ref: 9482f887f984582725e0ffbfa2232d00780e87eb
parent: ce97bb4998c06c964b1f3f9083cb726bd8176c66
author: rodri <rgl@antares-labs.eu>
date: Thu Sep 12 15:09:40 EDT 2024
jpg/tga: decode TGA32 images into RGBA32 ones
--- a/sys/src/cmd/jpg/imagefile.h
+++ b/sys/src/cmd/jpg/imagefile.h
@@ -29,6 +29,7 @@
CRGBA32 = 6, /* one channel in correct data order for loadimage(RGBA32) */
CYA16 = 7, /* one channel in correct data order for loadimage(Grey8+Alpha8) */
CRGBVA16= 8, /* one channel in correct data order for loadimage(CMAP8+Alpha8) */
+ CRGBA = 9, /* four channels, no map */
/* GIF flags */
TRANSP = 1,
--- a/sys/src/cmd/jpg/readtga.c
+++ b/sys/src/cmd/jpg/readtga.c
@@ -238,7 +238,7 @@
}
static int
-rgba(Biobuf *bp, int bpp, uchar *r, uchar *g, uchar *b, int num)
+rgba(Biobuf *bp, int bpp, uchar *r, uchar *g, uchar *b, uchar *a, int num)
{int i;
uchar buf[4], tmp;
@@ -275,6 +275,7 @@
*b++ = buf[0];
*g++ = buf[1];
*r++ = buf[2];
+ *a++ = buf[3];
}
break;
default:
@@ -285,7 +286,7 @@
}
static int
-rgba_rle(Biobuf *bp, int bpp, uchar *r, uchar *g, uchar *b, int num)
+rgba_rle(Biobuf *bp, int bpp, uchar *r, uchar *g, uchar *b, uchar *a, int num)
{uchar len;
int i, got;
@@ -296,23 +297,27 @@
if(len & 0x80){len &= 0x7f;
len += 1; /* run of zero is meaningless */
- if(rgba(bp, bpp, r, g, b, 1) != 1)
+ if(rgba(bp, bpp, r, g, b, a, 1) != 1)
break;
for(i = 1; i < len && got+i < num; i++){r[i] = *r;
g[i] = *g;
b[i] = *b;
+ if(bpp == 32)
+ a[i] = *a;
}
len = i;
}
else{len += 1; /* raw block of zero is meaningless */
- if(rgba(bp, bpp, r, g, b, len) != len)
+ if(rgba(bp, bpp, r, g, b, a, len) != len)
break;
}
r += len;
g += len;
b += len;
+ if(bpp == 32)
+ a += len;
}
return got;
}
@@ -380,7 +385,7 @@
{Tga *h;
int n, c, num;
- uchar *r, *g, *b;
+ uchar *r, *g, *b, *a;
Rawimage *ar, **array;
if((h = rdhdr(bp)) == nil){@@ -429,8 +434,8 @@
ar->chandesc = (h->cmapbpp == 32) ? CRGBV : CRGB1;
}
else{- ar->nchans = 3;
- ar->chandesc = CRGB;
+ ar->nchans = (h->bpp == 32) ? 4: 3;
+ ar->chandesc = (h->bpp == 32) ? CRGBA: CRGB;
}
ar->cmap = h->cmap;
@@ -445,6 +450,7 @@
r = ar->chans[0];
g = ar->chans[1];
b = ar->chans[2];
+ a = ar->chans[3];
num = h->width*h->height;
switch(h->datatype){@@ -452,7 +458,7 @@
n = cmap(bp, r, num);
break;
case 2:
- n = rgba(bp, h->bpp, r, g, b, num);
+ n = rgba(bp, h->bpp, r, g, b, a, num);
break;
case 3:
n = luma(bp, h->bpp, r, num);
@@ -461,7 +467,7 @@
n = cmap_rle(bp, r, num);
break;
case 10:
- n = rgba_rle(bp, h->bpp, r, g, b, num);
+ n = rgba_rle(bp, h->bpp, r, g, b, a, num);
break;
case 11:
n = luma_rle(bp, h->bpp, r, num);
--- a/sys/src/cmd/jpg/tga.c
+++ b/sys/src/cmd/jpg/tga.c
@@ -166,6 +166,9 @@
if(outchan==GREY8 || (r->chandesc==CY && threeflag==0)){c = totruecolor(r, CY);
outchan = GREY8;
+ }else if(r->chandesc==CRGBA){+ c = totruecolor(r, CRGBA32);
+ outchan = RGBA32;
}else
c = totruecolor(r, CRGB24);
}
--- a/sys/src/cmd/jpg/totruecolor.c
+++ b/sys/src/cmd/jpg/totruecolor.c
@@ -17,10 +17,11 @@
int j, k;
Rawimage *im;
char err[ERRMAX];
- uchar *rp, *gp, *bp, *cmap, *inp, *outp, cmap1[4*256];
+ uchar *rp, *gp, *bp, *ap, *cmap, *inp, *outp, cmap1[4*256];
int r, g, b, Y, Cr, Cb, psize;
+ double a;
- if(chandesc!=CY && chandesc!=CRGB24)
+ if(chandesc!=CY && chandesc!=CRGB24 && chandesc!=CRGBA32)
return _remaperror("remap: can't convert to chandesc %d", chandesc);err[0] = '\0';
@@ -31,8 +32,10 @@
memset(im, 0, sizeof(Rawimage));
if(chandesc == CY)
im->chanlen = i->chanlen;
- else
+ else if(chandesc == CRGB24)
im->chanlen = 3*i->chanlen;
+ else
+ im->chanlen = 4*i->chanlen;
im->chandesc = chandesc;
im->chans[0] = malloc(im->chanlen);
if(im->chans[0] == nil){@@ -101,11 +104,13 @@
break;
case CRGB:
- if(i->nchans != 3)
+ case CRGBA:
+ if(i->nchans != 3 && i->nchans != 4)
return _remaperror("remap: can't handle nchans %d", i->nchans);rp = i->chans[0];
gp = i->chans[1];
bp = i->chans[2];
+ ap = i->chans[3];
if(chandesc == CY){ for(j=0; j<i->chanlen; j++){r = *bp++;
@@ -116,6 +121,15 @@
}
}else
for(j=0; j<i->chanlen; j++){+ if(i->nchans == 4){+ *outp++ = *ap++;
+ /* pre-multiply alpha */
+ a = (double)ap[-1]/0xFF;
+ *outp++ = *bp++ * a;
+ *outp++ = *gp++ * a;
+ *outp++ = *rp++ * a;
+ continue;
+ }
*outp++ = *bp++;
*outp++ = *gp++;
*outp++ = *rp++;
--
⑨