel)
have = GIF_COLOREQ(&gfcm->col[i], &change->old_color);
else
have = (change->old_color.pixel == (uint32_t)i);
if (have) {
gfcm->col[i] = change->new_color;
break; /* ignore remaining color changes */
}
}
}
Gt_ColorTransform *
append_color_change(Gt_ColorTransform *list,
Gif_Color old_color, Gif_Color new_color)
{
Gt_ColorTransform *xform;
Gt_ColorChange *change = Gif_New(Gt_ColorChange);
change->old_color = old_color;
change->new_color = new_color;
change->next = 0;
for (xform = list; xform && xform->next; xform = xform->next)
;
if (!xform || xform->func != &color_change_transformer)
return append_color_transform(list, &color_change_transformer, change);
else {
Gt_ColorChange *prev = (Gt_ColorChange *)(xform->data);
while (prev->next) prev = prev->next;
prev->next = change;
return list;
}
}
void
pipe_color_transformer(Gif_Colormap *gfcm, void *thunk)
{
int i, status;
FILE *f;
Gif_Color *col = gfcm->col;
Gif_Colormap *new_cm = 0;
char *command = (char *)thunk;
#ifdef HAVE_MKSTEMP
# ifdef P_tmpdir
char tmp_file[] = P_tmpdir "/gifsicle.XXXXXX";
# else
char tmp_file[] = "/tmp/gifsicle.XXXXXX";
# endif
#else
char *tmp_file = tmpnam(0);
#endif
char *new_command;
#ifdef HAVE_MKSTEMP
{
mode_t old_mode = umask(077);
if (mkstemp(tmp_file) < 0)
fatal_error("can%,t create temporary file!");
umask(old_mode);
}
#else
if (!tmp_file)
fatal_error("can%,t create temporary file!");
#endif
new_command = Gif_NewArray(char, strlen(command) + strlen(tmp_file) + 4);
sprintf(new_command, "%s >%s", command, tmp_file);
f = popen(new_command, "w");
if (!f)
fatal_error("can%,t run color transformation command: %s", strerror(errno));
Gif_DeleteArray(new_command);
for (i = 0; i < gfcm->ncol; i++)
fprintf(f, "%d %d %d\n", col[i].gfc_red, col[i].gfc_green, col[i].gfc_blue);
errno = 0;
status = pclose(f);
if (status < 0) {
error(1, "color transformation error: %s", strerror(errno));
goto done;
} else if (status > 0) {
error(1, "color transformation command failed");
goto done;
}
f = fopen(tmp_file, "r");
if (!f || feof(f)) {
error(1, "color transformation command generated no output", command);
if (f) fclose(f);
goto done;
}
new_cm = read_colormap_file("<color transformation>", f);
fclose(f);
if (new_cm) {
int nc = new_cm->ncol;
if (nc < gfcm->ncol) {
nc = gfcm->ncol;
warning(1, "too few colors in color transformation results");
} else if (nc > gfcm->ncol)
warning(1, "too many colors in color transformation results");
for (i = 0; i < nc; i++)
col[i] = new_cm->col[i];
}
done:
remove(tmp_file);
Gif_DeleteColormap(new_cm);
}
/*****
* crop image; returns true if the image exists
**/
void
combine_crop(Gt_Crop* dstcrop, const Gt_Crop* srccrop, const Gif_Image* gfi)
{
int cl = srccrop->x - gfi->left, cr = cl + srccrop->w,
ct = srccrop->y - gfi->top, cb = ct + srccrop->h,
dl = cl > 0 ? cl : 0, dr = cr < gfi->width ? cr : gfi->width,
dt = ct > 0 ? ct : 0, db = cb < gfi->height ? cb : gfi->height;
if (dl < dr) {
dstcrop->x = dl;
dstcrop->w = dr - dl;
} else {
dstcrop->x = (cl <= 0 ? 0 : srccrop->w - 1) + (srccrop->left_offset - gfi->left);
