--- ray/src/common/bmpfile.c	2004/03/26 22:58:21	2.3
+++ ray/src/common/bmpfile.c	2004/04/10 02:54:44	2.8
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: bmpfile.c,v 2.3 2004/03/26 22:58:21 greg Exp $";
+static const char RCSid[] = "$Id: bmpfile.c,v 2.8 2004/04/10 02:54:44 greg Exp $";
 #endif
 /*
  *  Windows and OS/2 BMP file support
@@ -37,7 +37,7 @@ BMPheaderOK(const BMPHeader *hdr)
 {
 	if (!hdr)
 		return 0;
-	if ((hdr->width <= 0 | hdr->height <= 0))
+	if ((hdr->width <= 0) | (hdr->height <= 0))
 		return 0;
 	switch (hdr->bpp) {		/* check compression */
 	case 1:
@@ -47,15 +47,15 @@ BMPheaderOK(const BMPHeader *hdr)
 		break;
 	case 16:
 	case 32:
-		if ((hdr->compr != BI_UNCOMPR & hdr->compr != BI_BITFIELDS))
+		if ((hdr->compr != BI_UNCOMPR) & (hdr->compr != BI_BITFIELDS))
 			return 0;
 		break;
 	case 4:
-		if ((hdr->compr != BI_UNCOMPR & hdr->compr != BI_RLE4))
+		if ((hdr->compr != BI_UNCOMPR) & (hdr->compr != BI_RLE4))
 			return 0;
 		break;
 	case 8:
-		if ((hdr->compr != BI_UNCOMPR & hdr->compr != BI_RLE8))
+		if ((hdr->compr != BI_UNCOMPR) & (hdr->compr != BI_RLE8))
 			return 0;
 		break;
 	default:
@@ -64,7 +64,7 @@ BMPheaderOK(const BMPHeader *hdr)
 	if (hdr->compr == BI_BITFIELDS && (BMPbitField(hdr)[0] &
 				BMPbitField(hdr)[1] & BMPbitField(hdr)[2]))
 		return 0;
-	if ((hdr->nColors < 0 | hdr->impColors < 0))
+	if ((hdr->nColors < 0) | (hdr->impColors < 0))
 		return 0;
 	if (hdr->impColors > hdr->nColors)
 		return 0;
@@ -74,7 +74,7 @@ BMPheaderOK(const BMPHeader *hdr)
 }
 
 					/* compute uncompressed scan size */
-#define getScanSiz(h)   ( (((h)->bpp*(h)->width+7 >>3) + 3) & ~03 )
+#define getScanSiz(h)   ( ((((h)->bpp*(h)->width+7) >>3) + 3) & ~03 )
 
 					/* get next byte from reader */
 #define rdbyte(c,br)    ((br)->fpos += (c=(*(br)->cget)((br)->c_data))!=EOF, c)
@@ -219,8 +219,8 @@ BMPopenReader(int (*cget)(void *), int (*seek)(uint32,
 	if (br->scanline == NULL)
 		goto err;
 	br->yscan = -1;
-	if (seek != NULL && (br->hdr->compr == BI_RLE8 |
-					br->hdr->compr == BI_RLE4)) {
+	if (seek != NULL && ((br->hdr->compr == BI_RLE8) |
+					(br->hdr->compr == BI_RLE4))) {
 		BMPReader       *newbr = (BMPReader *)realloc((void *)br,
 						sizeof(BMPReader) +
 						sizeof(br->scanpos[0]) *
@@ -255,7 +255,7 @@ BMPisGrayscale(const BMPHeader *hdr)
 		return -1;
 	if (hdr->bpp > 8)		/* assume they had a reason for it */
 		return 0;
-	for (rgbp = hdr->palette, n = hdr->impColors; n-- > 0; rgbp++)
+	for (rgbp = hdr->palette, n = hdr->nColors; n-- > 0; rgbp++)
 		if (((rgbp->r != rgbp->g) | (rgbp->g != rgbp->b)))
 			return 0;
 	return 1;			/* all colors neutral in map */
@@ -279,10 +279,10 @@ BMPreadScanline(BMPReader *br)
 	 *
 	 * Certain aspects of this scheme are completely insane, so
 	 * we don't support them.  Fortunately, they rarely appear.
-	 * One is the mid-file EOD (0x0001) and another is the insane
+	 * One is the mid-file EOD (0x0001) and another is the ill-conceived
 	 * "delta" (0x0002), which is like a "goto" statement for bitmaps.
 	 * Whoever thought this up should be shot, then told why
-	 * it's impossible to support in any reasonable way.
+	 * it's impossible to support such a scheme in any reasonable way.
 	 * Also, RLE4 mode allows runs to stop halfway through a byte,
 	 * which is likewise uncodeable, so we don't even try.
 	 * Finally, the scanline break is ambiguous -- we assume here that
@@ -291,7 +291,7 @@ BMPreadScanline(BMPReader *br)
 	 * the end of the scanline, assuming the next bit of data belongs
 	 * the following scan.  If a break follows the last pixel, as it
 	 * seems to in the files I've tested out of Photoshop, you end up
-	 * painting every other line black.  BTW, I assume any skipped
+	 * painting every other line black.  Also, I assume any skipped
 	 * pixels are painted with color 0, which is often black.  Nowhere
 	 * is it specified what we should assume for missing pixels.  This
 	 * is undoubtedly the most brain-dead format I've ever encountered.
@@ -323,6 +323,7 @@ BMPreadScanline(BMPReader *br)
 		case 0:			/* end of line */
 			while (n--)
 				*sp++ = 0;
+			/* leaves n == -1 as flag for test after loop */
 			continue;
 		case 1:			/* end of bitmap */
 		case 2:			/* delta */
@@ -347,8 +348,8 @@ BMPreadScanline(BMPReader *br)
 			return BIR_TRUNCATED;
 	}
 					/* verify break at end of line */
-	if (rdbyte(n, br) != 0 || (rdbyte(n, br) != 0 &&
-				(n != 1 || br->yscan != br->hdr->height-1)))
+	if (!n && (rdbyte(n, br) != 0 || (rdbyte(n, br) != 0 &&
+				(n != 1 || br->yscan != br->hdr->height-1))))
 		return BIR_RLERROR;
 	if (br->seek != NULL)		/* record next scanline position */
 		br->scanpos[br->yscan + 1] = br->fpos;
@@ -444,7 +445,7 @@ BMPdecodePixel(int i, const BMPReader *br)
 	case 8:
 		return br->hdr->palette[br->scanline[i]];
 	case 1:
-		return br->hdr->palette[br->scanline[i>>3]>>(7-i&7) & 1];
+		return br->hdr->palette[br->scanline[i>>3]>>((7-i)&7) & 1];
 	case 4:
 		return br->hdr->palette[br->scanline[i>>1]>>(i&1?4:0) & 0xf];
 	case 16:
@@ -522,7 +523,7 @@ BMPtruecolorHeader(int xr, int yr, int infolen)
 	return hdr;
 }
 
