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#include "fitz-internal.h"
/* PDF 1.4 blend modes. These are slow. */
typedef unsigned char byte;
static const char *fz_blendmode_names[] =
{
"Normal",
"Multiply",
"Screen",
"Overlay",
"Darken",
"Lighten",
"ColorDodge",
"ColorBurn",
"HardLight",
"SoftLight",
"Difference",
"Exclusion",
"Hue",
"Saturation",
"Color",
"Luminosity",
};
int fz_lookup_blendmode(char *name)
{
int i;
for (i = 0; i < nelem(fz_blendmode_names); i++)
if (!strcmp(name, fz_blendmode_names[i]))
return i;
return FZ_BLEND_NORMAL;
}
char *fz_blendmode_name(int blendmode)
{
if (blendmode >= 0 && blendmode < nelem(fz_blendmode_names))
return (char*)fz_blendmode_names[blendmode];
return "Normal";
}
/* Separable blend modes */
static inline int fz_screen_byte(int b, int s)
{
return b + s - fz_mul255(b, s);
}
static inline int fz_hard_light_byte(int b, int s)
{
int s2 = s << 1;
if (s <= 127)
return fz_mul255(b, s2);
else
return fz_screen_byte(b, s2 - 255);
}
static inline int fz_overlay_byte(int b, int s)
{
return fz_hard_light_byte(s, b); /* note swapped order */
}
static inline int fz_darken_byte(int b, int s)
{
return fz_mini(b, s);
}
static inline int fz_lighten_byte(int b, int s)
{
return fz_maxi(b, s);
}
static inline int fz_color_dodge_byte(int b, int s)
{
s = 255 - s;
if (b == 0)
return 0;
else if (b >= s)
return 255;
else
return (0x1fe * b + s) / (s << 1);
}
static inline int fz_color_burn_byte(int b, int s)
{
b = 255 - b;
if (b == 0)
return 255;
else if (b >= s)
return 0;
else
return 0xff - (0x1fe * b + s) / (s << 1);
}
static inline int fz_soft_light_byte(int b, int s)
{
/* review this */
if (s < 128) {
return b - fz_mul255(fz_mul255((255 - (s<<1)), b), 255 - b);
}
else {
int dbd;
if (b < 64)
dbd = fz_mul255(fz_mul255((b << 4) - 12, b) + 4, b);
else
dbd = (int)sqrtf(255.0f * b);
return b + fz_mul255(((s<<1) - 255), (dbd - b));
}
}
static inline int fz_difference_byte(int b, int s)
{
return fz_absi(b - s);
}
static inline int fz_exclusion_byte(int b, int s)
{
return b + s - (fz_mul255(b, s)<<1);
}
/* Non-separable blend modes */
static void
fz_luminosity_rgb(unsigned char *rd, unsigned char *gd, unsigned char *bd, int rb, int gb, int bb, int rs, int gs, int bs)
{
int delta, scale;
int r, g, b, y;
/* 0.3, 0.59, 0.11 in fixed point */
delta = ((rs - rb) * 77 + (gs - gb) * 151 + (bs - bb) * 28 + 0x80) >> 8;
r = rb + delta;
g = gb + delta;
b = bb + delta;
if ((r | g | b) & 0x100)
{
y = (rs * 77 + gs * 151 + bs * 28 + 0x80) >> 8;
if (delta > 0)
{
int max;
max = fz_maxi(r, fz_maxi(g, b));
scale = (max == y ? 0 : ((255 - y) << 16) / (max - y));
}
else
{
int min;
min = fz_mini(r, fz_mini(g, b));
scale = (y == min ? 0 : (y << 16) / (y - min));
}
r = y + (((r - y) * scale + 0x8000) >> 16);
g = y + (((g - y) * scale + 0x8000) >> 16);
b = y + (((b - y) * scale + 0x8000) >> 16);
}
*rd = fz_clampi(r, 0, 255);
*gd = fz_clampi(g, 0, 255);
*bd = fz_clampi(b, 0, 255);
}
static void
fz_saturation_rgb(unsigned char *rd, unsigned char *gd, unsigned char *bd, int rb, int gb, int bb, int rs, int gs, int bs)
{
