ui/cocoa: Fix stride resolution of pixman image

Commit Message

Akihiko Odaki Feb. 21, 2021, 5:30 p.m. UTC

Signed-off-by: Akihiko Odaki <[e-mail]>
---
 ui/cocoa.m | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Peter Maydell Feb. 21, 2021, 7:35 p.m. UTC | #1

On Sun, 21 Feb 2021 at 17:31, Akihiko Odaki <[e-mail]> wrote:
>
> Signed-off-by: Akihiko Odaki <[e-mail]>

In what situations does this change make a difference?
Obviously most of the time it works fine, or we'd have noticed
before now.

(This is the kind of detail that it's useful to provide in
the commit message.)

thanks
-- PMM

Patch

diff --git a/ui/cocoa.m b/ui/cocoa.m
index 0ef5fdf3b7a..2de72155dea 100644
--- a/ui/cocoa.m
+++ b/ui/cocoa.m
@@ -450,19 +450,19 @@  - (void) drawRect:(NSRect) rect
         int w = pixman_image_get_width(pixman_image);
         int h = pixman_image_get_height(pixman_image);
         int bitsPerPixel = PIXMAN_FORMAT_BPP(pixman_image_get_format(pixman_image));
-        int bitsPerComponent = DIV_ROUND_UP(bitsPerPixel, 8) * 2;
+        int stride = pixman_image_get_stride(pixman_image);
         CGDataProviderRef dataProviderRef = CGDataProviderCreateWithData(
             NULL,
             pixman_image_get_data(pixman_image),
-            w * 4 * h,
+            stride * h,
             NULL
         );
         CGImageRef imageRef = CGImageCreate(
             w, //width
             h, //height
-            bitsPerComponent, //bitsPerComponent
+            DIV_ROUND_UP(bitsPerPixel, 8) * 2, //bitsPerComponent
             bitsPerPixel, //bitsPerPixel
-            (w * (bitsPerComponent/2)), //bytesPerRow
+            stride, //bytesPerRow
 #ifdef __LITTLE_ENDIAN__
             CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB), //colorspace for OS X >= 10.4
             kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,