Apply some arithmetic fixes

1 files changed, 3 insertions, 5 deletions

diff --git a/src/main.rs b/src/main.rs
index 8aec593..7d052bc 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -103,16 +103,15 @@ impl DDS {
         let mut out_i = Vec::with_capacity(len);
         let mut out_q = Vec::with_capacity(len);
         for _ in 0..len {
-            let phase = self.phase as i32;
             // get current carrier phase, add phase mod, calculate table index
-            let phase_idx_i = (phase - self.phase_delta) >> TRIG_TABLE_SHIFT;
-            let phase_idx_q = (phase + self.phase_delta) >> TRIG_TABLE_SHIFT;
+            let phase_idx_i = self.phase.overflowing_sub(self.phase_delta as u32).0 >> TRIG_TABLE_SHIFT;
+            let phase_idx_q = self.phase.overflowing_add(self.phase_delta as u32).0 >> TRIG_TABLE_SHIFT;
 
             if phase_idx_q > 255 || phase_idx_i > 255 {
                 panic!("Phase IDX out of bounds");
             }
 
-            self.phase = phase as u32 + self.phase_step;
+            self.phase = self.phase.overflowing_add(self.phase_step).0;
 
             let amp = (self.amplitude * 32767.0) as i32;                               // 0..15
             let amp_i = amp * self.trig_table_inphase[phase_idx_i as usize] as i32;    // 0..31
@@ -295,7 +294,6 @@ fn main() {
                 }
 
                 let pdslope = slope * modulation_index * INT32_MAX_AS_FLOAT;
-                println!("Samp = {}, Slope {} = {} * {} * {}", sample, pdslope, slope, modulation_index, INT32_MAX_AS_FLOAT);
                 if pdslope < MIN_VAL || pdslope > MAX_VAL {
                     panic!("pdslope out of bounds {}", pdslope);
                 }