dstcrop->w = 0;
}
if (dt < db) {
dstcrop->y = dt;
dstcrop->h = db - dt;
} else {
dstcrop->y = (ct <= 0 ? 0 : srccrop->h - 1) + (srccrop->top_offset - gfi->top);
dstcrop->h = 0;
}
}
int
crop_image(Gif_Image* gfi, Gt_Frame* fr, int preserve_total_crop)
{
Gt_Crop c;
int j;
combine_crop(&c, fr->crop, gfi);
fr->left_offset = fr->crop->left_offset;
fr->top_offset = fr->crop->top_offset;
if (c.w > 0 && c.h > 0) {
uint8_t** old_img = gfi->img;
gfi->img = Gif_NewArray(uint8_t *, c.h + 1);
for (j = 0; j < c.h; j++)
gfi->img[j] = old_img[c.y + j] + c.x;
gfi->img[c.h] = 0;
Gif_DeleteArray(old_img);
gfi->width = c.w;
gfi->height = c.h;
} else if (preserve_total_crop)
Gif_MakeImageEmpty(gfi);
else {
Gif_DeleteArray(gfi->img);
gfi->img = 0;
gfi->width = gfi->height = 0;
}
gfi->left += c.x - fr->left_offset;
gfi->top += c.y - fr->top_offset;
return gfi->img != 0;
}
/*****
* flip and rotate
**/
void
flip_image(Gif_Image* gfi, Gt_Frame *fr, int is_vert)
{
int x, y;
int width = gfi->width;
int height = gfi->height;
uint8_t **img = gfi->img;
/* horizontal flips */
if (!is_vert) {
uint8_t *buffer = Gif_NewArray(uint8_t, width);
uint8_t *trav;
for (y = 0; y < height; y++) {
memcpy(buffer, img[y], width);
trav = img[y] + width - 1;
for (x = 0; x < width; x++)
*trav-- = buffer[x];
}
gfi->left = fr->stream->screen_width - (gfi->left + width);
if (fr->crop)
fr->left_offset = fr->stream->screen_width - (fr->left_offset + fr->crop->w);
Gif_DeleteArray(buffer);
}
/* vertical flips */
if (is_vert) {
uint8_t **buffer = Gif_NewArray(uint8_t *, height);
memcpy(buffer, img, height * sizeof(uint8_t *));
for (y = 0; y < height; y++)
img[y] = buffer[height - y - 1];
gfi->top = fr->stream->screen_height - (gfi->top + height);
if (fr->crop)
fr->top_offset = fr->stream->screen_height - (fr->top_offset + fr->crop->h);
Gif_DeleteArray(buffer);
}
}
void
rotate_image(Gif_Image* gfi, Gt_Frame* fr, int rotation)
{
int x, y;
int width = gfi->width;
int height = gfi->height;
uint8_t **img = gfi->img;
uint8_t *new_data = Gif_NewArray(uint8_t, (unsigned) width * height);
uint8_t *trav = new_data;
/* this function can only rotate by 90 or 270 degrees */
assert(rotation == 1 || rotation == 3);
if (rotation == 1) {
for (x = 0; x < width; x++)
for (y = height - 1; y >= 0; y--)
*trav++ = img[y][x];
x = gfi->left;
gfi->left = fr->stream->screen_height - (gfi->top + height);
gfi->top = x;
if (fr->crop) {
x = fr->left_offset;
fr->left_offset = fr->stream->screen_height - (fr->top_offset + fr->crop->h);
fr->top_offset = x;
}
} else {
for (x = width - 1; x >= 0; x--)
for (y = 0; y < height; y++)
*trav++ = img[y][x];
y = gfi->top;
gfi->top = fr->stream->screen_width - (gfi->left + width);
gfi->left = y;
if (fr->crop) {
y = fr->top_offset;
fr->top_offset = fr->stream->screen_width - (fr->left_offset + fr->crop->w);
fr->left_offset = y;
}
}
Gif_ReleaseUncompressedImage(gfi);
gfi->width = height;
gfi->height = width;
Gif_SetUncompressedImage(gfi, new_data, Gif_Free, 0);
}
/*****
* scale
**/
/* kcscreen: A frame buffer containing `kacolor`s (one per pixel).
