fix text rendering

teleprof/src/lib.rs

@@ -1372,7 +1372,7 @@ mod window {
         
         draw_text(framebuffer, width, text_x, text_y, hover.name, font, 14.0, 0xFFFFFF);
         draw_text(framebuffer, width, text_x, text_y + 20, 
-                 &format!("Duration: {:.2} μs", hover.duration_us), font, 12.0, 0xCCCCCC);
+                 &format!("Duration: {} μs", format_number(hover.duration_us)), font, 12.0, 0xCCCCCC);
         draw_text(framebuffer, width, text_x, text_y + 38,
                  &format!("Thread: {}", hover.thread_id), font, 12.0, 0xCCCCCC);
         draw_text(framebuffer, width, text_x, text_y + 56,
@@ -1409,17 +1409,23 @@ mod window {
         size: f32,
         color: u32,
     ) {
-        let mut cursor_x = x as f32;
+        let mut cursor_x = x as i32;
         
         for ch in text.chars() {
             let (metrics, bitmap) = font.rasterize(ch, size);
             
+            // xmin is the offset from the cursor to the left edge of the glyph
+            // ymin is the offset from the baseline to the bottom edge of the glyph
+            // The glyph's position is: (cursor + xmin, baseline - height - ymin)
+            let glyph_x = (cursor_x + metrics.xmin).max(0) as usize;
+            let glyph_y = (size as i32 + y as i32 - metrics.height as i32 - metrics.ymin).max(0) as usize;
+            
             for (i, &alpha) in bitmap.iter().enumerate() {
                 if alpha > 0 {
-                    let px = cursor_x as usize + (i % metrics.width);
-                    let py = y + (i / metrics.width) + (size as usize - metrics.height);
+                    let px = glyph_x + (i % metrics.width);
+                    let py = glyph_y + (i / metrics.width);
                     
-                    if px < width {
+                    if px < width && py < framebuffer.len() / width {
                         let idx = py * width + px;
                         if idx < framebuffer.len() {
                             let alpha_f = alpha as f32 / 255.0;
@@ -1430,7 +1436,8 @@ mod window {
                 }
             }
             
-            cursor_x += metrics.advance_width;
+            // Advance cursor by the advance_width (includes spacing)
+            cursor_x += metrics.advance_width as i32;
         }
     }
 
@@ -1438,4 +1445,26 @@ mod window {
         let hash = name.bytes().fold(0u32, |acc, b| acc.wrapping_mul(31).wrapping_add(b as u32));
         COLORS[(hash as usize) % COLORS.len()]
     }
+    
+    // Format a number with thousands separators
+    fn format_number(n: f64) -> String {
+        let s = format!("{:.2}", n);
+        let parts: Vec<&str> = s.split('.').collect();
+        let integer_part = parts[0];
+        let decimal_part = if parts.len() > 1 { parts[1] } else { "00" };
+        
+        // Add commas to integer part
+        let mut result = String::new();
+        let chars: Vec<char> = integer_part.chars().collect();
+        for (i, ch) in chars.iter().enumerate() {
+            if i > 0 && (chars.len() - i) % 3 == 0 {
+                result.push(',');
+            }
+            result.push(*ch);
+        }
+        
+        result.push('.');
+        result.push_str(decimal_part);
+        result
+    }
 }