Merge pull request #6 from j4james/fix-background-fill

Fix background select interpretation and 0:1 aspect ratio

Author: hackerb9

j4james/margin_clipping.sh

@@ -81,6 +81,7 @@ echo -n ${ST}
 set_margin 4 21
 set_cursor_pos 4 41
 echo ${DCS}'2;0q'
+echo '?' # trigger background fill
 blank_lines 2
 multicolor_lines 4 '#9' '#11' true '!80?'
 multicolor_lines 4 '#11' '#9' false '!80?'

j4james/raster_aspect_ratio.sh

@@ -3,9 +3,11 @@
 # Test of the raster attributes aspect ratio in a Sixel image.
 
 # If an image includes a raster attributes command, the first two parameters
-# define numerator and denominator of the pixel aspect ratio. On a genuine
-# VT340, this ratio is rounded up to the nearest integer value. For example.
-# 3:2 is 1.5, which rounds up to 2 (i.e. an aspect ratio of 2:1). 
+# define the numerator and denominator of the pixel aspect ratio. On a genuine
+# VT340, this ratio is rounded up to the nearest integer value, with a minimum
+# value of 1. For example, 3:2 is 1.5, which rounds up to 2 (i.e. an aspect
+# ratio of 2:1). If the denominator is zero, the aspect ratio is ignored, and
+# will fall back to the value determined by the initial macro parameter.
 
 CSI=$'\e['			# Control Sequence Introducer 
 DCS=$'\eP'			# Device Control String
@@ -49,13 +51,13 @@ range_test() {
   done
 }
 
-aspect_ratio_test  8 ''     2
-aspect_ratio_test 18 '0;0'  2
-aspect_ratio_test 28 '0;1'  2
-aspect_ratio_test 38 '1;3' 10
-aspect_ratio_test 48 '3;2'  5
-aspect_ratio_test 58 '7;4'  5
-aspect_ratio_test 68 '37;4' 1
+aspect_ratio_test  8 ''     2    # a blank AR falls back to the macro parameter value (5:1)
+aspect_ratio_test 18 '0;0'  2    # a zero denominator also falls back to 5:1
+aspect_ratio_test 28 '0;1' 10    # 0:1 = 0, but the minimum is 1:1
+aspect_ratio_test 38 '1;3' 10    # 1:3 = 0.333, which rounds up to 1:1
+aspect_ratio_test 48 '3;2'  5    # 3:2 = 1.5, which rounds up to 2:1
+aspect_ratio_test 58 '7;4'  5    # 7:4 = 1.75, which rounds up to 2:1
+aspect_ratio_test 68 '37;4' 1    # 37:4 = 9.25, which rounds up to 10:1
 
 range_test
 

j4james/raster_dimensions.sh

@@ -31,11 +31,11 @@ raster_test() {
   echo ${ST}${suffix}
 }
 
-raster_test  4  8 1 '2;1;120;60' '#1----!48?!24~-!48?!24~'
-raster_test  4 26 1 '2;1;60;60'  '#1!12?!108~-!24?!96~-!36?!84~-!48?!72~-!60?!60~' '.'
-raster_test  4 44 1 '2;1;120;30' '#1!12~-!24~-!36~-!48~-!60~-!60~-!60~-!60~-!60~-!60~'
-raster_test  4 62 1 '2;1;0;0'    '#1!12?!108~-!24?!96~-!36?!84~-!48?!72~-!60?!60~-!60?-!60?-!60?-!60?-!60?-'
-raster_test 16  7 2 '5;1;245;17' '#1!245~#0!35~-#1!30~-!30~-#0!30~'
-raster_test 13 41 2 '5;1'        '#1--!60?!280~-!60?!280~-!60?!280~-!60?!280~'
+raster_test  4  8 1 '2;1;120;120' '#1?----!48?!24~-!48?!24~'
+raster_test  4 26 1 '2;1;60;120'  '#1!12?!108~-!24?!96~-!36?!84~-!48?!72~-!60?!60~' '.'
+raster_test  4 44 1 '2;1;120;60'  '#1!12~-!24~-!36~-!48~-!60~-!60~-!60~-!60~-!60~-!60~'
+raster_test  1 62 1 '2;1;60;120'  '#1-----!12?!108~-!24?!96~-!36?!84~-!48?!72~-!60?!60~'
+raster_test 16  7 2 '5;1;245;90'  '#1!245~#0!35~-#1!30~-!30~-#0!30~'
+raster_test 13 41 2 '5;1;;0'      '#1?--!60?!280~-!60?!280~-!60?!280~-!60?!280~'
 
 set_cursor_pos 11 1