Kcolors with components < 0 represent transparency. */
typedef struct {
kacolor* data; /* data buffer: (x,y) in data[y*width + x] */
kacolor* scratch; /* scratch buffer, used for previous disposal */
unsigned width; /* screen width */
unsigned height; /* screen height */
kacolor bg; /* background color */
} kcscreen;
/* initialize `kcs` to an empty state */
static void kcscreen_clear(kcscreen* kcs) {
kcs->data = kcs->scratch = NULL;
}
/* initialize `kcs` for stream `gfs`. Screen size is `sw`x`sh`; if either
component is <= 0, the value of `gfs->screen_*` is taken. */
static void kcscreen_init(kcscreen* kcs, Gif_Stream* gfs, int sw, int sh) {
unsigned i, sz;
assert(!kcs->data && !kcs->scratch);
kcs->width = sw <= 0 ? gfs->screen_width : sw;
kcs->height = sh <= 0 ? gfs->screen_height : sh;
sz = (unsigned) kcs->width * kcs->height;
kcs->data = Gif_NewArray(kacolor, sz);
if ((gfs->nimages == 0 || gfs->images[0]->transparent < 0)
&& gfs->global && gfs->background < gfs->global->ncol) {
kcs->bg.k = kc_makegfcg(&gfs->global->col[gfs->background]);
kcs->bg.a[3] = KC_MAX;
} else
kcs->bg.a[0] = kcs->bg.a[1] = kcs->bg.a[2] = kcs->bg.a[3] = 0;
for (i = 0; i != sz; ++i)
kcs->data[i] = kcs->bg;
}
/* free memory associated with `kcs` */
static void kcscreen_cleanup(kcscreen* kcs) {
Gif_DeleteArray(kcs->data);
Gif_DeleteArray(kcs->scratch);
}
/* apply image `gfi` to screen `kcs`, using the color array `ks` */
static void kcscreen_apply(kcscreen* kcs, const Gif_Image* gfi,
const kcolor* ks) {
int x, y;
assert((unsigned) gfi->left + gfi->width <= kcs->width);
assert((unsigned) gfi->top + gfi->height <= kcs->height);
if (gfi->disposal == GIF_DISPOSAL_PREVIOUS) {
if (!kcs->scratch)
kcs->scratch = Gif_NewArray(kacolor, kcs->width * kcs->height);
for (y = gfi->top; y != gfi->top + gfi->height; ++y)
memcpy(&kcs->scratch[y * kcs->width + gfi->left],
&kcs->data[y * kcs->width + gfi->left],
sizeof(kacolor) * gfi->width);
}
for (y = gfi->top; y != gfi->top + gfi->height; ++y) {
const uint8_t* linein = gfi->img[y - gfi->top];
kacolor* lineout = &kcs->data[y * kcs->width + gfi->left];
for (x = 0; x != gfi->width; ++x)
if (linein[x] != gfi->transparent) {
lineout[x].k = ks[linein[x]];
lineout[x].a[3] = KC_MAX;
}
}
}
/* dispose of image `gfi`, which was previously applied by kcscreen_apply */
static void kcscreen_dispose(kcscreen* kcs, const Gif_Image* gfi) {
int x, y;
assert((unsigned) gfi->left + gfi->width <= kcs->width);
assert((unsigned) gfi->top + gfi->height <= kcs->height);
if (gfi->disposal == GIF_DISPOSAL_PREVIOUS) {
for (y = gfi->top; y != gfi->top + gfi->height; ++y)
memcpy(&kcs->data[y * kcs->width + gfi->left],
&kcs->scratch[y * kcs->width + gfi->left],
sizeof(kacolor) * gfi->width);
} else if (gfi->disposal == GIF_DISPOSAL_BACKGROUND) {
for (y = gfi->top; y != gfi->top + gfi->height; ++y)
for (x = gfi->left; x != gfi->left + gfi->width; ++x)
kcs->data[y * kcs->width + x] = kcs->bg;
}
}
/* ksscreen: A frame buffer containing `scale_color`s (one per pixel).
