[PATCH 0/1] MR10835: gdiplus: Add support for CMYK to ARGB pixel format conversion.

[Yongjie Yao (＠yaoyongjie)]

Add conversion from PixelFormat32bppCMYK to PixelFormat32bppARGB in
convert_pixels(), using the standard subtractive color model formula
where RGB = (255 - CMY) * (255 - K) / 255.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10835

[PATCH 1/1] gdiplus: Add support for CMYK to ARGB pixel format conversion.

[yaoyongjie]

From: yaoyongjie <[e-mail]>

Add conversion from PixelFormat32bppCMYK to PixelFormat32bppARGB in
convert_pixels(), using the standard subtractive color model formula
where RGB = (255 - CMY) * (255 - K) / 255.

Signed-off-by: yaoyongjie <[e-mail]>
Change-Id: I4b0991ccd50b648a5bafc6feca723755ca691301
---
 dlls/gdiplus/image.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/dlls/gdiplus/image.c b/dlls/gdiplus/image.c
index 17e1437eb5f..b1a3c4a7bd8 100644
--- a/dlls/gdiplus/image.c
+++ b/dlls/gdiplus/image.c
@@ -312,6 +312,15 @@ static inline void getpixel_64bppPARGB(BYTE *r, BYTE *g, BYTE *b, BYTE *a,
     }
 }
 
+static inline void getpixel_32bppCMYK(BYTE *c, BYTE *m, BYTE *y, BYTE *k,
+    const BYTE *row, UINT x)
+{
+    *c = row[x*4];
+    *m = row[x*4+1];
+    *y = row[x*4+2];
+    *k = row[x*4+3];
+}
+
 GpStatus WINGDIPAPI GdipBitmapGetPixel(GpBitmap* bitmap, INT x, INT y,
     ARGB *color)
 {
@@ -654,6 +663,21 @@ GpStatus convert_pixels(INT width, INT height,
     return Ok; \
 } while (0);
 
+#define convert_cmyk_to_rgb(getpixel_function, setpixel_function) do { \
+    for (y=0; y<height; y++) \
+        for (x=0; x<width; x++) { \
+            BYTE r, g, b, a; \
+            BYTE cc, cm, cy, ck; \
+            getpixel_function(&cc, &cm, &cy, &ck, src_bits+src_stride*y, x); \
+            r = (255-cc) * (255-ck)/255; \
+            g = (255-cm) * (255-ck)/255; \
+            b = (255-cy) * (255-ck)/255; \
+            a = 255; \
+            setpixel_function(r, g, b, a, dst_bits+dst_stride*y, x); \
+        } \
+    return Ok; \
+} while (0);
+
     switch (src_format)
     {
     case PixelFormat1bppIndexed:
@@ -1091,6 +1115,15 @@ GpStatus convert_pixels(INT width, INT height,
             break;
         }
         break;
+    case PixelFormat32bppCMYK:
+        switch (dst_format)
+        {
+        case PixelFormat32bppARGB:
+            convert_cmyk_to_rgb(getpixel_32bppCMYK, setpixel_32bppARGB);
+        default:
+            break;
+        }
+        break;
     default:
         break;
     }
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10835