int minb, maxb;
int mins, maxs;
int y;
int scale;
int r, g, b;
minb = fz_mini(rb, fz_mini(gb, bb));
maxb = fz_maxi(rb, fz_maxi(gb, bb));
if (minb == maxb)
{
/* backdrop has zero saturation, avoid divide by 0 */
gb = fz_clampi(gb, 0, 255);
*rd = gb;
*gd = gb;
*bd = gb;
return;
}
mins = fz_mini(rs, fz_mini(gs, bs));
maxs = fz_maxi(rs, fz_maxi(gs, bs));
scale = ((maxs - mins) << 16) / (maxb - minb);
y = (rb * 77 + gb * 151 + bb * 28 + 0x80) >> 8;
r = y + ((((rb - y) * scale) + 0x8000) >> 16);
g = y + ((((gb - y) * scale) + 0x8000) >> 16);
b = y + ((((bb - y) * scale) + 0x8000) >> 16);
if ((r | g | b) & 0x100)
{
int scalemin, scalemax;
int min, max;
min = fz_mini(r, fz_mini(g, b));
max = fz_maxi(r, fz_maxi(g, b));
if (min < 0)
scalemin = (y << 16) / (y - min);
else
scalemin = 0x10000;
if (max > 255)
scalemax = ((255 - y) << 16) / (max - y);
else
scalemax = 0x10000;
scale = fz_mini(scalemin, scalemax);
r = y + (((r - y) * scale + 0x8000) >> 16);
g = y + (((g - y) * scale + 0x8000) >> 16);
b = y + (((b - y) * scale + 0x8000) >> 16);
}
*rd = fz_clampi(r, 0, 255);
*gd = fz_clampi(g, 0, 255);
*bd = fz_clampi(b, 0, 255);
}
static void
fz_color_rgb(unsigned char *rr, unsigned char *rg, unsigned char *rb, int br, int bg, int bb, int sr, int sg, int sb)
{
fz_luminosity_rgb(rr, rg, rb, sr, sg, sb, br, bg, bb);
}
static void
fz_hue_rgb(unsigned char *rr, unsigned char *rg, unsigned char *rb, int br, int bg, int bb, int sr, int sg, int sb)
{
unsigned char tr, tg, tb;
fz_luminosity_rgb(&tr, &tg, &tb, sr, sg, sb, br, bg, bb);
fz_saturation_rgb(rr, rg, rb, tr, tg, tb, br, bg, bb);
}
void
fz_blend_pixel(unsigned char dp[3], unsigned char bp[3], unsigned char sp[3], int blendmode)
{
int k;
/* non-separable blend modes */
switch (blendmode)
{
case FZ_BLEND_HUE: fz_hue_rgb(&dp[0], &dp[1], &dp[2], bp[0], bp[1], bp[2], sp[0], sp[1], sp[2]); return;
case FZ_BLEND_SATURATION: fz_saturation_rgb(&dp[0], &dp[1], &dp[2], bp[0], bp[1], bp[2], sp[0], sp[1], sp[2]); return;
case FZ_BLEND_COLOR: fz_color_rgb(&dp[0], &dp[1], &dp[2], bp[0], bp[1], bp[2], sp[0], sp[1], sp[2]); return;
case FZ_BLEND_LUMINOSITY: fz_luminosity_rgb(&dp[0], &dp[1], &dp[2], bp[0], bp[1], bp[2], sp[0], sp[1], sp[2]); return;
}
/* separable blend modes */
for (k = 0; k < 3; k++)
{
switch (blendmode)
{
default:
case FZ_BLEND_NORMAL: dp[k] = sp[k]; break;
case FZ_BLEND_MULTIPLY: dp[k] = fz_mul255(bp[k], sp[k]); break;
case FZ_BLEND_SCREEN: dp[k] = fz_screen_byte(bp[k], sp[k]); break;
case FZ_BLEND_OVERLAY: dp[k] = fz_overlay_byte(bp[k], sp[k]); break;
case FZ_BLEND_DARKEN: dp[k] = fz_darken_byte(bp[k], sp[k]); break;
case FZ_BLEND_LIGHTEN: dp[k] = fz_lighten_byte(bp[k], sp[k]); break;
case FZ_BLEND_COLOR_DODGE: dp[k] = fz_color_dodge_byte(bp[k], sp[k]); break;
case FZ_BLEND_COLOR_BURN: dp[k] = fz_color_burn_byte(bp[k], sp[k]); break;
case FZ_BLEND_HARD_LIGHT: dp[k] = fz_hard_light_byte(bp[k], sp[k]); break;
case FZ_BLEND_SOFT_LIGHT: dp[k] = fz_soft_light_byte(bp[k], sp[k]); break;
case FZ_BLEND_DIFFERENCE: dp[k] = fz_difference_byte(bp[k], sp[k]); break;
