X-Git-Url: https://git.draconx.ca/gitweb/liblbx.git/blobdiff_plain/395b742050af148137758f1d4492a3922569fb91..HEAD:/src/pnm.c

diff --git a/src/pnm.c b/src/pnm.c
index 1596c5a..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
@@ -322,12 +385,18 @@ int img_output_pam(FILE *f, const char *filename,
                    struct lbx_colour *palette)
 {
 	bool masked = img_is_masked(mask, width, height);
-	unsigned x, y, depth, maxval = palette ? 63 : 255;
 	unsigned char *rowbuf;
+	unsigned long offset;
+	unsigned y, depth;
 	int rc;
 
 	depth = (palette ? 3 : 1) + masked;
-	if (width > (size_t)-1 / depth || !(rowbuf = malloc(width * depth))) {
+	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;
 	}
@@ -337,8 +406,9 @@ int img_output_pam(FILE *f, const char *filename,
 	if (rc < 0)
 		goto write_err;
 
-	rc = fprintf_ascii(f, "MAXVAL %u\nTUPLTYPE %s",
-	                      maxval, palette ? "RGB" : "GRAYSCALE");
+	rc = fprintf_ascii(f, "MAXVAL %d\nTUPLTYPE %s",
+	                      palette ? 63 : 255,
+			      palette ? "RGB" : "GRAYSCALE");
 	if (rc < 0)
 		goto write_err;
 
@@ -346,26 +416,20 @@ int img_output_pam(FILE *f, const char *filename,
 	if (rc < 0)
 		goto write_err;
 
-	for (y = 0; y < height; y++) {
-		for (x = 0; x < width; x++) {
-			unsigned long offset = (unsigned long) y * width + x;
-			size_t p = (size_t)depth * x; // pixel start
-
-			if (palette) {
-				struct lbx_colour *c = &palette[pixels[offset]];
-				rowbuf[p+0] = c->red;
-				rowbuf[p+1] = c->green;
-				rowbuf[p+2] = c->blue;
-			} else {
-				rowbuf[p+0] = pixels[offset];
-			}
-
-			if (masked) {
-				bool vis = 1 & ( mask[offset/CHAR_BIT]
-				                 >> (offset%CHAR_BIT) );
-
-				rowbuf[p+depth-1] = vis*maxval;
-			}
+	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;
 		}
 
 		if (fwrite(rowbuf, depth, width, f) < width)
@@ -376,7 +440,6 @@ int img_output_pam(FILE *f, const char *filename,
 	return 0;
 write_err:
 	tool_err(0, "error writing %s", filename);
-
 	free(rowbuf);
 	return -1;
 }