import unittest
import os
import platform

from pygame.tests import test_utils
from pygame.tests.test_utils import example_path

import pygame
import pygame.transform
from pygame.locals import *


def show_image(s, images=[]):
    # pygame.display.init()
    size = s.get_rect()[2:]
    screen = pygame.display.set_mode(size)
    screen.blit(s, (0, 0))
    pygame.display.flip()
    pygame.event.pump()
    going = True
    idx = 0
    while going:
        events = pygame.event.get()
        for e in events:
            if e.type == QUIT:
                going = False
            if e.type == KEYDOWN:
                if e.key in [K_s, K_a]:
                    if e.key == K_s:
                        idx += 1
                    if e.key == K_a:
                        idx -= 1
                    s = images[idx]
                    screen.blit(s, (0, 0))
                    pygame.display.flip()
                    pygame.event.pump()
                elif e.key in [K_ESCAPE]:
                    going = False
    pygame.display.quit()
    pygame.display.init()


def threshold(
    return_surf,
    surf,
    color,
    threshold=(0, 0, 0),
    diff_color=(0, 0, 0),
    change_return=True,
):
    """given the color it makes return_surf only have areas with the given colour."""

    width, height = surf.get_width(), surf.get_height()

    if change_return:
        return_surf.fill(diff_color)

    try:
        r, g, b = color
    except ValueError:
        r, g, b, a = color

    try:
        tr, tg, tb = color
    except ValueError:
        tr, tg, tb, ta = color

    similar = 0
    for y in range(height):
        for x in range(width):
            c1 = surf.get_at((x, y))

            if (abs(c1[0] - r) < tr) & (abs(c1[1] - g) < tg) & (abs(c1[2] - b) < tb):
                # this pixel is within the threshold.
                if change_return:
                    return_surf.set_at((x, y), c1)
                similar += 1
            # else:
            #    print(c1, c2)

    return similar


class TransformModuleTest(unittest.TestCase):
    def test_scale__alpha(self):
        """see if set_alpha information is kept."""

        s = pygame.Surface((32, 32))
        s.set_alpha(55)
        self.assertEqual(s.get_alpha(), 55)

        s = pygame.Surface((32, 32))
        s.set_alpha(55)
        s2 = pygame.transform.scale(s, (64, 64))
        s3 = s.copy()
        self.assertEqual(s.get_alpha(), s3.get_alpha())
        self.assertEqual(s.get_alpha(), s2.get_alpha())

    def test_scale__destination(self):
        """see if the destination surface can be passed in to use."""

        s = pygame.Surface((32, 32), depth=32)
        s2 = pygame.transform.scale(s, (64, 64))
        s3 = s2.copy()

        # Also validate keyword arguments
        s3 = pygame.transform.scale(surface=s, size=(64, 64), dest_surface=s3)
        pygame.transform.scale(s, (64, 64), s2)

        # the wrong size surface is past in.  Should raise an error.
        self.assertRaises(ValueError, pygame.transform.scale, s, (33, 64), s3)

        s = pygame.Surface((32, 32))
        s2 = pygame.transform.smoothscale(s, (64, 64))
        s3 = s2.copy()

        # Also validate keyword arguments
        s3 = pygame.transform.smoothscale(surface=s, size=(64, 64), dest_surface=s3)

        # the wrong size surface is past in.  Should raise an error.
        self.assertRaises(ValueError, pygame.transform.smoothscale, s, (33, 64), s3)

        alpha_surf = pygame.Surface((64, 64), pygame.SRCALPHA)
        pygame.transform.scale(alpha_surf, (32, 32), s)

        alpha_surf_weird = pygame.Surface(
            (64, 64), pygame.SRCALPHA, 32, (0xFF000000, 0xFF0000, 0xFF00, 0xFF)
        )
        assert alpha_surf_weird.get_shifts() != alpha_surf.get_shifts()

        self.assertRaises(
            ValueError, pygame.transform.scale, alpha_surf_weird, (32, 32), s
        )

    def test_scale__vector2(self):
        s = pygame.Surface((32, 32))
        s2 = pygame.transform.scale(s, pygame.Vector2(64, 64))
        s3 = pygame.transform.smoothscale(s, pygame.Vector2(64, 64))

        self.assertEqual((64, 64), s2.get_size())
        self.assertEqual((64, 64), s3.get_size())

    def test_scale__zero_surface_transform(self):
        tmp_surface = pygame.transform.scale(pygame.Surface((128, 128)), (0, 0))
        self.assertEqual(tmp_surface.get_size(), (0, 0))
        tmp_surface = pygame.transform.scale(tmp_surface, (128, 128))
        self.assertEqual(tmp_surface.get_size(), (128, 128))

    def test_scale_by(self):
        s = pygame.Surface((32, 32))

        s2 = pygame.transform.scale_by(s, 2)
        self.assertEqual((64, 64), s2.get_size())

        s2 = pygame.transform.scale_by(s, factor=(2.0, 1.5))
        self.assertEqual((64, 48), s2.get_size())

        dest = pygame.Surface((64, 48))
        pygame.transform.scale_by(s, (2.0, 1.5), dest_surface=dest)

    def test_smoothscale_by(self):
        s = pygame.Surface((32, 32))

        s2 = pygame.transform.smoothscale_by(s, 2)
        self.assertEqual((64, 64), s2.get_size())

        s2 = pygame.transform.smoothscale_by(s, factor=(2.0, 1.5))
        self.assertEqual((64, 48), s2.get_size())

        dest = pygame.Surface((64, 48))
        pygame.transform.smoothscale_by(s, (2.0, 1.5), dest_surface=dest)

    def test_grayscale(self):
        s = pygame.Surface((32, 32))
        s.fill((255, 0, 0))

        s2 = pygame.transform.grayscale(s)
        self.assertEqual(pygame.transform.average_color(s2)[0], 76)
        self.assertEqual(pygame.transform.average_color(s2)[1], 76)
        self.assertEqual(pygame.transform.average_color(s2)[2], 76)

        dest = pygame.Surface((32, 32), depth=32)
        pygame.transform.grayscale(s, dest)
        self.assertEqual(pygame.transform.average_color(dest)[0], 76)
        self.assertEqual(pygame.transform.average_color(dest)[1], 76)
        self.assertEqual(pygame.transform.average_color(dest)[2], 76)

        dest = pygame.Surface((32, 32), depth=32)
        s.fill((34, 12, 65))
        pygame.transform.grayscale(s, dest)
        self.assertEqual(pygame.transform.average_color(dest)[0], 24)
        self.assertEqual(pygame.transform.average_color(dest)[1], 24)
        self.assertEqual(pygame.transform.average_color(dest)[2], 24)

        dest = pygame.Surface((32, 32), depth=32)
        s.fill((123, 123, 123))
        pygame.transform.grayscale(s, dest)
        self.assertIn(pygame.transform.average_color(dest)[0], [123, 122])
        self.assertIn(pygame.transform.average_color(dest)[1], [123, 122])
        self.assertIn(pygame.transform.average_color(dest)[2], [123, 122])

        s = pygame.Surface((32, 32), depth=24)
        s.fill((255, 0, 0))
        dest = pygame.Surface((32, 32), depth=24)
        pygame.transform.grayscale(s, dest)
        self.assertEqual(pygame.transform.average_color(dest)[0], 76)
        self.assertEqual(pygame.transform.average_color(dest)[1], 76)
        self.assertEqual(pygame.transform.average_color(dest)[2], 76)

        s = pygame.Surface((32, 32), depth=16)
        s.fill((255, 0, 0))
        dest = pygame.Surface((32, 32), depth=16)
        pygame.transform.grayscale(s, dest)
        self.assertEqual(pygame.transform.average_color(dest)[0], 72)
        self.assertEqual(pygame.transform.average_color(dest)[1], 76)
        self.assertEqual(pygame.transform.average_color(dest)[2], 72)

    def test_threshold__honors_third_surface(self):
        # __doc__ for threshold as of Tue 07/15/2008

        # pygame.transform.threshold(DestSurface, Surface, color, threshold =
        # (0,0,0,0), diff_color = (0,0,0,0), change_return = True, Surface =
        # None): return num_threshold_pixels

        # When given the optional third
        # surface, it would use the colors in that rather than the "color"
        # specified in the function to check against.

