Canvas drawImageRect cannot restrict sampling to only pixels in the source rect #67881
Description
I am making a game using Flutter, but I noticed something weird while trying to draw a sprite from a spritesheet, so I made an example to show the problem:
Lets say this image is a spritesheet, it is 64x128:
I split it in two and want to draw only the second part, I do it this way:
final src = Rect.fromLTWH(0, 64, 64, 64);
final dst = Rect.fromLTWH(0, y, 64, 64);
canvas.drawImageRect(testImage, src, dst, Paint());If then, I move this sprite through the canvas, by incrementing the value of y by 0.1 every frame, the last row of the first part is drawn.
It should not draw the last row of the first sprite, because I made explicity that I only want the second half of the image to be drawn.
I tried it on iOS and macOS and got the same problem.
I made a repository where you can run it and see this behavior.
https://github.com/lslv1243/draw_image_rect_bug
flutter doctor
[✓] Flutter (Channel unknown, 1.22.0-12.1.pre, on Mac OS X 10.15.6 19G2021, locale pt)
• Flutter version 1.22.0-12.1.pre at /Users/leonardosilva/development/flutter/flutter
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[!] Android toolchain - develop for Android devices (Android SDK version 29.0.3)
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[✓] Connected device (4 available)
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