Kcolors with components < 0 represent transparency. */
typedef struct {
scale_color* data; /* data buffer: (x,y) in data[y*width + x] */
scale_color* scratch; /* scratch buffer, used for previous disposal */
unsigned width; /* screen width */
unsigned height; /* screen height */
scale_color bg; /* background color */
} ksscreen;
/* initialize `kss` to an empty state */
static void ksscreen_clear(ksscreen* kss) {
kss->data = kss->scratch = NULL;
}
/* initialize `kss` for stream `gfs`. Screen size is `sw`x`sh`; if either
component is <= 0, the value of `gfs->screen_*` is taken. */
static void ksscreen_init(ksscreen* kss, Gif_Stream* gfs, int sw, int sh) {
unsigned i, sz;
assert(!kss->data && !kss->scratch);
kss->width = sw <= 0 ? gfs->screen_width : sw;
kss->height = sh <= 0 ? gfs->screen_height : sh;
sz = (unsigned) kss->width * kss->height;
kss->data = Gif_NewArray(scale_color, sz);
if ((gfs->nimages == 0 || gfs->images[0]->transparent < 0)
&& gfs->global && gfs->background < gfs->global->ncol) {
kcolor k = kc_makegfcg(&gfs->global->col[gfs->background]);
kss->bg = sc_makekc(&k);
} else
sc_clear(&kss->bg);
for (i = 0; i != sz; ++i)
kss->data[i] = kss->bg;
}
/* free memory associated with `kss` */
static void ksscreen_cleanup(ksscreen* kss) {
Gif_DeleteArray(kss->data);
Gif_DeleteArray(kss->scratch);
}
/* apply image `gfi` to screen `kss`, using the color array `ks` */
static void ksscreen_apply(ksscreen* kss, const Gif_Image* gfi,
const kcolor* ks) {
int x, y;
assert((unsigned) gfi->left + gfi->width <= kss->width);
assert((unsigned) gfi->top + gfi->height <= kss->height);
if (gfi->disposal == GIF_DISPOSAL_PREVIOUS) {
if (!kss->scratch)
kss->scratch = Gif_NewArray(scale_color, kss->width * kss->height);
for (y = gfi->top; y != gfi->top + gfi->height; ++y)
memcpy(&kss->scratch[y * kss->width + gfi->left],
&kss->data[y * kss->width + gfi->left],
sizeof(scale_color) * gfi->width);
}
for (y = gfi->top; y != gfi->top + gfi->height; ++y) {
const uint8_t* linein = gfi->img[y - gfi->top];
scale_color* lineout = &kss->data[y * kss->width + gfi->left];
for (x = 0; x != gfi->width; ++x)
if (linein[x] != gfi->transparent)
lineout[x] = sc_makekc(&ks[linein[x]]);
}
}
/* dispose of image `gfi`, which was previously applied by ksscreen_apply */
static void ksscreen_dispose(ksscreen* kss, const Gif_Image* gfi) {
int x, y;
assert((unsigned) gfi->left + gfi->width <= kss->width);
assert((unsigned) gfi->top + gfi->height <= kss->height);
if (gfi->disposal == GIF_DISPOSAL_PREVIOUS) {
for (y = gfi->top; y != gfi->top + gfi->height; ++y)
memcpy(&kss->data[y * kss->width + gfi->left],
&kss->scratch[y * kss->width + gfi->left],
sizeof(scale_color) * gfi->width);
} else if (gfi->disposal == GIF_DISPOSAL_BACKGROUND) {
for (y = gfi->top; y != gfi->top + gfi->height; ++y)
for (x = gfi->left; x != gfi->left + gfi->width; ++x)
kss->data[y * kss->width + x] = kss->bg;
}
}
typedef struct {
float w;
int ipos;
int opos;
} scale_weight;
typedef struct {
scale_weight* ws;
int n;