        # New in pygame 1.8

        ################################################################
        # Sizes
        (w, h) = size = (32, 32)

        # the original_color is within the threshold of the threshold_color
        threshold = (20, 20, 20, 20)

        original_color = (25, 25, 25, 25)
        threshold_color = (10, 10, 10, 10)

        # Surfaces
        original_surface = pygame.Surface(size, pygame.SRCALPHA, 32)
        dest_surface = pygame.Surface(size, pygame.SRCALPHA, 32)

        # Third surface is used in lieu of 3rd position arg color
        third_surface = pygame.Surface(size, pygame.SRCALPHA, 32)

        # Color filling
        original_surface.fill(original_color)
        third_surface.fill(threshold_color)

        ################################################################
        # All pixels for color should be within threshold
        #
        pixels_within_threshold = pygame.transform.threshold(
            dest_surface=None,
            surface=original_surface,
            search_color=threshold_color,
            threshold=threshold,
            set_color=None,
            set_behavior=0,
        )

        self.assertEqual(w * h, pixels_within_threshold)

        ################################################################
        # This should respect third_surface colors in place of 3rd arg
        # color Should be the same as: surface.fill(threshold_color)
        # all within threshold

        pixels_within_threshold = pygame.transform.threshold(
            dest_surface=None,
            surface=original_surface,
            search_color=None,
            threshold=threshold,
            set_color=None,
            set_behavior=0,
            search_surf=third_surface,
        )
        self.assertEqual(w * h, pixels_within_threshold)

    def test_threshold_dest_surf_not_change(self):
        """the pixels within the threshold.

        All pixels not within threshold are changed to set_color.
        So there should be none changed in this test.
        """
        (w, h) = size = (32, 32)
        threshold = (20, 20, 20, 20)
        original_color = (25, 25, 25, 25)
        original_dest_color = (65, 65, 65, 55)
        threshold_color = (10, 10, 10, 10)
        set_color = (255, 10, 10, 10)

        surf = pygame.Surface(size, pygame.SRCALPHA, 32)
        dest_surf = pygame.Surface(size, pygame.SRCALPHA, 32)
        search_surf = pygame.Surface(size, pygame.SRCALPHA, 32)

        surf.fill(original_color)
        search_surf.fill(threshold_color)
        dest_surf.fill(original_dest_color)

        # set_behavior=1, set dest_surface from set_color.
        # all within threshold of third_surface, so no color is set.

        THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR = 1
        pixels_within_threshold = pygame.transform.threshold(
            dest_surface=dest_surf,
            surface=surf,
            search_color=None,
            threshold=threshold,
            set_color=set_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR,
            search_surf=search_surf,
        )

        # # Return, of pixels within threshold is correct
        self.assertEqual(w * h, pixels_within_threshold)

        # # Size of dest surface is correct
        dest_rect = dest_surf.get_rect()
        dest_size = dest_rect.size
        self.assertEqual(size, dest_size)

        # The color is not the change_color specified for every pixel As all
        # pixels are within threshold

        for pt in test_utils.rect_area_pts(dest_rect):
            self.assertNotEqual(dest_surf.get_at(pt), set_color)
            self.assertEqual(dest_surf.get_at(pt), original_dest_color)

    def test_threshold_dest_surf_all_changed(self):
        """Lowering the threshold, expecting changed surface"""

        (w, h) = size = (32, 32)
        threshold = (20, 20, 20, 20)
        original_color = (25, 25, 25, 25)
        original_dest_color = (65, 65, 65, 55)
        threshold_color = (10, 10, 10, 10)
        set_color = (255, 10, 10, 10)

        surf = pygame.Surface(size, pygame.SRCALPHA, 32)
        dest_surf = pygame.Surface(size, pygame.SRCALPHA, 32)
        search_surf = pygame.Surface(size, pygame.SRCALPHA, 32)

        surf.fill(original_color)
        search_surf.fill(threshold_color)
        dest_surf.fill(original_dest_color)

        THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR = 1
        pixels_within_threshold = pygame.transform.threshold(
            dest_surf,
            surf,
            search_color=None,
            set_color=set_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR,
            search_surf=search_surf,
        )

        self.assertEqual(0, pixels_within_threshold)

        dest_rect = dest_surf.get_rect()
        dest_size = dest_rect.size
        self.assertEqual(size, dest_size)

        # The color is the set_color specified for every pixel As all
        # pixels are not within threshold
        for pt in test_utils.rect_area_pts(dest_rect):
            self.assertEqual(dest_surf.get_at(pt), set_color)

    def test_threshold_count(self):
        """counts the colors, and not changes them."""
        surf_size = (32, 32)
        surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)
        search_surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)
        search_color = (55, 55, 55, 255)
        original_color = (10, 10, 10, 255)

        surf.fill(original_color)
        # set 2 pixels to the color we are searching for.
        surf.set_at((0, 0), search_color)
        surf.set_at((12, 5), search_color)

        # There is no destination surface, but we ask to change it.
        #   This should be an error.
        self.assertRaises(
            TypeError, pygame.transform.threshold, None, surf, search_color
        )
        # from pygame.transform import THRESHOLD_BEHAVIOR_COUNT
        THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF = 2
        self.assertRaises(
            TypeError,
            pygame.transform.threshold,
            None,
            surf,
            search_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
        )

        THRESHOLD_BEHAVIOR_COUNT = 0
        num_threshold_pixels = pygame.transform.threshold(
            dest_surface=None,
            surface=surf,
            search_color=search_color,
            set_behavior=THRESHOLD_BEHAVIOR_COUNT,
        )
        self.assertEqual(num_threshold_pixels, 2)

    def test_threshold_search_surf(self):
        surf_size = (32, 32)
        surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)
        search_surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)
        dest_surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)

        original_color = (10, 10, 10, 255)
        search_color = (55, 55, 55, 255)

        surf.fill(original_color)
        dest_surf.fill(original_color)
        # set 2 pixels to the color we are searching for.
        surf.set_at((0, 0), search_color)
        surf.set_at((12, 5), search_color)

        search_surf.fill(search_color)

        # We look in the other surface for matching colors.
        #  Change it in dest_surf
        THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF = 2

        # TypeError: if search_surf is used, search_color should be None
        self.assertRaises(
            TypeError,
            pygame.transform.threshold,
            dest_surf,
            surf,
            search_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
            search_surf=search_surf,
        )

        # surf, dest_surf, and search_surf should all be the same size.
        # Check surface sizes are the same size.
        different_sized_surf = pygame.Surface((22, 33), pygame.SRCALPHA, 32)
        self.assertRaises(
            TypeError,
            pygame.transform.threshold,
            different_sized_surf,
            surf,
            search_color=None,
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
            search_surf=search_surf,
        )

        self.assertRaises(
            TypeError,
            pygame.transform.threshold,
            dest_surf,
            surf,
            search_color=None,
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
            search_surf=different_sized_surf,
        )

