Problems with PcbDraw when generating PNG and JPG.

Currently the script uses ImageMagick library. But the SVG conversion
is handled unreliably. ImageMagick has various backends to do it and
some of them don't work. I saw this problem many times, and is now
affecting my system. A more reliable conversion can be achieved using
`rsvg-convert`. Isn't as good as InkScape, but is smaller and works
well.
In the process I'm trimming the extra blank space generated by
PcbDraw when we have objects in layers like "User Drawings" that
extends beyond the PCB size.
I'm also compressing JPGs more aggressively, this makes a real
difference between PNG and JPG outputs. Otherwise the difference
is too small.

CHANGELOG.md

@@ -15,6 +15,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   more than one variant.
 - Removed warnings about malformed values for DNF components indicating it in
   its value.
+- Problems with PcbDraw when generating PNG and JPG outputs. Now we use a more
+  reliable conversion methode when available.
 
 ## [0.6.1] - 2020-08-20
 ### Added

debian/control

@@ -11,7 +11,7 @@ Package: kibot
 Architecture: all
 Multi-Arch: foreign
 Depends: ${misc:Depends}, ${python3:Depends}, python3-yaml, kicad (>= 5.1.0), python3-wxgtk4.0
-Recommends: kibom.inti-cmnb (>= 1.8.0), kicad-automation-scripts.inti-cmnb (>= 1.1.2), interactivehtmlbom.inti-cmnb, pcbdraw, python3-xlsxwriter
+Recommends: kibom.inti-cmnb (>= 1.8.0), kicad-automation-scripts.inti-cmnb (>= 1.1.2), interactivehtmlbom.inti-cmnb, pcbdraw, imagemagick, librsvg2-bin, python3-xlsxwriter
 Description: KiCad Bot
  KiBot is a program which helps you to automate the generation of KiCad
  output documents easily, repeatable, and most of all, scriptably.

kibot/out_pcbdraw.py

@@ -5,6 +5,7 @@
 # Project: KiBot (formerly KiPlot)
 import os
 import re
+from shutil import which
 from tempfile import (NamedTemporaryFile)
 from subprocess import (check_output, STDOUT, CalledProcessError)
 from .misc import (PCBDRAW, PCBDRAW_ERR)
@@ -15,6 +16,8 @@ from .macros import macros, document, output_class  # noqa: F401
 from . import log
 
 logger = log.get_logger(__name__)
+SVG2PNG = 'rsvg-convert'
+CONVERT = 'convert'
 
 
 class PcbDrawStyle(Optionable):
@@ -76,6 +79,29 @@ class PcbDrawRemap(Optionable):
         pass
 
 
+def _get_tmp_name(ext):
+    with NamedTemporaryFile(mode='w', suffix=ext, delete=False) as f:
+        f.close()
+    return f.name
+
+
+def _run_command(cmd, tmp_remap=False, tmp_style=False):
+    logger.debug('Executing: '+str(cmd))
+    try:
+        cmd_output = check_output(cmd, stderr=STDOUT)
+    except CalledProcessError as e:
+        logger.error('Failed to run %s, error %d', cmd[0], e.returncode)
+        if e.output:
+            logger.debug('Output from command: '+e.output.decode())
+        exit(PCBDRAW_ERR)
+    finally:
+        if tmp_remap:
+            os.remove(tmp_remap)
+        if tmp_style:
+            os.remove(tmp_style)
+    logger.debug('Output from command:\n'+cmd_output.decode())
+
+
 class PcbDrawOptions(BaseOptions):
     def __init__(self):
         with document:
@@ -218,22 +244,33 @@ class PcbDrawOptions(BaseOptions):
             tmp_remap = None
         # The board & output
         cmd.append(GS.pcb_file)
-        cmd.append(output)
+        svg = None
+        if self.format == 'svg':
+            cmd.append(output)
+        else:
+            # PNG and JPG outputs are unreliable
+            if which(SVG2PNG) is None:
+                logger.warning('`{}` not installed, using unreliable PNG/JPG conversion'.format(SVG2PNG))
+                logger.warning('If you experiment problems install `librsvg2-bin` or equivalent')
+                cmd.append(output)
+            elif which(CONVERT) is None:
+                logger.warning('`{}` not installed, using unreliable PNG/JPG conversion'.format(CONVERT))
+                logger.warning('If you experiment problems install `imagemagick` or equivalent')
+                cmd.append(output)
+            else:
+                svg = _get_tmp_name('.svg')
+                cmd.append(svg)
         # Execute and inform is successful
-        logger.debug('Executing: '+str(cmd))
-        try:
-            cmd_output = check_output(cmd, stderr=STDOUT)
-        except CalledProcessError as e:
-            logger.error('Failed to run %s, error %d', PCBDRAW, e.returncode)
-            if e.output:
-                logger.debug('Output from command: '+e.output.decode())
-            exit(PCBDRAW_ERR)
-        finally:
-            if tmp_remap:
-                os.remove(tmp_remap)
-            if tmp_style:
-                os.remove(tmp_style)
-        logger.debug('Output from command:\n'+cmd_output.decode())
+        _run_command(cmd, tmp_remap, tmp_style)
+        if svg is not None:
+            # Manually convert the SVG to PNG
+            png = _get_tmp_name('.png')
+            _run_command([SVG2PNG, '-d', str(self.dpi), '-p', str(self.dpi), svg, '-o', png], svg)
+            cmd = [CONVERT, '-trim', png]
+            if self.format == 'jpg':
+                cmd += ['-quality', '85%']
+            cmd.append(output)
+            _run_command(cmd, png)
 
 
 @output_class