kolibrios/contrib/media/updf/draw/draw_edge.c
Serhii Sakhno cd35d38ad2 updf: restore menuetlibc version
git-svn-id: svn://kolibrios.org@8429 a494cfbc-eb01-0410-851d-a64ba20cac60
2020-12-16 18:41:33 +00:00

736 lines
14 KiB
C

#include "fitz.h"
#define BBOX_MIN -(1<<20)
#define BBOX_MAX (1<<20)
/* divide and floor towards -inf */
static inline int fz_idiv(int a, int b)
{
return a < 0 ? (a - b + 1) / b : a / b;
}
/* If AA_BITS is defined, then we assume constant N bits of antialiasing. We
* will attempt to provide at least that number of bits of accuracy in the
* antialiasing (to a maximum of 8). If it is defined to be 0 then no
* antialiasing is done. If it is undefined to we will leave the antialiasing
* accuracy as a run time choice.
*/
#ifndef AA_BITS
#define AA_SCALE(x) ((x * fz_aa_scale) >> 8)
static int fz_aa_hscale = 17;
static int fz_aa_vscale = 15;
static int fz_aa_scale = 256;
static int fz_aa_level = 8;
#elif AA_BITS > 6
#define AA_SCALE(x) (x)
#define fz_aa_hscale 17
#define fz_aa_vscale 15
#define fz_aa_level 8
#elif AA_BITS > 4
#define AA_SCALE(x) ((x * 255) >> 6)
#define fz_aa_hscale 8
#define fz_aa_vscale 8
#define fz_aa_level 6
#elif AA_BITS > 2
#define AA_SCALE(x) (x * 17)
#define fz_aa_hscale 5
#define fz_aa_vscale 3
#define fz_aa_level 4
#elif AA_BITS > 0
#define AA_SCALE(x) ((x * 255) >> 2)
#define fz_aa_hscale 2
#define fz_aa_vscale 2
#define fz_aa_level 2
#else
#define AA_SCALE(x) (x * 255)
#define fz_aa_hscale 1
#define fz_aa_vscale 1
#define fz_aa_level 0
#endif
int
fz_get_aa_level(void)
{
return fz_aa_level;
}
void
fz_set_aa_level(int level)
{
#ifdef AA_BITS
fz_warn("anti-aliasing was compiled with a fixed precision of %d bits", fz_aa_level);
#else
if (level > 6)
{
fz_aa_hscale = 17;
fz_aa_vscale = 15;
fz_aa_level = 8;
}
else if (level > 4)
{
fz_aa_hscale = 8;
fz_aa_vscale = 8;
fz_aa_level = 6;
}
else if (level > 2)
{
fz_aa_hscale = 5;
fz_aa_vscale = 3;
fz_aa_level = 4;
}
else if (level > 0)
{
fz_aa_hscale = 2;
fz_aa_vscale = 2;
fz_aa_level = 2;
}
else
{
fz_aa_hscale = 1;
fz_aa_vscale = 1;
fz_aa_level = 0;
}
fz_aa_scale = 0xFF00 / (fz_aa_hscale * fz_aa_vscale);
#endif
}
/*
* Global Edge List -- list of straight path segments for scan conversion
*
* Stepping along the edges is with bresenham's line algorithm.