} scale_weightset;
typedef struct {
Gif_Stream* gfs;
Gif_Image* gfi;
int imageno;
kd3_tree* kd3;
ksscreen iscr;
kcscreen oscr;
kcscreen xscr;
double oxf; /* (input width) / (output width) */
double oyf; /* (input height) / (output height) */
double ixf; /* (output width) / (input width) */
double iyf; /* (output height) / (input height) */
scale_weightset xweights;
scale_weightset yweights;
kd3_tree global_kd3;
kd3_tree local_kd3;
unsigned max_desired_dist;
int scale_colors;
} scale_context;
#if ENABLE_THREADS
static pthread_mutex_t global_colormap_lock = PTHREAD_MUTEX_INITIALIZER;
#define GLOBAL_COLORMAP_LOCK() pthread_mutex_lock(&global_colormap_lock)
#define GLOBAL_COLORMAP_UNLOCK() pthread_mutex_unlock(&global_colormap_lock)
#else
#define GLOBAL_COLORMAP_LOCK() /* nada */
#define GLOBAL_COLORMAP_UNLOCK() /* nada */
#endif
static void sctx_init(scale_context* sctx, Gif_Stream* gfs, int nw, int nh) {
sctx->gfs = gfs;
sctx->gfi = NULL;
sctx->global_kd3.ks = NULL;
sctx->local_kd3.ks = NULL;
ksscreen_clear(&sctx->iscr);
kcscreen_clear(&sctx->oscr);
kcscreen_clear(&sctx->xscr);
sctx->iscr.width = gfs->screen_width;
sctx->iscr.height = gfs->screen_height;
sctx->oscr.width = nw;
sctx->oscr.height = nh;
sctx->xscr.width = nw;
sctx->xscr.height = nh;
sctx->ixf = (double) nw / gfs->screen_width;
sctx->iyf = (double) nh / gfs->screen_height;
sctx->oxf = gfs->screen_width / (double) nw;
sctx->oyf = gfs->screen_height / (double) nh;
sctx->xweights.ws = sctx->yweights.ws = NULL;
sctx->xweights.n = sctx->yweights.n = 0;
sctx->max_desired_dist = 16000;
sctx->scale_colors = 0;
sctx->kd3 = NULL;
sctx->imageno = 0;
}
static void sctx_cleanup(scale_context* sctx) {
if (sctx->global_kd3.ks)
kd3_cleanup(&sctx->global_kd3);
ksscreen_cleanup(&sctx->iscr);
kcscreen_cleanup(&sctx->oscr);
kcscreen_cleanup(&sctx->xscr);
Gif_DeleteArray(sctx->xweights.ws);
Gif_DeleteArray(sctx->yweights.ws);
}
static void scale_image_data_point(scale_context* sctx, Gif_Image* gfo) {
Gif_Image* gfi = sctx->gfi;
uint8_t* data = gfo->image_data;
int xo, yo;
uint16_t* xoff = Gif_NewArray(uint16_t, gfo->width);
for (xo = 0; xo != gfo->width; ++xo)
xoff[xo] = (int) ((gfo->left + xo + 0.5) * sctx->oxf) - gfi->left;
for (yo = 0; yo != gfo->height; ++yo) {
int yi = (int) ((gfo->top + yo + 0.5) * sctx->oyf) - gfi->top;
const uint8_t* in_line = gfi->img[yi];
for (xo = 0; xo != gfo->width; ++xo, ++data)
*data = in_line[xoff[xo]];
}
Gif_DeleteArray(xoff);
}
static void scale_image_update_global_kd3(scale_context* sctx) {
Gif_Colormap* gfcm = sctx->gfs->global;
assert(sctx->kd3 == &sctx->global_kd3);
while (sctx->kd3->nitems < gfcm->ncol) {
Gif_Color* gfc = &gfcm->col[sctx->kd3->nitems];
kd3_add8g(sctx->kd3, gfc->gfc_red, gfc->gfc_green, gfc->gfc_blue);
}
}
static void scale_image_prepare(scale_context* sctx) {
if (sctx->gfi->local) {
sctx->kd3 = &sctx->local_kd3;
kd3_init_build(sctx->kd3, NULL, sctx->gfi->local);
} else {
sctx->kd3 = &sctx->global_kd3;
if (!sctx->kd3->ks)
kd3_init(sctx->kd3, NULL);
