static int hls_to_rgb(int hue, int lum, int sat)
{
int R, G, B;
int Magic1, Magic2;
const int RGBMAX = 255;
const int HLSMAX = 100;
if (sat == 0) {
R = G = B = (lum * RGBMAX) / HLSMAX;
} else {
if (lum <= (HLSMAX / 2)) {
Magic2 = (lum * (HLSMAX + sat) + (HLSMAX / 2)) / HLSMAX;
} else {
Magic2 = lum + sat - ((lum * sat) + (HLSMAX / 2)) / HLSMAX;
}
Magic1 = 2 * lum - Magic2;
R = (hue_to_rgb(Magic1, Magic2, hue + (HLSMAX / 3)) * RGBMAX + (HLSMAX / 2)) / HLSMAX;
G = (hue_to_rgb(Magic1, Magic2, hue) * RGBMAX + (HLSMAX / 2)) / HLSMAX;
B = (hue_to_rgb(Magic1, Magic2, hue - (HLSMAX / 3)) * RGBMAX + (HLSMAX/2)) / HLSMAX;
}
return SIXEL_RGB(R, G, B);
}
/* convert sixel data into indexed pixel bytes and palette data */
MagickBooleanType sixel_decode(unsigned char /* in */ *p, /* sixel bytes */
unsigned char /* out */ **pixels, /* decoded pixels */
size_t /* out */ *pwidth, /* image width */
size_t /* out */ *pheight, /* image height */
unsigned char /* out */ **palette, /* ARGB palette */
size_t /* out */ *ncolors /* palette size (<= 256) */)
{
int n, i, r, g, b, sixel_vertical_mask, c;
int posision_x, posision_y;
int max_x, max_y;
int attributed_pan, attributed_pad;
int attributed_ph, attributed_pv;
int repeat_count, color_index, max_color_index = 2, background_color_index;
int param[10];
int sixel_palet[SIXEL_PALETTE_MAX];
unsigned char *imbuf, *dmbuf;
int imsx, imsy;
int dmsx, dmsy;
int y;
posision_x = posision_y = 0;
max_x = max_y = 0;
attributed_pan = 2;
attributed_pad = 1;
attributed_ph = attributed_pv = 0;
repeat_count = 1;
color_index = 0;
background_color_index = 0;
imsx = 2048;
imsy = 2048;
imbuf = (unsigned char *) AcquireQuantumMemory(imsx * imsy,1);
if (imbuf == NULL) {
return(MagickFalse);
}
for (n = 0; n < 16; n++) {
sixel_palet[n] = sixel_default_color_table[n];
}
/* colors 16-231 are a 6x6x6 color cube */
for (r = 0; r < 6; r++) {
for (g = 0; g < 6; g++) {
for (b = 0; b < 6; b++) {
sixel_palet[n++] = SIXEL_RGB(r * 51, g * 51, b * 51);
}
}
}
/* colors 232-255 are a grayscale ramp, intentionally leaving out */
for (i = 0; i < 24; i++) {
sixel_palet[n++] = SIXEL_RGB(i * 11, i * 11, i * 11);
}
for (; n < SIXEL_PALETTE_MAX; n++) {
sixel_palet[n] = SIXEL_RGB(255, 255, 255);
}
(void) ResetMagickMemory(imbuf, background_color_index, imsx * imsy);
while (*p != '\0') {
if ((p[0] == '\033' && p[1] == 'P') || *p == 0x90) {
if (*p == '\033') {
p++;
}
p = get_params(++p, param, &n);
if (*p == 'q') {
p++;
if (n > 0) { /* Pn1 */
switch(param[0]) {
case 0:
case 1:
attributed_pad = 2;
break;
case 2:
attributed_pad = 5;
break;
case 3:
attributed_pad = 4;
break;
case 4:
attributed_pad = 4;
break;
case 5:
attributed_pad = 3;
break;
case 6:
attributed_pad = 3;
break;
case 7:
attributed_pad = 2;
break;
case 8:
attributed_pad = 2;
break;
case 9:
attributed_pad = 1;
break;
}
}
if (n > 2) { /* Pn3 */
if (param[2] == 0) {
param[2] = 10;
}
attributed_pan = attributed_pan * param[2] / 10;
attributed_pad = attributed_pad * param[2] / 10;
if (attributed_pan <= 0) attributed_pan = 1;
