Optimizations and debug options

internal/portal/portal.go

@@ -98,6 +98,10 @@ func (p *Portal) Update(dt float64) {
 		return
 	}
 
+	if dt > 0.1 {
+		dt = 0.1
+	}
+
 	p.GlowIntensity += dt * 2.0
 	if p.GlowIntensity > 6.28 { // 2*PI
 		p.GlowIntensity -= 6.28
@@ -109,18 +113,24 @@ func (p *Portal) Draw(screen *ebiten.Image) {
 		return
 	}
 
+	drawX := float32(int(p.X + 0.5))
+	drawY := float32(int(p.Y + 0.5))
+	drawWidth := float32(int(p.Width + 0.5))
+	drawHeight := float32(int(p.Height + 0.5))
+
 	vector.FillRect(
 		screen,
-		float32(p.X),
-		float32(p.Y),
-		float32(p.Width),
-		float32(p.Height),
+		drawX,
+		drawY,
+		drawWidth,
+		drawHeight,
 		p.Color,
 		false,
 	)
 
 	if p.Enabled {
-		glowAlpha := uint8(float64(p.GlowColor.A) * (0.5 + 0.5*float64(p.GlowIntensity)))
+		glowPulse := 0.5 + 0.5*float64(p.GlowIntensity)/6.28
+		glowAlpha := uint8(float64(p.GlowColor.A) * glowPulse)
 		glowColor := color.NRGBA{
 			R: p.GlowColor.R,
 			G: p.GlowColor.G,
@@ -131,10 +141,10 @@ func (p *Portal) Draw(screen *ebiten.Image) {
 		borderWidth := float32(4)
 		vector.StrokeRect(
 			screen,
-			float32(p.X)-borderWidth/2,
-			float32(p.Y)-borderWidth/2,
-			float32(p.Width)+borderWidth,
-			float32(p.Height)+borderWidth,
+			drawX-borderWidth/2,
+			drawY-borderWidth/2,
+			drawWidth+borderWidth,
+			drawHeight+borderWidth,
 			borderWidth,
 			glowColor,
 			false,
@@ -182,12 +192,20 @@ func (m *Manager) Clear() {
 }
 
 func (m *Manager) Update(dt float64) {
+	// clamp delta time to prevent physics issues
+	if dt > 0.1 {
+		dt = 0.1
+	}
+
 	for _, p := range m.Portals {
 		p.Update(dt)
 	}
 
 	if m.transitionCooldown > 0 {
 		m.transitionCooldown -= dt
+		if m.transitionCooldown < 0 {
+			m.transitionCooldown = 0
+		}
 	}
 }