fix: flicker-free delta redraws for pupils/lids; visible smile curve

Full-eye repaints on every pupil step and blink frame flickered badly on
the 8-bit bus. Pupils now erase/redraw only themselves; lids paint
incrementally (BG rect closing, sclera chords opening). Mouth curve
deepened 20->32px and mood tiers raised so mood ~60 reads as an actual
smile instead of a 6px bend.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

googly/googly.ino

@@ -87,16 +87,59 @@ void drawEyes(int8_t lid, int8_t pdx, int8_t pdy) {
   cur.lid = lid; cur.pdx = pdx; cur.pdy = pdy;
 }
 
+// Delta redraw: erase old pupil with sclera, draw new. No full-eye repaint,
+// no flicker. Pupil range + radius never reaches the sclera edge, so the
+// erase circle can't bleed outside the eye.
+void movePupils(int8_t pdx, int8_t pdy) {
+  const int cxs[2] = {EYE_LX, EYE_RX};
+  for (uint8_t i = 0; i < 2; i++) {
+    int cx = cxs[i];
+    tft.fillCircle(cx + cur.pdx, EYE_Y + cur.pdy, PUPIL_R + 2, SCLERA);
+    tft.fillCircle(cx + pdx, EYE_Y + pdy, PUPIL_R, PUPIL);
+    tft.fillCircle(cx + pdx - 8, EYE_Y + pdy - 8, 7, SCLERA);
+    if (cur.lid > 0) {
+      int h = (int32_t)cur.lid * 2 * EYE_R / 100;
+      tft.fillRect(cx - EYE_R, EYE_Y - EYE_R, 2 * EYE_R + 1, h, BG);
+    }
+  }
+  cur.pdx = pdx; cur.pdy = pdy;
+}
+
+// Incremental lids: closing = paint one BG rect over the top of the eye;
+// opening = reveal the exposed band with sclera chords, then restore pupil.
+void setLids(int8_t pct) {
+  int newH = (int32_t)pct * 2 * EYE_R / 100;
+  int oldH = (int32_t)cur.lid * 2 * EYE_R / 100;
+  const int cxs[2] = {EYE_LX, EYE_RX};
+  for (uint8_t i = 0; i < 2; i++) {
+    int cx = cxs[i];
+    if (newH > oldH) {
+      tft.fillRect(cx - EYE_R, EYE_Y - EYE_R + oldH, 2 * EYE_R + 1, newH - oldH, BG);
+    } else if (newH < oldH) {
+      for (int y = EYE_Y - EYE_R + newH; y < EYE_Y - EYE_R + oldH; y++) {
+        int dy = y - EYE_Y;
+        int w = (int)sqrt((float)(EYE_R * EYE_R - dy * dy));
+        tft.drawFastHLine(cx - w, y, 2 * w + 1, SCLERA);
+      }
+      tft.fillCircle(cx + cur.pdx, EYE_Y + cur.pdy, PUPIL_R, PUPIL);
+      tft.fillCircle(cx + cur.pdx - 8, EYE_Y + cur.pdy - 8, 7, SCLERA);
+      if (newH > 0)
+        tft.fillRect(cx - EYE_R, EYE_Y - EYE_R, 2 * EYE_R + 1, newH, BG);
+    }
+  }
+  cur.lid = pct;
+}
+
 void drawMouth(int8_t curve, int8_t openR) {
-  tft.fillRect(MOUTH_X - MOUTH_HW - 8, MOUTH_Y - 30, 2 * (MOUTH_HW + 8), 64, BG);
+  tft.fillRect(MOUTH_X - MOUTH_HW - 8, MOUTH_Y - 38, 2 * (MOUTH_HW + 8), 80, BG);
   if (openR > 0) {
     tft.fillCircle(MOUTH_X, MOUTH_Y, openR, PUPIL);
     tft.drawCircle(MOUTH_X, MOUTH_Y, openR, SCLERA);
     tft.drawCircle(MOUTH_X, MOUTH_Y, openR + 1, SCLERA);
   } else {
     for (int x = -MOUTH_HW; x <= MOUTH_HW; x += 4) {
-      int y = MOUTH_Y - (int32_t)curve * (20 - (x * x) / 180) / 100;
+      int y = MOUTH_Y - (int32_t)curve * (32 - (x * x) / 113) / 100;
-      tft.fillCircle(MOUTH_X + x, y, 4, SCLERA);
+      tft.fillCircle(MOUTH_X + x, y, 5, SCLERA);
     }
   }
   cur.curve = curve; cur.openR = openR;
@@ -133,7 +176,7 @@ void setFace(int8_t lid, int8_t pdx, int8_t pdy, int8_t curve, int8_t openR, boo
   if (blush != cur.blush) drawBlush(blush);
 }
 