if (attributed_pad <= 0) attributed_pad = 1;
}
}
} else if ((p[0] == '\033' && p[1] == '\\') || *p == 0x9C) {
break;
} else if (*p == '"') {
/* DECGRA Set Raster Attributes " Pan; Pad; Ph; Pv */
p = get_params(++p, param, &n);
if (n > 0) attributed_pad = param[0];
if (n > 1) attributed_pan = param[1];
if (n > 2 && param[2] > 0) attributed_ph = param[2];
if (n > 3 && param[3] > 0) attributed_pv = param[3];
if (attributed_pan <= 0) attributed_pan = 1;
if (attributed_pad <= 0) attributed_pad = 1;
if (imsx < attributed_ph || imsy < attributed_pv) {
dmsx = imsx > attributed_ph ? imsx : attributed_ph;
dmsy = imsy > attributed_pv ? imsy : attributed_pv;
dmbuf = (unsigned char *) AcquireQuantumMemory(dmsx * dmsy,1);
if (dmbuf == (unsigned char *) NULL) {
imbuf = (unsigned char *) RelinquishMagickMemory(imbuf);
return (MagickFalse);
}
(void) ResetMagickMemory(dmbuf, background_color_index, dmsx * dmsy);
for (y = 0; y < imsy; ++y) {
(void) CopyMagickMemory(dmbuf + dmsx * y, imbuf + imsx * y, imsx);
}
imbuf = (unsigned char *) RelinquishMagickMemory(imbuf);
imsx = dmsx;
imsy = dmsy;
imbuf = dmbuf;
}
} else if (*p == '!') {
/* DECGRI Graphics Repeat Introducer ! Pn Ch */
p = get_params(++p, param, &n);
if (n > 0) {
repeat_count = param[0];
}
} else if (*p == '#') {
/* DECGCI Graphics Color Introducer # Pc; Pu; Px; Py; Pz */
p = get_params(++p, param, &n);
if (n > 0) {
if ((color_index = param[0]) < 0) {
color_index = 0;
} else if (color_index >= SIXEL_PALETTE_MAX) {
color_index = SIXEL_PALETTE_MAX - 1;
}
}
if (n > 4) {
if (param[1] == 1) { /* HLS */
if (param[2] > 360) param[2] = 360;
if (param[3] > 100) param[3] = 100;
if (param[4] > 100) param[4] = 100;
sixel_palet[color_index] = hls_to_rgb(param[2] * 100 / 360, param[3], param[4]);
} else if (param[1] == 2) { /* RGB */
if (param[2] > 100) param[2] = 100;
if (param[3] > 100) param[3] = 100;
if (param[4] > 100) param[4] = 100;
sixel_palet[color_index] = SIXEL_XRGB(param[2], param[3], param[4]);
}
}
} else if (*p == '$') {
/* DECGCR Graphics Carriage Return */
p++;
posision_x = 0;
repeat_count = 1;
} else if (*p == '-') {
/* DECGNL Graphics Next Line */
p++;
posision_x = 0;
posision_y += 6;
repeat_count = 1;
} else if (*p >= '?' && *p <= '\177') {
if (imsx < (posision_x + repeat_count) || imsy < (posision_y + 6)) {
int nx = imsx * 2;
int ny = imsy * 2;
while (nx < (posision_x + repeat_count) || ny < (posision_y + 6)) {
nx *= 2;
ny *= 2;
}
dmsx = nx;
dmsy = ny;
dmbuf = (unsigned char *) AcquireQuantumMemory(dmsx * dmsy,1);
if (dmbuf == (unsigned char *) NULL) {
imbuf = (unsigned char *) RelinquishMagickMemory(imbuf);
return (MagickFalse);
}
(void) ResetMagickMemory(dmbuf, background_color_index, dmsx * dmsy);
for (y = 0; y < imsy; ++y) {
(void) CopyMagickMemory(dmbuf + dmsx * y, imbuf + imsx * y, imsx);
}
imbuf = (unsigned char *) RelinquishMagickMemory(imbuf);
imsx = dmsx;
imsy = dmsy;
imbuf = dmbuf;
}
if (color_index > max_color_index) {
max_color_index = color_index;
}
if ((b = *(p++) - '?') == 0) {
