From 37e0b80b6829e46092ed83b6c3122acab3ef8693 Mon Sep 17 00:00:00 2001
From: Zack Buhman <zack@buhman.org>
Date: Sat, 26 Apr 2025 02:50:06 -0500
Subject: [PATCH] render_model: use numeric conversion from float

---
 color_convert.py | 29 +++++++++++++++++++++++++++++
 fixed_point.py   | 16 ++++++++++++++--
 render_model.py  | 10 +++++-----
 3 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/color_convert.py b/color_convert.py
index 4a8a369..12b218f 100644
--- a/color_convert.py
+++ b/color_convert.py
@@ -45,6 +45,23 @@ class color_format:
             ("axxx4444", color_format.axxx4444),
         ])[s]
 
+class unconvert_color_format:
+    def argb1555(value):
+        a = (value >> 15) & 0b1
+        r = (value >> 10) & 0b11111
+        g = (value >> 5 ) & 0b11111
+        b = (value >> 0 ) & 0b11111
+        return (r * 8, g * 8, b * 8, a * 255)
+
+    def from_string(s):
+        return dict([
+            #("gbgr1555", unconvert_color_format.gbgr1555),
+            #("argb4444", unconvert_color_format.argb4444),
+            ("argb1555", unconvert_color_format.argb1555),
+            #("rgb565", unconvert_color_format.rgb565),
+            #("axxx4444", unconvert_color_format.axxx4444),
+        ])[s]
+
 def convert_colors(convert, colors):
     for color in colors:
         value = convert(*color)
@@ -122,6 +139,12 @@ def write_mips(f, im: Image, is_twiddled: bool, convert):
     for mip in generate_mips(im):
         write_mip(f, mip, is_twiddled, convert)
 
+def write_png_reference(size, filename, unconvert, colors):
+    im = Image.new("RGBA", size)
+    data = [unconvert(value) for value in colors]
+    im.putdata(data)
+    im.save(filename)
+
 def main():
     in_file = sys.argv[1]
     format = sys.argv[2]
@@ -130,6 +153,7 @@ def main():
     assert sys.argv[4] in {"mipmapped", "non_mipmapped"}
     is_mipmapped = sys.argv[4] == "mipmapped"
     out_file = sys.argv[5]
+    ref_file = sys.argv[6] if len(sys.argv) > 6 else None
 
     convert = color_format.from_string(format)
 
@@ -145,6 +169,11 @@ def main():
                     write_mips(f, im, is_twiddled, convert)
                 else:
                     write_mip(f, im, is_twiddled, convert)
+            """
+            if ref_file is not None:
+                unconvert = unconvert_color_format.from_string(format)
+                write_png_reference(im.size, ref_file, unconvert, colors)
+            """
         else:
             assert False
             pixels = list(im.convert("P").getdata())
diff --git a/fixed_point.py b/fixed_point.py
index b105407..ea36c00 100644
--- a/fixed_point.py
+++ b/fixed_point.py
@@ -47,8 +47,8 @@ def parse(s):
     sign = -1 if s.startswith('-') else 1
     s = s.removeprefix('-')
     integer, fraction = s.split('.')
-    assert all(c in string.digits for c in integer), integer
-    assert all(c in string.digits for c in fraction), fraction
+    assert all(c in string.digits for c in integer), (integer, s)
+    assert all(c in string.digits for c in fraction), (fraction, s)
     assert len(integer) > 0 and len(fraction) > 0, s
     point = 10 ** len(fraction)
     value = int(integer) * point + int(fraction)
@@ -58,6 +58,18 @@ def parse(s):
         point
     )
 
+def from_float(f):
+    sign = -1 if f < 0 else 1
+    f = f * sign
+
+    point = 10 ** 6
+    value = int(f * point)
+    return FixedPoint(
+        sign,
+        value,
+        point
+    )
+
 def equal(a, b):
     epsilon = 0.00001
     return (a - b) < epsilon
diff --git a/render_model.py b/render_model.py
index 30460d7..94f8a45 100644
--- a/render_model.py
+++ b/render_model.py
@@ -25,7 +25,7 @@ def render_face(face):
     yield "}},"
 
 def render_faces(prefix, name, faces):
-    yield f"union {name} {prefix}_{name}[] = {{"
+    yield f"const union {name} {prefix}_{name}[] = {{"
     for face in faces:
         yield from render_face(face)
     yield "};"
@@ -42,9 +42,9 @@ def unit_vector(vec):
     z = vec.z.to_float()
     norm = math.sqrt(x ** 2 + y ** 2 + z ** 2)
     return type(vec)(
-        fixed_point.parse(f"{x / norm:f}"),
-        fixed_point.parse(f"{y / norm:f}"),
-        fixed_point.parse(f"{z / norm:f}")
+        fixed_point.from_float(x / norm),
+        fixed_point.from_float(y / norm),
+        fixed_point.from_float(z / norm)
     )
 
 def xyz(vec):
@@ -113,7 +113,7 @@ def render_object(prefix, object_name, d, material):
     yield f".quadrilateral_count = {quadrilateral_count},"
 
     if material is None:
-        yield f".material = -1,",
+        yield f".material = -1,"
     else:
         yield f".material = {prefix}_{material.name},"