Adding better code documentation.

diff --git a/Graphics/Animations/txtpal.bas b/Graphics/Animations/txtpal.bas
index 9ab2e56..973a299 100755 (executable)
--- a/Graphics/Animations/txtpal.bas
+++ b/Graphics/Animations/txtpal.bas
@@ -1,33 +1,56 @@
-' Svjatoslav Agejenko 2003.01\r
-' svjatoslav@svjatoslav.eu\r
+' This application produces beautiful colorful horizontal rainbows on the screen in text mode.\r
+' It works only on CRT monitors, because it accomplishes the effect by changing the color palette\r
+' while the CRT monitor is drawing the screen. As a result, unlimited number of colors can be\r
+' displayed on the screen simultaneously, regardless of the video card's color depth.\r
+'\r
+' By Svjatoslav Agejenko.\r
+' Email: svjatoslav@svjatoslav.eu\r
+' Homepage: http://www.svjatoslav.eu\r
+\r
+' Changelog:\r
+' 2003.01, Initial version\r
+' 2024, Improved program readability\r
 \r
 DEFINT A-Z\r
 CLS\r
 COLOR 7\r
 \r
+' Fill background with random colored random numbers.\r
 FOR b = 1 TO 500\r
-COLOR RND * 15\r
-PRINT RND;\r
+    COLOR RND * 15\r
+    PRINT RND;\r
 NEXT b\r
 \r
+' Set the background and text colors\r
 COLOR 0, 1\r
+\r
+' Clear rectangular area\r
 FOR y = 5 TO 20\r
-FOR x = 20 TO 50\r
-LOCATE y, x\r
-PRINT " "\r
-NEXT x\r
+    FOR x = 20 TO 50\r
+        LOCATE y, x\r
+        PRINT " "\r
+    NEXT x\r
 NEXT y\r
+\r
+' Print "[ TEST ]" at position (10, 25)\r
 LOCATE 10, 25\r
 PRINT "[ TEST ]"\r
 \r
+' Print "[ TEST ]" in color 2 at position (15, 37)\r
 LOCATE 15, 37\r
 COLOR 2\r
 PRINT "[ TEST ]"\r
 \r
+' Initialize variables\r
 wa = 1\r
 p = &H3DA\r
+\r
+' Loop to wait until CRT monitor has drawn single frame\r
 1\r
+' measure how much time was spent waiting for screen redraw to complete\r
 w = w + 1\r
+\r
+' Check if monitor is still drawing frame\r
 a = INP(p)\r
 IF a >= 128 THEN a = a - 128\r
 IF a >= 64 THEN a = a - 64\r
@@ -38,30 +61,41 @@ IF a < 8 THEN GOTO 1
 frm = frm + 1\r
 IF frm > 10000 THEN frm = -10000\r
 \r
-\r
+' Adjust the color palette change speed so that it takes approximately all of the time\r
+' when Ray is actually moving along screen surface and is drawing pixels.\r
+' So if we had to wait too long for drawing to complete at the end, it means\r
+' next frame we can be slower with our palette updates.\r
 IF w > 300 THEN wa = wa + 1 ELSE wa = wa - 1\r
 IF w < 250 THEN wa = wa - 5\r
 IF w > 3000 THEN wa = wa + 30\r
 IF w > 1000 THEN wa = wa + 5\r
 \r
+' Check if a key has been pressed\r
 IF INKEY$ <> "" THEN\r
-  OUT &H3C8, 0\r
-  OUT &H3C9, 0\r
-  OUT &H3C9, 0\r
-  OUT &H3C9, 0\r
-  SYSTEM\r
+    ' Reset color palette\r
+    OUT &H3C8, 0\r
+    OUT &H3C9, 0\r
+    OUT &H3C9, 0\r
+    OUT &H3C9, 0\r
+    ' exit application\r
+    SYSTEM\r
 END IF\r
 \r
+' Alter video graphics color palette while CRT screen in drawing scanlines simultaneously\r
 FOR a = 0 TO 70\r
-  b = a * 6 + frm\r
-  OUT &H3C8, 0\r
-  OUT &H3C9, SIN(b / 20) * 30 + 30\r
-  OUT &H3C9, SIN(b / 27) * 30 + 30\r
-  OUT &H3C9, SIN(b / 31) * 30 + 30\r
-  FOR u = 1 TO wa\r
-  NEXT u\r
+\r
+    b = a * 6 + frm\r
+\r
+    ' Alter palette within video card\r
+    OUT &H3C8, 0\r
+    OUT &H3C9, SIN(b / 20) * 30 + 30\r
+    OUT &H3C9, SIN(b / 27) * 30 + 30\r
+    OUT &H3C9, SIN(b / 31) * 30 + 30\r
+\r
+    ' Delay to give time for CRT screen to complete horizontal scanlines\r
+    FOR u = 1 TO wa\r
+    NEXT u\r
 NEXT a\r
 \r
 w = 0\r
 GOTO 1\r
-\r