Add option to print possibilities in generated PDF puzzles

src/bin/generator.rs

@@ -102,6 +102,7 @@ fn main() {
     let mut filename: Option<String> = None;
     let mut difficulty = Difficulty::Challenge;
     let mut threads = 1;
+    let mut print_possibilities = false;
 
     {
         // this block limits scope of borrows by ap.refer() method
@@ -137,6 +138,13 @@ fn main() {
             "Number of threads to use when generating possible puzzles",
         );
 
+        ap.refer(&mut print_possibilities)
+            .add_option(
+            &["-p", "--possibilities"],
+            argparse::StoreTrue,
+            "Include each cell's possibilities in the output; applies only to PDF output"
+            );
+
         ap.parse_args_or_exit();
     }
 
@@ -202,7 +210,7 @@ fn main() {
         Some(filename) => {
             // check if we save to a csv or a pdf
             if filename.ends_with(".pdf") {
-                sudoku_solver::pdf::draw_grid(&grid, &filename).unwrap();
+                sudoku_solver::pdf::draw_grid(&grid, &filename, print_possibilities).unwrap();
                 println!("Grid saved as pdf to {}", filename);
             } else {
                 save_grid_csv(&grid, &filename).unwrap();

src/pdf.rs

@@ -9,12 +9,13 @@ const GRID_DIMENSION: f64 = 190.0;
 
 const A4: (Mm, Mm) = (Mm(215.0), Mm(279.0));
 
-pub fn draw_grid(grid: &Grid, filename: &str) -> Result<(), Box<dyn std::error::Error>> {
+pub fn draw_grid(grid: &Grid, filename: &str, print_possibilities: bool) -> Result<(), Box<dyn std::error::Error>> {
     let (doc, page1, layer1) = PdfDocument::new("Sudoku Puzzle", A4.0, A4.1, "Layer 1");
     let layer = doc.get_page(page1).get_layer(layer1);
 
     let font = doc.add_builtin_font(BuiltinFont::HelveticaBold)?;
-    let font_size = 45;
+    let fixed_value_font_size = 45;
+    let possibility_font_size = 12;
 
     draw_empty_grid(&layer);
 
@@ -39,9 +40,23 @@ pub fn draw_grid(grid: &Grid, filename: &str) -> Result<(), Box<dyn std::error::
             match value {
                 CellValue::Fixed(digit) => {
                     let text = digit.to_string();
-                    layer.use_text(text, font_size, x, y, &font);
+                    layer.use_text(text, fixed_value_font_size, x, y, &font);
+                }
+                CellValue::Unknown(possibilities) => {
+                    if print_possibilities {
+                        for (_, possibility) in possibilities.iter().enumerate() {
+
+                            let sub_row = (possibility - 1) / 3;
+                            let sub_column = (possibility - 1) % 3;
+                            // Need to adjust x & y
+                            let x = Mm(x.0 - 4.0 + (GRID_DIMENSION / 27.0) * (sub_column as f64));
+                            let y = Mm(y.0 - 9.5 + (GRID_DIMENSION / 27.0) * (3.0 - sub_row as f64));
+
+                            let text = possibility.to_string();
+                            layer.use_text(text, possibility_font_size, x, y, &font);
+                        }
+                    }
                 }
-                _ => {}
             }
         }
     }