        # We look to see if colors in search_surf are in surf.
        num_threshold_pixels = pygame.transform.threshold(
            dest_surface=dest_surf,
            surface=surf,
            search_color=None,
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
            search_surf=search_surf,
        )

        num_pixels_within = 2
        self.assertEqual(num_threshold_pixels, num_pixels_within)

        dest_surf.fill(original_color)
        num_threshold_pixels = pygame.transform.threshold(
            dest_surf,
            surf,
            search_color=None,
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
            search_surf=search_surf,
            inverse_set=True,
        )

        self.assertEqual(num_threshold_pixels, 2)

    def test_threshold_inverse_set(self):
        """changes the pixels within the threshold, and not outside."""
        surf_size = (32, 32)
        _dest_surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)
        _surf = pygame.Surface(surf_size, pygame.SRCALPHA, 32)

        dest_surf = _dest_surf  # surface we are changing.
        surf = _surf  # surface we are looking at
        search_color = (55, 55, 55, 255)  # color we are searching for.
        threshold = (0, 0, 0, 0)  # within this distance from search_color.
        set_color = (245, 245, 245, 255)  # color we set.
        inverse_set = 1  # pixels within threshold are changed to 'set_color'

        original_color = (10, 10, 10, 255)
        surf.fill(original_color)
        # set 2 pixels to the color we are searching for.
        surf.set_at((0, 0), search_color)
        surf.set_at((12, 5), search_color)

        dest_surf.fill(original_color)
        # set 2 pixels to the color we are searching for.
        dest_surf.set_at((0, 0), search_color)
        dest_surf.set_at((12, 5), search_color)

        THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR = 1
        num_threshold_pixels = pygame.transform.threshold(
            dest_surf,
            surf,
            search_color=search_color,
            threshold=threshold,
            set_color=set_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR,
            inverse_set=1,
        )

        self.assertEqual(num_threshold_pixels, 2)
        # only two pixels changed to diff_color.
        self.assertEqual(dest_surf.get_at((0, 0)), set_color)
        self.assertEqual(dest_surf.get_at((12, 5)), set_color)

        # other pixels should be the same as they were before.
        # We just check one other pixel, not all of them.
        self.assertEqual(dest_surf.get_at((2, 2)), original_color)

    # XXX
    def test_threshold_non_src_alpha(self):
        result = pygame.Surface((10, 10))
        s1 = pygame.Surface((10, 10))
        s2 = pygame.Surface((10, 10))
        s3 = pygame.Surface((10, 10))
        s4 = pygame.Surface((10, 10))

        x = s1.fill((0, 0, 0))
        s1.set_at((0, 0), (32, 20, 0))

        x = s2.fill((0, 20, 0))
        x = s3.fill((0, 0, 0))
        x = s4.fill((0, 0, 0))
        s2.set_at((0, 0), (33, 21, 0))
        s2.set_at((3, 0), (63, 61, 0))
        s3.set_at((0, 0), (112, 31, 0))
        s4.set_at((0, 0), (11, 31, 0))
        s4.set_at((1, 1), (12, 31, 0))

        self.assertEqual(s1.get_at((0, 0)), (32, 20, 0, 255))
        self.assertEqual(s2.get_at((0, 0)), (33, 21, 0, 255))
        self.assertEqual((0, 0), (s1.get_flags(), s2.get_flags()))

        similar_color = (255, 255, 255, 255)
        diff_color = (222, 0, 0, 255)
        threshold_color = (20, 20, 20, 255)

        THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR = 1
        num_threshold_pixels = pygame.transform.threshold(
            dest_surface=result,
            surface=s1,
            search_color=similar_color,
            threshold=threshold_color,
            set_color=diff_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR,
        )
        self.assertEqual(num_threshold_pixels, 0)

        num_threshold_pixels = pygame.transform.threshold(
            dest_surface=result,
            surface=s1,
            search_color=(40, 40, 0),
            threshold=threshold_color,
            set_color=diff_color,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_COLOR,
        )
        self.assertEqual(num_threshold_pixels, 1)

        self.assertEqual(result.get_at((0, 0)), diff_color)

    def test_threshold__uneven_colors(self):
        (w, h) = size = (16, 16)

        original_surface = pygame.Surface(size, pygame.SRCALPHA, 32)
        dest_surface = pygame.Surface(size, pygame.SRCALPHA, 32)

        original_surface.fill(0)

        threshold_color_template = [5, 5, 5, 5]
        threshold_template = [6, 6, 6, 6]

        ################################################################

        for pos in range(len("rgb")):
            threshold_color = threshold_color_template[:]
            threshold = threshold_template[:]

            threshold_color[pos] = 45
            threshold[pos] = 50

            pixels_within_threshold = pygame.transform.threshold(
                None,
                original_surface,
                threshold_color,
                threshold,
                set_color=None,
                set_behavior=0,
            )

            self.assertEqual(w * h, pixels_within_threshold)

        ################################################################

    def test_threshold_set_behavior2(self):
        """raises an error when set_behavior=2 and set_color is not None."""
        from pygame.transform import threshold

        s1 = pygame.Surface((32, 32), SRCALPHA, 32)
        s2 = pygame.Surface((32, 32), SRCALPHA, 32)
        THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF = 2
        self.assertRaises(
            TypeError,
            threshold,
            dest_surface=s2,
            surface=s1,
            search_color=(30, 30, 30),
            threshold=(11, 11, 11),
            set_color=(255, 0, 0),
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
        )

    def test_threshold_set_behavior0(self):
        """raises an error when set_behavior=1
        and set_color is not None,
        and dest_surf is not None.
        """
        from pygame.transform import threshold

        s1 = pygame.Surface((32, 32), SRCALPHA, 32)
        s2 = pygame.Surface((32, 32), SRCALPHA, 32)
        THRESHOLD_BEHAVIOR_COUNT = 0

        self.assertRaises(
            TypeError,
            threshold,
            dest_surface=None,
            surface=s2,
            search_color=(30, 30, 30),
            threshold=(11, 11, 11),
            set_color=(0, 0, 0),
            set_behavior=THRESHOLD_BEHAVIOR_COUNT,
        )

        self.assertRaises(
            TypeError,
            threshold,
            dest_surface=s1,
            surface=s2,
            search_color=(30, 30, 30),
            threshold=(11, 11, 11),
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_COUNT,
        )

        threshold(
            dest_surface=None,
            surface=s2,
            search_color=(30, 30, 30),
            threshold=(11, 11, 11),
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_COUNT,
        )

    def test_threshold_from_surface(self):
        """Set similar pixels in 'dest_surf' to color in the 'surf'."""
        from pygame.transform import threshold

        surf = pygame.Surface((32, 32), SRCALPHA, 32)
        dest_surf = pygame.Surface((32, 32), SRCALPHA, 32)
        surf_color = (40, 40, 40, 255)
        dest_color = (255, 255, 255)
        surf.fill(surf_color)
        dest_surf.fill(dest_color)
        THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF = 2

        num_threshold_pixels = threshold(
            dest_surface=dest_surf,
            surface=surf,
            search_color=(30, 30, 30),
            threshold=(11, 11, 11),
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF,
            inverse_set=1,
        )

        self.assertEqual(
            num_threshold_pixels, dest_surf.get_height() * dest_surf.get_width()
        )
        self.assertEqual(dest_surf.get_at((0, 0)), surf_color)

    def test_threshold__surface(self):
        """ """
        from pygame.transform import threshold

        s1 = pygame.Surface((32, 32), SRCALPHA, 32)
        s2 = pygame.Surface((32, 32), SRCALPHA, 32)
        s3 = pygame.Surface((1, 1), SRCALPHA, 32)
        THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF = 2