*
* See Mike Abrash -- Graphics Programming Black Book (notably chapter 40)
*/
typedef struct fz_edge_s fz_edge;
struct fz_edge_s
{
int x, e, h, y;
int adj_up, adj_down;
int xmove;
int xdir, ydir; /* -1 or +1 */
};
struct fz_gel_s
{
fz_bbox clip;
fz_bbox bbox;
int cap, len;
fz_edge *edges;
int acap, alen;
fz_edge **active;
};
fz_gel *
fz_new_gel(void)
{
fz_gel *gel;
gel = fz_malloc(sizeof(fz_gel));
gel->cap = 512;
gel->len = 0;
gel->edges = fz_calloc(gel->cap, sizeof(fz_edge));
gel->clip.x0 = gel->clip.y0 = BBOX_MAX;
gel->clip.x1 = gel->clip.y1 = BBOX_MIN;
gel->bbox.x0 = gel->bbox.y0 = BBOX_MAX;
gel->bbox.x1 = gel->bbox.y1 = BBOX_MIN;
gel->acap = 64;
gel->alen = 0;
gel->active = fz_calloc(gel->acap, sizeof(fz_edge*));
return gel;
}
void
fz_reset_gel(fz_gel *gel, fz_bbox clip)
{
if (fz_is_infinite_rect(clip))
{
gel->clip.x0 = gel->clip.y0 = BBOX_MAX;
gel->clip.x1 = gel->clip.y1 = BBOX_MIN;
}
else {
gel->clip.x0 = clip.x0 * fz_aa_hscale;
gel->clip.x1 = clip.x1 * fz_aa_hscale;
gel->clip.y0 = clip.y0 * fz_aa_vscale;
gel->clip.y1 = clip.y1 * fz_aa_vscale;
}
gel->bbox.x0 = gel->bbox.y0 = BBOX_MAX;
gel->bbox.x1 = gel->bbox.y1 = BBOX_MIN;
gel->len = 0;
}
void
fz_free_gel(fz_gel *gel)
{
fz_free(gel->active);
fz_free(gel->edges);
fz_free(gel);
}
fz_bbox
fz_bound_gel(fz_gel *gel)
{
fz_bbox bbox;
if (gel->len == 0)
return fz_empty_bbox;
bbox.x0 = fz_idiv(gel->bbox.x0, fz_aa_hscale);
bbox.y0 = fz_idiv(gel->bbox.y0, fz_aa_vscale);
bbox.x1 = fz_idiv(gel->bbox.x1, fz_aa_hscale) + 1;
bbox.y1 = fz_idiv(gel->bbox.y1, fz_aa_vscale) + 1;
return bbox;
}
enum { INSIDE, OUTSIDE, LEAVE, ENTER };
#define clip_lerp_y(v,m,x0,y0,x1,y1,t) clip_lerp_x(v,m,y0,x0,y1,x1,t)
static int
clip_lerp_x(int val, int m, int x0, int y0, int x1, int y1, int *out)
{
int v0out = m ? x0 > val : x0 < val;
int v1out = m ? x1 > val : x1 < val;
if (v0out + v1out == 0)
return INSIDE;
if (v0out + v1out == 2)
return OUTSIDE;
if (v1out)
{
*out = y0 + (y1 - y0) * (val - x0) / (x1 - x0);
return LEAVE;
}
else
{
*out = y1 + (y0 - y1) * (val - x1) / (x0 - x1);
return ENTER;
}
}
static void
fz_insert_gel_raw(fz_gel *gel, int x0, int y0, int x1, int y1)
{
fz_edge *edge;
int dx, dy;
int winding;
int width;
int tmp;
if (y0 == y1)
return;
if (y0 > y1) {
winding = -1;
tmp = x0; x0 = x1; x1 = tmp;
tmp = y0; y0 = y1; y1 = tmp;
}
else
winding = 1;
if (x0 < gel->bbox.x0) gel->bbox.x0 = x0;
if (x0 > gel->bbox.x1) gel->bbox.x1 = x0;
if (x1 < gel->bbox.x0) gel->bbox.x0 = x1;
if (x1 > gel->bbox.x1) gel->bbox.x1 = x1;
if (y0 < gel->bbox.y0) gel->bbox.y0 = y0;
if (y1 > gel->bbox.y1) gel->bbox.y1 = y1;
if (gel->len + 1 == gel->cap) {
gel->cap = gel->cap + 512;
gel->edges = fz_realloc(gel->edges, gel->cap, sizeof(fz_edge));
}
edge = &gel->edges[gel->len++];
dy = y1 - y0;
dx = x1 - x0;
width = ABS(dx);
edge->xdir = dx > 0 ? 1 : -1;
