TTF build using fontforge

OTFbuild/tga_reader.py

@@ -0,0 +1,90 @@
+"""
+TGA reader for uncompressed true-colour images (Type 2).
+Stores pixels as RGBA8888: (R<<24 | G<<16 | B<<8 | A).
+
+Matches the convention in TerrarumSansBitmap.kt where .and(255) checks
+the alpha channel (lowest byte).
+"""
+
+import struct
+from typing import List
+
+
+class TgaImage:
+    __slots__ = ('width', 'height', 'pixels')
+
+    def __init__(self, width: int, height: int, pixels: List[int]):
+        self.width = width
+        self.height = height
+        self.pixels = pixels  # flat array, row-major
+
+    def get_pixel(self, x: int, y: int) -> int:
+        """Get pixel at (x, y) as RGBA8888 (R in bits 31-24, A in bits 7-0)."""
+        if x < 0 or x >= self.width or y < 0 or y >= self.height:
+            return 0
+        return self.pixels[y * self.width + x]
+
+
+def read_tga(path: str) -> TgaImage:
+    """Read an uncompressed true-colour TGA file."""
+    with open(path, 'rb') as f:
+        data = f.read()
+
+    pos = 0
+
+    def u8():
+        nonlocal pos
+        val = data[pos]
+        pos += 1
+        return val
+
+    def u16():
+        nonlocal pos
+        val = struct.unpack_from('<H', data, pos)[0]
+        pos += 2
+        return val
+
+    id_length = u8()
+    colour_map_type = u8()
+    image_type = u8()
+
+    # colour map spec (5 bytes)
+    u16(); u16(); u8()
+
+    # image spec
+    x_origin = u16()
+    y_origin = u16()
+    width = u16()
+    height = u16()
+    bits_per_pixel = u8()
+    descriptor = u8()
+
+    top_to_bottom = (descriptor & 0x20) != 0
+    bytes_per_pixel = bits_per_pixel // 8
+
+    # skip ID
+    pos += id_length
+
+    if colour_map_type != 0:
+        raise ValueError("Colour-mapped TGA not supported")
+    if image_type != 2:
+        raise ValueError(f"Only uncompressed true-colour TGA supported (type 2), got type {image_type}")
+    if bytes_per_pixel not in (3, 4):
+        raise ValueError(f"Only 24-bit or 32-bit TGA supported, got {bits_per_pixel}-bit")
+
+    pixels = [0] * (width * height)
+
+    for row in range(height):
+        y = row if top_to_bottom else (height - 1 - row)
+        for x in range(width):
+            b = data[pos]; pos += 1
+            g = data[pos]; pos += 1
+            r = data[pos]; pos += 1
+            a = data[pos] if bytes_per_pixel == 4 else 0xFF
+            if bytes_per_pixel == 4:
+                pos += 1
+
+            # Store as RGBA8888: R in high byte, A in low byte
+            pixels[y * width + x] = (r << 24) | (g << 16) | (b << 8) | a
+
+    return TgaImage(width, height, pixels)