        #     # only one pixel should not be changed.
        #     s1.fill((40,40,40))
        #     s2.fill((255,255,255))
        #     s1.set_at( (0,0), (170, 170, 170) )
        #     # set the similar pixels in destination surface to the color
        #     #     in the first surface.
        #     num_threshold_pixels = threshold(
        #         dest_surface=s2,
        #         surface=s1,
        #         search_color=(30,30,30),
        #         threshold=(11,11,11),
        #         set_color=None,
        #         set_behavior=THRESHOLD_BEHAVIOR_FROM_SEARCH_SURF)

        #     #num_threshold_pixels = threshold(s2, s1, (30,30,30))
        #     self.assertEqual(num_threshold_pixels, (s1.get_height() * s1.get_width()) -1)
        #     self.assertEqual(s2.get_at((0,0)), (0,0,0, 255))
        #     self.assertEqual(s2.get_at((0,1)), (40, 40, 40, 255))
        #     self.assertEqual(s2.get_at((17,1)), (40, 40, 40, 255))

        # # abs(40 - 255) < 100
        # #(abs(c1[0] - r) < tr)

        #     s1.fill((160,160,160))
        #     s2.fill((255,255,255))
        #     num_threshold_pixels = threshold(s2, s1, (255,255,255), (100,100,100), (0,0,0), True)

        #     self.assertEqual(num_threshold_pixels, (s1.get_height() * s1.get_width()))

        # only one pixel should not be changed.
        s1.fill((40, 40, 40))
        s1.set_at((0, 0), (170, 170, 170))
        THRESHOLD_BEHAVIOR_COUNT = 0

        num_threshold_pixels = threshold(
            dest_surface=None,
            surface=s1,
            search_color=(30, 30, 30),
            threshold=(11, 11, 11),
            set_color=None,
            set_behavior=THRESHOLD_BEHAVIOR_COUNT,
        )

        # num_threshold_pixels = threshold(s2, s1, (30,30,30))
        self.assertEqual(num_threshold_pixels, (s1.get_height() * s1.get_width()) - 1)

        # test end markers.  0, and 255

        # the pixels are different by 1.
        s1.fill((254, 254, 254))
        s2.fill((255, 255, 255))
        s3.fill((255, 255, 255))
        s1.set_at((0, 0), (170, 170, 170))
        num_threshold_pixels = threshold(
            None, s1, (254, 254, 254), (1, 1, 1), None, THRESHOLD_BEHAVIOR_COUNT
        )
        self.assertEqual(num_threshold_pixels, (s1.get_height() * s1.get_width()) - 1)

        # compare the two surfaces.  Should be all but one matching.
        num_threshold_pixels = threshold(
            None, s1, None, (1, 1, 1), None, THRESHOLD_BEHAVIOR_COUNT, s2
        )
        self.assertEqual(num_threshold_pixels, (s1.get_height() * s1.get_width()) - 1)

        # within (0,0,0) threshold?  Should match no pixels.
        num_threshold_pixels = threshold(
            None, s1, (253, 253, 253), (0, 0, 0), None, THRESHOLD_BEHAVIOR_COUNT
        )
        self.assertEqual(num_threshold_pixels, 0)

        # other surface within (0,0,0) threshold?  Should match no pixels.
        num_threshold_pixels = threshold(
            None, s1, None, (0, 0, 0), None, THRESHOLD_BEHAVIOR_COUNT, s2
        )
        self.assertEqual(num_threshold_pixels, 0)

    def test_threshold__subclassed_surface(self):
        """Ensure threshold accepts subclassed surfaces."""
        expected_size = (13, 11)
        expected_flags = 0
        expected_depth = 32
        expected_color = (90, 80, 70, 255)
        expected_count = 0
        surface = test_utils.SurfaceSubclass(
            expected_size, expected_flags, expected_depth
        )
        dest_surface = test_utils.SurfaceSubclass(
            expected_size, expected_flags, expected_depth
        )
        search_surface = test_utils.SurfaceSubclass(
            expected_size, expected_flags, expected_depth
        )
        surface.fill((10, 10, 10))
        dest_surface.fill((255, 255, 255))
        search_surface.fill((20, 20, 20))

        count = pygame.transform.threshold(
            dest_surface=dest_surface,
            surface=surface,
            threshold=(1, 1, 1),
            set_color=expected_color,
            search_color=None,
            search_surf=search_surface,
        )

        self.assertIsInstance(dest_surface, pygame.Surface)
        self.assertIsInstance(dest_surface, test_utils.SurfaceSubclass)
        self.assertEqual(count, expected_count)
        self.assertEqual(dest_surface.get_at((0, 0)), expected_color)
        self.assertEqual(dest_surface.get_bitsize(), expected_depth)
        self.assertEqual(dest_surface.get_size(), expected_size)
        self.assertEqual(dest_surface.get_flags(), expected_flags)

    def test_laplacian(self):
        """ """

        SIZE = 32
        s1 = pygame.Surface((SIZE, SIZE))
        s2 = pygame.Surface((SIZE, SIZE))
        s1.fill((10, 10, 70))
        pygame.draw.line(s1, (255, 0, 0), (3, 10), (20, 20))

        # a line at the last row of the image.
        pygame.draw.line(s1, (255, 0, 0), (0, 31), (31, 31))

        pygame.transform.laplacian(s1, s2)

        # show_image(s1)
        # show_image(s2)

        self.assertEqual(s2.get_at((0, 0)), (0, 0, 0, 255))
        self.assertEqual(s2.get_at((3, 10)), (255, 0, 0, 255))
        self.assertEqual(s2.get_at((0, 31)), (255, 0, 0, 255))
        self.assertEqual(s2.get_at((31, 31)), (255, 0, 0, 255))

        # here we create the return surface.
        s2 = pygame.transform.laplacian(s1)

        self.assertEqual(s2.get_at((0, 0)), (0, 0, 0, 255))
        self.assertEqual(s2.get_at((3, 10)), (255, 0, 0, 255))
        self.assertEqual(s2.get_at((0, 31)), (255, 0, 0, 255))
        self.assertEqual(s2.get_at((31, 31)), (255, 0, 0, 255))

    def test_laplacian__24_big_endian(self):
        """ """
        pygame.display.init()
        try:
            surf_1 = pygame.image.load(
                example_path(os.path.join("data", "laplacian.png"))
            )
            SIZE = 32
            surf_2 = pygame.Surface((SIZE, SIZE), 0, 24)
            # s1.fill((10, 10, 70))
            # pygame.draw.line(s1, (255, 0, 0), (3, 10), (20, 20))

            # a line at the last row of the image.
            # pygame.draw.line(s1, (255, 0, 0), (0, 31), (31, 31))

            # Also validate keyword arguments
            pygame.transform.laplacian(surface=surf_1, dest_surface=surf_2)

            # show_image(s1)
            # show_image(s2)

            self.assertEqual(surf_2.get_at((0, 0)), (0, 0, 0, 255))
            self.assertEqual(surf_2.get_at((3, 10)), (255, 0, 0, 255))
            self.assertEqual(surf_2.get_at((0, 31)), (255, 0, 0, 255))
            self.assertEqual(surf_2.get_at((31, 31)), (255, 0, 0, 255))

            # here we create the return surface.
            surf_2 = pygame.transform.laplacian(surf_1)

            self.assertEqual(surf_2.get_at((0, 0)), (0, 0, 0, 255))
            self.assertEqual(surf_2.get_at((3, 10)), (255, 0, 0, 255))
            self.assertEqual(surf_2.get_at((0, 31)), (255, 0, 0, 255))
            self.assertEqual(surf_2.get_at((31, 31)), (255, 0, 0, 255))
        finally:
            pygame.display.quit()

    def test_average_surfaces(self):
        """ """