edge->ydir = winding;
edge->x = x0;
edge->y = y0;
edge->h = dy;
edge->adj_down = dy;
/* initial error term going l->r and r->l */
if (dx >= 0)
edge->e = 0;
else
edge->e = -dy + 1;
/* y-major edge */
if (dy >= width) {
edge->xmove = 0;
edge->adj_up = width;
}
/* x-major edge */
else {
edge->xmove = (width / dy) * edge->xdir;
edge->adj_up = width % dy;
}
}
void
fz_insert_gel(fz_gel *gel, float fx0, float fy0, float fx1, float fy1)
{
int x0, y0, x1, y1;
int d, v;
fx0 = floorf(fx0 * fz_aa_hscale);
fx1 = floorf(fx1 * fz_aa_hscale);
fy0 = floorf(fy0 * fz_aa_vscale);
fy1 = floorf(fy1 * fz_aa_vscale);
x0 = CLAMP(fx0, BBOX_MIN, BBOX_MAX);
y0 = CLAMP(fy0, BBOX_MIN, BBOX_MAX);
x1 = CLAMP(fx1, BBOX_MIN, BBOX_MAX);
y1 = CLAMP(fy1, BBOX_MIN, BBOX_MAX);
d = clip_lerp_y(gel->clip.y0, 0, x0, y0, x1, y1, &v);
if (d == OUTSIDE) return;
if (d == LEAVE) { y1 = gel->clip.y0; x1 = v; }
if (d == ENTER) { y0 = gel->clip.y0; x0 = v; }
d = clip_lerp_y(gel->clip.y1, 1, x0, y0, x1, y1, &v);
if (d == OUTSIDE) return;
if (d == LEAVE) { y1 = gel->clip.y1; x1 = v; }
if (d == ENTER) { y0 = gel->clip.y1; x0 = v; }
d = clip_lerp_x(gel->clip.x0, 0, x0, y0, x1, y1, &v);
if (d == OUTSIDE) {
x0 = x1 = gel->clip.x0;
}
if (d == LEAVE) {
fz_insert_gel_raw(gel, gel->clip.x0, v, gel->clip.x0, y1);
x1 = gel->clip.x0;
y1 = v;
}
if (d == ENTER) {
fz_insert_gel_raw(gel, gel->clip.x0, y0, gel->clip.x0, v);
x0 = gel->clip.x0;
y0 = v;
}
d = clip_lerp_x(gel->clip.x1, 1, x0, y0, x1, y1, &v);
if (d == OUTSIDE) {
x0 = x1 = gel->clip.x1;
}
if (d == LEAVE) {
fz_insert_gel_raw(gel, gel->clip.x1, v, gel->clip.x1, y1);
x1 = gel->clip.x1;
y1 = v;
}
if (d == ENTER) {
fz_insert_gel_raw(gel, gel->clip.x1, y0, gel->clip.x1, v);
x0 = gel->clip.x1;
y0 = v;
}
fz_insert_gel_raw(gel, x0, y0, x1, y1);
}
void
fz_sort_gel(fz_gel *gel)
{
fz_edge *a = gel->edges;
int n = gel->len;
int h, i, k;
fz_edge t;
h = 1;
if (n < 14) {
h = 1;
}
else {
while (h < n)
h = 3 * h + 1;
h /= 3;
h /= 3;
}
while (h > 0)
{
for (i = 0; i < n; i++) {
t = a[i];
k = i - h;
/* TODO: sort on y major, x minor */
while (k >= 0 && a[k].y > t.y) {
a[k + h] = a[k];
k -= h;
}
a[k + h] = t;
}
h /= 3;
}
}
int
fz_is_rect_gel(fz_gel *gel)
{
/* a rectangular path is converted into two vertical edges of identical height */
if (gel->len == 2)
{
fz_edge *a = gel->edges + 0;
fz_edge *b = gel->edges + 1;
return a->y == b->y && a->h == b->h &&
a->xmove == 0 && a->adj_up == 0 &&
b->xmove == 0 && b->adj_up == 0;
}
return 0;
}
/*
* Active Edge List -- keep track of active edges while sweeping
*/
static void
sort_active(fz_edge **a, int n)
{
int h, i, k;
fz_edge *t;
h = 1;
if (n < 14) {
h = 1;
}
else {
while (h < n)
h = 3 * h + 1;
h /= 3;
h /= 3;
}
while (h > 0)
{
for (i = 0; i < n; i++) {
t = a[i];
k = i - h;
while (k >= 0 && a[k]->x > t->x) {
a[k + h] = a[k];
k -= h;
}
a[k + h] = t;