posision_x += repeat_count;
} else {
sixel_vertical_mask = 0x01;
if (repeat_count <= 1) {
for (i = 0; i < 6; i++) {
if ((b & sixel_vertical_mask) != 0) {
imbuf[imsx * (posision_y + i) + posision_x] = color_index;
if (max_x < posision_x) {
max_x = posision_x;
}
if (max_y < (posision_y + i)) {
max_y = posision_y + i;
}
}
sixel_vertical_mask <<= 1;
}
posision_x += 1;
} else { /* repeat_count > 1 */
for (i = 0; i < 6; i++) {
if ((b & sixel_vertical_mask) != 0) {
c = sixel_vertical_mask << 1;
for (n = 1; (i + n) < 6; n++) {
if ((b & c) == 0) {
break;
}
c <<= 1;
}
for (y = posision_y + i; y < posision_y + i + n; ++y) {
(void) ResetMagickMemory(imbuf + imsx * y + posision_x, color_index, repeat_count);
}
if (max_x < (posision_x + repeat_count - 1)) {
max_x = posision_x + repeat_count - 1;
}
if (max_y < (posision_y + i + n - 1)) {
max_y = posision_y + i + n - 1;
}
i += (n - 1);
sixel_vertical_mask <<= (n - 1);
}
sixel_vertical_mask <<= 1;
}
posision_x += repeat_count;
}
}
repeat_count = 1;
} else {
p++;
}
}
if (++max_x < attributed_ph) {
max_x = attributed_ph;
}
if (++max_y < attributed_pv) {
max_y = attributed_pv;
}
if (imsx > max_x || imsy > max_y) {
dmsx = max_x;
dmsy = max_y;
if ((dmbuf = (unsigned char *) AcquireQuantumMemory(dmsx * dmsy,1)) == NULL) {
imbuf = (unsigned char *) RelinquishMagickMemory(imbuf);
return (MagickFalse);
}
for (y = 0; y < dmsy; ++y) {
(void) CopyMagickMemory(dmbuf + dmsx * y, imbuf + imsx * y, dmsx);
}
imbuf = (unsigned char *) RelinquishMagickMemory(imbuf);
imsx = dmsx;
imsy = dmsy;
imbuf = dmbuf;
}
*pixels = imbuf;
*pwidth = imsx;
*pheight = imsy;
*ncolors = max_color_index + 1;
*palette = (unsigned char *) AcquireQuantumMemory(*ncolors,4);
for (n = 0; n < (ssize_t) *ncolors; ++n) {
(*palette)[n * 4 + 0] = sixel_palet[n] >> 16 & 0xff;
(*palette)[n * 4 + 1] = sixel_palet[n] >> 8 & 0xff;
(*palette)[n * 4 + 2] = sixel_palet[n] & 0xff;
(*palette)[n * 4 + 3] = 0xff;
}
return(MagickTrue);
}
int
hls_to_rgb(int hue, int lum, int sat)
{
double hs = (hue + 240) % 360;
double hv = hs / 360.0;
double lv = lum / 100.0;
double sv = sat / 100.0;
double c, x, m, c2;
double r1, g1, b1;
int r, g, b;
int hpi;
if (sat == 0) {
r = g = b = lum * 255 / 100;
return SIXEL_RGB(r, g, b);
}
if ((c2 = ((2.0 * lv) - 1.0)) < 0.0) {
c2 = -c2;
}
c = (1.0 - c2) * sv;
hpi = (int) (hv * 6.0);
x = (hpi & 1) ? c : 0.0;
m = lv - 0.5 * c;
switch (hpi) {
case 0:
r1 = c;
g1 = x;
b1 = 0.0;
break;
case 1:
r1 = x;
g1 = c;
b1 = 0.0;
break;
case 2:
r1 = 0.0;
g1 = c;
b1 = x;
break;
case 3:
r1 = 0.0;
g1 = x;
b1 = c;
break;
case 4:
r1 = x;
g1 = 0.0;
b1 = c;
break;
case 5:
r1 = c;
g1 = 0.0;
b1 = x;
break;
default:
return SIXEL_RGB(255, 255, 255);
}
r = (int) ((r1 + m) * 100.0 + 0.5);
g = (int) ((g1 + m) * 100.0 + 0.5);
b = (int) ((b1 + m) * 100.0 + 0.5);
if (r < 0) {
r = 0;
} else if (r > 100) {
r = 100;
}
if (g < 0) {
g = 0;
} else if (g > 100) {
g = 100;
}
if (b < 0) {
b = 0;
} else if (b > 100) {
b = 100;
}
return SIXEL_RGB(r * 255 / 100, g * 255 / 100, b * 255 / 100);
}