GLOBAL_COLORMAP_LOCK();
scale_image_update_global_kd3(sctx);
GLOBAL_COLORMAP_UNLOCK();
if (!sctx->kd3->tree)
kd3_build(sctx->kd3);
kd3_enable_all(sctx->kd3);
}
if (sctx->gfi->transparent >= 0
&& sctx->gfi->transparent < sctx->kd3->nitems)
kd3_disable(sctx->kd3, sctx->gfi->transparent);
/* apply image to sctx->iscr */
if (!sctx->iscr.data) {
/* first image, set up screens */
ksscreen_init(&sctx->iscr, sctx->gfs, 0, 0);
kcscreen_init(&sctx->oscr, sctx->gfs,
sctx->oscr.width, sctx->oscr.height);
kcscreen_init(&sctx->xscr, sctx->gfs,
sctx->xscr.width, sctx->xscr.height);
}
ksscreen_apply(&sctx->iscr, sctx->gfi, sctx->kd3->ks);
}
static void scale_image_output_row(scale_context* sctx, scale_color* sc,
Gif_Image* gfo, int yo) {
int k, xo;
kacolor* oscr = &sctx->xscr.data[sctx->xscr.width * (yo + gfo->top)
+ gfo->left];
for (xo = 0; xo != gfo->width; ++xo)
if (sc[xo].a[3] <= (int) (KC_MAX / 4))
oscr[xo] = kac_transparent();
else {
/* don't effectively mix partially transparent pixels with black */
if (sc[xo].a[3] <= (int) (KC_MAX * 31 / 32))
SCVEC_MULF(sc[xo], KC_MAX / sc[xo].a[3]);
/* find closest color */
for (k = 0; k != 3; ++k) {
int v = (int) (sc[xo].a[k] + 0.5);
oscr[xo].a[k] = KC_CLAMPV(v);
}
oscr[xo].a[3] = KC_MAX;
}
}
static int scale_image_add_colors(scale_context* sctx, Gif_Image* gfo) {
kchist kch;
kcdiversity div;
Gif_Color gfc;
Gif_Colormap* gfcm = sctx->gfi->local ? sctx->gfi->local : sctx->gfs->global;
int yo, xo, i, nadded;
kchist_init(&kch);
for (yo = 0; yo != gfo->height; ++yo) {
kacolor* xscr = &sctx->xscr.data[sctx->xscr.width * (yo + gfo->top)
+ gfo->left];
for (xo = 0; xo != gfo->width; ++xo)
if (xscr[xo].a[3])
kchist_add(&kch, xscr[xo].k, 1);
}
for (i = 0; i != gfcm->ncol; ++i)
kchist_add(&kch, kc_makegfcg(&gfcm->col[i]), (kchist_count_t) -1);
kchist_compress(&kch);
kcdiversity_init(&div, &kch, 0);
for (i = 0; i != kch.n && i != gfcm->ncol
&& kch.h[i].count == (kchist_count_t) -1; ++i)
kcdiversity_choose(&div, i, 0);
nadded = 0;
while (gfcm->ncol < sctx->scale_colors) {
int chosen = kcdiversity_find_diverse(&div, 0);
if (chosen >= kch.n || div.min_dist[chosen] <= sctx->max_desired_dist)
break;
kcdiversity_choose(&div, chosen, 0);
gfc = kc_togfcg(&kch.h[chosen].ka.k);
Gif_AddColor(gfcm, &gfc, gfcm->ncol);
kd3_add8g(sctx->kd3, gfc.gfc_red, gfc.gfc_green, gfc.gfc_blue);
++nadded;
}
kcdiversity_cleanup(&div);
kchist_cleanup(&kch);
return nadded != 0;
}
static void scale_image_complete(scale_context* sctx, Gif_Image* gfo) {
int yo, xo, transparent = sctx->gfi->transparent;
unsigned dist, dist2, max_dist;
retry:
max_dist = 0;
/* look up palette for output screen */
for (yo = 0; yo != gfo->height; ++yo) {
uint8_t* data = gfo->img[yo];
kacolor* xscr = &sctx->xscr.data[sctx->xscr.width * (yo + gfo->top)
+ gfo->left];
kacolor* oscr = &sctx->oscr.data[sctx->oscr.width * (yo + gfo->top)
+ gfo->left];
for (xo = 0; xo != gfo->width; ++xo)
if (xscr[xo].a[3]) {
data[xo] = kd3_closest_transformed(sctx->kd3, &xscr[xo].k, &dist);
/* maybe previous color is actually closer to desired */