case FZ_BLEND_EXCLUSION: dp[k] = fz_exclusion_byte(bp[k], sp[k]); break;
}
}
}
/* Blending loops */
void
fz_blend_separable(byte * restrict bp, byte * restrict sp, int n, int w, int blendmode)
{
int k;
int n1 = n - 1;
while (w--)
{
int sa = sp[n1];
int ba = bp[n1];
int saba = fz_mul255(sa, ba);
/* ugh, division to get non-premul components */
int invsa = sa ? 255 * 256 / sa : 0;
int invba = ba ? 255 * 256 / ba : 0;
for (k = 0; k < n1; k++)
{
int sc = (sp[k] * invsa) >> 8;
int bc = (bp[k] * invba) >> 8;
int rc;
switch (blendmode)
{
default:
case FZ_BLEND_NORMAL: rc = sc; break;
case FZ_BLEND_MULTIPLY: rc = fz_mul255(bc, sc); break;
case FZ_BLEND_SCREEN: rc = fz_screen_byte(bc, sc); break;
case FZ_BLEND_OVERLAY: rc = fz_overlay_byte(bc, sc); break;
case FZ_BLEND_DARKEN: rc = fz_darken_byte(bc, sc); break;
case FZ_BLEND_LIGHTEN: rc = fz_lighten_byte(bc, sc); break;
case FZ_BLEND_COLOR_DODGE: rc = fz_color_dodge_byte(bc, sc); break;
case FZ_BLEND_COLOR_BURN: rc = fz_color_burn_byte(bc, sc); break;
case FZ_BLEND_HARD_LIGHT: rc = fz_hard_light_byte(bc, sc); break;
case FZ_BLEND_SOFT_LIGHT: rc = fz_soft_light_byte(bc, sc); break;
case FZ_BLEND_DIFFERENCE: rc = fz_difference_byte(bc, sc); break;
case FZ_BLEND_EXCLUSION: rc = fz_exclusion_byte(bc, sc); break;
}
bp[k] = fz_mul255(255 - sa, bp[k]) + fz_mul255(255 - ba, sp[k]) + fz_mul255(saba, rc);
}
bp[k] = ba + sa - saba;
sp += n;
bp += n;
}
}
void
fz_blend_nonseparable(byte * restrict bp, byte * restrict sp, int w, int blendmode)
{
while (w--)
{
unsigned char rr, rg, rb;
int sa = sp[3];
int ba = bp[3];
int saba = fz_mul255(sa, ba);
/* ugh, division to get non-premul components */
int invsa = sa ? 255 * 256 / sa : 0;
int invba = ba ? 255 * 256 / ba : 0;
int sr = (sp[0] * invsa) >> 8;
int sg = (sp[1] * invsa) >> 8;
int sb = (sp[2] * invsa) >> 8;
int br = (bp[0] * invba) >> 8;
int bg = (bp[1] * invba) >> 8;
int bb = (bp[2] * invba) >> 8;
switch (blendmode)
{
default:
case FZ_BLEND_HUE:
fz_hue_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
case FZ_BLEND_SATURATION:
fz_saturation_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
case FZ_BLEND_COLOR:
fz_color_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
case FZ_BLEND_LUMINOSITY:
fz_luminosity_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
}
bp[0] = fz_mul255(255 - sa, bp[0]) + fz_mul255(255 - ba, sp[0]) + fz_mul255(saba, rr);
bp[1] = fz_mul255(255 - sa, bp[1]) + fz_mul255(255 - ba, sp[1]) + fz_mul255(saba, rg);
bp[2] = fz_mul255(255 - sa, bp[2]) + fz_mul255(255 - ba, sp[2]) + fz_mul255(saba, rb);
bp[3] = ba + sa - saba;
sp += 4;
bp += 4;
}
}
static void
fz_blend_separable_nonisolated(byte * restrict bp, byte * restrict sp, int n, int w, int blendmode, byte * restrict hp, int alpha)
{
int k;
int n1 = n - 1;
if (alpha == 255 && blendmode == 0)
{
/* In this case, the uncompositing and the recompositing
* cancel one another out, and it's just a simple copy. */
/* FIXME: Maybe we can avoid using the shape plane entirely
* and just copy? */
while (w--)
{
int ha = fz_mul255(*hp++, alpha); /* ha = shape_alpha */