        SIZE = 32
        s1 = pygame.Surface((SIZE, SIZE))
        s2 = pygame.Surface((SIZE, SIZE))
        s3 = pygame.Surface((SIZE, SIZE))
        s1.fill((10, 10, 70))
        s2.fill((10, 20, 70))
        s3.fill((10, 130, 10))

        surfaces = [s1, s2, s3]
        surfaces = [s1, s2]
        sr = pygame.transform.average_surfaces(surfaces)

        self.assertEqual(sr.get_at((0, 0)), (10, 15, 70, 255))

        self.assertRaises(TypeError, pygame.transform.average_surfaces, 1)
        self.assertRaises(TypeError, pygame.transform.average_surfaces, [])

        self.assertRaises(TypeError, pygame.transform.average_surfaces, [1])
        self.assertRaises(TypeError, pygame.transform.average_surfaces, [s1, 1])
        self.assertRaises(TypeError, pygame.transform.average_surfaces, [1, s1])
        self.assertRaises(TypeError, pygame.transform.average_surfaces, [s1, s2, 1])

        self.assertRaises(
            TypeError, pygame.transform.average_surfaces, (s for s in [s1, s2, s3])
        )

    def test_average_surfaces__24(self):
        SIZE = 32
        depth = 24
        s1 = pygame.Surface((SIZE, SIZE), 0, depth)
        s2 = pygame.Surface((SIZE, SIZE), 0, depth)
        s3 = pygame.Surface((SIZE, SIZE), 0, depth)
        s1.fill((10, 10, 70, 255))
        s2.fill((10, 20, 70, 255))
        s3.fill((10, 130, 10, 255))

        surfaces = [s1, s2, s3]
        sr = pygame.transform.average_surfaces(surfaces)
        self.assertEqual(sr.get_masks(), s1.get_masks())
        self.assertEqual(sr.get_flags(), s1.get_flags())
        self.assertEqual(sr.get_losses(), s1.get_losses())

        if 0:
            print(sr, s1)
            print(sr.get_masks(), s1.get_masks())
            print(sr.get_flags(), s1.get_flags())
            print(sr.get_losses(), s1.get_losses())
            print(sr.get_shifts(), s1.get_shifts())

        self.assertEqual(sr.get_at((0, 0)), (10, 53, 50, 255))

    def test_average_surfaces__24_big_endian(self):
        pygame.display.init()
        try:
            surf_1 = pygame.image.load(example_path(os.path.join("data", "BGR.png")))

            surf_2 = surf_1.copy()

            surfaces = [surf_1, surf_2]
            self.assertEqual(surf_1.get_at((0, 0)), (255, 0, 0, 255))
            self.assertEqual(surf_2.get_at((0, 0)), (255, 0, 0, 255))

            surf_av = pygame.transform.average_surfaces(surfaces)
            self.assertEqual(surf_av.get_masks(), surf_1.get_masks())
            self.assertEqual(surf_av.get_flags(), surf_1.get_flags())
            self.assertEqual(surf_av.get_losses(), surf_1.get_losses())

            self.assertEqual(surf_av.get_at((0, 0)), (255, 0, 0, 255))
        finally:
            pygame.display.quit()

    def test_average_surfaces__subclassed_surfaces(self):
        """Ensure average_surfaces accepts subclassed surfaces."""
        expected_size = (23, 17)
        expected_flags = 0
        expected_depth = 32
        expected_color = (50, 50, 50, 255)
        surfaces = []

        for color in ((40, 60, 40), (60, 40, 60)):
            s = test_utils.SurfaceSubclass(
                expected_size, expected_flags, expected_depth
            )
            s.fill(color)
            surfaces.append(s)

        surface = pygame.transform.average_surfaces(surfaces)

        self.assertIsInstance(surface, pygame.Surface)
        self.assertNotIsInstance(surface, test_utils.SurfaceSubclass)
        self.assertEqual(surface.get_at((0, 0)), expected_color)
        self.assertEqual(surface.get_bitsize(), expected_depth)
        self.assertEqual(surface.get_size(), expected_size)
        self.assertEqual(surface.get_flags(), expected_flags)

    def test_average_surfaces__subclassed_destination_surface(self):
        """Ensure average_surfaces accepts a destination subclassed surface."""
        expected_size = (13, 27)
        expected_flags = 0
        expected_depth = 32
        expected_color = (15, 15, 15, 255)
        surfaces = []

        for color in ((10, 10, 20), (20, 20, 10), (30, 30, 30)):
            s = test_utils.SurfaceSubclass(
                expected_size, expected_flags, expected_depth
            )
            s.fill(color)
            surfaces.append(s)
        expected_dest_surface = surfaces.pop()

        # Also validate keyword arguments
        dest_surface = pygame.transform.average_surfaces(
            surfaces=surfaces, dest_surface=expected_dest_surface
        )

        self.assertIsInstance(dest_surface, pygame.Surface)
        self.assertIsInstance(dest_surface, test_utils.SurfaceSubclass)
        self.assertIs(dest_surface, expected_dest_surface)
        self.assertEqual(dest_surface.get_at((0, 0)), expected_color)
        self.assertEqual(dest_surface.get_bitsize(), expected_depth)
        self.assertEqual(dest_surface.get_size(), expected_size)
        self.assertEqual(dest_surface.get_flags(), expected_flags)

    def test_average_color(self):
        """ """
        for i in (24, 32):
            with self.subTest(f"Testing {i}-bit surface"):
                s = pygame.Surface((32, 32), 0, i)
                s.fill((0, 100, 200))
                s.fill((10, 50, 100), (0, 0, 16, 32))

                self.assertEqual(pygame.transform.average_color(s), (5, 75, 150, 0))

                # Also validate keyword arguments
                avg_color = pygame.transform.average_color(
                    surface=s, rect=(16, 0, 16, 32)
                )
                self.assertEqual(avg_color, (0, 100, 200, 0))

    def test_average_color_considering_alpha_all_pixels_opaque(self):
        """ """
        s = pygame.Surface((32, 32), pygame.SRCALPHA, 32)
        s.fill((0, 100, 200, 255))
        s.fill((10, 50, 100, 255), (0, 0, 16, 32))

        self.assertEqual(
            pygame.transform.average_color(s, consider_alpha=True), (5, 75, 150, 255)
        )

        # Also validate keyword arguments
        avg_color = pygame.transform.average_color(
            surface=s, rect=(16, 0, 16, 32), consider_alpha=True
        )
        self.assertEqual(avg_color, (0, 100, 200, 255))

    def test_average_color_considering_alpha(self):
        """ """
        s = pygame.Surface((32, 32), pygame.SRCALPHA, 32)
        s.fill((0, 100, 200, 255))
        s.fill((10, 50, 100, 128), (0, 0, 16, 32))

        # formula for this example of half filled square
        # n = number of pixels, e.g. 32 * 32
        # rgb = (n/2 * ( a_left * rgb_left) + n/2 (a_right * rgb_right) ) / (n/2 * a_left + n/2 * a_right)
        # a = (n/2 * a_left + n/2 * a_right) / n
        self.assertEqual(
            pygame.transform.average_color(s, consider_alpha=True), (3, 83, 166, 191)
        )