-int8_t moodCurve() { return pet.mood > 66 ? 80 : (pet.mood > 33 ? 30 : -40); }
+int8_t moodCurve() { return pet.mood > 66 ? 100 : (pet.mood > 33 ? 70 : -50); }
 int8_t moodLid()   { return pet.mood > 66 ? 0  : (pet.mood > 33 ? 10 : 30); }
 
 void clearZs() { tft.fillRect(380, 20, 100, 90, BG); }
@@ -182,9 +225,9 @@ void bumpMood(int8_t d) {
 
 void blinkOnce() {
   int8_t base = moodLid();
-  const int8_t seq[3] = {60, 100, 60};
+  setLids(100);
-  for (uint8_t i = 0; i < 3; i++) { drawEyes(seq[i], cur.pdx, cur.pdy); delay(35); }
+  delay(90);
-  drawEyes(base, cur.pdx, cur.pdy);
+  setLids(base);
 }
 
 void wakeAnim() {
@@ -214,7 +257,7 @@ void dizzyAnim() {
   drawMouth(0, 10);
   for (int a = 0; a < 720; a += 40) {
     float r = a * 0.01745;
-    drawEyes(0, (int8_t)(PUPIL_RANGE * cos(r)), (int8_t)(PUPIL_RANGE * sin(r)));
+    movePupils((int8_t)(PUPIL_RANGE * cos(r)), (int8_t)(PUPIL_RANGE * sin(r)));
     delay(28);
   }
   drawEyes(30, 0, 8); drawMouth(-30, 0); delay(500);
@@ -223,9 +266,10 @@ void dizzyAnim() {
 
 void yawnAnim() {
   Serial.println(F("yawn"));
+  setLids(50);
   const int8_t seq[8] = {8, 14, 20, 24, 24, 20, 12, 0};
   for (uint8_t i = 0; i < 8; i++) {
-    drawMouth(0, seq[i]); drawEyes(50, cur.pdx, cur.pdy); delay(140);
+    drawMouth(0, seq[i]); delay(140);
   }
   setFace(moodLid(), cur.pdx, cur.pdy, moodCurve(), 0, false);
 }
@@ -251,7 +295,7 @@ void flyAnim() {
     tft.fillCircle(fx, fy, 3, FLYCLR);
     px = fx; py = fy;
     int8_t pdx = constrain((fx - MOUTH_X) / 8, -PUPIL_RANGE, PUPIL_RANGE);
-    if (pdx != cur.pdx) drawEyes(0, pdx, -14);
+    if (pdx != cur.pdx) movePupils(pdx, -14);
     delay(30);
     if (touched()) break;  // a poke scares the fly off
   }
@@ -352,7 +396,7 @@ void loop() {
         } else {
           int8_t sx = constrain(targPdx - cur.pdx, -6, 6);
           int8_t sy = constrain(targPdy - cur.pdy, -6, 6);
-          drawEyes(cur.lid, cur.pdx + sx, cur.pdy + sy);
+          movePupils(cur.pdx + sx, cur.pdy + sy);
           nextWanderMs = now + 60;
         }
       }