test_image_access.py

from __future__ import annotations

import os
import subprocess
import sys
import sysconfig
from types import ModuleType

import pytest

from PIL import Image

from .helper import assert_image_equal, hopper, is_win32

# CFFI imports pycparser which doesn't support PYTHONOPTIMIZE=2
# https://github.com/eliben/pycparser/pull/198#issuecomment-317001670
cffi: ModuleType | None
if os.environ.get("PYTHONOPTIMIZE") == "2":
    cffi = None
else:
    try:
        import cffi

        from PIL import PyAccess
    except ImportError:
        cffi = None

numpy: ModuleType | None
try:
    import numpy
except ImportError:
    numpy = None


class AccessTest:
    # Initial value
    _init_cffi_access = Image.USE_CFFI_ACCESS
    _need_cffi_access = False

    @classmethod
    def setup_class(cls) -> None:
        Image.USE_CFFI_ACCESS = cls._need_cffi_access

    @classmethod
    def teardown_class(cls) -> None:
        Image.USE_CFFI_ACCESS = cls._init_cffi_access


class TestImagePutPixel(AccessTest):
    def test_sanity(self) -> None:
        im1 = hopper()
        im2 = Image.new(im1.mode, im1.size, 0)

        for y in range(im1.size[1]):
            for x in range(im1.size[0]):
                pos = x, y
                im2.putpixel(pos, im1.getpixel(pos))

        assert_image_equal(im1, im2)

        im2 = Image.new(im1.mode, im1.size, 0)
        im2.readonly = 1

        for y in range(im1.size[1]):
            for x in range(im1.size[0]):
                pos = x, y
                im2.putpixel(pos, im1.getpixel(pos))

        assert not im2.readonly
        assert_image_equal(im1, im2)

        im2 = Image.new(im1.mode, im1.size, 0)

        pix1 = im1.load()
        pix2 = im2.load()

        with pytest.raises(TypeError):
            pix1[0, "0"]
        with pytest.raises(TypeError):
            pix1["0", 0]

        for y in range(im1.size[1]):
            for x in range(im1.size[0]):
                pix2[x, y] = pix1[x, y]

        assert_image_equal(im1, im2)

    def test_sanity_negative_index(self) -> None:
        im1 = hopper()
        im2 = Image.new(im1.mode, im1.size, 0)

        width, height = im1.size
        assert im1.getpixel((0, 0)) == im1.getpixel((-width, -height))
        assert im1.getpixel((-1, -1)) == im1.getpixel((width - 1, height - 1))

        for y in range(-1, -im1.size[1] - 1, -1):
            for x in range(-1, -im1.size[0] - 1, -1):
                pos = x, y
                im2.putpixel(pos, im1.getpixel(pos))

        assert_image_equal(im1, im2)

        im2 = Image.new(im1.mode, im1.size, 0)
        im2.readonly = 1

        for y in range(-1, -im1.size[1] - 1, -1):
            for x in range(-1, -im1.size[0] - 1, -1):
                pos = x, y
                im2.putpixel(pos, im1.getpixel(pos))

        assert not im2.readonly
        assert_image_equal(im1, im2)

        im2 = Image.new(im1.mode, im1.size, 0)

        pix1 = im1.load()
        pix2 = im2.load()

        for y in range(-1, -im1.size[1] - 1, -1):
            for x in range(-1, -im1.size[0] - 1, -1):
                pix2[x, y] = pix1[x, y]

        assert_image_equal(im1, im2)

