1 files changed, 70 insertions, 0 deletions
diff --git a/tools/coverage.py b/tools/coverage.py
new file mode 100644
index 0000000..3e57255
--- /dev/null
+++ b/tools/coverage.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+
+"""
+Usage: python3 coverage.py [picross.map] [coverage.png]
+
+Generate a PNG visualizing the space used by each bank in the ROM.
+"""
+
+import sys
+import png
+from colorsys import hls_to_rgb
+
+from parsemap import MapReader
+
+def main():
+    mapfile = sys.argv[1] if len(sys.argv) >= 2 else 'picross.map'
+    filename = sys.argv[2] if len(sys.argv) >= 3 else 'coverage.png'
+
+    num_banks = 0x80
+    bank_mask = 0x3FFF
+    bank_size = 0x4000 # bytes
+
+    bpp = 8 # bytes per pixel
+    height = 256 # pixels
+    assert bank_size % bpp == 0 and (bank_size // bpp) % height == 0
+
+    pixels_per_bank = bank_size // bpp # 2048 pixels
+    bank_width = pixels_per_bank // height # 8 pixels
+    width = bank_width * num_banks # 1024 pixels
+
+    r = MapReader()
+    with open(mapfile, 'r', encoding='utf-8') as f:
+        l = f.readlines()
+    r.read_map_data(l)
+
+    hit_data = []
+    default_bank_data = {'sections': [], 'used': 0, 'slack': bank_size}
+    for bank in range(num_banks):
+        hits = [0] * pixels_per_bank
+        data = r.bank_data['rom bank'].get(bank, default_bank_data)
+        for s in data['sections']:
+            if s['beg'] > s['end']:
+                continue
+            if s['beg'] == 0x0000 and s['end'] > 0xFFFF:
+                # https://github.com/rednex/rgbds/issues/515
+                continue
+            beg = s['beg'] & bank_mask
+            end = s['end'] & bank_mask
+            for i in range(beg, end + 1):
+                hits[i // bpp] += 1
+        hit_data.append(hits)
+
+    pixels = [[(0xFF, 0xFF, 0xFF)] * width for _ in range(height)]
+    for bank, hits in enumerate(hit_data):
+        hue = 0 if not bank else 210 if bank % 2 else 270
+        for i, h in enumerate(hits):
+            y = i // bank_width
+            x = i % bank_width + bank * bank_width
+            hls = (hue / 360.0, 1.0 - (h / bpp * (100 - 15)) / 100.0, 1.0)
+            rgb = tuple(int(c * 255) for c in hls_to_rgb(*hls))
+            pixels[y][x] = rgb
+
+    png_data = [tuple(c for pixel in row for c in pixel) for row in pixels]
+    with open(filename, 'wb') as f:
+        w = png.Writer(width, height)
+        w.write(f, png_data)
+
+if __name__ == '__main__':
+    main()