        # Also validate keyword arguments
        avg_color = pygame.transform.average_color(
            surface=s, rect=(0, 0, 16, 32), consider_alpha=True
        )
        self.assertEqual(avg_color, (10, 50, 100, 128))

    def test_rotate(self):
        # setting colors and canvas
        blue = (0, 0, 255, 255)
        red = (255, 0, 0, 255)
        black = (0, 0, 0)
        canvas = pygame.Surface((3, 3))
        rotation = 0

        canvas.set_at((2, 0), blue)
        canvas.set_at((0, 2), red)

        self.assertEqual(canvas.get_at((0, 0)), black)
        self.assertEqual(canvas.get_at((2, 0)), blue)
        self.assertEqual(canvas.get_at((0, 2)), red)

        for i in range(0, 4):
            if i % 2 == 0:
                self.assertEqual(canvas.get_at((0, 0)), black)
            elif i == 1:
                self.assertEqual(canvas.get_at((0, 0)), blue)
            elif i == 3:
                self.assertEqual(canvas.get_at((0, 0)), red)

            rotation += 90
            # Also validate keyword arguments
            canvas = pygame.transform.rotate(surface=canvas, angle=90)

        self.assertEqual(canvas.get_at((0, 0)), black)

    def test_rotate_of_0_sized_surface(self):
        # This function just tests possible Segmentation Fault
        canvas1 = pygame.Surface((0, 1))
        canvas2 = pygame.Surface((1, 0))
        pygame.transform.rotate(canvas1, 42)
        pygame.transform.rotate(canvas2, 42)

    def test_rotate__lossless_at_90_degrees(self):
        w, h = 32, 32
        s = pygame.Surface((w, h), pygame.SRCALPHA)

        gradient = list(test_utils.gradient(w, h))

        for pt, color in gradient:
            s.set_at(pt, color)

        for rotation in (90, -90):
            s = pygame.transform.rotate(s, rotation)

        for pt, color in gradient:
            self.assertTrue(s.get_at(pt) == color)

    def test_scale2x(self):
        # __doc__ (as of 2008-06-25) for pygame.transform.scale2x:

        # pygame.transform.scale2x(Surface, DestSurface = None): Surface
        # specialized image doubler

        w, h = 32, 32
        s = pygame.Surface((w, h), pygame.SRCALPHA, 32)

        # s.set_at((0,0), (20, 20, 20, 255))

        s1 = pygame.transform.scale2x(s)
        # Also validate keyword arguments
        s2 = pygame.transform.scale2x(surface=s)
        self.assertEqual(s1.get_rect().size, (64, 64))
        self.assertEqual(s2.get_rect().size, (64, 64))

    def test_scale2xraw(self):
        # Even though transform.scale no longer has a special
        # case for 2x upscaling, this test validates that the behavior
        # is preserved.

        w, h = 32, 32
        s = pygame.Surface((w, h), pygame.SRCALPHA, 32)
        s.fill((0, 0, 0))
        pygame.draw.circle(s, (255, 0, 0), (w // 2, h // 2), (w // 3))

        s2 = pygame.transform.scale(s, (w * 2, h * 2))
        s2_2 = pygame.transform.scale(s2, (w * 4, h * 4))
        s4 = pygame.transform.scale(s, (w * 4, h * 4))

        self.assertEqual(s2_2.get_rect().size, (128, 128))

        for pt in test_utils.rect_area_pts(s2_2.get_rect()):
            self.assertEqual(s2_2.get_at(pt), s4.get_at(pt))

    def test_get_smoothscale_backend(self):
        filter_type = pygame.transform.get_smoothscale_backend()
        self.assertTrue(filter_type in ["GENERIC", "MMX", "SSE"])
        # It would be nice to test if a non-generic type corresponds to an x86
        # processor. But there is no simple test for this. platform.machine()
        # returns process version specific information, like 'i686'.

    def test_set_smoothscale_backend(self):
        # All machines should allow 'GENERIC'.
        original_type = pygame.transform.get_smoothscale_backend()
        pygame.transform.set_smoothscale_backend("GENERIC")
        filter_type = pygame.transform.get_smoothscale_backend()
        self.assertEqual(filter_type, "GENERIC")
        # All machines should allow returning to original value.
        # Also check that keyword argument works.
        pygame.transform.set_smoothscale_backend(backend=original_type)

        # Something invalid.
        def change():
            pygame.transform.set_smoothscale_backend("mmx")

        self.assertRaises(ValueError, change)

        # Invalid argument keyword.
        def change():
            pygame.transform.set_smoothscale_backend(t="GENERIC")

        self.assertRaises(TypeError, change)

        # Invalid argument type.
        def change():
            pygame.transform.set_smoothscale_backend(1)

        self.assertRaises(TypeError, change)
        # Unsupported type, if possible.
        if original_type != "SSE":

            def change():
                pygame.transform.set_smoothscale_backend("SSE")

            self.assertRaises(ValueError, change)
        # Should be back where we started.
        filter_type = pygame.transform.get_smoothscale_backend()
        self.assertEqual(filter_type, original_type)

    def test_chop(self):
        original_surface = pygame.Surface((20, 20))
        pygame.draw.rect(original_surface, (255, 0, 0), (0, 0, 10, 10))
        pygame.draw.rect(original_surface, (0, 255, 0), (0, 10, 10, 10))
        pygame.draw.rect(original_surface, (0, 0, 255), (10, 0, 10, 10))
        pygame.draw.rect(original_surface, (255, 255, 0), (10, 10, 10, 10))
        # Test chopping the corner of image
        rect = pygame.Rect(0, 0, 5, 15)
        test_surface = pygame.transform.chop(original_surface, rect)
        # Check the size of chopped image
        self.assertEqual(test_surface.get_size(), (15, 5))
        # Check if the colors of the chopped image are correct
        for x in range(15):
            for y in range(5):
                if x < 5:
                    self.assertEqual(test_surface.get_at((x, y)), (0, 255, 0))
                else:
                    self.assertEqual(test_surface.get_at((x, y)), (255, 255, 0))
        # Check if the original image stayed the same
        self.assertEqual(original_surface.get_size(), (20, 20))
        for x in range(20):
            for y in range(20):
                if x < 10 and y < 10:
                    self.assertEqual(original_surface.get_at((x, y)), (255, 0, 0))
                if x < 10 < y:
                    self.assertEqual(original_surface.get_at((x, y)), (0, 255, 0))
                if x > 10 > y:
                    self.assertEqual(original_surface.get_at((x, y)), (0, 0, 255))
                if x > 10 and y > 10:
                    self.assertEqual(original_surface.get_at((x, y)), (255, 255, 0))
        # Test chopping the center of the surface:
        rect = pygame.Rect(0, 0, 10, 10)
        rect.center = original_surface.get_rect().center
        # Also validate keyword arguments
        test_surface = pygame.transform.chop(surface=original_surface, rect=rect)
        self.assertEqual(test_surface.get_size(), (10, 10))
        for x in range(10):
            for y in range(10):
                if x < 5 and y < 5:
                    self.assertEqual(test_surface.get_at((x, y)), (255, 0, 0))
                if x < 5 < y:
                    self.assertEqual(test_surface.get_at((x, y)), (0, 255, 0))
                if x > 5 > y:
                    self.assertEqual(test_surface.get_at((x, y)), (0, 0, 255))
                if x > 5 and y > 5:
                    self.assertEqual(test_surface.get_at((x, y)), (255, 255, 0))
        # Test chopping with the empty rect
        rect = pygame.Rect(10, 10, 0, 0)
        test_surface = pygame.transform.chop(original_surface, rect)
        self.assertEqual(test_surface.get_size(), (20, 20))
        # Test chopping the entire surface
        rect = pygame.Rect(0, 0, 20, 20)
        test_surface = pygame.transform.chop(original_surface, rect)
        self.assertEqual(test_surface.get_size(), (0, 0))
        # Test chopping outside of surface
        rect = pygame.Rect(5, 15, 20, 20)
        test_surface = pygame.transform.chop(original_surface, rect)
        self.assertEqual(test_surface.get_size(), (5, 15))
        rect = pygame.Rect(400, 400, 10, 10)
        test_surface = pygame.transform.chop(original_surface, rect)
        self.assertEqual(test_surface.get_size(), (20, 20))

    def test_rotozoom(self):
        # __doc__ (as of 2008-08-02) for pygame.transform.rotozoom:

