Files
sideline/engine/display/backends/terminal.py
David Gwilliam 73ca72d920 fix(display): correct FPS calculation in all display backends
BUG: FPS display showed incorrect values (e.g., >1000 when actual FPS was ~60)

ROOT CAUSE: Display backends were looking for avg_ms at the wrong level
in the stats dictionary. The PerformanceMonitor.get_stats() returns:
  {
    'frame_count': N,
    'pipeline': {'avg_ms': X, ...},
    'effects': {...}
  }

But the display backends were using:
  avg_ms = stats.get('avg_ms', 0)  #  Returns 0 (not found at top level)

FIXED: All display backends now use:
  avg_ms = stats.get('pipeline', {}).get('avg_ms', 0)  #  Correct path

Updated backends:
- engine/display/backends/terminal.py
- engine/display/backends/websocket.py
- engine/display/backends/sixel.py
- engine/display/backends/pygame.py
- engine/display/backends/kitty.py

Now FPS displays correctly (e.g., 60 FPS for 16.67ms avg frame time).
2026-03-16 20:03:53 -07:00

127 lines
4.0 KiB
Python

"""
ANSI terminal display backend.
"""
import os
import time
class TerminalDisplay:
"""ANSI terminal display backend.
Renders buffer to stdout using ANSI escape codes.
Supports reuse - when reuse=True, skips re-initializing terminal state.
Auto-detects terminal dimensions on init.
"""
width: int = 80
height: int = 24
_initialized: bool = False
def __init__(self, target_fps: float = 30.0):
self.target_fps = target_fps
self._frame_period = 1.0 / target_fps if target_fps > 0 else 0
self._last_frame_time = 0.0
def init(self, width: int, height: int, reuse: bool = False) -> None:
"""Initialize display with dimensions.
If width/height are not provided (0/None), auto-detects terminal size.
Otherwise uses provided dimensions or falls back to terminal size
if the provided dimensions exceed terminal capacity.
Args:
width: Desired terminal width (0 = auto-detect)
height: Desired terminal height (0 = auto-detect)
reuse: If True, skip terminal re-initialization
"""
from engine.terminal import CURSOR_OFF
# Auto-detect terminal size (handle case where no terminal)
try:
term_size = os.get_terminal_size()
term_width = term_size.columns
term_height = term_size.lines
except OSError:
# No terminal available (e.g., in tests)
term_width = width if width > 0 else 80
term_height = height if height > 0 else 24
# Use provided dimensions if valid, otherwise use terminal size
if width > 0 and height > 0:
self.width = min(width, term_width)
self.height = min(height, term_height)
else:
self.width = term_width
self.height = term_height
if not reuse or not self._initialized:
print(CURSOR_OFF, end="", flush=True)
self._initialized = True
def get_dimensions(self) -> tuple[int, int]:
"""Get current terminal dimensions.
Returns:
(width, height) in character cells
"""
try:
term_size = os.get_terminal_size()
return (term_size.columns, term_size.lines)
except OSError:
return (self.width, self.height)
def show(self, buffer: list[str], border: bool = False) -> None:
import sys
from engine.display import get_monitor, render_border
t0 = time.perf_counter()
# FPS limiting - skip frame if we're going too fast
if self._frame_period > 0:
now = time.perf_counter()
elapsed = now - self._last_frame_time
if elapsed < self._frame_period:
# Skip this frame - too soon
return
self._last_frame_time = now
# Get metrics for border display
fps = 0.0
frame_time = 0.0
monitor = get_monitor()
if monitor:
stats = monitor.get_stats()
avg_ms = stats.get("pipeline", {}).get("avg_ms", 0) if stats else 0
frame_count = stats.get("frame_count", 0) if stats else 0
if avg_ms and frame_count > 0:
fps = 1000.0 / avg_ms
frame_time = avg_ms
# Apply border if requested
if border:
buffer = render_border(buffer, self.width, self.height, fps, frame_time)
# Clear screen and home cursor before each frame
from engine.terminal import CLR
output = CLR + "".join(buffer)
sys.stdout.buffer.write(output.encode())
sys.stdout.flush()
elapsed_ms = (time.perf_counter() - t0) * 1000
if monitor:
chars_in = sum(len(line) for line in buffer)
monitor.record_effect("terminal_display", elapsed_ms, chars_in, chars_in)
def clear(self) -> None:
from engine.terminal import CLR
print(CLR, end="", flush=True)
def cleanup(self) -> None:
from engine.terminal import CURSOR_ON
print(CURSOR_ON, end="", flush=True)