if (transparent >= 0 && oscr[xo].a[3]) {
dist2 = kc_distance(&oscr[xo].k, &xscr[xo].k);
if (dist2 <= dist) {
data[xo] = transparent;
dist = dist2;
}
}
max_dist = dist > max_dist ? dist : max_dist;
} else
data[xo] = transparent;
}
/* if the global colormap has changed, we must retry
(this can only happen if ENABLE_THREADS) */
if (!sctx->gfi->local) {
Gif_Colormap* gfcm = sctx->gfs->global;
GLOBAL_COLORMAP_LOCK();
if (gfcm->ncol > sctx->kd3->nitems) {
scale_image_update_global_kd3(sctx);
GLOBAL_COLORMAP_UNLOCK();
goto retry;
}
}
/* maybe add some colors */
if (max_dist > sctx->max_desired_dist) {
Gif_Colormap* gfcm = sctx->gfi->local ? sctx->gfi->local : sctx->gfs->global;
if (gfcm->ncol < sctx->scale_colors
&& scale_image_add_colors(sctx, gfo)) {
if (!sctx->gfi->local)
GLOBAL_COLORMAP_UNLOCK();
goto retry;
}
}
if (!sctx->gfi->local)
GLOBAL_COLORMAP_UNLOCK();
/* apply disposal to sctx->iscr and sctx->oscr */
if (sctx->imageno != sctx->gfs->nimages - 1) {
ksscreen_dispose(&sctx->iscr, sctx->gfi);
if (sctx->gfi->disposal == GIF_DISPOSAL_BACKGROUND)
kcscreen_dispose(&sctx->oscr, gfo);
else if (sctx->gfi->disposal != GIF_DISPOSAL_PREVIOUS)
kcscreen_apply(&sctx->oscr, gfo, sctx->kd3->ks);
}
if (sctx->gfi->local)
kd3_cleanup(sctx->kd3);
}
typedef struct pixel_range {
int lo;
int hi;
} pixel_range;
typedef struct pixel_range2 {
float bounds[2];
int lo;
int hi;
} pixel_range2;
static inline pixel_range make_pixel_range(int xi, int maxi,
int maxo, float f) {
pixel_range pr;
pr.lo = (int) (xi * f);
pr.hi = (int) ((xi + 1) * f);
pr.hi = (xi + 1 == maxi ? maxo : pr.hi);
pr.hi = (pr.hi == pr.lo ? pr.hi + 1 : pr.hi);
return pr;
}
static inline pixel_range2 make_pixel_range2(int xi, int maxi,
int maxo, float f) {
pixel_range2 pr;
pr.bounds[0] = xi * f;
pr.bounds[1] = (xi + 1) * f;
pr.lo = (int) pr.bounds[0];
if (xi + 1 == maxi)
pr.hi = maxo;
else
pr.hi = (int) ceil(pr.bounds[1]);
if (pr.hi == pr.lo)
++pr.hi;
return pr;
}
static void scale_image_data_box(scale_context* sctx, Gif_Image* gfo) {
uint16_t* xoff = Gif_NewArray(uint16_t, sctx->iscr.width);
scale_color* sc = Gif_NewArray(scale_color, gfo->width);
int* nsc = Gif_NewArray(int, gfo->width);
int xi0, xi1, xo, yo, i, j;
scale_image_prepare(sctx);
/* develop scale mapping of input -> output pixels */
for (xo = 0; xo != gfo->width; ++xo) {
pixel_range xpr = make_pixel_range(xo + gfo->left, sctx->oscr.width,
sctx->iscr.width, sctx->oxf);
for (i = xpr.lo; i != xpr.hi; ++i)
xoff[i] = xo;
}
xi0 = (int) (gfo->left * sctx->oxf);
xi1 = make_pixel_range(gfo->left + gfo->width - 1, sctx->oscr.width,
sctx->iscr.width, sctx->oxf).hi;
/* walk over output image */
for (yo = 0; yo != gfo->height; ++yo) {
pixel_range ypr = make_pixel_range(yo + gfo->top, sctx->oscr.height,
sctx->iscr.height, sctx->oyf);
for (xo = 0; xo != gfo->width; ++xo)
sc_clear(&sc[xo]);
for (xo = 0; xo != gfo->width; ++xo)
nsc[xo] = 0;
/* collect input mixes */
for (j = ypr.lo; j != ypr.hi; ++j) {
const scale_color* indata = &sctx->iscr.data[sctx->iscr.width*j];
