#!/data/data/com.termux/files/usr/bin/bash
# Times a fullscreen background shader's per-pixel cost. Same Xvfb + Mesa
# softpipe rig as screenshot.sh (see the long note there about llvmpipe
# crashing with SIGILL in this environment), because a fragment shader can
# only be timed if something actually rasterizes it - --headless renders
# nothing at all.
#
# Softpipe is a CPU rasterizer, so treat the numbers as RELATIVE only:
# comparing two versions of the same shader is meaningful, comparing against
# a phone's frame budget is not.
#
# Usage: bash tests/profile_shader.sh <shader_res_path> [timed_frames] [warmup] [WxH]
# Example: bash tests/profile_shader.sh res://lunar_surface.gdshader 30 10 720x1280

set -e
PROJECT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
GODOT_BIN="/root/Godot_v4.7.1-stable_linux.arm64"

SHADER_PATH="${1:?usage: profile_shader.sh <shader_res_path> [timed_frames] [warmup] [WxH]}"
TIMED_FRAMES="${2:-30}"
WARMUP_FRAMES="${3:-10}"
RESOLUTION="${4:-720x1280}"

proot-distro login ubuntu -- bash -c "
pkill -x Xvfb >/dev/null 2>&1 || true
rm -f /tmp/.X99-lock /tmp/.X11-unix/X99
Xvfb :99 -screen 0 ${RESOLUTION}x24 &
XVFB_PID=\$!
trap 'kill \$XVFB_PID >/dev/null 2>&1 || true' EXIT
sleep 2
mkdir -p /tmp/xdgrt && chmod 700 /tmp/xdgrt
cd '$PROJECT_DIR'
DISPLAY=:99 XDG_RUNTIME_DIR=/tmp/xdgrt GALLIUM_DRIVER=softpipe '$GODOT_BIN' --audio-driver Dummy --rendering-driver opengl3 --rendering-method gl_compatibility --resolution '$RESOLUTION' -s res://tests/_profile_surface_shader.gd -- '$SHADER_PATH' '$TIMED_FRAMES' '$WARMUP_FRAMES'
"