/* If ha == 0 then leave everything unchanged */
if (ha != 0)
{
for (k = 0; k < n; k++)
{
bp[k] = sp[k];
}
}
sp += n;
bp += n;
}
return;
}
while (w--)
{
int ha = *hp++;
int haa = fz_mul255(ha, alpha); /* ha = shape_alpha */
/* If haa == 0 then leave everything unchanged */
while (haa != 0) /* Use while, so we can break out */
{
int sa, ba, bahaa, ra, invsa, invba, invha, invra;
sa = sp[n1];
if (sa == 0)
break; /* No change! */
invsa = sa ? 255 * 256 / sa : 0;
ba = bp[n1];
if (ba == 0)
{
/* Just copy pixels (allowing for change in
* premultiplied alphas) */
for (k = 0; k < n1; k++)
{
bp[k] = fz_mul255((sp[k] * invsa) >> 8, haa);
}
bp[n1] = haa;
break;
}
bahaa = fz_mul255(ba, haa);
/* ugh, division to get non-premul components */
invba = ba ? 255 * 256 / ba : 0;
/* Calculate result_alpha - a combination of the
* background alpha, and 'shape' */
ra = bp[n1] = ba - bahaa + haa;
if (ra == 0)
break;
/* Because we are a non-isolated group, we need to
* 'uncomposite' before we blend (recomposite).
* We assume that normal blending has been done inside
* the group, so: rc = (1-ha).bc + ha.sc
* A bit of rearrangement, and that gives us that:
* sc = (rc - bc)/ha + bc
* Now, the result of the blend (rc) was stored in src, so
* we actually want to calculate:
* sc = (sc-bc)/ha + bc
*/
invha = ha ? 255 * 256 / ha : 0;
invra = ra ? 255 * 256 / ra : 0;
/* sa = the final alpha to blend with - this
* is calculated from the shape + alpha,
* divided by ra. */
sa = (haa*invra + 128)>>8;
if (sa < 0) sa = 0;
if (sa > 255) sa = 255;
for (k = 0; k < n1; k++)
{
/* Read pixels (and convert to non-premultiplied form) */
int sc = (sp[k] * invsa + 128) >> 8;
int bc = (bp[k] * invba + 128) >> 8;
int rc;
/* Uncomposite (see above) */
sc = (((sc-bc) * invha + 128)>>8) + bc;
if (sc < 0) sc = 0;
if (sc > 255) sc = 255;
switch (blendmode)
{
default:
case FZ_BLEND_NORMAL: rc = sc; break;
case FZ_BLEND_MULTIPLY: rc = fz_mul255(bc, sc); break;
case FZ_BLEND_SCREEN: rc = fz_screen_byte(bc, sc); break;
case FZ_BLEND_OVERLAY: rc = fz_overlay_byte(bc, sc); break;
case FZ_BLEND_DARKEN: rc = fz_darken_byte(bc, sc); break;
case FZ_BLEND_LIGHTEN: rc = fz_lighten_byte(bc, sc); break;
case FZ_BLEND_COLOR_DODGE: rc = fz_color_dodge_byte(bc, sc); break;
case FZ_BLEND_COLOR_BURN: rc = fz_color_burn_byte(bc, sc); break;
case FZ_BLEND_HARD_LIGHT: rc = fz_hard_light_byte(bc, sc); break;
case FZ_BLEND_SOFT_LIGHT: rc = fz_soft_light_byte(bc, sc); break;
case FZ_BLEND_DIFFERENCE: rc = fz_difference_byte(bc, sc); break;
case FZ_BLEND_EXCLUSION: rc = fz_exclusion_byte(bc, sc); break;
}
/* Composition formula, as given in pdf_reference17.pdf:
* rc = ( 1 - (ha/ra)) * bc + (ha/ra) * ((1-ba)*sc + ba * rc)
*/
rc = bc + fz_mul255(sa, fz_mul255(255 - ba, sc) + fz_mul255(ba, rc) - bc);
if (rc < 0) rc = 0;
if (rc > 255) rc = 255;
bp[k] = fz_mul255(rc, ra);
}
break;
}
sp += n;
bp += n;
}
}
static void
fz_blend_nonseparable_nonisolated(byte * restrict bp, byte * restrict sp, int w, int blendmode, byte * restrict hp, int alpha)
{
while (w--)
{
int ha = *hp++;
int haa = fz_mul255(ha, alpha);
if (haa != 0)
