X-Git-Url: http://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/5f678b5604af19ce003930897e77fd78d7ab5c72..bd5f6b55320b6889827908762197642b484ea28d:/src/pnm.c

diff --git a/src/pnm.c b/src/pnm.c
index 5359ac2..43108f8 100644
--- a/src/pnm.c
+++ b/src/pnm.c
@@ -20,6 +20,7 @@
 #include <config.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <stdbool.h>
 #include <stdarg.h>
 #include <assert.h>
@@ -311,6 +312,68 @@ err:
 	return -1;
 }
 
+static void pam_format_rgba(unsigned char *rowbuf, const unsigned char *pixels,
+                            unsigned char *mask, unsigned width,
+                            unsigned long offset, struct lbx_colour *palette)
+{
+	unsigned x;
+
+	for (x = 0; x < width; x++) {
+		struct lbx_colour val = palette[pixels[offset+x]];
+		unsigned vis = 1 & ( mask[(offset+x)/CHAR_BIT]
+		                      >> ((offset+x)%CHAR_BIT) );
+
+		if (sizeof val == 4) {
+			memcpy(rowbuf+4ul*x, &val, 4);
+		} else {
+			rowbuf[4ul*x+0] = val.red;
+			rowbuf[4ul*x+1] = val.green;
+			rowbuf[4ul*x+2] = val.blue;
+		}
+		rowbuf[4ul*x+3] = -vis & 0x3f;
+	}
+}
+
+static void pam_format_rgb(unsigned char *rowbuf, const unsigned char *pixels,
+                           unsigned width, unsigned long offset,
+                           struct lbx_colour *palette)
+{
+	unsigned x;
+
+	for (x = 0; x < width; x++) {
+		struct lbx_colour val = palette[pixels[offset+x]];
+
+		if (sizeof val == 4) {
+			memcpy(rowbuf+3ul*x, &val, 4);
+		} else {
+			rowbuf[3ul*x+0] = val.red;
+			rowbuf[3ul*x+1] = val.green;
+			rowbuf[3ul*x+2] = val.blue;
+		}
+	}
+}
+
+static void pam_format_ga(unsigned char *rowbuf,
+                          const unsigned char *pixels, const unsigned char *mask,
+                          unsigned width, unsigned long offset)
+{
+	unsigned x;
+
+	for (x = 0; x < width; x++) {
+		unsigned vis = 1 & ( mask[(offset+x)/CHAR_BIT]
+		                      >> ((offset+x)%CHAR_BIT) );
+
+		rowbuf[2ul*x+0] = pixels[offset+x];
+		rowbuf[2ul*x+1] = -vis & 0xff;
+	}
+}
+
+static void pam_format_g(unsigned char *rowbuf, const unsigned char *pixels,
+                         unsigned width, unsigned long offset)
+{
+	memcpy(rowbuf, pixels+offset, width);
+}
+
 /*
  * Output filter for Netpbm's PAM format.  This format combines the features
  * of all the other Netpbm formats, supporting RGB and grayscale images with
@@ -322,59 +385,61 @@ int img_output_pam(FILE *f, const char *filename,
                    struct lbx_colour *palette)
 {
 	bool masked = img_is_masked(mask, width, height);
-	unsigned x, y;
-	size_t depth;
-
-	if (fprintf_ascii(f, "P7\nWIDTH %u\nHEIGHT %u\n", width, height) < 0)
-		goto err;
-
-	if (palette) {
-		depth = masked ? 4 : 3;
-
-		if (fprintf_ascii(f, "DEPTH %zu\nMAXVAL 63\n"
-		                     "TUPLTYPE RGB%s\nENDHDR\n",
-		                     depth, masked ? "_ALPHA" : "") < 0)
-			goto err;
-
-		for (x = y = 0; y < height; ++x < width || (x = 0, y++)) {
-			unsigned long offset = (unsigned long) y * width + x;
-			struct lbx_colour *c = &palette[pixels[offset]];
-			unsigned char buf[4];
-			bool vis;
-
-			vis = mask[offset/CHAR_BIT] & (1u << offset%CHAR_BIT);
-			buf[0] = c->red;
-			buf[1] = c->green;
-			buf[2] = c->blue;
-			buf[3] = vis ? 63 : 0;
+	unsigned char *rowbuf;
+	unsigned long offset;
+	unsigned y, depth;
+	int rc;
+
+	depth = (palette ? 3 : 1) + masked;
+	if (width >= (size_t)-1 / depth)
+		goto alloc_err;
+
+	rowbuf = malloc(width * depth + 1);
+	if (!rowbuf) {
+alloc_err:
+		tool_err(-1, "failed to allocate memory");
+		return -1;
+	}
 
-			if (fwrite(buf, 1, depth, f) < depth)
-				goto err;
+	rc = fprintf_ascii(f, "P7\nWIDTH %u\nHEIGHT %u\nDEPTH %u\n",
+	                      width, height, depth);
+	if (rc < 0)
+		goto write_err;
+
+	rc = fprintf_ascii(f, "MAXVAL %d\nTUPLTYPE %s",
+	                      palette ? 63 : 255,
+			      palette ? "RGB" : "GRAYSCALE");
+	if (rc < 0)
+		goto write_err;
+
+	rc = fprintf_ascii(f, "_ALPHA\nENDHDR\n" + 6*!masked);
+	if (rc < 0)
+		goto write_err;
+
+	for (offset = y = 0; y < height; y++, offset += width) {
+		switch (depth) {
+		case 4:
+			pam_format_rgba(rowbuf, pixels, mask, width, offset, palette);
+			break;
+		case 3:
+			pam_format_rgb(rowbuf, pixels, width, offset, palette);
+			break;
+		case 2:
+			pam_format_ga(rowbuf, pixels, mask, width, offset);
+			break;
+		case 1:
+			pam_format_g(rowbuf, pixels, width, offset);
+			break;
 		}
-	} else {
-		depth = masked ? 2 : 1;
-
-		if (fprintf_ascii(f, "DEPTH %zu\nMAXVAL 255\n"
-		                     "TUPLTYPE GRAYSCALE%s\nENDHDR\n",
-		                     depth, masked ? "_ALPHA" : "") < 0)
-			goto err;
 
-		for (x = y = 0; y < height; ++x < width || (x = 0, y++)) {
-			unsigned long offset = (unsigned long) y * width + x;
-			unsigned char buf[2];
-			bool vis;
-
-			vis = mask[offset/CHAR_BIT] & (1u << offset%CHAR_BIT);
-			buf[0] = pixels[offset];
-			buf[1] = vis ? 255 : 0;
-
-			if (fwrite(buf, 1, depth, f) < depth)
-				goto err;
-		}
+		if (fwrite(rowbuf, depth, width, f) < width)
+			goto write_err;
 	}
 
+	free(rowbuf);
 	return 0;
-err:
+write_err:
 	tool_err(0, "error writing %s", filename);
+	free(rowbuf);
 	return -1;
 }