for (i = xi0; i != xi1; ++i) {
++nsc[xoff[i]];
SCVEC_ADDV(sc[xoff[i]], indata[i]);
}
}
/* scale channels */
for (xo = 0; xo != gfo->width; ++xo)
SCVEC_DIVF(sc[xo], (float) nsc[xo]);
/* generate output */
scale_image_output_row(sctx, sc, gfo, yo);
}
scale_image_complete(sctx, gfo);
Gif_DeleteArray(xoff);
Gif_DeleteArray(sc);
Gif_DeleteArray(nsc);
}
static inline float mix_factor(int val, const float bounds[2]) {
if (val < bounds[0] && bounds[1] < val + 1)
return bounds[1] - bounds[0];
else if (val < bounds[0])
return 1 - (bounds[0] - val);
else if (bounds[1] < val + 1)
return bounds[1] - val;
else
return 1.0;
}
typedef struct scale_mixinfo {
uint16_t xi;
uint16_t xo;
float f;
} scale_mixinfo;
static void scale_image_data_mix(scale_context* sctx, Gif_Image* gfo) {
int xo, yo, i, j, nmix = 0, mixcap = sctx->iscr.width * 2;
scale_color* sc = Gif_NewArray(scale_color, gfo->width);
scale_mixinfo* mix = Gif_NewArray(scale_mixinfo, mixcap);
scale_image_prepare(sctx);
/* construct mixinfo */
for (xo = 0; xo != gfo->width; ++xo) {
pixel_range2 xpr = make_pixel_range2(xo + gfo->left, sctx->oscr.width,
sctx->iscr.width, sctx->oxf);
while (nmix + xpr.hi - xpr.lo > mixcap) {
mixcap *= 2;
Gif_ReArray(mix, scale_mixinfo, mixcap);
}
for (i = xpr.lo; i < xpr.hi; ++i, ++nmix) {
mix[nmix].xi = i;
mix[nmix].xo = xo;
mix[nmix].f = mix_factor(i, xpr.bounds);
}
}
for (yo = 0; yo != gfo->height; ++yo) {
pixel_range2 ypr = make_pixel_range2(yo + gfo->top, sctx->oscr.height,
sctx->iscr.height, sctx->oyf);
for (xo = 0; xo != gfo->width; ++xo)
sc_clear(&sc[xo]);
/* collect input mixes */
for (j = ypr.lo; j < ypr.hi; ++j) {
float jf = mix_factor(j, ypr.bounds) * sctx->ixf * sctx->iyf;
const scale_color* indata = &sctx->iscr.data[sctx->iscr.width*j];
for (i = 0; i != nmix; ++i)
SCVEC_ADDVxF(sc[mix[i].xo], indata[mix[i].xi],
(float) (mix[i].f * jf));
}
/* generate output */
scale_image_output_row(sctx, sc, gfo, yo);
}
scale_image_complete(sctx, gfo);
Gif_DeleteArray(sc);
Gif_DeleteArray(mix);
}
static void scale_weightset_add(scale_weightset* wset,
int ipos, int opos, double w) {
if (wset->n && wset->ws[wset->n - 1].ipos == ipos
&& wset->ws[wset->n - 1].opos == opos)
wset->ws[wset->n - 1].w += w;
else {
if (!wset->ws)
wset->ws = Gif_NewArray(scale_weight, 256);
else if (wset->n > 128 && (wset->n & (wset->n - 1)) == 0)
Gif_ReArray(wset->ws, scale_weight, wset->n * 2);
wset->ws[wset->n].w = w;
wset->ws[wset->n].ipos = ipos;
wset->ws[wset->n].opos = opos;
++wset->n;
}
}
static inline double scale_weight_cubic(double x, double b, double c) {
x = fabs(x);
if (x < 1)
return ((12 - 9*b - 6*c) * x*x*x
+ (-18 + 12*b + 6*c) * x*x
+ (6 - 2*b)) / 6;
else if (x < 2)
return ((-b - 6*c) * x*x*x
+ (6*b + 30*c) * x*x
+ (-12*b - 48*c) * x
+ (8*b + 24*c)) / 6;
else
return 0;
}
static inline double scale_weight_catrom(double x) {
return scale_weight_cubic(x, 0, 0.5);
}
static inline double scale_weight_mitchell(double x) {
return scale_weight_cubic(x, 1.0/3, 1.0/3);
}