    @pytest.mark.skipif(numpy is None, reason="NumPy not installed")
    def test_numpy(self) -> None:
        im = hopper()
        pix = im.load()

        assert numpy is not None
        assert pix[numpy.int32(1), numpy.int32(2)] == (18, 20, 59)


class TestImageGetPixel(AccessTest):
    @staticmethod
    def color(mode: str) -> int | tuple[int, ...]:
        bands = Image.getmodebands(mode)
        if bands == 1:
            return 1
        if mode in ("BGR;15", "BGR;16"):
            # These modes have less than 8 bits per band,
            # so (1, 2, 3) cannot be roundtripped.
            return (16, 32, 49)
        return tuple(range(1, bands + 1))

    def check(self, mode: str, expected_color_int: int | None = None) -> None:
        if self._need_cffi_access and mode.startswith("BGR;"):
            pytest.skip("Support not added to deprecated module for BGR;* modes")

        expected_color = (
            self.color(mode) if expected_color_int is None else expected_color_int
        )

        # Check putpixel
        im = Image.new(mode, (1, 1), None)
        im.putpixel((0, 0), expected_color)
        actual_color = im.getpixel((0, 0))
        assert actual_color == expected_color, (
            f"put/getpixel roundtrip failed for mode {mode}, "
            f"expected {expected_color} got {actual_color}"
        )

        # Check putpixel negative index
        im.putpixel((-1, -1), expected_color)
        actual_color = im.getpixel((-1, -1))
        assert actual_color == expected_color, (
            f"put/getpixel roundtrip negative index failed for mode {mode}, "
            f"expected {expected_color} got {actual_color}"
        )

        # Check 0x0 image with None initial color
        im = Image.new(mode, (0, 0), None)
        assert im.load() is not None
        error = ValueError if self._need_cffi_access else IndexError
        with pytest.raises(error):
            im.putpixel((0, 0), expected_color)
        with pytest.raises(error):
            im.getpixel((0, 0))
        # Check negative index
        with pytest.raises(error):
            im.putpixel((-1, -1), expected_color)
        with pytest.raises(error):
            im.getpixel((-1, -1))

        # Check initial color
        im = Image.new(mode, (1, 1), expected_color)
        actual_color = im.getpixel((0, 0))
        assert actual_color == expected_color, (
            f"initial color failed for mode {mode}, "
            f"expected {expected_color} got {actual_color}"
        )

        # Check initial color negative index
        actual_color = im.getpixel((-1, -1))
        assert actual_color == expected_color, (
            f"initial color failed with negative index for mode {mode}, "
            f"expected {expected_color} got {actual_color}"
        )

        # Check 0x0 image with initial color
        im = Image.new(mode, (0, 0), expected_color)
        with pytest.raises(error):
            im.getpixel((0, 0))
        # Check negative index
        with pytest.raises(error):
            im.getpixel((-1, -1))

    @pytest.mark.parametrize("mode", Image.MODES)
    def test_basic(self, mode: str) -> None:
        self.check(mode)

    @pytest.mark.parametrize("mode", ("BGR;15", "BGR;16", "BGR;24"))
    def test_deprecated(self, mode: str) -> None:
        with pytest.warns(DeprecationWarning):
            self.check(mode)

    def test_list(self) -> None:
        im = hopper()
        assert im.getpixel([0, 0]) == (20, 20, 70)

    @pytest.mark.parametrize("mode", ("I;16", "I;16B"))
    @pytest.mark.parametrize("expected_color", (2**15 - 1, 2**15, 2**15 + 1, 2**16 - 1))
    def test_signedness(self, mode: str, expected_color: int) -> None:
        # See https://github.com/python-pillow/Pillow/issues/452
        # pixelaccess is using signed int* instead of uint*
        self.check(mode, expected_color)

    @pytest.mark.parametrize("mode", ("P", "PA"))
    @pytest.mark.parametrize("color", ((255, 0, 0), (255, 0, 0, 255)))
    def test_p_putpixel_rgb_rgba(self, mode: str, color: tuple[int, ...]) -> None:
        im = Image.new(mode, (1, 1))
        im.putpixel((0, 0), color)

        alpha = color[3] if len(color) == 4 and mode == "PA" else 255
        assert im.convert("RGBA").getpixel((0, 0)) == (255, 0, 0, alpha)


@pytest.mark.filterwarnings("ignore::DeprecationWarning")
@pytest.mark.skipif(cffi is None, reason="No CFFI")
class TestCffiPutPixel(TestImagePutPixel):
    _need_cffi_access = True