        # pygame.transform.rotozoom(Surface, angle, scale): return Surface
        # filtered scale and rotation
        #
        # This is a combined scale and rotation transform. The resulting
        # Surface will be a filtered 32-bit Surface. The scale argument is a
        # floating point value that will be multiplied by the current
        # resolution. The angle argument is a floating point value that
        # represents the counterclockwise degrees to rotate. A negative
        # rotation angle will rotate clockwise.

        s = pygame.Surface((10, 0))
        pygame.transform.scale(s, (10, 2))
        s1 = pygame.transform.rotozoom(s, 30, 1)
        # Also validate keyword arguments
        s2 = pygame.transform.rotozoom(surface=s, angle=30, scale=1)

        self.assertEqual(s1.get_rect(), pygame.Rect(0, 0, 0, 0))
        self.assertEqual(s2.get_rect(), pygame.Rect(0, 0, 0, 0))

    def test_invert(self):
        surface = pygame.Surface((10, 10), depth=32)

        surface.fill((255, 0, 0))
        surface = pygame.transform.invert(surface)
        self.assertEqual(surface.get_at((4, 4)), (0, 255, 255, 255))

        surface.fill((200, 0, 45))
        surface = pygame.transform.invert(surface)
        self.assertEqual(surface.get_at((4, 4)), (55, 255, 210, 255))

        surface.fill((38, 201, 12))
        surface = pygame.transform.invert(surface)
        self.assertEqual(surface.get_at((4, 4)), (217, 54, 243, 255))

        surface.fill((39, 210, 30))
        surface = pygame.transform.invert(surface)
        self.assertEqual(surface.get_at((4, 4)), (216, 45, 225, 255))

        surface.fill((255, 0, 0))
        pygame.transform.invert(surface, surface)
        self.assertEqual(surface.get_at((4, 4)), (0, 255, 255, 255))

        surface.fill((200, 0, 45))
        pygame.transform.invert(surface, surface)
        self.assertEqual(surface.get_at((4, 4)), (55, 255, 210, 255))

        surface.fill((38, 201, 12))
        pygame.transform.invert(surface, surface)
        self.assertEqual(surface.get_at((4, 4)), (217, 54, 243, 255))

        surface.fill((39, 210, 30))
        pygame.transform.invert(surface, surface)
        self.assertEqual(surface.get_at((4, 4)), (216, 45, 225, 255))

        self.assertRaises(
            ValueError, pygame.transform.invert, surface, pygame.Surface((100, 100))
        )
        self.assertRaises(
            ValueError, pygame.transform.invert, surface, pygame.Surface((5, 5))
        )
        self.assertRaises(
            ValueError,
            pygame.transform.invert,
            surface,
            pygame.Surface((10, 10), depth=24),
        )
        self.assertRaises(
            ValueError,
            pygame.transform.invert,
            surface,
            pygame.Surface((10, 10), depth=16),
        )
        self.assertRaises(
            ValueError,
            pygame.transform.invert,
            surface,
            pygame.Surface((10, 10), depth=8),
        )

    def test_smoothscale(self):
        """Tests the stated boundaries, sizing, and color blending of smoothscale function"""
        # __doc__ (as of 2008-08-02) for pygame.transform.smoothscale:

        # pygame.transform.smoothscale(Surface, (width, height), DestSurface =
        # None): return Surface
        #
        # scale a surface to an arbitrary size smoothly
        #
        # Uses one of two different algorithms for scaling each dimension of
        # the input surface as required.  For shrinkage, the output pixels are
        # area averages of the colors they cover.  For expansion, a bilinear
        # filter is used. For the amd64 and i686 architectures, optimized MMX
        # routines are included and will run much faster than other machine
        # types. The size is a 2 number sequence for (width, height). This
        # function only works for 24-bit or 32-bit surfaces.  An exception
        # will be thrown if the input surface bit depth is less than 24.
        #
        # New in pygame 1.8

        # check stated exceptions
        def smoothscale_low_bpp():
            starting_surface = pygame.Surface((20, 20), depth=12)
            smoothscaled_surface = pygame.transform.smoothscale(
                starting_surface, (10, 10)
            )

        self.assertRaises(ValueError, smoothscale_low_bpp)

        def smoothscale_high_bpp():
            starting_surface = pygame.Surface((20, 20), depth=48)
            smoothscaled_surface = pygame.transform.smoothscale(
                starting_surface, (10, 10)
            )

        self.assertRaises(ValueError, smoothscale_high_bpp)

        def smoothscale_invalid_scale():
            starting_surface = pygame.Surface((20, 20), depth=32)
            smoothscaled_surface = pygame.transform.smoothscale(
                starting_surface, (-1, -1)
            )

        self.assertRaises(ValueError, smoothscale_invalid_scale)

        # Test Color Blending Scaling-Up
        two_pixel_surface = pygame.Surface((2, 1), depth=32)
        two_pixel_surface.fill(pygame.Color(0, 0, 0), pygame.Rect(0, 0, 1, 1))
        two_pixel_surface.fill(pygame.Color(255, 255, 255), pygame.Rect(1, 0, 1, 1))
        for k in [2**x for x in range(5, 8)]:  # Enlarge to targets 32, 64...256
            bigger_surface = pygame.transform.smoothscale(two_pixel_surface, (k, 1))
            self.assertEqual(
                bigger_surface.get_at((k // 2, 0)), pygame.Color(127, 127, 127)
            )
            self.assertEqual(bigger_surface.get_size(), (k, 1))
        # Test Color Blending Scaling-Down
        two_five_six_surf = pygame.Surface((256, 1), depth=32)
        two_five_six_surf.fill(pygame.Color(0, 0, 0), pygame.Rect(0, 0, 128, 1))
        two_five_six_surf.fill(pygame.Color(255, 255, 255), pygame.Rect(128, 0, 128, 1))
        for k in range(3, 11, 2):  # Shrink to targets 3, 5...11 pixels wide
            smaller_surface = pygame.transform.smoothscale(two_five_six_surf, (k, 1))
            self.assertEqual(
                smaller_surface.get_at(((k // 2), 0)), pygame.Color(127, 127, 127)
            )
            self.assertEqual(smaller_surface.get_size(), (k, 1))


class TransformDisplayModuleTest(unittest.TestCase):
    def setUp(self):
        pygame.display.init()
        pygame.display.set_mode((320, 200))

    def tearDown(self):
        pygame.display.quit()

    def test_blur_indexed_surface(self):
        data_fname = example_path("data")
        path = os.path.join(data_fname, "alien3.png")
        sf = pygame.image.load(path)  # Get an indexed surface.

        self.assertRaises(ValueError, lambda: pygame.transform.box_blur(sf, 10))
        self.assertRaises(ValueError, lambda: pygame.transform.gaussian_blur(sf, 10))

    def test_blur_in_place(self):
        # When source and destination surfaces are the same,
        # A ValueError should be raised.

