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compare_auto_brightness.py
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| import xml.etree.ElementTree as ET | |
| from pathlib import Path | |
| import matplotlib.pyplot as plt | |
| import bisect | |
| XML_CONFIGS = [ | |
| ("overlay/Frameworks/res/values/config.xml", "unicorn"), | |
| # ("overlay/Frameworks/res/values/config-new.xml", "unicorn - new"), | |
| # ("../cupid/overlay/Frameworks/res/values/config.xml", "cupid"), | |
| # ("pantah/panther/overlay/frameworks/base/core/res/res/values/config.xml", "pantah"), | |
| ("/home/arian/android/vendor/pixel/blazer/blazer-bp4a.260105.004.e1/framework-res__blazer__auto_generated_rro_vendor/res/values/arrays.xml", "blazer"), | |
| ] | |
| LEVELS_NAME = "config_autoBrightnessLevels" | |
| NITS_NAME = "config_autoBrightnessDisplayValuesNits" | |
| MAX_LUX = 30000.0 | |
| SCALE_FROM_LUX = 15000.0 | |
| BASE_LUX = 15000.0 | |
| def adjust_curve(lux_levels, nits_values, | |
| max_lux=MAX_LUX, base_lux=BASE_LUX): | |
| """ | |
| Adjust one auto-brightness config: | |
| 1. Remove all lux levels > max_lux | |
| 2. Let B_base = brightness at base_lux (15000). | |
| For lux >= base_lux, only scale the *extra* brightness above B_base | |
| so that the brightness at max_lux (30000) reaches the global max nits. | |
| Assumes: | |
| len(nits_values) == len(lux_levels) + 1 | |
| lux_levels sorted ascending. | |
| """ | |
| assert len(nits_values) == len(lux_levels) + 1 | |
| # Global max brightness before any changes (we want to reach this at 30000) | |
| max_nits_global = max(nits_values) | |
| # --- 1) Truncate all lux levels above max_lux --- | |
| # cut_idx = number of lux levels <= max_lux | |
| cut_idx = bisect.bisect_right(lux_levels, max_lux) | |
| lux_trunc = lux_levels[:cut_idx] | |
| nits_trunc = nits_values[:cut_idx + 1] # +1 because of the extra segment | |
| # --- 2) Find the segment index for base_lux (15000) --- | |
| # segment index i: nits_trunc[i] is used for lux in: | |
| # [ 0, lux_trunc[0] ) -> i = 0 | |
| # [ lux_trunc[0], lux_trunc[1] ) -> i = 1 | |
| # ... | |
| base_seg = bisect.bisect_right(lux_trunc, base_lux) | |
| base_nits = nits_trunc[base_seg] | |
| # Segment index for ">= last lux" (this contains 30000 after truncation) | |
| last_idx = len(nits_trunc) - 1 | |
| last_nits_before = nits_trunc[last_idx] | |
| tail_delta = last_nits_before - base_nits | |
| if tail_delta <= 0: | |
| # Nothing to scale above base (already flat or decreasing) | |
| # -> just return with truncation applied. | |
| return lux_trunc, nits_trunc | |
| # Desired brightness at 30000 = global max | |
| desired_last = max_nits_global | |
| if desired_last <= base_nits: | |
| # Would not make sense to scale if target <= base | |
| return lux_trunc, nits_trunc | |
| # --- 3) Scale only the *extra* brightness above base_nits --- | |
| scale_factor = (desired_last - base_nits) / tail_delta | |
| # Keep everything <= 15000 (incl. its segment) unchanged: | |
| # start scaling from the *next* segment after base_seg | |
| for i in range(base_seg + 1, len(nits_trunc)): | |
| # old extra above base: | |
| extra = nits_trunc[i] - base_nits | |
| # scaled extra: | |
| nits_trunc[i] = base_nits + extra * scale_factor | |
| # clamp to [base_nits, desired_last] | |
| if nits_trunc[i] < base_nits: | |
| nits_trunc[i] = base_nits | |
| if nits_trunc[i] > desired_last: | |
| nits_trunc[i] = desired_last | |
| # Make sure the last segment really hits desired_last | |
| nits_trunc[-1] = desired_last | |
| return lux_trunc, nits_trunc | |
| def get_array(root, name, as_type=float): | |
| arr_elem = root.find(f".//integer-array[@name='{name}']") | |
| if arr_elem is None: | |
| arr_elem = root.find(f".//array[@name='{name}']") | |
| if arr_elem is None: | |
| raise ValueError(f"Array with name '{name}' not found") | |
| values = [] | |
| for item in arr_elem.findall("item"): | |
| text = (item.text or "").strip() | |
| if text: | |
| values.append(as_type(text)) | |
| return values | |
| def load_config(path): | |
| tree = ET.parse(path) | |
| root = tree.getroot() | |
| lux_levels = get_array(root, LEVELS_NAME, as_type=float) | |
| nits_values = get_array(root, NITS_NAME, as_type=float) | |
| return lux_levels, nits_values | |
| def plot_auto_brightness_curve(lux_levels, nits_values, label, ax): | |
| """Plot one auto-brightness curve as a step function onto ax.""" | |
| if len(nits_values) != len(lux_levels) + 1: | |
| print(f"[{label}] WARNING: len(nits)={len(nits_values)} " | |
| f"!= len(lux)+1={len(lux_levels)+1}; skipping this config.") | |
| return | |
| lower_bound = 0.0 | |
| last_lux = lux_levels[-1] | |
| lux_bounds = [lower_bound] + lux_levels | |
| y_step = list([n / nits_values[-1] for n in nits_values]) | |
| ax.step(lux_bounds, y_step, where="post", label=label) | |
| def main(): | |
| fig, ax = plt.subplots() | |
| for path_str, label in XML_CONFIGS: | |
| path = Path(path_str) | |
| if not path.is_file(): | |
| print(f"[{label}] File not found: {path}") | |
| continue | |
| lux_levels, nits_values = load_config(path) | |
| print(f"[{label}] lux_levels: {len(lux_levels)} entries") | |
| print(f"[{label}] nits_values: {len(nits_values)} entries") | |
| plot_auto_brightness_curve(lux_levels, nits_values, label, ax) | |
| lux_levels, nits_values = adjust_curve(lux_levels, nits_values) | |
| plot_auto_brightness_curve(lux_levels, nits_values, label + " (scaled)", ax) | |
| ax.set_xlabel("Ambient light (lux)") | |
| ax.set_ylabel("Display brightness") | |
| ax.set_title("Auto-brightness curve comparison") | |
| ax.grid(True) | |
| ax.legend() | |
| ax.set_xlim(left=0) | |
| ax.set_ylim(bottom=0) | |
| plt.tight_layout() | |
| plt.show() | |
| if __name__ == "__main__": | |
| main() |
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