Fix putSliceWithBorders extention function for Bitmap class #2144
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The function putSliceWithBorders is used to create an extruded tileset in LdtkView. The tiles were not extruded correctly into top and bottom left corners. This commit fixes that. It also adds a unit test which reproduces the error.
| @@ -53,8 +53,8 @@ fun Bitmap.putSliceWithBorder(x: Int, y: Int, bmp: BmpSlice, border: Int = 1) { | |||
| // Vertical replicate | |||
| for (n in 1..border) { | |||
| val rwidth = width + border * 2 | |||
| this.copy(x, y, this, x, y - n, rwidth, 1) | |||
| this.copy(x, y + height - 1, this, x, y + height - 1 + n, rwidth, 1) | |||
| this.copy(x - border, y, this, x - border, y - n, rwidth, 1) | |||
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Shouldn't be rwidth + border * 2?
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What do you exatly mean should I put that term?
I did the fix in a rush. Let me check it carefully with a bit more time on Friday :)
I will create also a "better" (more colorful) tile for visually checking if the expansion of the border works as we expect.
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fun Bitmap.copy(srcX: Int, srcY: Int, dst: Bitmap, dstX: Int, dstY: Int, width: Int, height: Int)
I mean, if border was not taken into account and if position is displaced now, width might need to be extended?
For example, let's imagine a segment: x=10, width=10 (right = 20)
If I want to add one pixel on both sides to the line: x=9, width=12 (right=21)
So subtracting N to the x (left), requires adding N*2 to the width, or N to the right coordinate.
In the case we are extending the same amount of pixels on both sides of the segment.
Not sure if that was the case here, but asked just in case.
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You are right. I checked now after my Friday stream again and my implementation actually adds the border twice. So, if I add border = 2 than 4 pixels are added to each side of the tile :)
I need to check again...
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I don't see the border error from last Friday anymore.
I checked again now and I could not find a problem anymore with my initial changes. Here is a screenshot for border = 1:
So it expands correctly by one pixel in each direction. I checked that visually with border = 2, 3 and 5 and it was correctly expanding with 2 resp. 3 and 5 pixels.
| @@ -27,6 +27,25 @@ class BitmapSliceTest { | |||
| assertEquals("Rectangle(x=24, y=24, width=24, height=24)", bmp.sliceWithSize(16, 16, 32, 32).sliceWithSize(8, 8, 40, 40).bounds.toString()) | |||
| } | |||
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| @Test | |||
| fun testPutSliceWithBorder() { | |||
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Regarding test. Maybe the Bitmap32 can be converted into a Bitmap1/Bitmap8 and then:
korge/korge-core/test/korlibs/image/bitmap/Bitmap1Test.kt
Lines 27 to 34 in 11993ae
bmp.tryToExactBitmap8().toLines(".*#")!!.joinToString("\n")
or use a reference image. Since we are in korge-core, we should be able to generate screenshots.
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I checked using Bitmap1 in the unit test but putWithBorder() is not implemented for Bitmap1. What seems to be missing is the implementation of slice() for Bitmap1.
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Since Slice() is not implemented for Bitmap1 I would like to keep the unit test as it is now.
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I can try with Bitmap8 indeed and create an imput and output image with indexes...
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Now unit test uses Bitmap8 and has a better visual test |
The function putSliceWithBorders is used to create an extruded tileset in LdtkView. The tiles were not extruded correctly into top and bottom left corners. This commit fixes that. It also adds a unit test which reproduces the error.
Incorrectly expanded example of a rectangle: