manage element density

profile.d/rain.sh

@@ -110,12 +110,24 @@ _rain_normalize_speed()
     fi
 }
 
+_rain_normalize_density()
+{
+    local raw_density="$1"
+
+    if [[ ! "$raw_density" =~ ^[0-9]+$ || "$raw_density" -lt 1 ]]; then
+        return 1
+    fi
+
+    printf "%s" "$raw_density"
+}
+
 _rain_engine()
 {
     local step_duration="$1"
     local base_color="$2"
     local mode="$3"
     local charset="$4"
+    local density_override="$5"
 
     command -v tput >/dev/null 2>&1 || {
         disp E "The program 'tput' is required but not installed."
@@ -175,6 +187,10 @@ _rain_engine()
                 frame_sleep="$step_duration"
                 ;;
         esac
+
+        if [[ -n "$density_override" ]]; then
+            max_rain_width="$density_override"
+        fi
     }
 
     do_exit()
@@ -251,7 +267,11 @@ _rain_engine()
         if ((num_rains < max_rain_width)) && ((100 * RANDOM / 32768 < new_rain_odd)); then
             rain_drop="${rain_chars[rain_tab * RANDOM / 32768]}"
             drop_color="${rain_colors[rain_color_tab * RANDOM / 32768]}"
-            drop_length=$((max_rain_height * RANDOM / 32768 + 1))
+            if [[ "$mode" == "matrix" ]]; then
+                drop_length=$((max_rain_height * RANDOM / 32768 + 2))
+            else
+                drop_length=$((max_rain_height * RANDOM / 32768 + 1))
+            fi
             X=$((term_width * RANDOM / 32768 + 1))
             Y=$((1 - drop_length))
             rains=("${rains[@]}" "$X" "$Y" "$rain_drop" "$drop_color" "$drop_length")
@@ -280,6 +300,7 @@ rain()
         printf "\t-s, --speed NUM    Set speed value (default: 5 => 0.050s).\n"
         printf "\t                   Values >=1 use a /100 scale (5 => 0.05s).\n"
         printf "\t                   Values <1 are interpreted as raw seconds.\n"
+        printf "\t-d, --density NUM  Maximum number of simultaneous falling elements.\n"
         printf "\t-c, --color COLOR  Set the color theme (default: white).\n"
         printf "\t-h, --help         Display this help message and exit.\n\n"
         printf "Available Colors:\n"
@@ -296,6 +317,11 @@ rain()
     local step_duration
     step_duration=$(_rain_normalize_speed "$_raw_speed") || step_duration=0.050
     local base_color="${RAIN_DEFAULT_COLOR:-white}"
+    local density_override="${RAIN_DEFAULT_DENSITY:-}"
+
+    if [[ -n "$density_override" ]]; then
+        density_override=$(_rain_normalize_density "$density_override") || density_override=""
+    fi
 
     while [[ "$#" -gt 0 ]]; do
         case $1 in
@@ -323,6 +349,20 @@ rain()
                     return 1
                 fi
                 ;;
+            -d|--density)
+                if [[ -n "$2" && ! "$2" =~ ^- ]]; then
+                    density_override=$(_rain_normalize_density "$2") || {
+                        disp E "--density requires a positive integer value."
+                        _rain_show_usage
+                        return 1
+                    }
+                    shift
+                else
+                    disp E "--density requires a positive integer value."
+                    _rain_show_usage
+                    return 1
+                fi
+                ;;
             -h|--help)
                 _rain_show_usage
                 return 0
@@ -340,7 +380,7 @@ rain()
         shift
     done
 
-    _rain_engine "$step_duration" "$base_color" "rain" ""
+    _rain_engine "$step_duration" "$base_color" "rain" "" "$density_override"
 }
 export -f rain
 
@@ -356,6 +396,7 @@ matrix()
         printf "\t-s, --speed NUM    Set speed value (default: 3.5 => 0.035s).\n"
         printf "\t                   Values >=1 use a /100 scale (3.5 => 0.035s).\n"
         printf "\t                   Values <1 are interpreted as raw seconds.\n"
+        printf "\t-d, --density NUM  Maximum number of simultaneous falling elements.\n"
         printf "\t-c, --color COLOR  Set color theme (default: green).\n"
         printf "\t-C, --charset SET  Character set: binary, kana, ascii (default: binary).\n"
         printf "\t-h, --help         Display this help message and exit.\n\n"
@@ -367,6 +408,11 @@ matrix()
     step_duration=$(_rain_normalize_speed "$_raw_speed") || step_duration=0.035
     local base_color="${MATRIX_DEFAULT_COLOR:-green}"
     local charset="${MATRIX_DEFAULT_CHARSET:-binary}"
+    local density_override="${MATRIX_DEFAULT_DENSITY:-}"
+
+    if [[ -n "$density_override" ]]; then
+        density_override=$(_rain_normalize_density "$density_override") || density_override=""
+    fi
 
     while [[ "$#" -gt 0 ]]; do
         case $1 in
@@ -412,6 +458,20 @@ matrix()
                     return 1
                 fi
                 ;;
+            -d|--density)
+                if [[ -n "$2" && ! "$2" =~ ^- ]]; then
+                    density_override=$(_rain_normalize_density "$2") || {
+                        disp E "--density requires a positive integer value."
+                        _matrix_show_usage
+                        return 1
+                    }
+                    shift
+                else
+                    disp E "--density requires a positive integer value."
+                    _matrix_show_usage
+                    return 1
+                fi
+                ;;
             -h|--help)
                 _matrix_show_usage
                 return 0
@@ -429,7 +489,7 @@ matrix()
         shift
     done
 
-    _rain_engine "$step_duration" "$base_color" "matrix" "$charset"
+    _rain_engine "$step_duration" "$base_color" "matrix" "$charset" "$density_override"
 }
 export -f matrix