}
h /= 3;
}
}
static void
insert_active(fz_gel *gel, int y, int *e)
{
/* insert edges that start here */
while (*e < gel->len && gel->edges[*e].y == y) {
if (gel->alen + 1 == gel->acap) {
int newcap = gel->acap + 64;
fz_edge **newactive = fz_realloc(gel->active, newcap, sizeof(fz_edge*));
gel->active = newactive;
gel->acap = newcap;
}
gel->active[gel->alen++] = &gel->edges[(*e)++];
}
/* shell-sort the edges by increasing x */
sort_active(gel->active, gel->alen);
}
static void
advance_active(fz_gel *gel)
{
fz_edge *edge;
int i = 0;
while (i < gel->alen)
{
edge = gel->active[i];
edge->h --;
/* terminator! */
if (edge->h == 0) {
gel->active[i] = gel->active[--gel->alen];
}
else {
edge->x += edge->xmove;
edge->e += edge->adj_up;
if (edge->e > 0) {
edge->x += edge->xdir;
edge->e -= edge->adj_down;
}
i ++;
}
}
}
/*
* Anti-aliased scan conversion.
*/
static inline void add_span_aa(int *list, int x0, int x1, int xofs)
{
int x0pix, x0sub;
int x1pix, x1sub;
if (x0 == x1)
return;
/* x between 0 and width of bbox */
x0 -= xofs;
x1 -= xofs;
x0pix = x0 / fz_aa_hscale;
x0sub = x0 % fz_aa_hscale;
x1pix = x1 / fz_aa_hscale;
x1sub = x1 % fz_aa_hscale;
if (x0pix == x1pix)
{
list[x0pix] += x1sub - x0sub;
list[x0pix+1] += x0sub - x1sub;
}
else
{
list[x0pix] += fz_aa_hscale - x0sub;
list[x0pix+1] += x0sub;
list[x1pix] += x1sub - fz_aa_hscale;
list[x1pix+1] += -x1sub;
}
}
static inline void non_zero_winding_aa(fz_gel *gel, int *list, int xofs)
{
int winding = 0;
int x = 0;
int i;
for (i = 0; i < gel->alen; i++)
{
if (!winding && (winding + gel->active[i]->ydir))
x = gel->active[i]->x;
if (winding && !(winding + gel->active[i]->ydir))
add_span_aa(list, x, gel->active[i]->x, xofs);
winding += gel->active[i]->ydir;
}
}
static inline void even_odd_aa(fz_gel *gel, int *list, int xofs)
{
int even = 0;
int x = 0;
int i;
for (i = 0; i < gel->alen; i++)
{
if (!even)
x = gel->active[i]->x;
else
add_span_aa(list, x, gel->active[i]->x, xofs);
even = !even;
}
}
static inline void undelta_aa(unsigned char * restrict out, int * restrict in, int n)
{
int d = 0;
while (n--)
{
d += *in++;
*out++ = AA_SCALE(d);
}
}
static inline void blit_aa(fz_pixmap *dst, int x, int y,
unsigned char *mp, int w, unsigned char *color)
{
unsigned char *dp;
dp = dst->samples + ( (y - dst->y) * dst->w + (x - dst->x) ) * dst->n;
if (color)
fz_paint_span_with_color(dp, mp, dst->n, w, color);
else
fz_paint_span(dp, mp, 1, w, 255);
}
static void
fz_scan_convert_aa(fz_gel *gel, int eofill, fz_bbox clip,
fz_pixmap *dst, unsigned char *color)
{
unsigned char *alphas;
int *deltas;
int y, e;
int yd, yc;
int xmin = fz_idiv(gel->bbox.x0, fz_aa_hscale);
int xmax = fz_idiv(gel->bbox.x1, fz_aa_hscale) + 1;
int xofs = xmin * fz_aa_hscale;
int skipx = clip.x0 - xmin;
int clipn = clip.x1 - clip.x0;
if (gel->len == 0)
return;
