On Sat, 20 Jan 2024 10:43:49 GMT, Martin Desruisseaux <[email protected]> wrote:
>> The `BufferedImage` Javadoc does not mention any constraint about the data
>> type. In practice, `BufferedImage` with floating point values can be
>> rendered by Java2D as well as integers, provided that a compatible
>> `ColorModel` was supplied at construction time. However calls to
>> `setData(Raster)` unexpectedly cast floating point values to integers. For
>> example sample value 0.8 become 0. This is demonstrated by the `SetData`
>> test case in this pull request.
>>
>> An easy fix, which is proposed in this pull request, is to replace the whole
>> `BufferedImage.setData(Raster)` method body by a simple call to
>> `WritableRaster.setRect(Raster)`, which handles all `DataBuffer` types
>> correctly. The method contracts documented in their respective Javadoc are
>> compatible. Furthermore an examination of their source code shows that they
>> are equivalent, except for the differences noted in the _Behavioural
>> changes_ section below.
>>
>> # Source code comparison
>> For demonstrating that delegating to `WritableRaster.setRect(Raster)` would
>> be equivalent to the current code, one can copy the method body and apply
>> the following changes:
>>
>> * Remove `dx` parameter, replaced by 0.
>> * Remove `dy` parameter, replaced by 0.
>> * Rename `srcRaster` parameter as `r` (like in `BufferedImage`).
>> * Rename `startY` variable as `i` (like in `BufferedImage`).
>> * Rename `srcOffX` variable as `startX` (like in `BufferedImage`).
>> * Rename `srcOffY` variable as `startY` (like in `BufferedImage`).
>> * Replace `this.minX` by 0 and simplify.
>> * Replace `this.minY` by 0 and simplify.
>> * Remove the `switch` statement, keeping only the `TYPE_INT` case.
>>
>> Then compare with `BufferedImage.setData(Raster)`. The modified block of
>> code from `WritableRaster` is:
>>
>>
>> int width = r.getWidth();
>> int height = r.getHeight();
>> int startX = r.getMinX();
>> int startY = r.getMinY();
>>
>> We can see that above code is identical to `BufferedImage`. The next
>> modified block of code from `WritableRaster`:
>>
>>
>> int dstOffX = startX;
>> int dstOffY = startY;
>>
>> // Clip to this raster
>> if (dstOffX < 0) {
>> width += dstOffX;
>> startX -= dstOffX; // = 0 because dstOffX == startX
>> dstOffX = 0;
>> }
>> if (dstOffY < 0) {
>> height += dstOffY;
>> startY -= dstOffY; // = 0 because dstOffY == startY
>> dstOffY = 0;
>> }
>> if (dstOffX+width > this.width) {
>> width = this.width - dstOffX;
>> }
>> if (dstOffY+height > this.height) {
>> height = this.height - dstOffY;
>> }
>> if (width <= 0 ||...
>
> Martin Desruisseaux has updated the pull request incrementally with one
> additional commit since the last revision:
>
> Update copyright years.
Updated the copyright years to 2024. The pre-submit tests are failing, but I
believe that it is because the branch is 8 months old. Should I commit a merge
from master? (a test on my local machine suggests that it fixes the issues).
-------------
PR Comment: https://git.openjdk.org/jdk/pull/13797#issuecomment-1902073920