@pytest.mark.filterwarnings("ignore::DeprecationWarning")
@pytest.mark.skipif(cffi is None, reason="No CFFI")
class TestCffiGetPixel(TestImageGetPixel):
    _need_cffi_access = True


@pytest.mark.skipif(cffi is None, reason="No CFFI")
class TestCffi(AccessTest):
    _need_cffi_access = True

    def _test_get_access(self, im: Image.Image) -> None:
        """Do we get the same thing as the old pixel access

        Using private interfaces, forcing a capi access and
        a pyaccess for the same image"""
        caccess = im.im.pixel_access(False)
        with pytest.warns(DeprecationWarning):
            access = PyAccess.new(im, False)

        w, h = im.size
        for x in range(0, w, 10):
            for y in range(0, h, 10):
                assert access[(x, y)] == caccess[(x, y)]

        # Access an out-of-range pixel
        with pytest.raises(ValueError):
            access[(access.xsize + 1, access.ysize + 1)]

    def test_get_vs_c(self) -> None:
        with pytest.warns(DeprecationWarning):
            rgb = hopper("RGB")
            rgb.load()
            self._test_get_access(rgb)
            for mode in ("RGBA", "L", "LA", "1", "P", "F"):
                self._test_get_access(hopper(mode))

            for mode in ("I;16", "I;16L", "I;16B", "I;16N", "I"):
                im = Image.new(mode, (10, 10), 40000)
                self._test_get_access(im)

    def _test_set_access(self, im: Image.Image, color: tuple[int, ...] | float) -> None:
        """Are we writing the correct bits into the image?

        Using private interfaces, forcing a capi access and
        a pyaccess for the same image"""
        caccess = im.im.pixel_access(False)
        with pytest.warns(DeprecationWarning):
            access = PyAccess.new(im, False)

        w, h = im.size
        for x in range(0, w, 10):
            for y in range(0, h, 10):
                access[(x, y)] = color
                assert color == caccess[(x, y)]

        # Attempt to set the value on a read-only image
        with pytest.warns(DeprecationWarning):
            access = PyAccess.new(im, True)
        with pytest.raises(ValueError):
            access[(0, 0)] = color

    def test_set_vs_c(self) -> None:
        rgb = hopper("RGB")
        with pytest.warns(DeprecationWarning):
            rgb.load()
        self._test_set_access(rgb, (255, 128, 0))
        self._test_set_access(hopper("RGBA"), (255, 192, 128, 0))
        self._test_set_access(hopper("L"), 128)
        self._test_set_access(hopper("LA"), (128, 128))
        self._test_set_access(hopper("1"), 255)
        self._test_set_access(hopper("P"), 128)
        self._test_set_access(hopper("PA"), (128, 128))
        self._test_set_access(hopper("F"), 1024.0)

        for mode in ("I;16", "I;16L", "I;16B", "I;16N", "I"):
            im = Image.new(mode, (10, 10), 40000)
            self._test_set_access(im, 45000)

    @pytest.mark.filterwarnings("ignore::DeprecationWarning")
    def test_not_implemented(self) -> None:
        assert PyAccess.new(hopper("BGR;15")) is None

    # Ref https://github.com/python-pillow/Pillow/pull/2009
    def test_reference_counting(self) -> None:
        size = 10

        for _ in range(10):
            # Do not save references to the image, only to the access object
            with pytest.warns(DeprecationWarning):
                px = Image.new("L", (size, 1), 0).load()
            for i in range(size):
                # Pixels can contain garbage if image is released
                assert px[i, 0] == 0