{
int sa = sp[3];
int ba = bp[3];
int baha = fz_mul255(ba, haa);
/* Calculate result_alpha */
int ra = bp[3] = ba - baha + haa;
if (ra != 0)
{
/* Because we are a non-isolated group, we
* need to 'uncomposite' before we blend
* (recomposite). We assume that normal
* blending has been done inside the group,
* so: ra.rc = (1-ha).bc + ha.sc
* A bit of rearrangement, and that gives us
* that: sc = (ra.rc - bc)/ha + bc
* Now, the result of the blend was stored in
* src, so: */
int invha = ha ? 255 * 256 / ha : 0;
unsigned char rr, rg, rb;
/* ugh, division to get non-premul components */
int invsa = sa ? 255 * 256 / sa : 0;
int invba = ba ? 255 * 256 / ba : 0;
int sr = (sp[0] * invsa) >> 8;
int sg = (sp[1] * invsa) >> 8;
int sb = (sp[2] * invsa) >> 8;
int br = (bp[0] * invba) >> 8;
int bg = (bp[1] * invba) >> 8;
int bb = (bp[2] * invba) >> 8;
/* Uncomposite */
sr = (((sr-br)*invha)>>8) + br;
sg = (((sg-bg)*invha)>>8) + bg;
sb = (((sb-bb)*invha)>>8) + bb;
switch (blendmode)
{
default:
case FZ_BLEND_HUE:
fz_hue_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
case FZ_BLEND_SATURATION:
fz_saturation_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
case FZ_BLEND_COLOR:
fz_color_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
case FZ_BLEND_LUMINOSITY:
fz_luminosity_rgb(&rr, &rg, &rb, br, bg, bb, sr, sg, sb);
break;
}
rr = fz_mul255(255 - haa, bp[0]) + fz_mul255(fz_mul255(255 - ba, sr), haa) + fz_mul255(baha, rr);
rg = fz_mul255(255 - haa, bp[1]) + fz_mul255(fz_mul255(255 - ba, sg), haa) + fz_mul255(baha, rg);
rb = fz_mul255(255 - haa, bp[2]) + fz_mul255(fz_mul255(255 - ba, sb), haa) + fz_mul255(baha, rb);
bp[0] = fz_mul255(ra, rr);
bp[1] = fz_mul255(ra, rg);
bp[2] = fz_mul255(ra, rb);
}
}
sp += 4;
bp += 4;
}
}
void
fz_blend_pixmap(fz_pixmap *dst, fz_pixmap *src, int alpha, int blendmode, int isolated, fz_pixmap *shape)
{
unsigned char *sp, *dp;
fz_irect bbox;
int x, y, w, h, n;
/* TODO: fix this hack! */
if (isolated && alpha < 255)
{
sp = src->samples;
n = src->w * src->h * src->n;
while (n--)
{
*sp = fz_mul255(*sp, alpha);
sp++;
}
}
bbox = fz_pixmap_bbox_no_ctx(dst);
bbox = fz_intersect_irect(bbox, fz_pixmap_bbox_no_ctx(src));
x = bbox.x0;
y = bbox.y0;
w = bbox.x1 - bbox.x0;
h = bbox.y1 - bbox.y0;
n = src->n;
sp = src->samples + (unsigned int)(((y - src->y) * src->w + (x - src->x)) * n);
dp = dst->samples + (unsigned int)(((y - dst->y) * dst->w + (x - dst->x)) * n);
assert(src->n == dst->n);
if (!isolated)
{
unsigned char *hp = shape->samples + (unsigned int)((y - shape->y) * shape->w + (x - shape->x));
while (h--)
{
if (n == 4 && blendmode >= FZ_BLEND_HUE)
fz_blend_nonseparable_nonisolated(dp, sp, w, blendmode, hp, alpha);
else
fz_blend_separable_nonisolated(dp, sp, n, w, blendmode, hp, alpha);
sp += src->w * n;
dp += dst->w * n;
hp += shape->w;
}
}
else
{
while (h--)
{
if (n == 4 && blendmode >= FZ_BLEND_HUE)
fz_blend_nonseparable(dp, sp, w, blendmode);
else
fz_blend_separable(dp, sp, n, w, blendmode);
sp += src->w * n;
dp += dst->w * n;
}
}
}
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