-/* allocate color-mapped header (defaults minimal grayscale) */
+/* allocate color-mapped header (defaults to minimal grayscale) */
 BMPHeader *
 BMPmappedHeader(int xr, int yr, int infolen, int ncolors)
 {
@@ -549,7 +550,7 @@ BMPmappedHeader(int xr, int yr, int infolen, int ncolo
 	hdr->height = yr;
 	hdr->yIsDown = 0;			/* default to upwards order */
 	hdr->bpp = n;
-	hdr->compr = BI_UNCOMPR;
+	hdr->compr = BI_UNCOMPR;		/* compression needs seek */
 	hdr->hRes = hdr->vRes = 2835;		/* default to 72 ppi */
 	hdr->nColors = ncolors;
 	hdr->impColors = 0;			/* says all colors important */
@@ -599,13 +600,8 @@ wrseek(uint32 pos, BMPWriter *bw)
 {
 	if (pos == bw->fpos)
 		return BIR_OK;
-	if (bw->seek == NULL) {
-		if (pos < bw->fpos)
-			return BIR_SEEKERR;
-		while (bw->fpos < pos)
-			wrbyte(0, bw);
-		return BIR_OK;
-	}
+	if (bw->seek == NULL)
+		return BIR_SEEKERR;
 	if ((*bw->seek)(pos, bw->c_data) != 0)
 		return BIR_SEEKERR;
 	bw->fpos = pos;
@@ -626,10 +622,12 @@ BMPopenWriter(void (*cput)(int, void *), int (*seek)(u
 		return NULL;
 	if (!BMPheaderOK(hdr))
 		return NULL;
-	if ((hdr->bpp == 16 | hdr->compr == BI_RLE4))
+	if ((hdr->bpp == 16) | (hdr->compr == BI_RLE4))
 		return NULL;			/* unsupported */
-	if (seek == NULL && (hdr->compr == BI_RLE8 | hdr->compr == BI_RLE4))
+/* no seek means we may have the wrong file length, but most app's don't care
+	if (seek == NULL && ((hdr->compr == BI_RLE8) | (hdr->compr == BI_RLE4)))
 		return NULL;
+*/
 						/* compute sizes */
 	hdrSiz = 2 + 6*4 + 2*2 + 6*4;
 	if (hdr->compr == BI_BITFIELDS)
@@ -691,13 +689,13 @@ findNextRun(const int8 *bp, int len)
 {
 	int     pos, cnt;
 						/* look for run */
-	for (pos = 0; len > 0 & pos < 255; pos++, bp++, len--) {
+	for (pos = 0; (len > 0) & (pos < 255); pos++, bp++, len--) {
 		if (len < 5)			/* no hope left? */
 			continue;
 		cnt = 1;			/* else let's try it */
 		while (bp[cnt] == bp[0])
-			if (++cnt >= 5)		/* long enough */
-				return pos;
+			if (++cnt >= 5)
+				return pos;     /* long enough */
 	}
 	return pos;				/* didn't find any */
 }
@@ -749,18 +747,21 @@ BMPwriteScanline(BMPWriter *bw)
 		if (n <= 0)			/* was that it? */
 			break;
 		val = *sp;			/* output run */
-		for (cnt = 1; --n > 0 & *++sp == val; cnt++)
-			;
+		for (cnt = 1; cnt < 255; cnt++)
+			if ((!--n) | (*++sp != val))
+				break;
 		wrbyte(cnt, bw);
 		wrbyte(val, bw);
 	}
-	bw->yscan++;				/* write file length at end */
+	bw->yscan++;				/* write line break or EOD */
 	if (bw->yscan == bw->hdr->height) {
 		wrbyte(0, bw); wrbyte(1, bw);   /* end of bitmap marker */
-		if (bw->seek == NULL || (*bw->seek)(2, bw->c_data) != 0)
-			return BIR_SEEKERR;
-		bw->fpos = 2;
-		wrint32(bw->flen, bw);		/* corrected file length */
+		if (wrseek(2, bw) != BIR_OK)
+			return BIR_OK;		/* no one may care */
+		wrint32(bw->flen, bw);		/* correct file length */
+		if (wrseek(34, bw) != BIR_OK)
+			return BIR_OK;
+		wrint32(bw->flen-bw->fbmp, bw); /* correct bitmap length */
 	} else {
 		wrbyte(0, bw); wrbyte(0, bw);   /* end of line marker */
 	}