From: Henri Verbeet <hverbeet@gmail.com>
Subject: Re: [PATCH v2] d2d1/tests: Add tests for 2D affine effect.
Message-Id: <CAOsNvwwzLnzZm5_LTN59=XZMzhcnAGhA9jivcFhna+0GoURUDw@mail.gmail.com>
Date: Thu, 16 Sep 2021 12:30:21 +0200
In-Reply-To: <20210914021447.961092-1-zhui@codeweavers.com>
References: <20210914021447.961092-1-zhui@codeweavers.com>

On Tue, 14 Sept 2021 at 04:15, Ziqing Hui <zhui@codeweavers.com> wrote:
> +    const struct effect_2d_affine_test
> +    {
> +        const DWORD *img_data;
> +        unsigned int img_width;
> +        unsigned int img_height;
> +
> +        D2D1_MATRIX_3X2_F *matrix;
> +
> +        D2D_RECT_F bounds;
> +        const char *figure;
> +    }
> +    effect_2d_affine_tests[] =
> +    {
> +        {image_4x4,   4,  4,  &rotate, {-6.0f,  -3.0f, 2.0f,  4.0f}, "AQ8B7wEA"},
> +        {image_4x4,   4,  4,  &scale,  {-2.0f,  -3.0f, 1.0f,  9.0f}, "AQ8BDwEPAQ8BDwEPAQ8BDwF/"},
> +        {image_4x4,   4,  4,  &skew,   {-7.0f,  -3.0f, 3.0f,  7.0f}, "AQ8BAQ4BAQ4BzwEA"},
> +        {image_16x16, 16, 16, &rotate, {-14.0f, -3.0f, 10.0f, 21.0f},
> +         "AQ8BAQ4CAQ0DAQwEAQsFAQoGAQkHAQgIAQcIAQEGBwEBBwYBAQgFAQEJBAEBCgMBAQsCAQEM"},
> +        {image_16x16, 16, 16, &scale,  {-2.0f,  -3.0f, 10.0f, 39.0f},
> +         "AQkGCgYKBgoGCgYKBgoGCgYKBgoGCgYKBgoGCgYKBgoG"},
> +        {image_16x16, 16, 16, &skew,   {-19.0f, -3.0f, 15.0f, 31.0f},
> +         "AQ8BAQ4CAQ0DAQwEAQsFAQoGAQkHAQgIAQcJAQYKAQULAQQMAQMNAQINAQIMAQMA"},
> +    };
...
> +        ID2D1DeviceContext_BeginDraw(context);
> +        ID2D1DeviceContext_Clear(context, 0);
> +        ID2D1DeviceContext_DrawImage(context, output, NULL, NULL, 0, 0);
> +        hr = ID2D1DeviceContext_EndDraw(context, NULL, NULL);
> +        ok(hr == S_OK, "Got unexpected hr %#x.\n", hr);
> +        match = compare_figure(&ctx, 0, 0, 16, 16, 0xff652e89, 0, test->figure);

In a certain sense that works, but we're only testing the part of the
image intersecting with the top-left corner. It doesn't seem much more
complicated to draw the image in the centre of the render target, and
then use the bounds in compare_figure. E.g.:

    ID2D1DeviceContext_DrawImage(..., 320, 240);
    ...
    x = 320.0f + output_bounds.left - 2.0f;
    y = 240.0f + output_bounds.top - 2.0f;
    w = (output_bounds.right - output_bounds.left) + 4.0f;
    h = (output_bounds.bottom - output_bounds.top) + 4.0f;
    match = compare_figure(&ctx, x, y, w, h, ...);