assert(clip.x0 >= xmin);
assert(clip.x1 <= xmax);
alphas = fz_malloc(xmax - xmin + 1);
deltas = fz_malloc((xmax - xmin + 1) * sizeof(int));
memset(deltas, 0, (xmax - xmin + 1) * sizeof(int));
e = 0;
y = gel->edges[0].y;
yc = fz_idiv(y, fz_aa_vscale);
yd = yc;
while (gel->alen > 0 || e < gel->len)
{
yc = fz_idiv(y, fz_aa_vscale);
if (yc != yd)
{
if (yd >= clip.y0 && yd < clip.y1)
{
undelta_aa(alphas, deltas, skipx + clipn);
blit_aa(dst, xmin + skipx, yd, alphas + skipx, clipn, color);
memset(deltas, 0, (skipx + clipn) * sizeof(int));
}
}
yd = yc;
insert_active(gel, y, &e);
if (yd >= clip.y0 && yd < clip.y1)
{
if (eofill)
even_odd_aa(gel, deltas, xofs);
else
non_zero_winding_aa(gel, deltas, xofs);
}
advance_active(gel);
if (gel->alen > 0)
y ++;
else if (e < gel->len)
y = gel->edges[e].y;
}
if (yd >= clip.y0 && yd < clip.y1)
{
undelta_aa(alphas, deltas, skipx + clipn);
blit_aa(dst, xmin + skipx, yd, alphas + skipx, clipn, color);
}
fz_free(deltas);
fz_free(alphas);
}
/*
* Sharp (not anti-aliased) scan conversion
*/
static inline void blit_sharp(int x0, int x1, int y,
fz_bbox clip, fz_pixmap *dst, unsigned char *color)
{
unsigned char *dp;
x0 = CLAMP(x0, dst->x, dst->x + dst->w);
x1 = CLAMP(x1, dst->x, dst->x + dst->w);
if (x0 < x1)
{
dp = dst->samples + ( (y - dst->y) * dst->w + (x0 - dst->x) ) * dst->n;
if (color)
fz_paint_solid_color(dp, dst->n, x1 - x0, color);
else
fz_paint_solid_alpha(dp, x1 - x0, 255);
}
}
static inline void non_zero_winding_sharp(fz_gel *gel, int y,
fz_bbox clip, fz_pixmap *dst, unsigned char *color)
{
int winding = 0;
int x = 0;
int i;
for (i = 0; i < gel->alen; i++)
{
if (!winding && (winding + gel->active[i]->ydir))
x = gel->active[i]->x;
if (winding && !(winding + gel->active[i]->ydir))
blit_sharp(x, gel->active[i]->x, y, clip, dst, color);
winding += gel->active[i]->ydir;
}
}
static inline void even_odd_sharp(fz_gel *gel, int y,
fz_bbox clip, fz_pixmap *dst, unsigned char *color)
{
int even = 0;
int x = 0;
int i;
for (i = 0; i < gel->alen; i++)
{
if (!even)
x = gel->active[i]->x;
else
blit_sharp(x, gel->active[i]->x, y, clip, dst, color);
even = !even;
}
}
static void
fz_scan_convert_sharp(fz_gel *gel, int eofill, fz_bbox clip,
fz_pixmap *dst, unsigned char *color)
{
int e = 0;
int y = gel->edges[0].y;
while (gel->alen > 0 || e < gel->len)
{
insert_active(gel, y, &e);
if (y >= clip.y0 && y < clip.y1)
{
if (eofill)
even_odd_sharp(gel, y, clip, dst, color);
else
non_zero_winding_sharp(gel, y, clip, dst, color);
}
advance_active(gel);
if (gel->alen > 0)
y ++;
else if (e < gel->len)
y = gel->edges[e].y;
}
}
void
fz_scan_convert(fz_gel *gel, int eofill, fz_bbox clip,
fz_pixmap *dst, unsigned char *color)
{
if (fz_aa_level > 0)
fz_scan_convert_aa(gel, eofill, clip, dst, color);
else
fz_scan_convert_sharp(gel, eofill, clip, dst, color);
}