    @pytest.mark.parametrize("mode", ("P", "PA"))
    def test_p_putpixel_rgb_rgba(self, mode: str) -> None:
        for color in ((255, 0, 0), (255, 0, 0, 127 if mode == "PA" else 255)):
            im = Image.new(mode, (1, 1))
            with pytest.warns(DeprecationWarning):
                access = PyAccess.new(im, False)
                access.putpixel((0, 0), color)

                if len(color) == 3:
                    color += (255,)
                assert im.convert("RGBA").getpixel((0, 0)) == color


class TestImagePutPixelError(AccessTest):
    IMAGE_MODES1 = ["LA", "RGB", "RGBA", "BGR;15"]
    IMAGE_MODES2 = ["L", "I", "I;16"]
    INVALID_TYPES = ["foo", 1.0, None]

    @pytest.mark.parametrize("mode", IMAGE_MODES1)
    def test_putpixel_type_error1(self, mode: str) -> None:
        im = hopper(mode)
        for v in self.INVALID_TYPES:
            with pytest.raises(TypeError, match="color must be int or tuple"):
                im.putpixel((0, 0), v)

    @pytest.mark.parametrize(
        ("mode", "band_numbers", "match"),
        (
            ("L", (0, 2), "color must be int or single-element tuple"),
            ("LA", (0, 3), "color must be int, or tuple of one or two elements"),
            (
                "BGR;15",
                (0, 2),
                "color must be int, or tuple of one or three elements",
            ),
            (
                "RGB",
                (0, 2, 5),
                "color must be int, or tuple of one, three or four elements",
            ),
        ),
    )
    def test_putpixel_invalid_number_of_bands(
        self, mode: str, band_numbers: tuple[int, ...], match: str
    ) -> None:
        im = hopper(mode)
        for band_number in band_numbers:
            with pytest.raises(TypeError, match=match):
                im.putpixel((0, 0), (0,) * band_number)

    @pytest.mark.parametrize("mode", IMAGE_MODES2)
    def test_putpixel_type_error2(self, mode: str) -> None:
        im = hopper(mode)
        for v in self.INVALID_TYPES:
            with pytest.raises(
                TypeError, match="color must be int or single-element tuple"
            ):
                im.putpixel((0, 0), v)

    @pytest.mark.parametrize("mode", IMAGE_MODES1 + IMAGE_MODES2)
    def test_putpixel_overflow_error(self, mode: str) -> None:
        im = hopper(mode)
        with pytest.raises(OverflowError):
            im.putpixel((0, 0), 2**80)


class TestEmbeddable:
    @pytest.mark.xfail(reason="failing test")
    @pytest.mark.skipif(not is_win32(), reason="requires Windows")
    def test_embeddable(self) -> None:
        import ctypes

        from setuptools.command import build_ext

        with open("embed_pil.c", "w", encoding="utf-8") as fh:
            home = sys.prefix.replace("\\", "\\\\")
            fh.write(
                f"""
#include "Python.h"

int main(int argc, char* argv[])
{{
    char *home = "{home}";
    wchar_t *whome = Py_DecodeLocale(home, NULL);
    Py_SetPythonHome(whome);

    Py_InitializeEx(0);
    Py_DECREF(PyImport_ImportModule("PIL.Image"));
    Py_Finalize();

    Py_InitializeEx(0);
    Py_DECREF(PyImport_ImportModule("PIL.Image"));
    Py_Finalize();

    PyMem_RawFree(whome);

    return 0;
}}
        """
            )

        compiler = getattr(build_ext, "new_compiler")()
        compiler.add_include_dir(sysconfig.get_config_var("INCLUDEPY"))

        libdir = sysconfig.get_config_var("LIBDIR") or sysconfig.get_config_var(
            "INCLUDEPY"
        ).replace("include", "libs")
        compiler.add_library_dir(libdir)
        objects = compiler.compile(["embed_pil.c"])
        compiler.link_executable(objects, "embed_pil")

        env = os.environ.copy()
        env["PATH"] = sys.prefix + ";" + env["PATH"]

        # Do not display the Windows Error Reporting dialog
        getattr(ctypes, "windll").kernel32.SetErrorMode(0x0002)

        process = subprocess.Popen(["embed_pil.exe"], env=env)
        process.communicate()
        assert process.returncode == 0