- API: add new zint_symbol dpmm field for output resolution (BMP/

EMF/PCX/PNG/TIF only, i.e. excluding EPS, GIF & SVG)
- Add support for specifying scale by X-dimension and resolution
  with new option `--scalexdimdp` for CLI/Tcl & new API function
  `ZBarcode_Scale_From_XdimDp()` (+ `ZBarcode_XdimDp_From_Scale()`
  & `ZBarcode_Default_Xdim()`) and new GUI popup; manual: document
- BMP/EMF/PCX/PNG/TIF: use new `dpmm` resolution field (for EMF
  following Inkscape)
- backend_qt: add `dpmm()`, `vectorWidth()`, `vectorHeight()`,
  `noPng()`, `getVersion()`, `takesGS1AIData()`, & `XdimDp` stuff
  incl. new `QZintXdimDp` struct for passing around scale vars &
  use in `getAsCLI()`; add comments
- Raise `scale` limit to 200 (from 100) to allow for large dpmm
- output: create directories & subdirectories as necessary for
  output path using new function `out_fopen()` and use in BMP/EMF/
  EPS/GIF/PCX/PNG/SVG/TIF
- DPLEIT/DPIDENT: format HRT according to (incomplete)
  documentation, and set default height to 72X (from 50X)
- CODE128B renamed to CODE128AB as can use subsets A and/or B
- CODABAR: fix minimum height calc
- EMF: fix indexing of handles (zero-based not 1-based)
- GUI: fix symbology zap (previous technique of clearing and
  re-loading settings without doing a sync no longer works);
  fix UPCEAN guard descent enable
- MAILMARK: better error message if input < 14 characters
- GUI: add "Default" button for DAFT tracker ratio & enable/disable
  various default buttons; use new `takesGS1AIData()` to
  enable/disable GS1-specific checkboxes
- CLI: use new `validate_float()` to parse float options (7
  significant digits allowed only, no scientific notation)
- DATAMATRIX/GRIDMATRIX/PDF417/QR/ULTRA: micro-optimize structapp
  ID parse
- library/CLI: fiddle with static asserts (make CHAR_BIT sensitive,
  supposedly)
- win32/README: update building libpng (assembly removed)
- README.linux: document incompatibility of Qt6 >= 6.3
- manual: expand Barcode Studio waffle
- test suite: change range separator to hyphen and allow multiple
  excludes

backend/bmp.c

@@ -31,12 +31,14 @@
 /* SPDX-License-Identifier: BSD-3-Clause */
 
 #include <errno.h>
+#include <math.h>
 #include <stdio.h>
 #ifdef _MSC_VER
 #include <io.h>
 #include <fcntl.h>
 #endif
 #include "common.h"
+#include "output.h"
 #include "bmp.h"        /* Bitmap header structure */
 
 INTERNAL int bmp_pixel_plot(struct zint_symbol *symbol, unsigned char *pixelbuf) {
@@ -44,6 +46,7 @@ INTERNAL int bmp_pixel_plot(struct zint_symbol *symbol, unsigned char *pixelbuf)
     int row_size;
     int bits_per_pixel;
     int colour_count;
+    int resolution;
     unsigned int data_offset, data_size, file_size;
     unsigned char *bitmap_file_start, *bmp_posn;
     unsigned char *bitmap;
@@ -157,8 +160,9 @@ INTERNAL int bmp_pixel_plot(struct zint_symbol *symbol, unsigned char *pixelbuf)
     info_header.bits_per_pixel = bits_per_pixel;
     info_header.compression_method = 0; /* BI_RGB */
     info_header.image_size = 0;
-    info_header.horiz_res = 0;
-    info_header.vert_res = 0;
+    resolution = symbol->dpmm ? (int) roundf(stripf(symbol->dpmm * 1000.0f)) : 0; /* pixels per metre */
+    info_header.horiz_res = resolution;
+    info_header.vert_res = resolution;
     info_header.colours = colour_count;
     info_header.important_colours = colour_count;
 
@@ -194,7 +198,7 @@ INTERNAL int bmp_pixel_plot(struct zint_symbol *symbol, unsigned char *pixelbuf)
 #endif
         bmp_file = stdout;
     } else {
-        if (!(bmp_file = fopen(symbol->outfile, "wb"))) {
+        if (!(bmp_file = out_fopen(symbol->outfile, "wb"))) {
             free(bitmap_file_start);
             sprintf(symbol->errtxt, "601: Could not open output file (%d: %.30s)", errno, strerror(errno));
             return ZINT_ERROR_FILE_ACCESS;