        data_fname = example_path("data")
        path = os.path.join(data_fname, "peppers3.tif")
        sf = pygame.image.load(path)
        sub1 = sf.subsurface((0, 0, 128, 128))
        sub2 = sf.subsurface((20, 20, 128, 128))

        self.assertRaises(
            ValueError, lambda: pygame.transform.box_blur(sf, 10, dest_surface=sf)
        )
        self.assertRaises(
            ValueError, lambda: pygame.transform.box_blur(sub1, 10, dest_surface=sub2)
        )
        self.assertRaises(
            ValueError, lambda: pygame.transform.gaussian_blur(sf, 10, dest_surface=sf)
        )
        self.assertRaises(
            ValueError,
            lambda: pygame.transform.gaussian_blur(sub1, 10, dest_surface=sub2),
        )

    def test_box_blur(self):
        data1 = {
            (1, 29): (67, 58, 26, 255),
            (47, 66): (132, 124, 60, 255),
            (84, 103): (139, 87, 51, 255),
            (131, 140): (159, 133, 74, 255),
            (158, 177): (161, 164, 81, 255),
            (195, 214): (168, 137, 71, 255),
            (232, 251): (130, 122, 67, 255),
            (269, 280): (122, 159, 96, 255),
            (306, 325): (113, 156, 84, 255),
            (353, 362): (114, 152, 74, 255),
            (380, 399): (107, 123, 58, 255),
            (417, 436): (123, 90, 53, 255),
            (458, 473): (146, 68, 52, 255),
            (491, 510): (65, 36, 29, 255),
        }
        data2 = {
            (1, 29): (67, 58, 26, 255),
            (47, 66): (132, 124, 60, 255),
            (84, 103): (139, 87, 51, 255),
            (131, 140): (159, 133, 74, 255),
            (158, 177): (161, 164, 81, 255),
            (195, 214): (168, 137, 71, 255),
            (232, 251): (130, 122, 67, 255),
            (269, 280): (122, 159, 96, 255),
            (306, 325): (113, 156, 84, 255),
            (353, 362): (114, 152, 74, 255),
            (380, 399): (107, 123, 58, 255),
            (417, 436): (123, 90, 53, 255),
            (458, 473): (146, 68, 52, 255),
            (491, 510): (65, 36, 29, 255),
        }

        data_fname = example_path("data")
        path = os.path.join(data_fname, "peppers3.tif")
        sf = pygame.image.load(path).convert()

        sf_b1 = pygame.transform.box_blur(sf, 50)
        for pos in data1:
            self.assertTrue(sf_b1.get_at(pos) == data1[pos])

        sf_b2 = pygame.transform.box_blur(sf, 50, repeat_edge_pixels=False)
        for pos in data2:
            self.assertTrue(sf_b2.get_at(pos) == data2[pos])

    def test_gaussian_blur(self):
        data1 = {
            (10, 49): (74, 67, 32, 255),
            (47, 66): (112, 93, 47, 255),
            (84, 103): (141, 104, 57, 255),
            (121, 140): (153, 118, 64, 255),
            (148, 177): (161, 140, 73, 255),
            (195, 214): (162, 137, 72, 255),
            (232, 21): (124, 50, 35, 255),
            (269, 288): (123, 146, 83, 255),
            (306, 325): (118, 154, 85, 255),
            (343, 362): (114, 141, 73, 255),
            (384, 379): (114, 116, 61, 255),
            (417, 436): (121, 78, 47, 255),
            (454, 473): (107, 54, 39, 255),
            (491, 510): (57, 28, 22, 255),
        }
        data2 = {
            (10, 49): (74, 67, 32, 255),
            (47, 66): (112, 93, 47, 255),
            (84, 103): (141, 104, 57, 255),
            (121, 140): (153, 118, 64, 255),
            (148, 177): (161, 140, 73, 255),
            (195, 214): (162, 137, 72, 255),
            (232, 21): (124, 50, 35, 255),
            (269, 288): (123, 146, 83, 255),
            (306, 325): (118, 154, 85, 255),
            (343, 362): (114, 141, 73, 255),
            (384, 379): (114, 116, 61, 255),
            (417, 436): (121, 78, 47, 255),
            (454, 473): (107, 54, 39, 255),
            (491, 510): (57, 28, 22, 255),
        }

        data_fname = example_path("data")
        path = os.path.join(data_fname, "peppers3.tif")
        sf = pygame.image.load(path).convert()

        sf_b1 = pygame.transform.gaussian_blur(sf, 50)
        for pos in data1:
            self.assertTrue(sf_b1.get_at(pos) == data1[pos])

        sf_b2 = pygame.transform.gaussian_blur(sf, 50, repeat_edge_pixels=False)
        for pos in data2:
            self.assertTrue(sf_b2.get_at(pos) == data2[pos])

    def test_flip(self):
        """honors the set_color key on the returned surface from flip."""
        image_loaded = pygame.image.load(example_path("data/chimp.png"))

        image = pygame.Surface(image_loaded.get_size(), 0, 32)
        image.blit(image_loaded, (0, 0))

        image_converted = image_loaded.convert()

        self.assertFalse(image.get_flags() & pygame.SRCALPHA)
        self.assertFalse(image_converted.get_flags() & pygame.SRCALPHA)

        surf = pygame.Surface(image.get_size(), 0, 32)
        surf2 = pygame.Surface(image.get_size(), 0, 32)

        surf.fill((255, 255, 255))
        surf2.fill((255, 255, 255))

        colorkey = image.get_at((0, 0))
        image.set_colorkey(colorkey, RLEACCEL)
        timage = pygame.transform.flip(image, 1, 0)

        colorkey = image_converted.get_at((0, 0))
        image_converted.set_colorkey(colorkey, RLEACCEL)
        # Also validate keyword arguments
        timage_converted = pygame.transform.flip(
            surface=image_converted, flip_x=1, flip_y=0
        )

        # blit the flipped surface, and non flipped surface.
        surf.blit(timage, (0, 0))
        surf2.blit(image, (0, 0))

        # the results should be the same.
        self.assertEqual(surf.get_at((0, 0)), surf2.get_at((0, 0)))
        self.assertEqual(surf2.get_at((0, 0)), (255, 255, 255, 255))

        # now we test the convert() ed image also works.
        surf.fill((255, 255, 255))
        surf2.fill((255, 255, 255))
        surf.blit(timage_converted, (0, 0))
        surf2.blit(image_converted, (0, 0))
        self.assertEqual(surf.get_at((0, 0)), surf2.get_at((0, 0)))

    def test_flip_alpha(self):
        """returns a surface with the same properties as the input."""
        image_loaded = pygame.image.load(example_path("data/chimp.png"))

        image_alpha = pygame.Surface(image_loaded.get_size(), pygame.SRCALPHA, 32)
        image_alpha.blit(image_loaded, (0, 0))

        surf = pygame.Surface(image_loaded.get_size(), 0, 32)
        surf2 = pygame.Surface(image_loaded.get_size(), 0, 32)

        colorkey = image_alpha.get_at((0, 0))
        image_alpha.set_colorkey(colorkey, RLEACCEL)
        timage_alpha = pygame.transform.flip(image_alpha, 1, 0)

        self.assertTrue(image_alpha.get_flags() & pygame.SRCALPHA)
        self.assertTrue(timage_alpha.get_flags() & pygame.SRCALPHA)

        # now we test the alpha image works.
        surf.fill((255, 255, 255))
        surf2.fill((255, 255, 255))
        surf.blit(timage_alpha, (0, 0))
        surf2.blit(image_alpha, (0, 0))
        self.assertEqual(surf.get_at((0, 0)), surf2.get_at((0, 0)))
        self.assertEqual(surf2.get_at((0, 0)), (255, 0, 0, 255))


if __name__ == "__main__":
    unittest.main()
